EDITORIAL: Japan: What's the Plutonium For?
Kenneth Ng
:"Sellefield is one of the world's largest nuclear processing
:plants, where the spent nuclear fuel from a rector is taken and
:broken down to its constituent parts, including plutonium.
:"The plutonium is being dumped in very large amounts in the
:Irish Sea, and children living there have a very high rate of
:leukemia."
This is interesting, the main purpose of this plant is to recover plutonium
from spent fuel, and supposedly plutonium is dumped in very large amounts into
the sea. But no clue is to the percentages, unless Greenpeace thinks nanograms
are very large amounts, which, strikes me as a distinct possibility.
: What we
:don't want to have is a lot of atom bomb material lying around,
:which could rapidly be converted into weapons if circumstances
:once again change for the worse.
While I do not know for sure the exact isotope ratios, I really doubt this
is atomic bomb grade material. It's like saying you can put the tar on the
road into your automobile engine because gasoline is very similar.
:"There is no debate really in the technical community that any
:form of plutonium, including the kind that is created in nuclear
:power reactors, can be made into weapons. We have among our
:advisors to the Nuclear Control Institute the former head of
:nuclear weapons design at the Los Alamos national laboratory for
:a quarter of a century, and he's got a paper for us in which
:this point is being made absolutely clear.
Does this paper have a name and a publication? I'd like to see it.
:"Another reason why Japan should not be shipping a lot of
:plutonium from spent fuel and injecting it into commerce is
:that now that the US and the former Soviet Union are dismantling
:their weapons, what's coming out of these weapons in addition
:to plutonium is highly enriched uranium, in enormous quantities.
Um, I kind of doubt it. The former USSR and the United States favored plutonium
over uranium for one reason: explosve power / weight. This is because the major
means of delivery was with aircraft or ICBM missiles, where weight is at a
premium. Last I read, plutonium has a lower critical mass than uranium, and
therefore a lower weight is needed. (I recall something like pu239 emits
an average of 3 neutrons vs U235 having an average of 2, are these numbers
correct?) Where one is not concerned with weight, a uranium bomb is much
simpler to design, build, and most importantly, test.
:That highly enriched uranium can be blended down with natural
:uranium to become low-enriched uranium and is perfectly suitable
:as a fuel for reactors. It is the ideal fuel for reactors. It is
:the Soviet highly-enriched uranium that Japan should be buying
:up as a future contingency reserve, while with plutonium, what
:the Japanese should be doing is sending their excess plutonium
:to Russia to be mixed in with the weapons plutonium and that in
:turn mixed with high-level radio-active waste and buried deep in
:the ground. (11/4)
Isn't it amazing how "environmentalists" want everyone EXCEPT the nuclear
industry to recycle its products? All the plutonium in the weapons and the
spent fuel rods represents an ENORMOUS energy source that they want us to just
throw away.
--
Kenneth Ng
Please reply to k...@eies2.njit.edu for now.
Apple and AT&T lawsuits: Just say NO!
John McCarthy
Apparently the amount of bomb grade U-235 possessed by the U.S. and
the Soviet Union is considerably larger than the amount of plutonium
they have. This is from a publication of the National Resources
Defense Council, and is thought to be correct. I suppose that once
uranium is enriched to reactor grade, the amount of material that
has to be handled to enrich some of it to bomb grade is not so much.
I am quite sure that Greenpeace is entirely insincere in their
recommendation that the Japanese buy Russian enriched uranium.
If the Japanese were doing that, Greenpeace would invent a reason
why they shouldn't.
--
John McCarthy, Computer Science Department, Stanford, CA 94305
*
He who refuses to do arithmetic is doomed to talk nonsense.
John McCarthy
.7 percent U-235 to 2.8 percent U-235. To start the next level of
enrichment you have only 1/4 the amount of material to handle and
therefore the next factor of 4 enrichment is only 1/4 the work.
Getting the cost of enriching it indefinitely involves summing the
series 1 + 1/4 + (1/4)^2 + ... , and the sum of this series is 4/3.
Thus it is less than 4/3 as much work to get all the U-235 from a
batch of natural uranium as it is to enrich it to reactor grade.
