Breeders
Gene Forrer
nuclear plant were to explode it would be due a steam explosion. A fadst
breeder is just a design that facilitates the removal of the plutonium. All
nuclear power plants produce plutonium during the fission process, a breeder
is just designed so that when it is ready the material can be extracted
easier and used for fuel in another reactor. Overall this means there is
less of the long lived radioactive waste that scares the crap out of
everyone. We could reprocess all of the spent fuel produced in the US and
get enough material to power our N plants for decades and reduce our waste
stockpiles.
Finally for a bomb to go boom you need two lumps of fisionable material of
appropriate mass and a device that will slam them together very hard and
fast. Since all of the fuel is in fixed plates in a reactor this can't
happen. True a reactor core could get very hot and melt to some extent and
you might get radioactive contamination of the surrounding area but the damn
thing is not going to blow up.
victor yodaiken
>Get real nuclear power plants don't explode due to nuclear fission. If a
From "Energy: a Guidebook" (Ramage, Oxford University Press,1983)
"The main concern about the FBR centres on its fuel, for three reasons:
The concentration of the fissile material
[ ...]
The first of these raises the question whether a runaway nuclear reaction
could occur. A fully efficient atomic bomb is not possible, and even a
"nuclear fizzle" would require a large number of improbable conditions at
the same moment. [..] Nevertheless, there is some disagreement about the
probabilities, and the degree of unlikelihood does seem to be of a lesser
order than the virtual impossibility in a thermal reactor.
(page 172)
From "Fast Reactor Safety" (John Graham, Academic Press 1971) page 210
Section 5.44 treats suggested design bases and outlines the behavior
following a loss of electrical power to the pumps associated with a
failure to scram the reactor. The sequence of events in that case is
as follows [.. reminder that this is hypothetical]
(a) Widespread voiding due to either sodium boiling or fission gas
release or both effects and consequent reactivity feedback.
(b) Prompt criticality resulting in widespread fuel failure and
melting. A slight dispersion shuts the system down.
(c) A second more violent superprompt criticality.
(d) Violent dispersion of the core
--
Tino
>From "Fast Reactor Safety" (John Graham, Academic Press 1971) page 210
> Section 5.44 treats suggested design bases and outlines the behavior
> following a loss of electrical power to the pumps associated with a
> failure to scram the reactor. The sequence of events in that case is
> as follows [.. reminder that this is hypothetical]
> (a) Widespread voiding due to either sodium boiling or fission gas
> release or both effects and consequent reactivity feedback.
> (b) Prompt criticality resulting in widespread fuel failure and
> melting. A slight dispersion shuts the system down.
> (c) A second more violent superprompt criticality.
> (d) Violent dispersion of the core
Didn't the experiments run by EBR-II show that their core could survive this?
I believe the monumental test simulated a loss of power to the pumps without
scram. The reactivity feedback from the temperature increase shut down the
core.
The book you quoted, which was published 15 years before this experiment, must
be reviewed in a different light.
Tino
--
--------------------------------------------------------------------------------"I'm very much opposed to nuclear testing, to any kind of nuclear activity whatsoever. We don't need nuclear power. We have plenty of alternative
power." - Casey Kasem, radio personality and self-proclaimed nuclear engineer
Gene Forrer
>From: cons...@gn.ecn.purdue.edu (Tino)
>Subject: Re: Breeders
>Date: Thu, 29 Apr 93 17:04:12 GMT
sources say nuclear explosion these are all thermal events. Also you are
talking about a sodium cooled reactor which has its own problems associated
with sodium and water.
By the way did you realize until the early 70's the Sierra club thought
nuclear was an excellant alternative to Hydro power. When they effectivly
casterated the hydro industry they turned on nuclear. Whats next wind
because it kills birdies or solar because making cells create toxic waste.
Every energy source has a down side.
Gene Forrer
>Subject: Re: Breeders
>Date: 29 Apr 1993 14:33:29 GMT
in nature and would happen, on a lesser scale, in any plant with a large
heat source. What all of this calls for are plants designed to be self
controling with little or no human interaction. And guess what? They exist,
its just that some uninformed or misled people are to up in arms to listen
to facts. Any one , including scientists, can manipulate data to make what
they want people to believe seem true.
By the way are you aware that until the early 70's the sierra club was a big
proponent of nuclear power. They claimed it to be a safe alternative to
hydro. When they made it immossible to site a hydro plant they turned on
nuclear power. Whats next thay get nuclear banned and they turn on wind
because it kills birdies or solar because making the cell creates toxic
waste.
P Angelo /RA/208G/osra 7550
>>From "Fast Reactor Safety" (John Graham, Academic Press 1971) page 210
>> Section 5.44 treats suggested design bases and outlines the behavior
>> following a loss of electrical power to the pumps associated with a
>> failure to scram the reactor. The sequence of events in that case is
>> as follows [.. reminder that this is hypothetical]
>> (a) Widespread voiding due to either sodium boiling or fission gas
>> release or both effects and consequent reactivity feedback.
>> (b) Prompt criticality resulting in widespread fuel failure and
>> melting. A slight dispersion shuts the system down.
>> (c) A second more violent superprompt criticality.
>> (d) Violent dispersion of the core
>
>Didn't the experiments run by EBR-II show that their core could survive this?
>
>I believe the monumental test simulated a loss of power to the pumps without
>scram. The reactivity feedback from the temperature increase shut down the
>core.
>
>The book you quoted, which was published 15 years before this experiment, must
>be reviewed in a different light.
>
issues!!!!!!
In 1986, the EBR-II undertook the most impressive tests to demonstrate
inherrent safety of metal fueled breeder reactors. The series of tests,
were the first step in demonstration of the Integral Fast Reactor (IFR)
concept, which also includes a closed Fuel Cycle which recycles long lived
actinides back in the reactor.
An open challenge to anyone concerned:
Please write your elected officials to support the IFR!!! I know nuclear
engineering students read this post, and if you people should be concerned
about future career opportunities, now is the time for action. The cutting
edge technology the IFR promises is falling on deaf ears in Washington
primarily due to the caustic and p.c. attitudes towards commercial
nuclear.
This project if not continued in the United States, will be developed
abroad (Monju reactor in Japan allready on line!). The sad part is this
is OUR technology, and the same people complaining about "international
competetiveness, and high tech workplace, and the future of our country",
are the very same people who would politicize the IFR (ala Clinch River)
to PAY FOR THE SINS of the commercial nuclear industry.
victor yodaiken
|In article <1993Apr29.1...@gn.ecn.purdue.edu> cons...@gn.ecn.purdue.edu (Tino) writes:
|>In article <1roovp...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
|>>From "Fast Reactor Safety" (John Graham, Academic Press 1971) page 210
|>> Section 5.44 treats suggested design bases and outlines the behavior
|>> following a loss of electrical power to the pumps associated with a
|>> failure to scram the reactor. The sequence of events in that case is
|>> as follows [.. reminder that this is hypothetical]
|>> (a) Widespread voiding due to either sodium boiling or fission gas
|>> release or both effects and consequent reactivity feedback.
|>> (b) Prompt criticality resulting in widespread fuel failure and
|>> melting. A slight dispersion shuts the system down.
|>> (c) A second more violent superprompt criticality.
|>> (d) Violent dispersion of the core
|>
|>Didn't the experiments run by EBR-II show that their core could survive this?
|>
|>I believe the monumental test simulated a loss of power to the pumps without
|>scram. The reactivity feedback from the temperature increase shut down the
|>core.
|>
|>The book you quoted, which was published 15 years before this experiment, must
|>be reviewed in a different light.
|>
| Yes!!!!!! Finally someone intelligent enough to understand the current
|issues!!!!!!
Well, intelligent folks, there are some caveats here. First, EBR-II is
not the only breeder reactor in the world and certainly there have been
other designs proposed in the US. Second, one experiment does not a
rule make: there are many people who have driven across railroad tracks
without checking for a train who have lived to tell the tale. It does not
follow that a HTAI (Hypothetical Train Automobile Intersection) is
impossible.
|In 1986, the EBR-II undertook the most impressive tests to demonstrate
|inherrent safety of metal fueled breeder reactors. The series of tests,
|were the first step in demonstration of the Integral Fast Reactor (IFR)
|concept, which also includes a closed Fuel Cycle which recycles long lived
|actinides back in the reactor.
I'll agree with you that the EBR-II project is interesting and has some
promise. On the other hand, the whole concept of a large complex machine
in which an intricate tubing system carries steam over radioactive
very hot liquid sodium that circulates over a core of highly enriched
nuclear fuel does not immediately strike the unconverted as the most
sensible way to run air-conditioners.
--
Michael R James
>In article (P Angelo /RA/208G/osra 7550) writes:
>|In article cons...@gn.ecn.purdue.edu (Tino) writes:
>|>In article yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>|>>From "Fast Reactor Safety" (John Graham, Academic Press 1971) page 210
>|>> Section 5.44 treats suggested design bases and outlines the behavior
>|>> following a loss of electrical power to the pumps associated with a
>|>> failure to scram the reactor. The sequence of events in that case is
>|>> as follows [.. reminder that this is hypothetical]
>|>> (a) Widespread voiding due to either sodium boiling or fission gas
>|>> release or both effects and consequent reactivity feedback.
>|>> (b) Prompt criticality resulting in widespread fuel failure and
>|>> melting. A slight dispersion shuts the system down.
>|>> (c) A second more violent superprompt criticality.
>|>> (d) Violent dispersion of the core
>|>
>|>Didn't the experiments run by EBR-II show that their core could survive this?
>|>I believe the monumental test simulated a loss of power to the pumps without
>|>scram. The reactivity feedback from the temperature increase shut down the
>|>core.
>Well, intelligent folks, there are some caveats here. First, EBR-II is
>not the only breeder reactor in the world and certainly there have been
>other designs proposed in the US. Second, one experiment does not a
>rule make: there are many people who have driven across railroad tracks
>without checking for a train who have lived to tell the tale. It does not
>follow that a HTAI (Hypothetical Train Automobile Intersection) is
>impossible.
The point is that an EBR-II style breeder can be designed so that
is is not _possible_ for the reactor to damage it's own fuel. The
core arrangement and fuel design simply do not permit the reactor
to generate the sufficient power densities required.
>|In 1986, the EBR-II undertook the most impressive tests to demonstrate
>|inherrent safety of metal fueled breeder reactors. The series of tests,
>|were the first step in demonstration of the Integral Fast Reactor (IFR)
>|concept, which also includes a closed Fuel Cycle which recycles long lived
>|actinides back in the reactor.
>I'll agree with you that the EBR-II project is interesting and has some
>promise. On the other hand, the whole concept of a large complex machine
>in which an intricate tubing system carries steam over radioactive
>very hot liquid sodium that circulates over a core of highly enriched
>nuclear fuel does not immediately strike the unconverted as the most
>sensible way to run air-conditioners.
How does the concept of travelling unrestrained in two-ton metal
machines guided by four small tires at high speeds
with a tank of an explosive liquid hanging off the back sound to you?
Sounds crazy to me.
--
Michael James mrjg...@uxa.cso.uiuc.edu
"Ludwig Boltzmann, who spent much of his life studying statistical
mechanics, died in 1906, by his own hand. Paul Ehrenfest, carrying
on the work, died similarly in 1933. Now it is our turn to study
statistical mechanics."
-David L. Goodstein "States of Matter"
Don Palmrose
>
> I'll agree with you that the EBR-II project is interesting and has some
> promise. On the other hand, the whole concept of a large complex machine
> in which an intricate tubing system carries steam over radioactive
> very hot liquid sodium that circulates over a core of highly enriched
> nuclear fuel does not immediately strike the unconverted as the most
> sensible way to run air-conditioners.
>
>
IFR would be less complex than the current generation of commercial nuclear
power plants, there is a secondary sodium loop so that water cannot come into
contact with the primary (with short-lived radionuclides from sodium absorbing
a neutron thus radioactive), and the fuel is not highly enriched since it will
not be more than 5% enriched if that.
And you like to call people from the NRC liars for what they say about
the integrity of the containment building at Yankee Rowe.
Don Palmrose
---
The views and opinions expressed herein are personal and are not necessarily
those of the United States Government or any of its agencies or contractors.
victor yodaiken
>The point is that an EBR-II style breeder can be designed so that
>is is not _possible_ for the reactor to damage it's own fuel. The
The original claim was not limited to EBR-II reactors. And,
"not _possible_" is a pretty strong claim. Doesn't it depend on
retaining the integrity of the reactor vessel? If the vessel cracks
and the sodium vaporizes, what happens?
>>I'll agree with you that the EBR-II project is interesting and has some
>>promise. On the other hand, the whole concept of a large complex machine
>>in which an intricate tubing system carries steam over radioactive
>>very hot liquid sodium that circulates over a core of highly enriched
>>nuclear fuel does not immediately strike the unconverted as the most
>>sensible way to run air-conditioners.
>
>How does the concept of travelling unrestrained in two-ton metal
>machines guided by four small tires at high speeds
>with a tank of an explosive liquid hanging off the back sound to you?
>Sounds crazy to me.
An interesting comparison. Automobiles fail all the time, but the social
cost of a failure is not catastraphic.
--
victor yodaiken
|In article <1rrmov...@ymir.cs.umass.edu>, yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
|>
|> I'll agree with you that the EBR-II project is interesting and has some
|> promise. On the other hand, the whole concept of a large complex machine
|> in which an intricate tubing system carries steam over radioactive
|> very hot liquid sodium that circulates over a core of highly enriched
|> nuclear fuel does not immediately strike the unconverted as the most
|> sensible way to run air-conditioners.
|>
|
|power plants, there is a secondary sodium loop so that water cannot come into
|contact with the primary (with short-lived radionuclides from sodium absorbing
|a neutron thus radioactive), and the fuel is not highly enriched since it will
|not be more than 5% enriched if that.
|
|And you like to call people from the NRC liars for what they say about
|the integrity of the containment building at Yankee Rowe.
Sometimes I get the impression that the people who pose as nuclear
advocates on this net are actually undercover anti-nuclear activists out
to create the impression that all supporters of nuclear energy are narrow
minded intolerant zealots with absolutely no sense of perspective.
Very effective work, guys.
--
Carl J Lydick
=Sometimes I get the impression that the people who pose as nuclear
=advocates on this net are actually undercover anti-nuclear activists out
=to create the impression that all supporters of nuclear energy are narrow
=minded intolerant zealots with absolutely no sense of perspective.
=Very effective work, guys.
Well, Victor, with idiots like you representing the anti-nukes, it seems only
fair to give you a break.
--------------------------------------------------------------------------------
Carl J Lydick | INTERnet: CA...@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL
Disclaimer: Hey, I understand VAXen and VMS. That's what I get paid for. My
understanding of astronomy is purely at the amateur level (or below). So
unless what I'm saying is directly related to VAX/VMS, don't hold me or my
organization responsible for it. If it IS related to VAX/VMS, you can try to
hold me responsible for it, but my organization had nothing to do with it.
Richard J. Fox
>
>An interesting comparison. Automobiles fail all the time, but the social
>
Yeah, I guess 50,000 lives every year is not catastrophic.
Very good Victor, but since most of your comments typify style over
substance, I find it difficult to take you seriously. If you are really
interested in contributing to a reasnable discussion then the one
liners are not going to cut it. However, if you're interested in
inflating your ego at the expense of another's compassion or
undesrstanding then by all means, please continue.
I would not waste such words on you if I didn't think you were
intelligent enough to understand.
Richard J. Fox
SEC...@psuvm.psu.edu
> is not catastrophic.
Brilliant Vic, just brilliant. Up until I read that I assumed you were just
your average closed minded activist with just enough knowledge to impress
people who didn't know what they were talking about. That little gem shows
that you have no real knowledge whatsoever about reality. Do you know the
least bit about risk assesment? Do you?
If you had the slightest clue in the world about what you were writing you
would understand how dangerous cars are. Automobiles and smoking are,from a
risk assesment point of veiw, EXTREAMLY dangerous. Cars are one of the most
likely things to cause your death my friend. My best friends have been hurt
in car accidents twice, one severely. In neither case was it their fault. One
of my friends brothers died in a pickup truck on his way to get a video. I
myself have been in more than one close call on the highway.
Smoking is another subject. I lost a grandfather who smoked for years to lung
disease.
But, strangely enough, I know nobody who has even been slightly hurt by a
runaway reactor. I know plenty of people who work around reactors. I have
friends who were sub-engineers, co-ops, reactor operators, and professors who
work around reactors for a living. I myself will be working at a reactor this
summer. Guess which is more dangerous Vic, working in the same building as a
reactor that is made prompt-critical for experiments or crossing the street
on the way to the building? Thats right amigo, crossing the street.
I strongly urge you to learn what your talking about before you post. You make
yourself look dumb and mislead people who don't know how ignorant of nuclear
power you really are. If your university has a nuclear engineering department
I suggest you find a professor and learn from them first hand. Here at Penn
State we have Nuc E classes for non-Nuc E students. If your university has
something like that you may find the class enlightening. What you will
discover is that the nuclear power industry is not some evil force bent on
destroying the world. It is the use of high level physics to generate power
in a clean and safe manner. If you insist on posting as much nuclear related
stuff as you do you really should learn some of the technical aspects of
nuclear power. The only way to combat ignorance is with education.