Is this the right arithmetic to do?
E. Michael Smith
>In article <1e51ao...@agate.berkeley.edu: j...@mica.berkeley.edu (ACTIV-L via Jym Dyer) writes:
>:"There is no debate really in the technical community that any
>:form of plutonium, including the kind that is created in nuclear
>:power reactors, can be made into weapons. We have among our
>:advisors to the Nuclear Control Institute the former head of
>:nuclear weapons design at the Los Alamos national laboratory for
>:a quarter of a century, and he's got a paper for us in which
>:this point is being made absolutely clear.
>
>Does this paper have a name and a publication? I'd like to see it.
I don't know about that paper, but the point has been made before ...
See the comments by Taylor in McPhee's book: 'The Curve of Binding Energy'.
(Taylor was a major bomb designer for the US for a bunch of years and,
among other things, has (I THINK!) both the largest and smallest
fission bombs to his credit. He stated that ANY Pu can be used for
bombs, that yes, some is better and some is worse but it all works.)
Unfortunately, the folks in Greepeace have taken this to mean that
all Pu isotopes work the same,and with similar ease, which they most
certainly do NOT! It is MUCH harder to make a big bomb with Pu from
power reactors. You are much more likely to get a small fizzle
yield device, and it is likely to require a bomb wizzard of the class
of Taylor to do the designing.. But the fact that it is hard to do
and that it is likely (but NOT CERTAIN!) to make fizzle yield
devices is often glossed over by the power nuke folks who like to,
falsely, claim that you can not make a bomb from power reactor Pu.
Both sides are out in the ozone on this one...
>:"Another reason why Japan should not be shipping a lot of
>:plutonium from spent fuel and injecting it into commerce is
>:that now that the US and the former Soviet Union are dismantling
>:their weapons, what's coming out of these weapons in addition
>:to plutonium is highly enriched uranium, in enormous quantities.
>
>Um, I kind of doubt it. The former USSR and the United States favored plutonium
>over uranium for one reason: explosve power / weight. This is because the major
>means of delivery was with aircraft or ICBM missiles, where weight is at a
>premium.
Doubt it all you want, but it is true. There was a fair quantity of
U used in bombs too. I don't know which ones (nuclear torpedoes?)
I forget where I saw it, but there was a list posted somewhere of the
quantities of Pu and U expected to be available from ex-bombs. I
vaguely remember that the quantity of U was far higher than I'd
expected. Something like 1/3 U 2/3 Pu ... (I think this was from
a news article in the San Jose Mercury News titled something like
"The Real Peace Dividend" - then again, It could have been the ravings
of a loony on some news group that my brain mis-filed ;-)
The weight of the nuclear fuel is irrelevant to the bomb. I'm quite
sure that other considerations, like how much U refining capacity
you have and how much Pu production capacity you have, and the
weight of all the other cruft that goes into each bomb dominate
the decisions ...
>Last I read, plutonium has a lower critical mass than uranium, and
>therefore a lower weight is needed.
Um, the critical mass is dependent on the pressure ... You can make
ever smaller bombs with ever larger conventional explosives (another
Taylor trick...). Pu was favored for this for reasons I don't know.
The bottom line is that you can make really dinky bombs if you want
by using one heck of a strong explosive to set off a very small core.
It was NOT just the weight that was the issue...
>(I recall something like pu239 emits
>an average of 3 neutrons vs U235 having an average of 2, are these numbers
>correct?) Where one is not concerned with weight, a uranium bomb is much
>simpler to design, build, and most importantly, test.
This is in exact opposition to what Taylor claimed. He claimed that
Pu was near ideal from a bomb designers point of view. Why do you
claim that U is simple to design with? I think you can make any U
design with Pu if you really want to, but that U is less suited to
the Pu designs due to the different pressure behaviours. (But then
again, I'm not a bomb designer and will cheerfully yeild to better
info on this speculative point.) Once you have the device designed and
built, testing should be no more difficult for one than for the other.
(How hard is it to push a button, anyway? Oh, you were talking about
some other aspect of building a test? Then what?)