*** sec...@psuvm.psu.edu Stephen Cumblidge ***
*** ***
*** "Put a drop of vanilla behind each ear smell like a cookie all day" ***
*** Crow T. Robot ***
*** ***
Kevin Brown
>>The point is that an EBR-II style breeder can be designed so that
>>is is not _possible_ for the reactor to damage it's own fuel. The
>
>The original claim was not limited to EBR-II reactors. And,
>"not _possible_" is a pretty strong claim. Doesn't it depend on
>retaining the integrity of the reactor vessel? If the vessel cracks
>and the sodium vaporizes, what happens?
>
>>>I'll agree with you that the EBR-II project is interesting and has some
>>>promise. On the other hand, the whole concept of a large complex machine
>>>in which an intricate tubing system carries steam over radioactive
>>>very hot liquid sodium that circulates over a core of highly enriched
>>>nuclear fuel does not immediately strike the unconverted as the most
>>>sensible way to run air-conditioners.
I don't think I've ever seen the answer to this question from you: what do
you think *is* the most sensible way to produce power?
No doubt the same thing can be said of the large, complex machinery in a
coal-fired plant, or an oil-fired plant, or gas-fired, or a hydroelectric
plant.
The existence of large, complex machinery is a fact of life. Admittedly,
it's often enough to boggle the mind when one thinks about just how much
is involved in so many of the things we otherwise think nothing of. Even
so, that large, complex machinery is involved is, I think, no particular
reason for concern.
No doubt you're concerned because the machinery in question is built around
a radioactive hunk of metal. How concerned would you be if it were built
around a large coal combustion chamber? Not much, I'd wager.
>>How does the concept of travelling unrestrained in two-ton metal
>>machines guided by four small tires at high speeds
>>with a tank of an explosive liquid hanging off the back sound to you?
>>Sounds crazy to me.
>
>An interesting comparison. Automobiles fail all the time, but the social
>cost of a failure is not catastraphic.
How are you measuring the social cost of each?
I suspect that you are more likely to be killed by a failing automobile than
by a nuclear power plant, even if that plant were next door. But I can't
prove it.
Do you believe that you are more likely to be killed by a next-door nuclear
power plant than by a failing automobile? If not, then exactly what is your
beef?
--
Kevin Brown ke...@nuchat.sccsi.com
This is your .signature virus: < begin 644 .signature (9V]T8VAA(0K0z end >
This is your .signature virus on drugs: <>
Any questions?
Paul Dietz
>In article <1rs2cm...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>> The original claim was not limited to EBR-II reactors. And,
>> "not _possible_" is a pretty strong claim. Doesn't it depend on
>> retaining the integrity of the reactor vessel? If the vessel cracks
>> and the sodium vaporizes, what happens?
Victor probably already knows this, but the vessel cracking would not
by itself cause the sodium to vaporize. Remember, the sodium, unlike
the coolant in a PWR, is not being kept in a liquid state by pressure.
The sodium remains below its boiling point at 1 atmosphere (1621 F) at
all times. Not only does this prevent the sodium from flashing to
vapor if the vessel's integrity is breached, but it also reduces the
energy available to drive sodium out of the vessel. Moreover, since
the vessel need not be so strong, it need not be thick, and one can
enclose it in another vessel so that even if the first does leak, the
sodium flows into the space between the two and the core remains
covered.
Perhaps Victor would feel more comfortable with liquid lead cooled
reactors? These have some interesting safety advantages over liquid
sodium coolant, including negative void coefficient, a higher boiling
point (3164 F) and less chemically reactive coolant that will
not float in water, and lower core power density. The significant
disadvantage is higher melting point (622 F), but that can be
reduced a little by adding a small amount of magnesium.
Paul
Tino
>by a nuclear power plant, even if that plant were next door. But I can't
>prove it.
Yes, you can.
How many people die each year from autos in the U.S.?
How many people die from nuclear power plants in the U.S.?
One number is 50,000 higher than the other...
Kevin Brown
>In article <1993May2.0...@nuchat.sccsi.com> ke...@sccsi.com (Kevin Brown) writes:
>>I suspect that you are more likely to be killed by a failing automobile than
>>by a nuclear power plant, even if that plant were next door. But I can't
>>prove it.
>
>Yes, you can.
>
>How many people die each year from autos in the U.S.?
>How many people die from nuclear power plants in the U.S.?
>
>One number is 50,000 higher than the other...
This is true. But be fair. :-)
Those 50,000 that die each year from automobile accidents do so primarily due
to driver error, whereas I was actually referring to equipment failure.
Victor seems to be talking primarily about equipment failure, possibly
combined with "driver error". If he insists on talking about both
simultaneously, however, then I think we are perfectly within reason to
include driver-error auto accidents in our comparison.
In which case, Victor's case rests solely on the difference between
the loss of many lives within a relatively confined area of spacetime
and the loss of that many lives within a significantly larger region of
spacetime.
>Tino
>--
>--------------------------------------------------------------------------------"I'm very much opposed to nuclear testing, to any kind of nuclear activity whatsoever. We don't need nuclear power. We have plenty of alternative
> power." - Casey Kasem, radio personality and self-proclaimed nuclear engineer
Don Palmrose
>
Real cute Vic. You do write good satire. ;-) Maybe you could become a
political speech writer after displaying talent like that above. :-)
Face the facts, you made a really off-based statement about the nature of
a fast reactor such as EBR-II (complex, water near radioactive sodium, and
highly enriched fuel). You finish by throwing in the snide comment about
air conditioners. If you knew about IFR and EBR-II like your statements lead
readers to assume that you are knowledgible, you know that my statement was
absolutely correct.
Clearly, you cannot offer any technical counter agruments to my last posting
(this is sci.energy after all) so you resort to a satirical insult. Now I
wonder who truly is the "narrow minded intolerant zealot with absolutely no
sense of perspective". ;-)
Do try and have a nice day, Vic. :-)
Michael R James
>In article <C6B73...@news.cso.uiuc.edu> mrjg...@uxa.cso.uiuc.edu (Michael R James) writes:
>>The point is that an EBR-II style breeder can be designed so that
>>is is not _possible_ for the reactor to damage it's own fuel. The
>The original claim was not limited to EBR-II reactors. And,
>"not _possible_" is a pretty strong claim. Doesn't it depend on
>retaining the integrity of the reactor vessel? If the vessel cracks
>and the sodium vaporizes, what happens?
I'm not very close to the present research but I've heard a few
talks, so I'll qualify my statements by saying that I could be
wrong. But it was my impression that given any Loss-of-Flow/
Loss-of-Coolant accident, that the current EBR design can 1)
Shut down safely (negative thermal coefficient?) and 2)
conduct away the decay heat safely even without coolant flowing.
Someone else has pointed out that the sodium in not under high
pressure so it would not simply vaporize in large quantities in
the case of a leak. Does anyone know if EBR could withstand
a complete LOCA from the core? I know most designs plan for
a large sodium pool to minimize this possibility.
>>>I'll agree with you that the EBR-II project is interesting and has some
>>>promise. On the other hand, the whole concept of a large complex machine
>>>in which an intricate tubing system carries steam over radioactive
>>>very hot liquid sodium that circulates over a core of highly enriched
>>>nuclear fuel does not immediately strike the unconverted as the most
>>>sensible way to run air-conditioners.
>>
>>How does the concept of travelling unrestrained in two-ton metal
>>machines guided by four small tires at high speeds
>>with a tank of an explosive liquid hanging off the back sound to you?
>>Sounds crazy to me.
>An interesting comparison. Automobiles fail all the time, but the social
>cost of a failure is not catastraphic.
Actually, I was just trying to point out how easy it can be to
characterize the most casually accepted practice (driving) as
enormously dangerous with flippant remarks.
Which is what I thought you were doing with the EBR concept.
P Angelo /RA/208G/osra 7550
>yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>
>>In article <C6B73...@news.cso.uiuc.edu> mrjg...@uxa.cso.uiuc.edu (Michael R James) writes:
>>>The point is that an EBR-II style breeder can be designed so that
>>>is is not _possible_ for the reactor to damage it's own fuel. The
>
reactor which is only 1/2 the equation of the IFR Concept!!!
It has allready been proven. Yodaiken et al have not done their research on
this reactor and its history...
Read "The EBR-II Story" (a 30 year chronology)
I doubt if any of you have ever heard of this reactor at ANL-W. Shows how
really informed you U Mass Crit.Mass/Clamshell types are!!!
>>The original claim was not limited to EBR-II reactors. And,
>>"not _possible_" is a pretty strong claim. Doesn't it depend on
>>retaining the integrity of the reactor vessel? If the vessel cracks
>>and the sodium vaporizes, what happens?
Once again, this is not germane to the issue. Not only is this impossible,
(since there is NO REACTOR VESSEL!!!!) but in large pool type breeders,
a rapid evacuation of Na would cause a shutdown (negative coefficient)
>
>I'm not very close to the present research but I've heard a few
>talks, so I'll qualify my statements by saying that I could be
>wrong. But it was my impression that given any Loss-of-Flow/
>Loss-of-Coolant accident, that the current EBR design can 1)
>Shut down safely (negative thermal coefficient?) and 2)
>conduct away the decay heat safely even without coolant flowing.
>Someone else has pointed out that the sodium in not under high
>pressure so it would not simply vaporize in large quantities in
>the case of a leak. Does anyone know if EBR could withstand
>a complete LOCA from the core? I know most designs plan for
>
The SHRT Tests of 1986 Proved this!!!!!!!
-------------------------------------------------------------------------------
Peter L. Angelo, PhD,P.E.,S.R.O I get paid for making neutrons,
Argonne National Laboratory not opinions. Any statement is my own,
email: b41...@anl.gov and not the U of Chi or ANL.
phone: (208) 533-7369
_______________________________________________________________________________
John De Armond
>In article <1rs4dk...@ymir.cs.umass.edu>, yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>=Sometimes I get the impression that the people who pose as nuclear
>=advocates on this net are actually undercover anti-nuclear activists out
>=to create the impression that all supporters of nuclear energy are narrow
>=minded intolerant zealots with absolutely no sense of perspective.
>=Very effective work, guys.
>Well, Victor, with idiots like you representing the anti-nukes, it seems only
>fair to give you a break.
C'mon Carl, don't waste such a valuable resource with cheap shots.
Yackadamn is not a person at all, but instead is an experimental artificial
ignorance automation. Think of it as an Elisa machine with a
Kennedy/Metzenbaum/Markey (or is that Malarky?) style propaganda sub-process.
Like all automations, within its narrow scope it is better at its task
than real humans. It has perfected the anti-nuclear argument. And it
never runs down so it teaches you not to try to out-talk it. Use it
to practice on. When you've practiced enough to send this automation
off into an endless do loop (fossil powered, of course), human anti-nukes
will be duck soup in comparison. Where else but the Usenet could you
find such a resource and at no cost to boot?
John
--
John De Armond, WD4OQC |Interested in high performance mobility?
Performance Engineering Magazine(TM) | Interested in high tech and computers?
Marietta, Ga | Send ur snail-mail address to
j...@dixie.com | per...@dixie.com for a free sample mag
Lee Harvey Oswald: Where are ya when we need ya?
victor yodaiken
>In article <1rs2cm...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>>
>>An interesting comparison. Automobiles fail all the time, but the social
>>cost of a failure is not catastrophic.
>>
>
>Yeah, I guess 50,000 lives every year is not catastrophic.
>
>Very good Victor, but since most of your comments typify style over
>substance, I find it difficult to take you seriously. If you are really
Sorry to disappoint.
--
victor yodaiken
>you think *is* the most sensible way to produce power?
I'm thinking about it. The UCS/Lovins/Epri people make quite persuasive
arguments that efficiency and conservation can take care of immediate needs
and I favor expanded research into renewables, advanced fossil, and believe
it or not, nuclear.
But, this thread started with a proposed FAQ by John McCarthy. The "FAQ"
began with a claim that no current or contemplated nuclear reactor could
"explode like a bomb". My effort to point out the flaw in this claim was
apparently not according to party line.
>The existence of large, complex machinery is a fact of life. Admittedly,
>it's often enough to boggle the mind when one thinks about just how much
>is involved in so many of the things we otherwise think nothing of. Even
>so, that large, complex machinery is involved is, I think, no particular
>reason for concern.
Well, I am not against the use of large-complex machines, but as a general
principle, I prefer them to be well designed, to allow for reasonable
workarounds, to not be overcentralized, and to have localized failures.
That's why I'm uncomfortable with LNG ports in major cities, but
quite happy with communictions satelites -- rather more complex machines.
>No doubt you're concerned because the machinery in question is built around
>a radioactive hunk of metal. How concerned would you be if it were built
>around a large coal combustion chamber? Not much, I'd wager.
Pretty concerned. Using sodium as a coolant bother me. I don't say
that it's necessarily a bad idea, it just inspires caution.
>Do you believe that you are more likely to be killed by a next-door nuclear
>power plant than by a failing automobile? If not, then exactly what is your
>beef?
I believe that, under current circumstances, the chances of a major
accident at a nuclear power plant are not negligable, and that the
possible consequences of such an accident are not acceptable. I don't
particularly want to be killed on the road, but I'm more willing to
accept that possibility than the possibility of, say, a major breach
of containment at Indian Point.
--
Don Palmrose
>
> In article <1993May2.0...@nuchat.sccsi.com> ke...@sccsi.com (Kevin Brown) writes:
>
> >No doubt you're concerned because the machinery in question is built around
> >a radioactive hunk of metal. How concerned would you be if it were built
> >around a large coal combustion chamber? Not much, I'd wager.
>
> Pretty concerned. Using sodium as a coolant bother me. I don't say
> that it's necessarily a bad idea, it just inspires caution.
>
> yoda...@chelm.cs.umass.edu
>
Every nuclear engineer I have ever been associated with (US Nuclear Navy and
commercial nuclear power industry) feels the _*exact same way*_. And we
design systems with caution in mind. You may not believe that but its true,
and I would not do it any other way! "Safety First" is not a slogan to me,
but a way of life.
Maybe there is hope for you after all, Vic. :-)
victor yodaiken
|>I suspect that you are more likely to be killed by a failing automobile than
|>by a nuclear power plant, even if that plant were next door. But I can't
|>prove it.
|
|Yes, you can.
|
|How many people die each year from autos in the U.S.?
|How many people die from nuclear power plants in the U.S.?
|
|One number is 50,000 higher than the other...
Is your knowledge of probability theory really this shallow?
--
Gene Forrer
>From: d...@inel.gov (Don Palmrose)
>Subject: Re: Breeders
>Date: Tue, 4 May 93 13:52:00 GMT
Seawolf. They refit her with a conventional reactor plant not because of
problems with the sodium, but in order to keep the water and the sodium as
far apart as possible the plant used a secondary cooling loop of mercury.
The problem was that they kept finding mercury in the bilge so th concept
was scrapped for use in a ship.
One side point. In the 60's and early 70's the sierra and other
environmental groups praised nuclear as the source to be used for electric
power generation. Once they hed basicly killed future hydro projcets they
decided maybe nuclear wasn't so good afterall. Whats next once nuclear is
killed. Ban solar because photo cells produce toxic waste during their
manufacture or wind because its noisy and slices and dices Birdies.
I don't make it up I just pass it on.
Gene
victor yodaiken
>> An interesting comparison. But the social consequenses of these failures
>> is not catastrophic.
>
>Brilliant Vic, just brilliant. Up until I read that I assumed you were just
>your average closed minded activist with just enough knowledge to impress
>people who didn't know what they were talking about. That little gem shows
>that you have no real knowledge whatsoever about reality. Do you know the
>least bit about risk assesment? Do you?
Try reading
D.J. Higson Nuclear Safety Assessment Criteria
Nuclear Safety 31-32 April-June 1990 193-185
I've got some more references you might find interesting as well.
The subject of risk estimation for low probability/high cost events and
events that are dependent on human error is a complex one, perhaps
a little more complex than you suppose.
--
P Angelo /RA/208G/osra 7550
>
>The subject of risk estimation for low probability/high cost events and
>events that are dependent on human error is a complex one, perhaps
>a little more complex than you suppose.
>
>
could be
victor yodaiken
>In article <1s6fqs...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>>
>>The subject of risk estimation for low probability/high cost events and
>>events that are dependent on human error is a complex one, perhaps
>>a little more complex than you suppose.
>>
>>
>That is why they pay us the big bucks Vic,while you can only ponder what
>could be
>
That's got to be a new low: argument by salary.
--
Joseph Askew
>In article <1rss93$f...@agate.berkeley.edu> f...@four-lab4.Berkeley.EDU (Richard J. Fox) writes:
>>In article <1rs2cm...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>>Yeah, I guess 50,000 lives every year is not catastrophic.
>No, it is not.
So 50,000 Americans dead every year is not catastrophic but 31 Ukranians
and Russians dead in *total* is!
Yeah right. A better argument for nuclear power I could not find or
are you goingto argue that somehow more than 50,000 people die every
year from peaceful, safe, clean and environmentally friendly nuclear
power? That is if this rate is constant by the end of the year 2000
350,000 people will have died from automobiles - how many dead do you
expect from nuclear power and would you care to put some money on it?
Joseph Askew
--
Joseph Askew, Gauche and Proud In the autumn stillness, see the Pleiades,
jas...@spam.maths.adelaide.edu Remote in thorny deserts, fell the grief.
Disclaimer? Sue, see if I care North of our tents, the sky must end somwhere,
Actually, I rather like Brenda Beyond the pale, the River murmurs on.
E. Michael Smith
>In article <1s500u...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>>In article <1rss93$f...@agate.berkeley.edu> f...@four-lab4.Berkeley.EDU (Richard J. Fox) writes:
>>>In article <1rs2cm...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>
>>>Yeah, I guess 50,000 lives every year is not catastrophic.
>
>>No, it is not.
>
>So 50,000 Americans dead every year is not catastrophic but 31 Ukranians
>and Russians dead in *total* is!
>
>Yeah right. A better argument for nuclear power I could not find or
>are you goingto argue that somehow more than 50,000 people die every
>year from peaceful, safe, clean and environmentally friendly nuclear
>power? That is if this rate is constant by the end of the year 2000
>350,000 people will have died from automobiles - how many dead do you
>expect from nuclear power and would you care to put some money on it?
Um, at the risk of ending a pointless battle of words ...
If you look up the word 'catastrophe' you will find something like:
1) A great and sudden calamity; disaster. 2. A sudden violent
change in the earths surface; cataclysm.
It is characterized by being sudden and large. That 50k people a
year die in cars is not sudden. It is large. That few Ukranians
died suddenly is not large. I submit that neither cars nor
nuclear accidents qualify as catastrophes in terms of deaths.
What Victor seems to be saying is that nuclear accidents can be
a sudden violent change in the earths surface, and that car
deaths, as dreadfull as they are, are spread out over time.
What this has to do with the relative values of nuclear and
non-nuclear power sources escapes me, but his definitions seem
sound.
What Richard and Josheph seen to be saying is that nuclear accidents
are not large killers and cars are, so cars are more damaging to life
than nuclear and are catastrophic. While I think their definition
of catastrophic is flawed and they should dis-engage from Victor
on that point, their basic assertion that cars are more hazardous
is sound. What this has to do with the relative values of
nuclear and non-nuclear power sources also escapes me.
Can you stop jousting over the meaning of catastrophe now and get
back to energy?
--
E. Michael Smith e...@apple.COM
'Whatever you can do, or dream you can, begin it. Boldness has
genius, power and magic in it.' - Goethe
I am not responsible nor is anyone else. Everything is disclaimed.
P Angelo /RA/208G/osra 7550
nuclear research arm, the notion of someone sitting on the sidelines
in a computer science department spouting off motherhood and rhetoric
as I have observed, is quite amusing.
victor yodaiken
|In article <1s6rft...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
|>In article <7365487...@flash.ra.anl.gov> b41...@flash.ra.anl.gov (P Angelo /RA/208G/osra 7550) writes:
|>>In article <1s6fqs...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
|>>>
|>>>The subject of risk estimation for low probability/high cost events and
|>>>events that are dependent on human error is a complex one, perhaps
|>>>a little more complex than you suppose.
|>>>
|>>>
|>>That is why they pay us the big bucks Vic,while you can only ponder what
|>>could be
|>>
|>That's got to be a new low: argument by salary.
|>
|>
| The point was to illustrate that while I do make my living in the
|nuclear research arm, the notion of someone sitting on the sidelines
|in a computer science department spouting off motherhood and rhetoric
|as I have observed, is quite amusing.
|
In discussing work within my field with non-specialists, I've never found
the need to resort to arguments by authority or salary. Here, I provided
a reference to back up my argument, and you provided an argument by
credentials. Either you don't know the literature, or you are unable to
formulate a rational argument. Who pays you, for what, and how much, can't
turn bullshit into scientific fact.
--
George William Herbert
after a month of pointless flame, that some breeders can
be made that can possibly explode, and some other breeders
can be made that can't.
Victor, stop arguing stupid semantic arguments over wether it's
possible to build a reactor that can explode. The point is not
wether you can, but wether it is done. None of the built reactors
can "explode", apparently, and none that are currently being
considered can. Arguing that choosing an unsafe path is dangerous
when safe paths are known to exist has no merit.
Everyone else: I think the point is proven.
-george
Gene Forrer
>From: g...@soda.berkeley.edu (George William Herbert)
>Subject: Breeders
>Date: 5 May 1993 20:26:09 GMT
>Summary: Great argument going here...
Reactors are of a conventional thermal or mechanical nature. True you will
have contamination of the surrounding area from radioactive material
released from the core but not as a result of a nuclear explosion. By the
way Chernobyl did not under go a nuclear explosion it was a steam and
hydrogen buildup explosion caused by two things. A design that sucked big
time and would never be allowed in this country and the operators defeating
most safety interlocks and generally being stupid. Another interesting note
is that it is possible to dramaticaly increase the safety of a Chernobyl
type plant with different control rods and fuel loading but it is not
possible to make an American reactor of similar design (Graphite, Water
cooling, etc.) as unsafe as a Chernobyl type reactor. In America we build
to keep the nasty stuff in and the outside world safe.
Tino
>|>I suspect that you are more likely to be killed by a failing automobile than
>|>by a nuclear power plant, even if that plant were next door. But I can't
>|>prove it.
>|
>|How many people die from nuclear power plants in the U.S.?
>|
>|One number is 50,000 higher than the other...
>
>Is your knowledge of probability theory really this shallow?
Sorry, Vic. I forgot to divide each by the total US population.
50,000 corpses
Autos: ---------------------- per year.
250,000,000 Americans
Unmeasurably small
Nuke plants: ---------------------- per year.
250,000,000 Americans
But then, you said
>>Yeah, I guess 50,000 lives every year is not catastrophic.
>
>No, it is not.
So it really doesn't matter, right?
Tino
--
"On Edward Teller's blackboard at Los Alamos I once saw a list of weapons -- ideas for weapons -- with their abilities and properties displayed. For the last one on the list, the largest, the method of delivery was listed as
'backyard.' Since that particular design would probably kill everyone on Earth, there was no use carting it elsewhere." - Robert Serber
victor yodaiken
|In article <1s696s...@ymir.cs.umass.edu> yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
|>|>I suspect that you are more likely to be killed by a failing automobile than
|>|>by a nuclear power plant, even if that plant were next door. But I can't
|>|>prove it.
|>|
|>|How many people die each year from autos in the U.S.?
|>|How many people die from nuclear power plants in the U.S.?
|>|
|>|One number is 50,000 higher than the other...
|>
|>Is your knowledge of probability theory really this shallow?
|
|Sorry, Vic. I forgot to divide each by the total US population.
i.e. "yes".
--
Tino
But when the denominators are exactly the same, one only needs to compare
numerators.
More trivial nitpicking, I suppose...
Kenneth Ng
:In article <1rs4dk...@ymir.cs.umass.edu>, yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
:> Sometimes I get the impression that the people who pose as nuclear
:> advocates on this net are actually undercover anti-nuclear activists out
:> to create the impression that all supporters of nuclear energy are narrow
:> minded intolerant zealots with absolutely no sense of perspective.
:> Very effective work, guys.
Please note: I am responding to Victor Yodaiken, not Don Palmrose, Victor's
article did not reach my machine for some reason.
Victor, actually I used to be an anti-nuclear activist. That was until I
checked out some books at some technical libraries to get more information
for my antinuclear arguements. I found that the very additional safety
systems that I was advocating were already present in nuclear power plants
(emergency cooling systems, boric acid in the cooling water, gosh I thought
I was going to be revolutionary back then). When I showed them to my local
group, I asked why the diagrams we were using didn't have them. I was told
that they were ommitted for simplicity. "You edited reality for the sake of
simplicity?" was my response. Reading more I determined that I was on
the wrong side of the arguement and switched sides. I've been on this
side ever sense.
--
Kenneth Ng
Please reply to k...@blue.njit.edu for now.
"All this might be an elaborate simulation running in a little device sitting
on someone's table" -- J.L. Picard: ST:TNG
victor yodaiken
>But when the denominators are exactly the same, one only needs to compare
>numerators.
>
>More trivial nitpicking, I suppose...
>
You cannot accurately estimate event probability over n+m trials by
averaging over the first n trials without some evidence that the
distribution of events is linear. The number of times the Titanic
sank divided by the number of days between its construction and
the day before it hit the iceberg is 0: it does not follow that the
probability of the Titanic being afloat is high. Not trivial nitpicking
at all. Don't they teach you anything beyond linear functions there
at Purdue?
--
Mark Wilson
|i.e. "yes".
Vic, you are really a sad case. First off you mistake sarcasm as support for
your position. Secondly you fail to realize that dividing both sides by the
same number does not change the relationship one iota.
On the other hand, given the quality of your previous posts, it is also
possible that you deliberatly edited the previous post to imply that he
had agreed with you, when in fact you know that he didn't.
--
Mob rule isn't any prettier merely because the mob calls itself a government
It ain't charity if you are using someone else's money.
Wilson's theory of relativity: If you go back far enough, we're all related.
Mark....@AtlantaGA.NCR.com
victor yodaiken
|Victor, actually I used to be an anti-nuclear activist. That was until I
|checked out some books at some technical libraries to get more information
|for my antinuclear arguements. I found that the very additional safety
|systems that I was advocating were already present in nuclear power plants
|(emergency cooling systems, boric acid in the cooling water, gosh I thought
|I was going to be revolutionary back then). When I showed them to my local
|group, I asked why the diagrams we were using didn't have them. I was told
|that they were ommitted for simplicity. "You edited reality for the sake of
|simplicity?" was my response. Reading more I determined that I was on
|the wrong side of the arguement and switched sides. I've been on this
|side ever sense.
I'm sorry, but not surprised, that you encountered misinformation from
the one side. What do you make of the repeated false assertions from the
other side that have been seen on this forum. For example, do you recall
Petr Beckmann's insistence that risk=prob(e)*penalty(e) is *the*
accepted definition and that any other measurement of risk is
anti-scientific? Or, even more apalling, Beckmann's claim that risk of
nuclear power plants could be measured with exactitude like "weight
or mass"? How about the repeated claims that US containment vessels were
*designed* to contain meltdowns? Or the repeated claims that
embrittlement was a *solved* problem and the there was no scientific
dispute on this issue?
--
Tino
Sorry, Vic, I've been wrong this whole time. I know nothing. We should close
all the nuclear power plants because one's gonna blow up and kill everyone in
the country. Is that what you wanted to hear?
Sheesh.
Kevin Brown
>In article <1993May2.0...@nuchat.sccsi.com> ke...@sccsi.com (Kevin Brown) writes:
>>I don't think I've ever seen the answer to this question from you: what do
>>you think *is* the most sensible way to produce power?
>
>I'm thinking about it. The UCS/Lovins/Epri people make quite persuasive
>arguments that efficiency and conservation can take care of immediate needs
>and I favor expanded research into renewables, advanced fossil, and believe
>it or not, nuclear.
I wonder just how much of a lead time we need for the research that you
mention to become something that is produced. Whatever that period of time
is, it defines how long "immediate" refers to, and thus how long efficiency
and conservation have to work. Do the sources you refer to say how long
they expect such measures to be sufficient?
>But, this thread started with a proposed FAQ by John McCarthy. The "FAQ"
>began with a claim that no current or contemplated nuclear reactor could
>"explode like a bomb". My effort to point out the flaw in this claim was
>apparently not according to party line.
Oh, well. I'm not much on political correctness of any form. I don't know
enough about nuclear engineering to say whether or not a nuclear reactor
can "explode like a bomb". I would guess that it depends on the design
(and on how you define "explode like a bomb"). While there are probably
reactors in existence that can explode in such a manner, there are probably
some that can't (i.e., physical law makes such an event astronomically
unlikely). But I don't *know*.
Do you really feel qualified to evaluate the safety of the new nuclear
power plant designs?
>>The existence of large, complex machinery is a fact of life. Admittedly,
>>it's often enough to boggle the mind when one thinks about just how much
>>is involved in so many of the things we otherwise think nothing of. Even
>>so, that large, complex machinery is involved is, I think, no particular
>>reason for concern.
>
>Well, I am not against the use of large-complex machines, but as a general
>principle, I prefer them to be well designed,
I agree with the sentiment, but there *are* reasonable limits to this, no?
What you and others seem to disagree about is exactly where those limits
are.
>to allow for reasonable
>workarounds, to not be overcentralized,
Hmm...how does one determine whether or not something is "overcentralized"?
>and to have localized failures.
>That's why I'm uncomfortable with LNG ports in major cities, but
>quite happy with communictions satelites -- rather more complex machines.
Well, there are certainly failure modes of satellites (especially low-orbit
satellites) which are not as localized as most of the failure modes such a
satellite would have. If the directional thruster control fails such that
the orbit of the satellite changes enough to intersect the earth (for all I
know, though, they may design the thing such that such a failure mode is not
possible. But then, they claim much the same thing with nuclear plants, and
you don't believe those claims, so can I assume that you won't believe
similar claims from the satellite design engineers either? :-)...
>>No doubt you're concerned because the machinery in question is built around
>>a radioactive hunk of metal. How concerned would you be if it were built
>>around a large coal combustion chamber? Not much, I'd wager.
>
>Pretty concerned. Using sodium as a coolant bother me. I don't say
>that it's necessarily a bad idea, it just inspires caution.
Sodium is admittedly nasty stuff. Do we not use equally nasty stuff
routinely elsewhere, though?
>>Do you believe that you are more likely to be killed by a next-door nuclear
>>power plant than by a failing automobile? If not, then exactly what is your
>>beef?
>
>I believe that, under current circumstances, the chances of a major
>accident at a nuclear power plant are not negligable, and that the
>possible consequences of such an accident are not acceptable.
Firstly: could you tell me how you define "major accident"? Does TMI
qualify?
Secondly: what would you say are the minimum unacceptable consequences of
a major accident?
>I don't
>particularly want to be killed on the road, but I'm more willing to
>accept that possibility than the possibility of, say, a major breach
>of containment at Indian Point.
I realize that this is a question of values here. Even so, could you
tell me *why* you're more willing to accept the possibility of being
killed by an automobile failure than by the failure of a nuclear power
plant?
Would you be willing to accept the risks of using current nuclear power
technology if the plants were built in very remote locations (e.g., out
in the middle of the Mojave Desert, at least 100 miles from any major
city)?
--
Kevin Brown ke...@nuchat.sccsi.com
This is your .signature virus: < begin 644 .signature (9V]T8VAA(0K0z end >
This is your .signature virus on drugs: <>
Any questions?
Tipton, Knights Fan Extraordinaire
>>But, this thread started with a proposed FAQ by John McCarthy. The "FAQ"
>>began with a claim that no current or contemplated nuclear reactor could
>>"explode like a bomb". My effort to point out the flaw in this claim was
>>apparently not according to party line.
>
>Oh, well. I'm not much on political correctness of any form. I don't know
>enough about nuclear engineering to say whether or not a nuclear reactor
>can "explode like a bomb". I would guess that it depends on the design
>(and on how you define "explode like a bomb"). While there are probably
>reactors in existence that can explode in such a manner, there are probably
>some that can't (i.e., physical law makes such an event astronomically
>unlikely). But I don't *know*.
I'd say that *I* probably *DO* know enough about Nuc Eng to say that a nuclear
reactor CAN NOT blow up like a nuclear weapon. If enough things go wrong, a
reactor facility (not the reactor itself) can go up like a conventional bomb
due to steam explosion possibility. After doing PRA work for the US Department
of Energy for a while at Savannah River, I seem to recall the chances of a
facility going up in a steam explosion being something on the order of 10e-12
or so (you have a better chance of being struck by lightning three times during
your lifetime!). That probability is based on several events ALSO happening,
and those events are on the order of 10e-7 or so (these numbers are occurrences
per reactor-year).
>Do you really feel qualified to evaluate the safety of the new nuclear
>power plant designs?
Anybody who can say that they're qualified to evaluate the safety had better
start putting their qualifications alongside their evaluations.
>>I believe that, under current circumstances, the chances of a major
>>accident at a nuclear power plant are not negligable, and that the
>>possible consequences of such an accident are not acceptable.
Okay-question here! The chances of a major accident in airliner travel are
not negligible, and the possible consequences of such an accident are also
not "acceptable", yet millions of people fly to their destinations yearly.
(If I recall here correctly (and I should-the book is right in front of me!),
the chances of an airliner crashing are on the order of 10000 more than that of a nuclear facility having an "accident.")
As far as accidents go, when that airliner crashed in Amsterdam, how many peoplewere killed-wasn't it on the order of 300-400?)
>Firstly: could you tell me how you define "major accident"? Does TMI
>qualify?
>
>Secondly: what would you say are the minimum unacceptable consequences of
>a major accident?
Yes-tell us, I'd like to know too!
Michael R James
>In article ke...@sccsi.com (Kevin Brown) writes:
>>>But, this thread started with a proposed FAQ by John McCarthy. The "FAQ"
>>>began with a claim that no current or contemplated nuclear reactor could
>>>"explode like a bomb". My effort to point out the flaw in this claim was
>>>apparently not according to party line.
>>
>>Oh, well. I'm not much on political correctness of any form. I don't know
>>enough about nuclear engineering to say whether or not a nuclear reactor
>>can "explode like a bomb". I would guess that it depends on the design
>>(and on how you define "explode like a bomb"). While there are probably
>>reactors in existence that can explode in such a manner, there are probably
>>some that can't (i.e., physical law makes such an event astronomically
>>unlikely). But I don't *know*.
>I'd say that *I* probably *DO* know enough about Nuc Eng to say that a nuclear
The previous poster made a very good point that it depends on how
you define "explode like a bomb". I can point to research
done mostly in the '60's where people concerned themselves
with this very problem (the explosions, not the definitions).
And breeders CAN be susceptible to
to this (unlike LWRs).
>Okay-question here! The chances of a major accident in airliner travel are
>not negligible, and the possible consequences of such an accident are also
>not "acceptable", yet millions of people fly to their destinations yearly.
>(If I recall here correctly (and I should-the book is right in front of me!),
The comparison with airline travel is probably more valid than
the one with automobiles. A pilot friend of mine made the point
one time that nuclear power and air travel often suffer from
similiar (mis?)perceptions of being unsafe.
--
Michael James mrjg...@uxa.cso.uiuc.edu
"Ludwig Boltzmann, who spent much of his life studying statistical
mechanics, died in 1906, by his own hand. Paul Ehrenfest, carrying
on the work, died similarly in 1933. Now it is our turn to study
statistical mechanics."
-David L. Goodstein "States of Matter"
victor yodaiken
>I wonder just how much of a lead time we need for the research that you
>mention to become something that is produced. Whatever that period of time
>is, it defines how long "immediate" refers to, and thus how long efficiency
>and conservation have to work. Do the sources you refer to say how long
>they expect such measures to be sufficient?
>
As others have posted on this newsgroup, there seems to be at least a
couple of decades of lead time.
>Do you really feel qualified to evaluate the safety of the new nuclear
>power plant designs?
Where the safety of the plants is an issue in matters of public policy,
e.g., plant siting, use of public money, regulation, etc., then don't all
citizens have an obligation to evaluate the safety of the plant designs?
Certainly, I would not attempt to create a pra from scratch or even feel
the slightest interest in recalculating a pra or going over xray of welds
or checking up on contracting records. But, I do have an obligation to make
a judgement between critics of nuclear power, both within the nuclear
industry and in such groups as UCS, and nuclear advocates. So far,
I've found the nuclear advocates to be quite unpersuasive.
I think that this is a general issue in an increasingly technological and
specialized society. Do you feel qualified to judge the safety of
oil refineries, agricultural pesticides, sewage treatment plants,
computerized autopilots, automobile pollution control systems, for-profit
kids TV, ..... ? Clearly, most of us will be lacking in professional
qualifications to judge the majority of these issues. Should we just
let the experts decide? What about when the experts disagree? What if
they experts judgement on the value of something differs from our own,
subjective, opinions?
>>Well, I am not against the use of large-complex machines, but as a general
>>principle, I prefer them to be well designed,
>
>I agree with the sentiment, but there *are* reasonable limits to this, no?
>What you and others seem to disagree about is exactly where those limits
>are.
Yes. My impression is that the current generation of nuclear power plants
are not well designed: the indicator _behind_ the operators panel at
TMI and the duplicated control cables bundled together in a single
conduit at Browns Ferry spring to mind. Others are free to disagree.
Okrent's sympatheitc history of nuclear power in the US shows how political
and profit considerations were allowed to repeatedly override technical
conserns, so the pastiche designs and absolute lack of standardization
should come as no surprise.
>>to allow for reasonable
>>workarounds, to not be overcentralized,
>
>Hmm...how does one determine whether or not something is "overcentralized"?
>
No hard and fast rule. Note that the failure at TMI turned a multibillion
dollar asset into a multibillion dollar debt in a few minutes.
>Well, there are certainly failure modes of satellites (especially low-orbit
>satellites) which are not as localized as most of the failure modes such a
>satellite would have. If the directional thruster control fails such that
>the orbit of the satellite changes enough to intersect the earth (for all I
>know, though, they may design the thing such that such a failure mode is not
>possible. But then, they claim much the same thing with nuclear plants, and
>you don't believe those claims, so can I assume that you won't believe
>similar claims from the satellite design engineers either? :-)...
If I see good arguments to the contrary. Haven't so far. Communication
satelites are rather low mass, and I haven't seen any reason to believe
that they could generate a significant impact on the surface if they
fell out of orbit.
>>Pretty concerned. Using sodium as a coolant bother me. I don't say
>>that it's necessarily a bad idea, it just inspires caution.
>
>Sodium is admittedly nasty stuff. Do we not use equally nasty stuff
>routinely elsewhere, though?
Well, I think that we are generally way too cavalier about industrial
accidents and spills. The contruction of a plant that places pressurized
steam, liquid sodium, and a fissioning core in close proximity gives me
pause. Are there better, cheaper, safer alternatives? Can such a plant
be safely entrusted to Generic Power Company? It seems to be only sensible
to be very cautious about such devices.
>>I believe that, under current circumstances, the chances of a major
>>accident at a nuclear power plant are not negligable, and that the
>>possible consequences of such an accident are not acceptable.
>
>Firstly: could you tell me how you define "major accident"? Does TMI
>qualify?
>
TMI was an expensive accident, and a messy one (the cleanup continues at
great cost). Even if nuclear accidents were limited to be no worse
than TMI, it would make me very dubious about nuclear simply because
of the cost. Add in a few TMI's per 20 years as a worst case figure and
the costs of nuclear become rather grim. But, I am not convinced that
TMI was a worst case accident. TMI had a unusually strong containment
structure because of a nearby airport. What would the effects of a
simialr accident have been at Indian Point or Zion? What's the
possibility of a turbine missile shattering a reactor vessel in an older
plant with a poorly maintained containment structure? An accident
that released the reactor core or a large part of it, or even worse
the contents of the spent fuel storage into the environment would not
be acceptable.
>>I don't
>>particularly want to be killed on the road, but I'm more willing to
>>accept that possibility than the possibility of, say, a major breach
>>of containment at Indian Point.
>
>I realize that this is a question of values here. Even so, could you
>tell me *why* you're more willing to accept the possibility of being
>killed by an automobile failure than by the failure of a nuclear power
>plant?
Not just me personally, but the population at large. I don't believe that
we have as much of a right to risk the lives of other people and the lives
and prosperity of future generations as we do with our own lives.
>Would you be willing to accept the risks of using current nuclear power
>technology if the plants were built in very remote locations (e.g., out
>in the middle of the Mojave Desert, at least 100 miles from any major
>city)?
I'd hate to see the Mohave desert trashed out by any big construction
project, but in principle, siting of nuclear power plants in areas that
were actually evacuable would be a step in the right direction.
--
KENNETH SOLLOWS
>
>I'd say that *I* probably *DO* know enough about Nuc Eng to say that a nuclear
>reactor CAN NOT blow up like a nuclear weapon. If enough things go wrong, a
>reactor facility (not the reactor itself) can go up like a conventional bomb
>due to steam explosion possibility.
By "steam explosion", I presume that you mean an event that occurs when
large numbers of small particles of high temperature fuel and cladding are
rapidly mixed with water. By what mechanism does the fuel/cladding become
finely divided and distributed through the coolant? Might a sudden,
localized power transient provide enough energy to do this? What is the
source of this energy? Is it chemical bonds, as in a "conventional bomb",
or is it fission?
No, I think it is still more correct to say that SOME reactors CAN blow up
like slow atomic bombs. Having acknowledged that, it's also important to
realize that reactors can be, and largely are, designed so that they will
not or, in some cases, probably will not!
Ken
Jeremy Whitlock
> [...]
>
>No, I think it is still more correct to say that SOME reactors CAN blow up
>like slow atomic bombs. Having acknowledged that, it's also important to
>realize that reactors can be, and largely are, designed so that they will
>not or, in some cases, probably will not!
"Slow atomic bomb?" Why not say that a reactor is brought up to power like
a "slow atomic bomb?" Or, what not just call a reactor a "slow atomic bomb?"
It's the same type of nuclear reaction taking place, just with a smaller
time constant (or, in the case of criticality, a zero time constant). Why
not? Because it would be *wrong* terminology, and I can't believe the
amount of argueing I see over a what should be a black-and-white issue. If
a firecracker goes off in a house and the house catches fire and burns down,
would you say the house blew up like a slow firecracker? Of course not.
Some reactors can blow up like a bomb; there is no debate about that.
*No* reactor can blow up like a nuclear bomb.
--
Jeremy Whitlock "My thoughts are mine, not Mac's"
Dept. Engineering Physics
McMaster University
Hamilton, Ontario, Canada
Gene Forrer
>e.g., plant siting, use of public money, regulation, etc., then don't all
>citizens have an obligation to evaluate the safety of the plant designs?
>Certainly, I would not attempt to create a pra from scratch or even feel
>the slightest interest in recalculating a pra or going over xray of welds
>or checking up on contracting records. But, I do have an obligation to make
>a judgement between critics of nuclear power, both within the nuclear
>industry and in such groups as UCS, and nuclear advocates. So far,
>I've found the nuclear advocates to be quite unpersuasive.
I've seen most opponents of nuclear power use hysteria and outdated
infornation for the basis of their protests. Further, most who manage to
get the chance to review plans aren't looking to confirm safety they only
use the opportunity to stall and make ridiculous demands about non existant
problems. Okay hers ethe scenerio the space shuttle goes hundreds of miles
of cours and crashes into the containment building at mach 4.3 we need to
plan for that, get real.
>Yes. My impression is that the current generation f nuclear power plants
>are not well designed: the indicator _behind_ the operators panel at
>TMI and the duplicated control cables bundled together in a single
>conduit at Browns Ferry spring to mind. Others are free to disagree.
current generation. These designs are 20-25 years old. What do you think
the nuclear industry sits on its butt and doesn't make any improvements at
all? We are 2 or 3 designs past trojan and Browns Ferry with new safety
features both mechanical and inherant. Further you can bet the farm that
as problems are discovered plants with a similar design are updated and
improved.
>Okrent's sympatheitc history of nuclear power in the US shows how political
>and profit considerations were allowed to repeatedly override technical
>conserns, so the pastiche designs and absolute lack of standardization
>should come as no surprise.
fast buck do you suppose we would have as much acid rain as we do and don'
t you think that we would have shut the coal plants down as soon as we
found a problem.
>Well, I think that we are generally way too cavalier about industrial
>accidents and spills. The contruction of a plant that places pressurized
>steam, liquid sodium, and a fissioning core in close proximity gives me
>pause. Are there better, cheaper, safer alternatives? Can such a plant
>be safely entrusted to Generic Power Company? It seems to be only sensible
>to be very cautious about such devices.
hysteria and/or ignorance. Can any potentialy dangerous technology be
trusted to anyone whose main goal is profit? As to non-standard design
current legislation has made standardized plans possible if not desirable.
The NRC will now be able to review and approve a plant design once and that
design can be used anywhere that siting has been approved. tyhis should go
a long way toward plant reliability since each plant won't be a unique
design.
>TMI was an expensive accident, and a messy one (the cleanup continues at
>great cost). Even if nuclear accidents were limited to be no worse
>than TMI, it would make me very dubious about nuclear simply because
>of the cost. Add in a few TMI's per 20 years as a worst case figure and
>the costs of nuclear become rather grim. But, I am not convinced that
>TMI was a worst case accident. TMI had a unusually strong containment
>structure because of a nearby airport. What would the effects of a
>simialr accident have been at Indian Point or Zion? What's the
>possibility of a turbine missile shattering a reactor vessel in an older
>plant with a poorly maintained containment structure? An accident
>that released the reactor core or a large part of it, or even worse
>the contents of the spent fuel storage into the environment would not
>be acceptable.
designed for large passanger jet impact because you don't have to be near
an airport for one to crash on you. Also the turbines in a PWR reactor
are not in the containment building with the reactor. The recent breakin
at TMI should tell you that. The nut who crashed the gate got into the
turbine building you know building where they keep the tubines. Also if
they did put the turbines into the same room as the reactor have you any
idea how thick a pressure vessel is. And finally this is what I am
talking about being part of the review process, coming up with ridiculous
scenarios. Non nuclear reviewer what if this part that hasn't broken in over
many years of use decides to do this really strange thing what happens then.
Designer well thats why we chose this part because it doesn't break.
Non nuke but if it did break that would be bad yes? Designer well yes.
Cleanup at TMI is going slow because of the radiation levels in the plant
are so high workers can only remain a short while and must use robots in
many cases. Also designers are using the chance to look at what happened
to help prevent the problem in future designs. Learning from their
mistake. If we had a TMI every 20 years I would want to shut the damn
things down also and I don't think it would remain profitable so even the
utilities would shy away. But realize that the new designs to replace the
plants that are being shut down are being tested and design so that if
every nasty thing in the world were to happen the plant will just shut it
self off.
construction >project, but in principle, siting of nuclear power plants in
areas that>were actually evacuable would be a step in the right direction.
plant, homes for the workers, industry that moves in because of the reliable
power, the shops and restaruants etc. Won't be long until you have some
kind of town there.
Gene
Gene Forrer
>Subject: Re: Breeders
>Summary: Nuclear Engineering response
>Keywords: Rx is NOT a bomb!
>Date: Mon, 10 May 1993 13:13:33 GMT
slow. Even Chernobyl was a conventional steam and thermal explosion. What
made Chernobyl so nasty was that the plant had no containment. Fuel does not
become finely divided and distributed in the coolant, fuel is in the form of
ceramic pellets. I checked with some Nuke Professors, they say can't happen
no way no how. Not to say if not designed right there couldn't be a nasty
steam expolosion which without containment would spread contamination all
over the general area.
Tipton, Knights Fan Extraordinaire
>large numbers of small particles of high temperature fuel and cladding are
>rapidly mixed with water. By what mechanism does the fuel/cladding become
>finely divided and distributed through the coolant? Might a sudden,
>localized power transient provide enough energy to do this? What is the
>source of this energy? Is it chemical bonds, as in a "conventional bomb",
>or is it fission?
A "steam explosion" is defined in NE as a transient in which steam pressure
builds up in some part of the primary system (be it Steam Generator,
Pressurizer, or the vessel itself) and that pressure becomes higher than
the rated pressure for that structure, failing it "catastrophically"-eg
blowing it into shreds. Normally, a steam explosion has absolutely nothing to
do with the fuel/cladding except for the fact that during an unusually potent
stm exp, the cladding can be vaporized (the fuel traditionally has too high a
melting point to be vaporized). A localized power transient would not have
enough energy to do this, as it takes the nearly simultaneous failure of not
less than seven different safety systems for this event to occur.
>No, I think it is still more correct to say that SOME reactors CAN blow up
>like slow atomic bombs. Having acknowledged that, it's also important to
>realize that reactors can be, and largely are, designed so that they will
>not or, in some cases, probably will not!
Define a "slow atomic bomb"! The definition of an atomic bomb (from Random
House College Dictionary) is "a bomb whose explosive force comes from a chain
reaction based on the nuclear fission of atoms of U-235 or Pu-239 with the
consequent conversion of part of their mass into energy." In the same book,
explosive is defined as "pertaining to or of the nature of a violent expansion
or bursting with noise, as of gunpowder or a boiler." ^^^^^^^^^^^^^^^^^
If it's "slow", then it's not a violent expansion, now is it?
Josh Rovero
>large numbers of small particles of high temperature fuel and cladding are
>rapidly mixed with water. By what mechanism does the fuel/cladding become
>finely divided and distributed through the coolant? Might a sudden,
>localized power transient provide enough energy to do this? What is the
>source of this energy? Is it chemical bonds, as in a "conventional bomb",
>or is it fission?
>
I don't think so. An event that leads to rapid vaporization of coolant,
which, as a gas, creates a sudden overpressure within the structure. No
"large numbers of small particles" of anything except H2O are required.
And I certainly wouldn't characterize it as a "nuclear" explosion. Nuclear
explosions result from a much more rapid fission or fusion process. Look
for blinding flashes and fireballs........
--
Josh Rovero (rov...@oc.nps.navy.mil) | Packet: KK1D @ K6LY
Department of Oceanography, Code OC/Rv |
Naval Postgraduate School |
Monterey, CA 93943 (408) 656-2084 |
KENNETH SOLLOWS
>From: whit...@dcss.mcmaster.ca (Jeremy Whitlock)
>Subject: Re: Breeders
>Keywords: Rx is NOT a bomb!
>In article <sollow...@UNBSJ.CA> sol...@UNBSJ.CA (KENNETH SOLLOWS) writes:
>> [...]
>>
>>No, I think it is still more correct to say that SOME reactors CAN blow up
>>like slow atomic bombs. Having acknowledged that, it's also important to
>>realize that reactors can be, and largely are, designed so that they will
>>not or, in some cases, probably will not!
>
>"Slow atomic bomb?" Why not say that a reactor is brought up to power like
>a "slow atomic bomb?" Or, what not just call a reactor a "slow atomic bomb?"
Because when they operate normally they don't produce an explosion that
causes damage to the environs. On the other hand, when they operate as the
Chernobyl reactor did immediately prior to blowing the roof off its
building, calling it an ~unanticipated core disassembly event~ or any
other such technospeak gobbledygook does great damage to the credibility
of the speaker. The damn thing blew up. It was like a bomb. Was it like
a glob of plastique, 3 sticks of dynamite, a truck load of fertilizer and
fuel oil, a tank full of napalm? I don't know, but Marshall said it was
like a "slow atomic bomb" and I see no reason to disbelieve him. I also
note that, in addition to understanding something of the physics of the
event, he is in a better position than most of us (me, anyway) to judge
the kind of language appropriate to the description of the event in a
public forum.
>It's the same type of nuclear reaction taking place, just with a smaller
>time constant (or, in the case of criticality, a zero time constant). Why
>not? Because it would be *wrong* terminology, and I can't believe the
>amount of argueing I see over a what should be a black-and-white issue.
Appropriate terminology depends upon context. As I acknowledged in my post
on April 25, the timescales are important in engineering and physics. They
just are just no so critical when it comes to policy. The important
words are "explode" and "bomb".
>If
>a firecracker goes off in a house and the house catches fire and burns down,
>would you say the house blew up like a slow firecracker? Of course not.
No, but if a gas explosion ignited a fire that burned the house, I
would say it exploded and burned. I would say the same for Chernobyl. As
to what the expolsion was like, I have no problem with Lord Marshall's
phrase ". . . like a slow atomic bomb."
>
>Some reactors can blow up like a bomb; there is no debate about that.
True, but it's also relevant that most can't, and of those that can, most
probably won't.
>*No* reactor can blow up like a nuclear bomb.
Also true, but totally irrelevant from a public policy perspective.
Ken
KENNETH SOLLOWS
>Sorry reactors don't blow up like atomic bombs. their fission rate is to
>slow. Even Chernobyl was a conventional steam and thermal explosion.
[...]
So tell me, while we seem to on the subject of misleading terminology, how
pray-tell, shall we make steam explode? :-) It kind of makes me squirm to
think of the Chernobyl accident as anything "conventional"!
Ken
KENNETH SOLLOWS
>
>builds up in some part of the primary system (be it Steam Generator,
>Pressurizer, or the vessel itself) and that pressure becomes higher than
>the rated pressure for that structure, failing it "catastrophically"-eg
>blowing it into shreds.
This is a pressure vessel failure.
> Normally, a steam explosion has absolutely nothing to
>do with the fuel/cladding except for the fact that during an unusually potent
>stm exp, the cladding can be vaporized (the fuel traditionally has too high a
>melting point to be vaporized). A localized power transient would not have
>enough energy to do this, as it takes the nearly simultaneous failure of not
>less than seven different safety systems for this event to occur.
Normally, a "steam explosion" has nothing to do with the operation of a
reactor! Why choose words that make it look like they happen all the
time? These are rare events.
Who said anything about vapourization? I said finely divided and
distributed, which is, if memory serves, thought to be a precondition for
evolving large quantities of steam in a very rapid fashion.
From the accident sequence at Chernobyl[1]:
"Time: 01:23:44
Event: The reactor power reached about 100 times full power, fuel
disintegrated, and excess steam pressure broke the pressure tubes.
Comments: The pressure in the reactor core blew the top shield off and
broke all the remaining pressure tubes."
This seems to imply that the power transient (in the lower portion of the
reactor?) caused the fuel to disintegrate (more consise than my "finely
divided and distributed", isn't it?) and that only some (localized)
pressure tubes failed initially.
Now, where do you suppose the excess steam pressure came from? Pixie dust?
Or was it maybe due to fuel/cladding/coolant interactions and, ultimately,
the reactor power transient?
[1] Snell, V.G. and Howieson, J.Q. (1986): Chernobyl -- A Canadian
Perspective, AECL Candu Operations, Table 1, p.9.
>Define a "slow atomic bomb"! The definition of an atomic bomb (from Random
>House College Dictionary) is "a bomb whose explosive force comes from a chain
>reaction based on the nuclear fission of atoms of U-235 or Pu-239 with the
>consequent conversion of part of their mass into energy." In the same book,
>explosive is defined as "pertaining to or of the nature of a violent expansion
>or bursting with noise, as of gunpowder or a boiler." ^^^^^^^^^^^^^^^^^
I'm happy with Lord Marshall's definition, which I previously posted.
Now, I hope we agree that Chernobyl exploded. Its explosive force came
from, ultimately, and in close temporal and spatial proximity to, nuclear
fission. That it took seconds rather than milliseconds to rip itself apart
is the principle difference, and the reason the size of the explosion was
much, much smaller than even a poorly designed atomic bomb. It is thus
slow, relative to the physical process that ocurrs in an atomic bomb.
>If it's "slow", then it's not a violent expansion, now is it?
So it's all right to be hit by a slow train, is it? ;-)
Ken
KENNETH SOLLOWS
>
>I don't think so. An event that leads to rapid vaporization of coolant,
>which, as a gas, creates a sudden overpressure within the structure. No
>"large numbers of small particles" of anything except H2O are required.
But from whence does the energy come to evaporate the water? Why does the
rate of vapour generation increase suddenly?
>
>And I certainly wouldn't characterize it as a "nuclear" explosion.
OK.
>Nuclear
>explosions result from a much more rapid fission or fusion process. Look
>for blinding flashes and fireballs........
Agreed, and acknowledged in the prior posts.
Ken
Dave Stephenson
>Sorry reactors don't blow up like atomic bombs. their fission rate is to
>slow. Even Chernobyl was a conventional steam and thermal explosion. What
Not quite, it was worse than a steam explosion. Graphite and water react
when they get hot and produce hydrogen. The Graphite in Chernobyl got
very hot and the result was a hydrogen explosion, which of course added
considerably to the destruction when it reached the air. If you must
douse a burning graphite moderated reactor (Windscale) with water, do it
real fast with LOTS of water to quench the hydrogen reaction.
--
Dave Stephenson
Geological Survey of Canada
Ottawa, Ontario, Canada *Om Mani Padme Hum 1-2-3*
Internet: step...@geod.emr.ca
Tino
>>Okay-question here! The chances of a major accident in airliner travel are
>>not negligible, and the possible consequences of such an accident are also
>>not "acceptable", yet millions of people fly to their destinations yearly.
>>(If I recall here correctly (and I should-the book is right in front of me!),
>
>The comparison with airline travel is probably more valid than
>the one with automobiles. A pilot friend of mine made the point
>one time that nuclear power and air travel often suffer from
>similiar (mis?)perceptions of being unsafe.
Dr. Ott, a reactor physics prof at Purdue, loves to tell this story:
He was a convention one time and ran into an old friend of his, who
designs commercial aircraft. After a discussion of public perception
of risk in both of their fields, Dr. Ott's friend turned to him and
said, "Do you know what the difference is between our jobs? I am
allowed to kill people and you are _not_."
Back to your regularly-scheduled flamewars...
Dave Stephenson
>In article <forrer...@ccmail.orst.edu> for...@ccmail.orst.edu (Gene Forrer) writes:
....steam explosion...
>think of the Chernobyl accident as anything "conventional"!
Technically a steam driven explosion is a mechanical explosion. Heat water
to well above 100 C in a sealed tube, and wait. The tube shatters the
water now well over one atm press immediately turns to steam with 1000's
the volume of water and hence a shock wave, i.e. an explosion. The largest
recorded explosion Krakatoa was a steam explosion. The instantanious
vapourization of several cubic miles of sea water. BTW if you insist on
trying the experiment, be sure to use a small tube that has farely thin
walls and STAND WELL BACK while wearing safety glasses. Bits can fly
quite far.
Gene Forrer
>From: sol...@UNBSJ.CA (KENNETH SOLLOWS)
>Subject: Re: Breeders
>Summary: Nuclear Engineering response
>Keywords: Rx is NOT a bomb!
steam it will expand rapidly. If you flash enough water fast enough in a
tight container the container will explode. The same basic theory as any
bomb. A great deal of energy in a small (relativly) contained space
released very quickly. What exploded at Chernobyl was the vessel full of
super hot steam. This does not make the fact that a lot of radioactive
material was spread all over the country side any better. Chernobyl was
a major bad design that even the Russian science minister admits was the
result of stupid people. In most countries the reactor is protected by a
containment building that is designed to contain such an explosion, so that
even if we had a plant do a Chernobyl (which can't happen with our designs)
it would not result in a release to the environment.
Gene Forrer
>From the accident sequence at Chernobyl[1]:
>
>"Time: 01:23:44
>
>Event: The reactor power reached about 100 times full power, fuel
>disintegrated, and excess steam pressure broke the pressure tubes.
>
>Comments: The pressure in the reactor core blew the top shield off and
>broke all the remaining pressure tubes."
>
>This seems to imply that the power transient (in the lower portion of the
>reactor?) caused the fuel to disintegrate (more consise than my "finely
>divided and distributed", isn't it?) and that only some (localized)
>pressure tubes failed initially.
>
>Now, where do you suppose the excess steam pressure came from? Pixie dust?
>Or was it maybe due to fuel/cladding/coolant interactions and, ultimately,
>the reactor power transient?
>
>Now, I hope we agree that Chernobyl exploded. Its explosive force came
>from, ultimately, and in close temporal and spatial proximity to, nuclear
>fission. That it took seconds rather than milliseconds to rip itself apart
>is the principle difference, and the reason the size of the explosion was
>much, much smaller than even a poorly designed atomic bomb. It is thus
>slow, relative to the physical process that ocurrs in an atomic bomb.
>
Lets compare apples and oranges. You can not use Chernobyl as a
justification for limiting nuclear power in the USA.
The steam came from the heat being produced by the fission process yes but,
and I will type slow here, the explosion was aresult of rapidly expaning
steam in a contained space. The fission process only provided heat and did
not contribute any explosive force as you would find in a nuclear bomb. If
you had any heat source large enough you could generate the same explosion
as the one that occured at Chernobyl. Finally a nuclear bomb explodes
because of the prompt criticality of two masses if fissile material slammed
together very fast. You cannot get that kind of energy release from just
having a lump of fissile material just sitting there.
KENNETH SOLLOWS
>Water has a specific density while steam has another. If you flash water to
>steam it will expand rapidly. If you flash enough water fast enough in a
>tight container the container will explode.
So how are we going to flash "enough water fast enough" in the reactor
without intermixing the fuel and coolant? The whole thing is designed to
boil water at high pressure. You need to have a mechanism that will
increase the vapour evolution rate >>very<< rapidly. The obvious mechanism
is a fuel/cladding/coolant interaction, but just how to do this without a
very substantial reactor power transient is not clear. Indeed, that is the
distinguishing feature of the Chernobyl accident. Without a power transient
that blows the fuel apart and into the coolant, the heat transfer to the
coolant will be limited by the transition to film boiling at high cladding
temperatures. This might lead to fuel damage, but it shouldn't cause a "
steam explosion"!
>The same basic theory as any
>bomb. A great deal of energy in a small (relativly) contained space
>released very quickly.
Hey. Is it politically correct for a pro nuke to write the "B" word?:-)
>What exploded at Chernobyl was the vessel full of
>super hot steam.
But only after the power transient blew the fuel into the coolant, evolving
steam that ruptured the pressure tubes. See my earlier post for the
reference.
>This does not make the fact that a lot of radioactive material was spread
>all over the country side any better. Chernobyl was a major bad design that
>even the Russian science minister admits was the result of stupid people.
>In most countries the reactor is protected by a containment building that
>is designed to contain such an explosion, so that even if we had a plant do
>a Chernobyl (which can't happen with our designs) it would not result in a
>release to the environment.
Perhaps all true, but lets be clear about what happened at Chernobyl. It
blew up. Why? Because steam formed more rapidly than it could be remove
from the reactor using the regular flow paths. How did this happen?
Enough cladding and fuel were mixed with coolant raise the vapour generation
rate very rapidly. How did the cladding and fuel get mixed up with the
coolant? I don't really know, but the reported 100x power transient seems a
likely candidate, doesn't it?
Ken
KENNETH SOLLOWS
>
>Technically a steam driven explosion is a mechanical explosion. Heat water
>to well above 100 C in a sealed tube, and wait. The tube shatters the
>water now well over one atm press immediately turns to steam with 1000's
>the volume of water and hence a shock wave, i.e. an explosion. The largest
>recorded explosion Krakatoa was a steam explosion. The instantanious
>vapourization of several cubic miles of sea water. BTW if you insist on
>trying the experiment, be sure to use a small tube that has farely thin
>walls and STAND WELL BACK while wearing safety glasses. Bits can fly
>quite far.
>
times. However, in the context of a reactor accident, the hard part is the
instantaneous (or even very fast) vapourization part of it. There is just
no obvious method to get this out of a reactor without a large power
transient. Remember, all the fuel pins are normally in contact with the
water and the pressure circuit is initially intact. Under these
conditions, how are you going to rapidly increase the vapour generation rate
without breaking up the fuel/cladding and intermixing it with the coolant
to greatly increase the heat transfer surface? And how are you going to do
that? At Chernobyl, it appears that a power transient did it.
Ken
KENNETH SOLLOWS
>Lets compare apples and oranges. You can not use Chernobyl as a
>justification for limiting nuclear power in the USA.
What is this, amateur hour at the sophistry club? At no time did I even
suggest that Chernobyl justified limiting nuclear power in the USA. Try
and stick to the subject at hand, please!
>The steam came from the heat being produced by the fission process yes but,
>and I will type slow here, the explosion was aresult of rapidly expaning
>steam in a contained space. The fission process only provided heat and did
>not contribute any explosive force as you would find in a nuclear bomb.
Come on now. In "the" bomb, it's really only the heat that gives the
explosion. So I guess they really aren't atomic or nuclear bombs? After
all, the explosion is simply rapidly expanding gas/plasma? The fision/
fusion only provides the heat! ;-) Those extra neutron and gamma rays are
really only a bonus, eh? ;-)
>If
>you had any heat source large enough you could generate the same explosion
>as the one that occured at Chernobyl.
Again, totally irrelevant, and most probably untrue! You need more than a
heat source to get an explosion. It's a matter of the rates of the
reactions: physical, nuclear, chemical, etc. In addition to the source of
energy, you need a viable process to convert that energy to produce a
rapidly expanding gas.
>Finally a nuclear bomb explodes
>because of the prompt criticality of two masses if fissile material slammed
>together very fast. You cannot get that kind of energy release from just
>having a lump of fissile material just sitting there.
So what? More irrelevant facts!
Ken
Michael R James
>In article <forrer...@ccmail.orst.edu> for...@ccmail.orst.edu (Gene Forrer) writes:
>>Water has a specific density while steam has another. If you flash water to
>>steam it will expand rapidly. If you flash enough water fast enough in a
>>tight container the container will explode.
>So how are we going to flash "enough water fast enough" in the reactor
>without intermixing the fuel and coolant? The whole thing is designed to
>boil water at high pressure. You need to have a mechanism that will
>increase the vapour evolution rate >>very<< rapidly. The obvious mechanism
>is a fuel/cladding/coolant interaction, but just how to do this without a
>very substantial reactor power transient is not clear. Indeed, that is the
>distinguishing feature of the Chernobyl accident. Without a power transient
>that blows the fuel apart and into the coolant, the heat transfer to the
>coolant will be limited by the transition to film boiling at high cladding
>temperatures. This might lead to fuel damage, but it shouldn't cause a "
>steam explosion"!
I thought that the water was carried through the the core
in the RBMKs in separate channels in the graphite. I don't
think the water ever contacted the fuel cladding.
One "advantage" of the RBMK was on-line refueling ( a leftover
from the design's weapons production days). I can't imagine
removing fuel that's in contact with coolant.
>>What exploded at Chernobyl was the vessel full of
>>super hot steam.
>But only after the power transient blew the fuel into the coolant, evolving
>steam that ruptured the pressure tubes. See my earlier post for the
>reference.
Wouldn't the fuel have to have been blown through the graphite?
John De Armond
>>"Slow atomic bomb?" Why not say that a reactor is brought up to power like
>>a "slow atomic bomb?" Or, what not just call a reactor a "slow atomic bomb?"
>Because when they operate normally they don't produce an explosion that
>causes damage to the environs. On the other hand, when they operate as the
>Chernobyl reactor did immediately prior to blowing the roof off its
>building, calling it an ~unanticipated core disassembly event~ or any
>other such technospeak gobbledygook does great damage to the credibility
>of the speaker. The damn thing blew up. It was like a bomb. Was it like
>a glob of plastique, 3 sticks of dynamite, a truck load of fertilizer and
>fuel oil, a tank full of napalm? I don't know, but Marshall said it was
>like a "slow atomic bomb" and I see no reason to disbelieve him. I also
>note that, in addition to understanding something of the physics of the
>event, he is in a better position than most of us (me, anyway) to judge
>the kind of language appropriate to the description of the event in a
>public forum.
This would be funny if it weren't so tragically ignorant. I wonder if
you so blindly accept the explanation of other non-nuclear events that
you don't understand without question. If so, your worldview must be
exceedlingly simple. Let's do this real slowly.
If I take a few million curies of high level waste, wrap it in dynamite
and set it off in the World Trade center, was that a nuclear explosion?
Say "No". Very good.
if I take a few million curies of HLW, put it in a sealed container
along with some water, build a fire under the container and allow it
to burst from steam pressure, was THAT a nuclear explosion?
Say "No". Very very good. We're making progress.
If I take a few million curies of HLW, put it in a sealed container along
with some water, insulate the whole thing very well and allow it
to burst from the decay-heat-generated-steam, was THAT a nuclear
explosion?
Say "No".
If I take a few million curies of HLW containing some fissionable
uranium, put it in a sealed container along with some water, insulate
the whole thing very well, arrange the geometry such that fission takes
place and allow it to burst from the fission-heat-generated-steam, was
THAT a nuclear explosion?
Say "No." Heeeyyy, we're getting there.
If I take a few million curies of HLW containing some fissionable
uranium, put it in a sealed container along with some water, insulate
the whole thing very well, arrange the geometry such that real fast
fission takes place and allow it to burst from the
fission-heat-generated-steam, was THAT a nuclear explosion?
You know the drill.
Now suppose I take a couple of sub-critical masses, arrange some
contraption capable of holding them together long enough for a substantial
portion of the mass to fission, thus raising the whole mass to 300,000,000
degrees or so, emitting zillions of gamma, X-rays and neutrons and vaporizing
the assembly and some amount of surrounding real estate, is THAT a
nuclear explosion?
BINGO!! You get to say "yes."
Nothing to do with steam, vaporized fuel, reactor vessels, conventional
explosives or any of the other tripe mentioned in this thread to justify
calling anything that explodes and involves radioactive materials a
"nuclear explosion."
Now that we've figured out what a nuclear explosion is and is not, let's
look at Chernobyl.
>No, but if a gas explosion ignited a fire that burned the house, I
>would say it exploded and burned. I would say the same for Chernobyl. As
>to what the expolsion was like, I have no problem with Lord Marshall's
>phrase ". . . like a slow atomic bomb."
Chernobyl is NOT about explosions. The steam explosion did relatively
little damage as far as the outside world was concerned. Sure the
core was destroyed and the reservation contaminated but that had
no effect on the civilians outside the plant. What DID have an effect
on the outside world was the nuclear fueled fire that burned for several
days AFTER the explosion. Because of the core design, the portions that
were not destroyed continued fissioning. The heat caused the graphite
to burn and vaporized the fuel and fission products. THIS SLOW BURN is
what generated the massive contamination that blanketed the region.
Had the reactor NOT continued fissioning, the impact would have been
orders of magnitude less. I know these are subtle details but they
MATTER not only from a scientific perspective but from a political
perspective. If public policy is to be set to fix some problem, it helps
to know the problem. Public policy would have prevented a flawed reactor
design like Chernobyl from ever beening built. For the record, Soviet
public policy, as it were, DID prohibit the construction of chernobyl-like
reactors. Problem was it was ignored. That is also a political problem
having nothing to do with explosions OR fires.
>Appropriate terminology depends upon context. As I acknowledged in my post
>on April 25, the timescales are important in engineering and physics. They
>just are just no so critical when it comes to policy. The important
>words are "explode" and "bomb".
So you would *advocate* the making of public policy based on scientific
ignorance and misconception? If so words fail me to describe the
revulsion I feel toward you. Understanding the difference between a
nuclear explosion and a thermal explosion from nuclear generated heat
has EVERYTHING to do with public policy. No one in his right mind
would support a design that could undergo even a nuclear fizzle.
Thermally generated explosions are easy to handle with conventional
containments. Indeed, I challenge anyone to distinguish between a steam
explosion and a "double ended guillotine break" of a primary coolant
pipe and the resultant release of a half million gallons of water at 650
degrees. This double ended guillotine break is the design-basis accident
for conventional LWR plants.
Acknowledging public policy is sometimes made in a factual vacuum is one
thing; accepting and perpetuating it is a whole 'nuther ball game. I
hope your position is one of technical ignorance rather than deceit.
I even more hope I misunderstood your position but I doubt it.
John
--
John De Armond, WD4OQC |Interested in high performance mobility?
Performance Engineering Magazine(TM) | Interested in high tech and computers?
Marietta, Ga | Send ur snail-mail address to
j...@dixie.com | per...@dixie.com for a free sample mag
Lee Harvey Oswald: Where are ya when we need ya?
Jeremy Whitlock
> [...] I don't know, but Marshall said it was
>like a "slow atomic bomb" and I see no reason to disbelieve him.
I haven't seen Lord Marshall's quote, but he may have been referring to the
prompt critical power rise as a "slow atomic bomb", which is correct. The
explosions that blew the reactor apart were conventional, however, as is any
conceivable explosion that would blow a reactor apart. Referring to my
"firecracker in the house" analogy from a previous post:
>>If a firecracker goes off in a house and the house catches fire and burns
>>down, would you say the house blew up like a slow firecracker? Of course
>>not.
The prompt critical power rise is the "firecracker", and the conventional
explosions are the "house burning down." Do not confuse the two. Referring
to the explosions at Chernobyl as "nuclear" or anything like an "atomic bomb"
is -- as I said before -- *wrong* terminology. This is important because
anti-nuclear chaps tend to make a living out of using wrong terminology, and
they don't need any encouragement.
Jeremy Whitlock
>
>I thought that the water was carried through the the core
>in the RBMKs in separate channels in the graphite. I don't
>think the water ever contacted the fuel cladding.
The water flows over the fuel, in the same channels (through the graphite) as
the fuel. (CANDU's are similar, but substitute D2O for graphite.)
Dave Stephenson
>sol...@UNBSJ.CA (KENNETH SOLLOWS) writes:
>>>"Slow atomic bomb?" Why not say that a reactor is brought up to power like
>>>a "slow atomic bomb?" Or, what not just call a reactor a "slow atomic bomb?"
>Chernobyl is NOT about explosions. The steam explosion did relatively
>little damage as far as the outside world was concerned. Sure the
>core was destroyed and the reservation contaminated but that had
>no effect on the civilians outside the plant. What DID have an effect
Almost true. The steam/hydrogen explosion a Chernobyl was powerful
enough to shoot bits of the reactor core in to the local company
town. The firefighters reported that some of their number were
picking up bits that glowed blue in the street. Most are now dead.
The comment about the slow burn is true. A water cooled graphite
moderated reactor is about the most unsafe reactor design. The
British graphite moderated reactors used carbon dioxide for cooling,
and of course have a containment vessel.
John De Armond
>I thought that the water was carried through the the core
>in the RBMKs in separate channels in the graphite. I don't
>think the water ever contacted the fuel cladding.
>One "advantage" of the RBMK was on-line refueling ( a leftover
>from the design's weapons production days). I can't imagine
>removing fuel that's in contact with coolant.
>
You're right. Sollows has simply argued himself into a corner and is trying
to wiggle out.
From the literature I've collected on the subject, here is what seems to
have happened at Chernobyl. (I'd not dispute variations on the theme.
It seems most everything associated with Chernobyl is clouded by official
lies.)
When the scram button was pressed, there was a total positive reactivity
insertion of 2.5 (HUGE!) which led to a local power transient estimated
to be in excess of 500 MWt. This transient cause enough steam pressure
and water hammer to rupture the cooling channels and jam the control rods
while they were still mostly out. The reactor continued running.
The water, now in contact with very hot fuel cladding and graphite,
chemically reacted with both, releasing hydrogen and carbon monoxide.
The fuel did not react because it is an oxide. The hydrogen and
carbon monoxide collected under the upper biological shield and when it
reached a flammable ratio, exploded, ignited by the still-running but
now-uncooled reactor. THIS hydrogen explosion is what blew the
top off the reactor building and scattered part of the core around
the compound. The reactor, or what was left of it, continued
running after this explosion. The heat generated vaporized the fuel
and set the graphite on fire. This nuclear-fed inferno is what
vaporized a large fraction of the core's fission product inventory.
It should be remembered a) that the core was at the end of its life
and thus ladden with fission products and b) the core was over 3 times
larger than free world designs, containing over 300 tons of fuel.
Explosions figured into Chernobyl only as a triggering event for a much
larger disaster - a still-critical, uncooled core with a fire in it that
burned for several days.
Jeremy Whitlock
In article <489v5!_@dixie.com> j...@dixie.com (John De Armond) writes:
>mrjg...@uxa.cso.uiuc.edu (Michael R James) writes:
>
>>I thought that the water was carried through the the core
>>in the RBMKs in separate channels in the graphite. I don't
>>think the water ever contacted the fuel cladding.
>>One "advantage" of the RBMK was on-line refueling ( a leftover
>>from the design's weapons production days). I can't imagine
>>removing fuel that's in contact with coolant.
>>
>You're right.
No, he's wrong. The fuel is immersed in pressurized water, and removed
while still immersed in pressurized water. A fuelling machine latches on
to the end of each tube and pressurizes. This is the same as with CANDU's.
>The water, now in contact with very hot fuel cladding and graphite,
>chemically reacted with both, releasing hydrogen and carbon monoxide.
The chemical reaction that produced hydrogen is between Zircalloy fuel
cladding and very hot steam. Thus, it is not a problem under normal
operation.
--
Jeremy Whitlock "My thoughts are mine, not Mac's"
Dept. Engineering Physics
McMaster University e-mail: whit...@mcmaster.ca
Hamilton, Ontario, Canada, L8S 4L7 phone: 416-525-9140 ext.7140
KENNETH SOLLOWS
>
>I haven't seen Lord Marshall's quote, but he may have been referring to the
>prompt critical power rise as a "slow atomic bomb", which is correct. The
>explosions that blew the reactor apart were conventional, however, as is any
>conceivable explosion that would blow a reactor apart.
I posted it with reference on 18 April 1992 @ 17:32:27 GMT
It was from the Sept '92 issue of NEI.
He said:
" . . ., in those circumstances [where the +ve void coefficients gave +ve
power coefficients], the reactor could take off like a slow atomic bomb. By
this I mean it could explode in a few seconds rather than a few
milliseconds."
He was clearly refering to an explosion. I happen to think his approach to
public discussion of these matters is much more productive than the simple-
minded mantra "Reactors can't explode like bombs". Like any mantra, one
might feel better to say it over and over, but it only affects the
individual. The rest of the public is left with the impression of someone
with a primitive belief in magic.
If by "conventional", you mean "not nuclear", then I agree. I was, and have
been, responding to the simple-minded assertion that reactors cannot explode
like bombs.
>Referring to my
>"firecracker in the house" analogy from a previous post:
>
>>>If a firecracker goes off in a house and the house catches fire and burns
>>>down, would you say the house blew up like a slow firecracker? Of course
>>>not.
>
>The prompt critical power rise is the "firecracker", and the conventional
>explosions are the "house burning down." Do not confuse the two. Referring
>to the explosions at Chernobyl as "nuclear" or anything like an "atomic bomb"
>is -- as I said before -- *wrong* terminology. This is important because
>anti-nuclear chaps tend to make a living out of using wrong terminology, and
>they don't need any encouragement.
And this is just how the industry loses it credibility. It says, for years
and years, that reactors can't blow up like bombs. When a reactor blows up,
we say: "Well yes, it can blow up, but it wasn't like a bomb!" It
degenerates into a debate about the number of angels that can dance on the
head of a pin and the public gets suspicious or tunes out. Marshall's
approach is much better. He confronts the issue, head on, in terms the
public can understand, and builds their confidence in his judgement. Such
confidence is far more important than any narrow distinctions of terminology.
There have always been people that make a living on the misfortune of
others. It's no reason to abandon effective public discourse in policy
issues.
Ken
KENNETH SOLLOWS
>mrjg...@uxa.cso.uiuc.edu (Michael R James) writes:
>
>>I thought that the water was carried through the the core
>>in the RBMKs in separate channels in the graphite. I don't
>>think the water ever contacted the fuel cladding.
>>One "advantage" of the RBMK was on-line refueling ( a leftover
>>from the design's weapons production days). I can't imagine
>>removing fuel that's in contact with coolant.
>>
>
>You're right.
[. . . ]
John, cull the comic books out of your library; they have no place in a
serious discussion of the merits of nuclear power. Michael is misinformed;
you're just ignorant!
Of course the fuel pins are in contact with water during normal operation,
in the RBMK and other water cooled reactors. The fuel pins are in bundles;
the bundles in tubes (in the RBMK and CANDU) and the tubes contain water.
If it transpires that the reactor is operated when the water isn't in
contact with the fuel cladding, it isn't going to operate for long, and a
lot of people are going to ask the operators some very serious questions,
like why they wrote-off the plant, for instance!
Michael, on-line refueling is accepted practice in CANDU reactors; it
happens daily here in the frozen North, generally without incident.
>[paranoid political polemic deleted]
>
>When the scram button was pressed, there was a total positive reactivity
>insertion of 2.5 (HUGE!) which led to a local power transient estimated
>to be in excess of 500 MWt.
500 MWt in what portion of a reactor rated at 3000 MWt or so? If you're
going to throw numbers about, throw enough to be meaningful.
>This transient cause enough steam pressure
>and water hammer to rupture the cooling channels and jam the control rods
>while they were still mostly out.
I love it. "Enough steam pressure and water hammer". John, just how much
is "enough", and how was it generated? No hand waving please, just reasoned
physical insight. How long will it take even a step change in internal heat
generation rate in the fuel pin to significantly affect the cladding
temperature? Is this time scale consistant with the accident? What happens
to the heat transfer coefficient, and thus the steam generation rate, when
the critical heat flux is exceeded? It's clear that you don't have even a
passing familiarity with the design of the reactor in question, or the basic
physical principles that come into play in the event you purport to describe?
Just a suggestion. Before you give up your day job and start lecturing on
energy policy and public safety, why not develop a passing familiarity with
the subject?
[rest deleted without comment. Hardly worth it.]
Ken
KENNETH SOLLOWS
>j...@dixie.com (John De Armond) writes:
>
>>sol...@UNBSJ.CA (KENNETH SOLLOWS) writes:
>
>>>>"Slow atomic bomb?" Why not say that a reactor is brought up to power like
>>>>a "slow atomic bomb?" Or, what not just call a reactor a "slow atomic bomb?"
Just to set the record straight, this was actually written by Jeremy
Whitlock in his critique of my posting of 10 May 1993 13:13:33 GMT.
Ken
Gene Forrer
but, >>and I will type slow here, the explosion was aresult of rapidly
expaning >>steam in a contained space. The fission process only provided
heat and did >>not contribute any explosive force as you would find in a
nuclear bomb.>
>Come on now. In "the" bomb, it's really only the heat that gives the
>explosion. So I guess they really aren't atomic or nuclear bombs? After
>all, the explosion is simply rapidly expanding gas/plasma? The fision/
>fusion only provides the heat! ;-) Those extra neutron and gamma rays are
>really only a bonus, eh? ;-)
>
>>If
>>you had any heat source large enough you could generate the same explosion
>>as the one that occured at Chernobyl.
>
>Again, totally irrelevant, and most probably untrue! You need more than a
>heat source to get an explosion. It's a matter of the rates of the
>reactions: physical, nuclear, chemical, etc. In addition to the source of
>energy, you need a viable process to convert that energy to produce a
>rapidly expanding gas.
>
>>Finally a nuclear bomb explodes
>>because of the prompt criticality of two masses if fissile material slammed
>>together very fast. You cannot get that kind of energy release from just
>>having a lump of fissile material just sitting there.
>
>So what? More irrelevant facts!
>
>Ken
reactor works. All a reactor does is heat water to make steam. Besides
having nuclear fuel it is no different than any other steam driven power
plant. What creates the heat is the fission proces in the fuel. Now if you
have water in contact with a large enough heat source it will turn to steam
and if that water is in a sealed system and it turns to steam fast enough it
will explode without any help ,from anything else. Because you see Ken it
is natural for water to turn to steam when heated. If you doubt this put a
pan on the stove fill it with water and turn the stove on, the water will
boil and turn to steam without any other process invloved. Another
experiment you might try to understand some of the laws of nature you can
take a light weight clean metal gas can and put boiling water in it you then
seal the can and put it in a pan of ice water. The condensing water will
cause the can to implode. If you take a reactor prompt super critical
uncontrolled you will add a shit load of heat to your system, and you will
probably get a steam explosion. This is why reactors are designed to scram
if you increase power to rapidly. If you watched the film on Chernobyl you
will see the morons running the plant over rode that safety feature. And if
you don't think you can get a huge explosion from a heat source and just
plain old water go talk to some of the sailors who managed to come back
after the boiler plant on their oil fired plant blew the bottom out of their
ship. Those explosions were steam caused also.
Gene, been working with this shit for ten years now.
Gene Forrer
>Perhaps all true, but lets be clear about what happened at Chernobyl. It
>blew up. Why? Because steam formed more rapidly than it could be remove
>from the reactor using the regular flow paths. How did this happen?
>Enough cladding and fuel were mixed with coolant raise the vapour generation
>rate very rapidly. How did the cladding and fuel get mixed up with the
>coolant? I don't really know, but the reported 100x power transient seems a
>likely candidate, doesn't it?
>
>Ken
coolant to flash to steam. A reactor taken prompt uncontrolled super-
critical wil provide enough thermal energy to flash the coolant to
superheated steam. The army had a portable reactor that had just this type
of accident. The rods were pulled to quickly and the water flashed. An
investigation showed that while the fuel and cladding had partialy melted
integrity had not been lost it was just a big blob.
Also if the fuel is mixed into the cladding the fuel density would be
decreased and this would cause power to drop. In other words you change the
physics and shut down the reaction.
Gene
Gene Forrer
pulled completly out the rods had a water slug at the end. Operating
procedures prohibited pulling as many rads as were actually out for the test
they were doing at the time of the accident. Because of a Xenon buildup the
supervisor deciced to pull more rods than was allowed. He then over rode
several safety features. When things started falling apart he ordered the
plant scrammed, that slug of water added the positive reactivity and then
everything went to hell. The russians have since modified the control
mechanism so that the rods cannot be pulled out far enough to create the
water pocket and will evetually replace the control rods with a better
design.
Gene
KENNETH SOLLOWS
>
[this is by Jeremy Whitlock]
>>>"Slow atomic bomb?" Why not say that a reactor is brought up to power like
>>>a "slow atomic bomb?" Or, what not just call a reactor a "slow atomic bomb?"
>
[this is by me]
>>Because when they operate normally they don't produce an explosion that
>>causes damage to the environs. On the other hand, when they operate as the
>>Chernobyl reactor did immediately prior to blowing the roof off its
>>building, calling it an ~unanticipated core disassembly event~ or any
>>other such technospeak gobbledygook does great damage to the credibility
>>of the speaker. The damn thing blew up. It was like a bomb. Was it like
>>a glob of plastique, 3 sticks of dynamite, a truck load of fertilizer and
>>fuel oil, a tank full of napalm? I don't know, but Marshall said it was
>>like a "slow atomic bomb" and I see no reason to disbelieve him. I also
>>note that, in addition to understanding something of the physics of the
>>event, he is in a better position than most of us (me, anyway) to judge
>>the kind of language appropriate to the description of the event in a
>>public forum.
[this is interesting, in a clinical sort of way ;-)]
>This would be funny if it weren't so tragically ignorant. I wonder if
>you so blindly accept the explanation of other non-nuclear events that
>you don't understand without question.
While I do not "blindly accept" anything, I, like most thoughtful people,
attempt to assess the credibilty of the messenger when I evaluate the
message. Sorry to disappoint you, but on a scale of 0 to 10, Lord Marshall
ranks close to the high end, and you aren't even worth rating.
>If so, your worldview must be
>exceedlingly simple. Let's do this real slowly.
Lets wait until you establish your credentials, shall we? Oh, I remember,
you're the guy that thinks that the fuel normally runs dry in a RBMK
reactor. Credibility rating? I guess -1 or so is fair.
[...]
>
>Say "No". Very good.
>
[...]
>
>Say "No". Very very good. We're making progress.
>
[...]
>
>Say "No".
>
[...]
I'm going along deleting stuff, Gary, but I've got one question. Who, or
what introduced this sealed container?
>
>Say "No." Heeeyyy, we're getting there.
>
>If I take a few million curies of HLW containing some fissionable
>uranium, put it in a sealed container along with some water, insulate
>the whole thing very well, arrange the geometry such that real fast
>fission takes place and allow it to burst from the
>fission-heat-generated-steam, was THAT a nuclear explosion?
Now we're getting down to brass tacks.
I sense this is wasted effort, but . . .
The problem with your line of arguement is that there was no "sealed"
container. Any local overpressure that could burst the open tube must
therefore derive from a very high rate of vapour generation, so that the
inertia of the coolant is sufficient to restrain the vapour, causing an
overpressure. You just aren't going to get that from an intact fuel
bundle because of some very fundamental heat transfer physics. If you work
really hard at it, you might get the fuel to melt and form a puddle, but you
won't get very high vapour generation rates because the vapour insulates the
water-fuel interface. To get very high vapour generation rates you need to
finely divide and distribute the hot fuel and cladding thru the water, so
you get a large area for heat transfer and large vapour generation rates.
Now, the nice thing about "western" reactors is that no ones been able to
find a reliable mechanism for breaking up the fuel in this way. In the
Chernobyl accident, however, the localized power transient could have done
the job quite nicely, leading to what so quaintly seems to be referred to
as a "steam explosion" in this forum. The whole point is that the fuel/
coolant interaction, the initiator for a "steam explosion" in this context,
is not awfully likely in a current design.
[more irrelevant stuff deleted]
>Chernobyl is NOT about explosions. [...]
People design and build a device like this, that can take itself apart in
such a spectacular manner, and you can say it's not about explosions!?!
What planet are you from?
>So you would *advocate* the making of public policy based on scientific
>ignorance and misconception?
More amateur sophistry! I've known 1st year law students that could argue a
better case for nuclear power than you can. Of course I don't, I just
advocate making public policy through debate by thoughtful, feeling people
with a concern for society and the world. Scientific ignorance and
misconception, of the kind demonstrated by you in these exchanges, has no
legitimate place in reasoned policy debates.
>If so words fail me to describe the
>revulsion I feel toward you.
Sorry if you're going to lose sleep over this. I won't. Fools like
you are seldom taken seriously in policy debates, thank God!
[...]
>Acknowledging public policy is sometimes made in a factual vacuum is one
>thing; accepting and perpetuating it is a whole 'nuther ball game.
So why do you do it?
>I
>hope your position is one of technical ignorance rather than deceit.
>I even more hope I misunderstood your position but I doubt it.
Hope springs eternal, but so far my impression is that you are neither
knowledgedable enough, nor thoughtful enough, to understand or misunderstand
my position.
Ken
Gene Forrer
>in the RBMK and other water cooled reactors. The fuel pins are in bundles;
>the bundles in tubes (in the RBMK and CANDU) and the tubes contain water.
>If it transpires that the reactor is operated when the water isn't in
>contact with the fuel cladding, it isn't going to operate for long, and a
>lot of people are going to ask the operators some very serious questions,
>like why they wrote-off the plant, for instance!
>>and water hammer to rupture the cooling channels and jam the control rods
>>while they were still mostly out.
>
>I love it. "Enough steam pressure and water hammer". John, just how much
>is "enough", and how was it generated? No hand waving please, just reasoned
>physical insight. How long will it take even a step change in internal heat
>generation rate in the fuel pin to significantly affect the cladding
>temperature? Is this time scale consistant with the accident? What happens
>to the heat transfer coefficient, and thus the steam generation rate, when
>the critical heat flux is exceeded? It's clear that you don't have even a
>passing familiarity with the design of the reactor in question, or the basic
>physical principles that come into play in the event you purport to describe?
with the coolant. The fuel pins are encased in a protective cladding the
cladding is what comes in contact with the coolant. As for water hammer,
have you ever shut off a water faucet real fst and heard the pipes bang?
That is a water hammer. Now imagine a slug of water being propelled by
several thousand [pound steam coming to a bend in the pipe. The water is
going to take that bend out of the system. This is all due non nuclear
reaction of water and heat. If you will do some checking (and please do
read some real material not the one sided half truth bullshit the non-nukes
put out) you will find that in almost all accidents the fuel and cladding
damage occurs after the steam has burst the system. This is why a loss of
coolant accident is considered to be one of the worst and designed for so
heavily with emergency cooloing systems etc.
Gene
P.S. Just curios what is your background?
KENNETH SOLLOWS
>OK Ken it has become extremely apparent that you haven't a clue how a
>reactor works.
Actually, Gene, I've got a rough idea.
[...]
>Now if you
>have water in contact with a large enough heat source it will turn to steam
>and if that water is in a sealed system and it turns to steam fast enough it
>will explode without any help ,from anything else.
True enough, but irrelevant. The "sealed system" in this case includes a
heat sink, and up until the power transient the whole works is in quasi-
staedy state. The reactor physics is all screwed up, but the sucker is
running. The question is: How does a localized power transient cause such
a spectacular tube failure?
Let me give you AECL's answer:
"The power surge put a sudden burst of heat into the uranuium fuel, and it
broke up into little pieces. The heat from these pieces caused a
rapid boiling of the cooling water, and a number of pressure tubes
burst under the strain. The steam escaped from the pressure tubes,
burst the metal container around the graphite, and lifted the concrete
shield on top of the reactor. This broke all the remaining pressure
tubes."
The reference is the same as posted previously, but page 11. It sound
pretty reasonable to me.
[...]
>If you take a reactor prompt super critical
>uncontrolled you will add a shit load of heat to your system, and you will
>probably get a steam explosion.
On this time scale, just to the fuel, not the whole "system". This will
blow the fuel into little pieces, and voila, "steam explosion"!
>This is why reactors are designed to scram
>if you increase power to rapidly. If you watched the film on Chernobyl you
>will see the morons running the plant over rode that safety feature.
Actually, the latest reports tend to shift more of the blame to the
designers, and place a little less on the operators.
[...]
Ken
KENNETH SOLLOWS
>>Of course the fuel pins are in contact with water during normal operation,
>>in the RBMK and other water cooled reactors. The fuel pins are in bundles;
>>the bundles in tubes (in the RBMK and CANDU) and the tubes contain water.
>>If it transpires that the reactor is operated when the water isn't in
>>contact with the fuel cladding, it isn't going to operate for long, and a
>>lot of people are going to ask the operators some very serious questions,
>>like why they wrote-off the plant, for instance!
>>>This transient cause enough steam pressure
>>>and water hammer to rupture the cooling channels and jam the control rods
>>>while they were still mostly out.
>>
>>I love it. "Enough steam pressure and water hammer". John, just how much
>>is "enough", and how was it generated? No hand waving please, just reasoned
>>physical insight. How long will it take even a step change in internal heat
>>generation rate in the fuel pin to significantly affect the cladding
>>temperature? Is this time scale consistant with the accident? What happens
>>to the heat transfer coefficient, and thus the steam generation rate, when
>>the critical heat flux is exceeded? It's clear that you don't have even a
>>passing familiarity with the design of the reactor in question, or the basic
>>physical principles that come into play in the event you purport to describe?
>Ken are you stupid or just terminally ignorant. The fuel is not in contact
>with the coolant.
Neither, and I can read too, which is more than I can say for you. I said
fuel pins, not fuel pellets! It's the fuel pellets that are encased in
cladding, forming the fuel pins.
>As for water hammer, have you ever shut off a water faucet real
>fst and heard the pipes bang?
Ahh. The folk-engineering approach to accident analysis.
> . . . you will find that in almost all accidents the fuel and cladding
> damage occurs after the steam has burst the system.
Maybe, but in the accident under discussion, it was the other way round for
the >>initial<< fuel/cladding damage.
>P.S. Just curios what is your background?
A filing cabinet and a yellow wall!
Now my "qualifications" for engaging in a debate such as this are no more
than a reasonably sharp mind, a reasonably sharp pencil, and a willingness
to laugh when the emperor wears no clothes. I've been doing a lot of
laughing!
Ken
Jeremy Whitlock
>>
>>I haven't seen Lord Marshall's quote, but he may have been referring to the
>>prompt critical power rise as a "slow atomic bomb", which is correct. The
>>explosions that blew the reactor apart were conventional, however, as is any
>>conceivable explosion that would blow a reactor apart.
>
>I posted it with reference on 18 April 1992 @ 17:32:27 GMT
>
>It was from the Sept '92 issue of NEI.
>
>He said:
>
>" . . ., in those circumstances [where the +ve void coefficients gave +ve
>power coefficients], the reactor could take off like a slow atomic bomb. By
>this I mean it could explode in a few seconds rather than a few
>milliseconds."
Thanks for the quote. I can see where the confusion stems from now, and it
has to do with Lord Marshall's unfortunate use of the word "explode", by
which he is *not* referring to either of the two explosions that blew the
reactor apart. He is referring to the prompt critical power rise (as I
suggested earlier) when he says "take off like a slow atomic bomb", and this
is essentially correct. This huge rise in energy generation did make the
fuel pins explode into the coolant, causing a steam flash that made the
coolant tubes explode open, and *this* was the explosion that blew the reactor
apart, along with the hydrogen ignition a moment later. The tragedy here is
the fact that Ken (I suspect) understands what went on at Chernobyl better
than many others who have been contributing to this thread, and I suggest
everyone involved take their hands off the keyboard for a moment and cool
down (please).
With all due respect to Marshall, his words (as quoted above) are poorly
phrased since they lead one to believe the reactor exploded like an atomic
bomb -- mushroom cloud, crater, the whole nine yards. Specifically, the
words "it could explode" are literally correct, but only when you realise what
he means by "it" and "explode" -- to the public, "it" is the reactor and
"explode" is the huge explosion(s) that the public knows about.
--
Jeremy Whitlock "My thoughts are mine, not Mac's"
Dept. Engineering Physics
Kenneth Ng
: How about the repeated claims that US containment vessels were
:*designed* to contain meltdowns?
While I do not have research material on all US containment vessels, I do
have the Kemery report on TMI-2 which examined steam explosions driving
the reactor head through the containment and fuel meltdowns penetrating
the concrete basement. The steam explosion was deemed to have insufficient
energy to penetrate the containment building, and that core debris would
solidify in 1 or 2 days after the onset of molten fuel/concreate
interactions. This is less than the three days minimum (4 day best estimate)
to erode the reactor foundation.
Whether or not this is indicative of all reactor containment designs I
do not know. I do not have the financial resources to buy the design
specifications, nor do I have access to the various INTER codes that they
mention in the analysis.
Oh yes, as added proof of how conservative WASH-1400 was, WASH-1400 had
estimated 18 -5+10 hours to breach a reactor basement.
: Or the repeated claims that
:embrittlement was a *solved* problem and the there was no scientific
:dispute on this issue?
Well, the Russians have done dry annealing on four reactors (EPRI Journal,
sometime last year). Unfortunately they did not list their source. EPRI
Journal also talks about something called "wet annealing". Supposedly all
one does is shut down the reactor core, and let the friction from the pumps
heat the core up to 600 (?) or so degrees for a few days. This technique
has never been tried, but it sounds a lot easier than dry annealing.
Hm, here is something interesting, according to Bernard L. Cohen, the
problem of neutron embrittlement has been solved on reactors that have
been designed after 1971 by reducing the amount of copper in the steel.
So apparently, this problem is only significant on the older reactor cores.
--
Kenneth Ng
Please reply to k...@blue.njit.edu for now.
"All this might be an elaborate simulation running in a little device sitting
on someone's table" -- J.L. Picard: ST:TNG
Gene Forrer
>>fst and heard the pipes bang?
>
>Ahh. The folk-engineering approach to accident analysis.
Its called an analogy and I use it because in water systems if you do not
include air chambers into the design, the force of the water, normal city
pressure, will eventually burst the pipes. Without the benifit of a nuclear
reactor. This type of explaination is not meant to insult your inteligence,
I was simply trying to make you realize that the forces that will most
likely tear a raector system apart are normal and you will find them in any
thermal and/or hydraulic system. Water hammer is a major concern in plant
design because of the pressures the plant operates at. If you look at plant
drawings you will find that where possible sharp bends in the pipe have been
eliminated.
>> . . . you will find that in almost all accidents the fuel and cladding
>> damage occurs after the steam has burst the system.
>
>Maybe, but in the accident under discussion, it was the other way round for
>the >>initial<< fuel/cladding damage.
I'm not sure anyone can state when initial fuel and cladding damage occured,
but regardless of when, the fuel damage did not cause or even
significantly contribute to the actual explosion. It was caused as we
have all been saying by a massive power transient, which caused the water
to flash to steam, hydrogen was produce from the graphite and steam and
the whole thing blew. Fuel failure was a result of the disaster not the
cause.
>>A filing cabinet and a yellow wall!
I should have known. You're one of those guys with a yellow wall background.
>>Now my "qualifications" for engaging in a debate such as this are no more
than a reasonably sharp mind, a reasonably sharp pencil, and a willingness
to laugh when the emperor wears no clothes. I've been doing a lot of
laughing!
Ken you do seem to have a very sharp mind. But you have gotten some bad
facts on some things, many of your points, however, are very good and do
give good food for thought.
Gene
Gene Forrer
>The problem with your line of arguement is that there was no "sealed"
>container. Any local overpressure that could burst the open tube must
>therefore derive from a very high rate of vapour generation, so that the
>inertia of the coolant is sufficient to restrain the vapour, causing an
>overpressure. You just aren't going to get that from an intact fuel
>bundle because of some very fundamental heat transfer physics. If you work
>really hard at it, you might get the fuel to melt and form a puddle, but you
>won't get very high vapour generation rates because the vapour insulates the
>water-fuel interface. To get very high vapour generation rates you need to
>finely divide and distribute the hot fuel and cladding thru the water, so
>you get a large area for heat transfer and large vapour generation rates.
>
water. A presurized water reactor heats water at over 2500 psi in a sealed
container. The pressure is to keep the coolant in the liquid state. If you
experiance a sudden los of pressure the water will flash to steam. Also if
you heat the water past the temperature at which it will remain liquid the
water will again flash to steam. Both cases will probably result in a steam
explosion and core damage if uncontrolled. I checked with some Nuclear
Engineering Proffesors and they feel in your scenerio what would happen if
you homoginized the fuel in the coolant initial you would get an increase in
temperature which would result in a decreased density of the moderator which
would cause the fision rate to drop and make the whole thing shut down. The
idea that the fuel would act as a bomb in this condition or have any kind of
real heat production other than decay heat was a misunderstanding of nuclear
physics.
Nice try B+ for effort and tenacity d- for comprehension.
victor yodaiken
>I've seen most opponents of nuclear power use hysteria and outdated
>infornation for the basis of their protests. Further, most who manage to
Well, perhaps you should expand your reading material. I recommend
Safety Second by the UCS as a good start.
The UCS has also got quite recent publications on alternative energy
strategies.
>get the chance to review plans aren't looking to confirm safety they only
>use the opportunity to stall and make ridiculous demands about non existant
>problems. Okay hers ethe scenerio the space shuttle goes hundreds of miles
This is not very accurate. David Okrent is willing to concede
that TMI gave a great deal of credibility to nuclear critics, you should
try to understand why.
>>Yes. My impression is that the current generation f nuclear power plants
>>are not well designed: the indicator _behind_ the operators panel at
>>TMI and the duplicated control cables bundled together in a single
>>conduit at Browns Ferry spring to mind. Others are free to disagree.
>TMI and Browns Ferry can by no stretch of the imagination be called the
>current generation. These designs are 20-25 years old. What do you think
>the nuclear industry sits on its butt and doesn't make any improvements at
>all? We are 2 or 3 designs past trojan and Browns Ferry with new safety
>features both mechanical and inherant. Further you can bet the farm that
>as problems are discovered plants with a similar design are updated and
>improved.
There are a couple of issues here. First, we often hear on this net that
the current economic failure of PRW/BWR designs is purely due to the
"hysteria" of "ignorant" anti-nukers. So, it's quite beside the point to
advance new reactor designs as support for that claim. If, as the anti
nuke folks claim, the reactors we actually have built are poorly
designed, then it tells us something very critical about the regulation
process and the nuclear industry. Second, the series of design flaws
discovered in current operating reactors tells us something about the
design process and about the advisability of crash projects that are
wrapped in secrecy. Third, I would be happy to bet real estate against
you on the claim that "as problems are discovered plants with a similar
design are updated and improved." The infamous "generic" problems list
of the NRC has been, as the Kemeny commission observed, a dumping
ground for problems that are too expensive or too hard to fix.
I'll also note that just last year, when the NRC discovered that
steam pipe cracks at Trojan had exceeded the safety range, its response
was to, secretly, change the allowable range.
>>Okrent's sympatheitc history of nuclear power in the US shows how political
>>and profit considerations were allowed to repeatedly override technical
>>conserns, so the pastiche designs and absolute lack of standardization
>>should come as no surprise.
>But doesn't political and profit corrupt everything. If it wern't for the
>fast buck do you suppose we would have as much acid rain as we do and don'
>t you think that we would have shut the coal plants down as soon as we
>found a problem.
And, so? Because we have done a poor job of managing other
environmental/technical hazards should we just not worry about nukes?
>>Well, I think that we are generally way too cavalier about industrial
>>accidents and spills. The contruction of a plant that places pressurized
>>steam, liquid sodium, and a fissioning core in close proximity gives me
>>pause. Are there better, cheaper, safer alternatives? Can such a plant
>>be safely entrusted to Generic Power Company? It seems to be only sensible
>>to be very cautious about such devices.
>Be cautious be very cautious but don't be closed minded and judge from
>hysteria and/or ignorance. Can any potentialy dangerous technology be
>trusted to anyone whose main goal is profit? As to non-standard design
I have not made up my mind about IFR, but I am really unimpressed by the
mindless zealousness of some of its advocates. I can't think of a better
reason to distrust a new technology than a strong feeling that its
developers are unwilling to allow for open debate, are grossly ignorant of
the limitations of any engineering effort, and are convinced that
their work is _entitled_ to public money.
>Most containment if not all is so over engineered its ridiculous. Most are
>designed for large passanger jet impact because you don't have to be near
Here are the actual facts. Most US nuclear power plants were designed
under the assumption that a melt-down could not happen -- meltdowns were
listed as "beyond design basis" accidents. TMI showed that this theory
was not a good one. The NRC has concluded that the margin of safety in
current containment designs is great enough so that even though they
were not designed with meltdowns in mind, they can be relied upon to contain
any credible accidents. This estimation is, however, a controversial one,
and even in the nuclear engineering literature questions have been raised
about how reliable it is.
>an airport for one to crash on you. Also the turbines in a PWR reactor
>are not in the containment building with the reactor. The recent breakin
Turbine missiles, as revealed in NRC memos obtained under FOI lawsuits, have
be a matter of concern for regulators, especially since some plants were
apparently designed without a proper orientation of the turbines.
>many years of use decides to do this really strange thing what happens then.
>Designer well thats why we chose this part because it doesn't break.
>Non nuke but if it did break that would be bad yes? Designer well yes.
Turbines do break. Not often, but it does happen.
>mistake. If we had a TMI every 20 years I would want to shut the damn
>things down also and I don't think it would remain profitable so even the
>utilities would shy away.
As they are doing right now.
>But realize that the new designs to replace the
>plants that are being shut down are being tested and design so that if
>every nasty thing in the world were to happen the plant will just shut it
>self off.
_every nasty thing_? Forgive me if I'm dubious.
>>I'd hate to see the Mohave desert trashed out by any big
>construction >project, but in principle, siting of nuclear power plants in
>areas that>were actually evacuable would be a step in the right direction.
>I agree, but what about the support facilities that spring up around the
>plant, homes for the workers, industry that moves in because of the reliable
>power, the shops and restaruants etc. Won't be long until you have some
>kind of town there.
That's an inherent problem, but siting Seabrook next to a very popular
beach with no realistic evacuation, or Indian Point just upriver of
New York city seems insane.
--
Gene Forrer
detail as to how the core pukes all of its fuel and cladding into the
coolant. You see the fuel and cladding will melt at about 2200 degrees,
long after all of the water in the plant has flashed to steam.
Gene
Gene Forrer
me over at Breeder Reactors.
Gene
P.S. Ken you'ra invited too.
victor yodaiken
>In article <1sdb29...@ymir.cs.umass.edu: yoda...@chelm.cs.umass.edu (victor yodaiken) writes:
>: How about the repeated claims that US containment vessels were
>:*designed* to contain meltdowns?
>
>While I do not have research material on all US containment vessels, I do
>have the Kemery report on TMI-2 which examined steam explosions driving
See R.F. Smmataro. Lifetime Integrity Requirements. NE&D 117(1989)67-77.
Containment design criteria to date hve not considered core melt as
credible. Consequently, containments have been limited to providing
containment function in conditions that do not include core melt. Since the
accident at TMI in 1978 and the more recent accident at Chernobyl in 1986,
regulatory interest and industry studies in the US have focused upon severe
accident conditions beyond the design basis accident. Tests and studies
to date show that the large volume, high design pressure containments that
do not rely on use of pressure suppression methods ... have the greatest
reliablity. THE BWR Mark I, Mark I, Mark II, and PWR Ice condenser pressure
suppression containments have inherently less resitence to severe accidents.
... Long term considerations include hydrogen control and plant redesign to
accommodate core melt scenarios.
>: Or the repeated claims that
>:embrittlement was a *solved* problem and the there was no scientific
>:dispute on this issue?
>
>Well, the Russians have done dry annealing on four reactors (EPRI Journal,
Right. Four russian experiments on military reactors and some conjectures
do not a "solution" make.
>Hm, here is something interesting, according to Bernard L. Cohen, the
>problem of neutron embrittlement has been solved on reactors that have
>been designed after 1971 by reducing the amount of copper in the steel.
>So apparently, this problem is only significant on the older reactor cores.
That is interesting. Anyone out there know anything more substantial
on this issue?
--
KENNETH SOLLOWS
>cause or even significantly contribute to the actual explosion.[...]
I'm getting tired of pointing this out, but your opinion in this matter
is not in agreement with the generally accepted sequence for the
Chernobyl accident. I given you some references. I'm sure you can find
others as well. Please review them.
[...]
Ken
KENNETH SOLLOWS
>I checked with some Nuclear
>Engineering Proffesors and they feel in your scenerio what would happen if
>you homoginized the fuel in the coolant initial you would get an increase in
>temperature which would result in a decreased density of the moderator which
>would cause the fision rate to drop and make the whole thing shut down.
Did you tell them we were discussing the Chernobyl RBMK reactor?
Ken
Jeremy Whitlock
The fuel temperature rises with a milli-second time constant, the power
density exceeds the fuel's limit, the fuel flies apart into the coolant.
The coolant temperature rises much, much more slowly (remember the ceramic's
high thermal inertia) and doesn't begin to take off until the fuel -- at
around 2000 deg. C. -- hits it.
KENNETH SOLLOWS
I presume this is aimed at me.
I don't know how a core could "puke all of its fuel and cladding into the
coolant". But then, I didn't claim it could happen. (I do like the phrase,
though!) If _you_ know how to make it happen, in a reactor of current
design, then you've got a serious obligation to report it in a more credible
forum than this!
I said that the localized power transient dumped a portion of the fuel into
the coolant in the Chernobyl accident, and this led to a pressuure pulse
that broke those tube(s). I may be wrong, but I haven't seen anything in
this thread that would convince me otherwise.
Ken
KENNETH SOLLOWS
Gee thanks, Gene. (I think!) :-)
Ken
victor yodaiken
The best you can hope for here is a complaint that you've quoted out
of context. None of these folks knows how to use a library.
>
>[...]
>
>Ken
--
John De Armond
>Almost true. The steam/hydrogen explosion a Chernobyl was powerful
>enough to shoot bits of the reactor core in to the local company
>town. The firefighters reported that some of their number were
>picking up bits that glowed blue in the street. Most are now dead.
>The comment about the slow burn is true. A water cooled graphite
>moderated reactor is about the most unsafe reactor design. The
>British graphite moderated reactors used carbon dioxide for cooling,
>and of course have a containment vessel.
No. Bits of fuel and graphite were scattered over part of the other
reactor buildings and the compound. Pripyat, the company town is about
3 km away from the compound. The firefighters who died fought the
reactor fire and work in the midst of the heaviest debris immediately
around the crater. An aerial photo of the plant pretty clearly shows the
blast radius and the debris. Many of the people who died were soviet
soldiers (nicknamed "bio-robots") brought in to remove the core debris
from the reactor building and immediately surrounding area. This was
done after the intense radiation scrambled even the nuclear-rated
robots loaned the Soviets by DOE.
A water cooled graphite reactor is not inherently unsafe. A graphite
reactor with large positive temperature coefficient and a large positive
void coefficient IS, as would be any other design with the same
characteristics.
John
--
John De Armond, WD4OQC |Interested in high performance mobility?
Performance Engineering Magazine(TM) | Interested in high tech and computers?
Marietta, Ga | Send ur snail-mail address to
j...@dixie.com | per...@dixie.com for a free sample mag
Lee Harvey Oswald: Where are ya when we need ya?
John De Armond
>In article <489v5!_@dixie.com> j...@dixie.com (John De Armond) writes:
>John, cull the comic books out of your library; they have no place in a
>serious discussion of the merits of nuclear power. Michael is misinformed;
>you're just ignorant!
Apparently then so is Grigori Mendvedev (Former section chief of
Soyuzatomenergo, Ministry of Energy & Electrification). In his book he
pretty clearly describes a dry channel design. Other of his facts
are at odds with other accounts so I'd not be terribly suprised that he
is wrong.
>500 MWt in what portion of a reactor rated at 3000 MWt or so? If you're
>going to throw numbers about, throw enough to be meaningful.
In a region described as a flattened sphere occupying approximately
50 tons of the 3000 tons of fuel. The power density obviously was
not uniform, the bulk probably occuring in the inner 2/3s.
>>This transient cause enough steam pressure
>>and water hammer to rupture the cooling channels and jam the control rods
>>while they were still mostly out.
>I love it. "Enough steam pressure and water hammer". John, just how much
>is "enough", and how was it generated? No hand waving please, just reasoned
>physical insight. How long will it take even a step change in internal heat
>generation rate in the fuel pin to significantly affect the cladding
>temperature? Is this time scale consistant with the accident? What happens
>to the heat transfer coefficient, and thus the steam generation rate, when
>the critical heat flux is exceeded?
Not the issue. Film boiling is only part of the equation in a transient
such as this. Gamma and neutron heating contributes more than enough
to flash the water long before heat transport from the fuel pins occurs.
>It's clear that you don't have even a passing familiarity with the design of
the reactor in question, or the basic
>physical principles that come into play in the event you purport to describe?
I can see the ignorance but not on this side. Why don't you go back and
look at the analysis of the SL-1 reactor steam explosion? This steam
explosion was also caused by a prompt criticality. And just like
Chernobyl, the initial mechanism of destruction was steam-driven water
hammer slamming into the top of the reactor vessel with enough force to
blow off the control rod drives, pull out the closure studs, shear the
cooling pipes and jack the whole vessel several feet upward. Unlike
chernobyl, the large negative moderator coefficient shut the reaction
down in microseconds. And unlike Chernobyl, bulk fuel failuer of the
ALUMINUM-clad fuel did not occur. The fuel was distorted and the
control blades were locked in place (greatly assisting the analysis of
the accident) but the cladding did NOT bulk melt. Hey, if you're really
reading-impaired, there's even a video available from DOE. SL-1 (and
BORAX, for that matter) is a classic example of the relatively minor
aftermath of a prompt criticality accident in a properly designed
reactor.
I cite this example because unlike Chernobyl the facts are well known and
undisputed.
Back to the explosion thread, the power transient at Chernobyl did NOT
cause an explosion. It is described in the literature as a series of
rumbles. The reactor foreman, Valery Perevozchenko, who was above the
biological shield at that instant, described the shield plates as
"dancing as if shook by a giant hand" from the vibration. He was able
to report this because the explosion happened 40 seconds later after the
cladding/graphite/water reaction had produced enough hydrogen and oxygen
to explode under the biological shield. He (fairly rapidly, I'd
imagine) returned to the control hall to report what he had seen BEFORE
the explosion.
>Just a suggestion. Before you give up your day job and start lecturing on
>energy policy and public safety, why not develop a passing familiarity with
>the subject?
Good suggestion, Ken. Follow it. Actually it worked the other way for
me, Ken. I quit my day nuclear job to pursue this magazine venture.
I'm a health-physicist and a former ARO (not licensed only because I
took a higher paying job in engineering before my plant, Sequoyah, was
licensed.) with over 15 years experience and hundreds of hours on the
reactor simulators. (BWR and Westinghouse PWR). I've consulted to
about a third of the US utilities on radiation and emergency planning
matters. The post- accident radiation monitoring system at TMI-1 is my
design and installation, for example. And as the past TEMA radiological
safety officer for East Tennessee, a region that encompasses Oak Rdige
and the Sequoyah and Watts Bar nuclear plants, I've had a significant
positive impact on public policy in the area. I take at least partial
credit for emergency workers in the region being educated enough about
nuclear matters not to go ballistic when they see a magenta and yellow
propeller.
You're right about one thing. I don't know as much about the RMBK as
I'd like. I've been collecting literature for a couple of years as a
hobby. If you had done the same thing, you'd realize that the accounts
even by the people who were there vary widely. I was on the DOE
volunteer team that the Soviets declined to accept so I didn't get the
first-hand view of Chernobyl I desired. Nontheless, I know enough about
reactor dynamics to be able to filter the BS from the descriptions of
the events. And unlike you, I freely admit my areas of weakness, the
details of the RMBK being one. Also unlike you, I won't get in a public
forum and make an ass out of myself by claiming a reactor can undergo a
nuclear explosion. And then continuing to claim same after any number
of experts have shown you the error of your ways. One would almost
believe Yackadamn artificial ignorance automation had forked itself and
taken on the name "Ken".
Gene Forrer
>Subject: Re: Reactor explosions (was Re: Breeders)
>Keywords: Rx is NOT a bomb!
>Date: Wed, 12 May 1993 17:35:43 GMT
happened happen. You see, the fuel cladding has pretty good heat transfer.
So the fuel would not have to disperse into the coolant for enough energy to
be transfered for the water to flash to steam and cause an explosion.
Gene