And, if one wants Really Big Bombs, like the USSR did, and wants
them in a hurry, putting a U blanket around a Pu core/bomb, makes for
a big bomb in a big hurry! (Though, for this particular technique, one
uses depleted U.) Don't forget the hybrid fuel bombs! (The worlds
largest fission bomb was something like 80 Mt, and was designed with a
depleted U breeder blanket around a Pu core. Yes, the Taylor design...
I can get the correct specs if anyone is really interested - rather
than just the rough memory presented here. It is a neat technique!)
BTW, in the early days of the bomb program Pu was in short supply
so a lot of U designs were used. To get around the limits on Pu
production, Taylor (in his usual radical style) suggested spreading
out a football field of natural U and setting off a fission bomb
in the air over it. He calculated that in one burst he could breed
enough Pu in the blanket to run the whole program for years!
For some reason, the more conservative elements in the bomb program
were not interested in his plan! ;-) (And just think about the
purity of the Pu isotopes; that is one heck of a short time in
the 'reactor'!)
>:That highly enriched uranium can be blended down with natural
>:uranium to become low-enriched uranium and is perfectly suitable
>:as a fuel for reactors. It is the ideal fuel for reactors. It is
>:the Soviet highly-enriched uranium that Japan should be buying
>:up as a future contingency reserve, while with plutonium, what
>:the Japanese should be doing is sending their excess plutonium
>:to Russia to be mixed in with the weapons plutonium and that in
>:turn mixed with high-level radio-active waste and buried deep in
>:the ground. (11/4)
>
>Isn't it amazing how "environmentalists" want everyone EXCEPT the nuclear
>industry to recycle its products? All the plutonium in the weapons and the
>spent fuel rods represents an ENORMOUS energy source that they want us to just
>throw away.
This is my major complaint with BOTH the 'environmental movement' AND
the nuclear power industry. The Greenpeace folks want all Pu burried
rather than (nuclear) burned up. The nuke industry wants to just stuff
spent fuel rods in a hole in Nevada and call it waste disposal, when
they should really be reprocessed to remove the fuel. (I know, some
of the nuclear industry is pro-reprocessing, but most of the power
structure seems to be Gung-Ho on burial for reasons beyond me...).
BTW, I'm not pro-reprocessing due to a pro-nuke stance. I'm sort of
neutral on nukes (so BOTH side take pot shots at me!). I'm pro
reprocessing because it reduces the quantity of mining needed (with
attendant hazards) and it reduces the hazardous life of the nuclear
wastes. The fact that it is also stupid to be burrying so much
valuable neuclear fuel is just gravy ...
In this case, to take refined Pu and do anything with it other than
blend it to make MOX would be criminal. (MOX is mixed oxide fuel,
a blend of Pu and U used in power reactors). Given the quantity of
time, environmental destruction, money, lives, et. al. that that refined
Pu represents, to throw it away would be insane. Use it to displace
new neuclear fuel mining and refining! The world stock of neuclear
reactors is NOT going to go away in the next few decades, we might
as well be efficient in how we fuel them and minimize the environmental
damage in the fuel cycle.
--
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.
Carl J Lydick
=This is my major complaint with BOTH the 'environmental movement' AND
=the nuclear power industry. The Greenpeace folks want all Pu burried
=rather than (nuclear) burned up. The nuke industry wants to just stuff
=spent fuel rods in a hole in Nevada and call it waste disposal, when
=they should really be reprocessed to remove the fuel. (I know, some
=of the nuclear industry is pro-reprocessing, but most of the power
=structure seems to be Gung-Ho on burial for reasons beyond me...).
Perhaps it's got something to do with President Peanut (you remember, the
NUCULAR engineer) making it illegal for them to do anything else.
--------------------------------------------------------------------------------
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.
Gary Coffman
>Suppose it takes one unit of work to enrich fuel by a factor of 4 from
>.7 percent U-235 to 2.8 percent U-235. To start the next level of
>enrichment you have only 1/4 the amount of material to handle and
>therefore the next factor of 4 enrichment is only 1/4 the work.
>Getting the cost of enriching it indefinitely involves summing the
>series 1 + 1/4 + (1/4)^2 + ... , and the sum of this series is 4/3.
>Thus it is less than 4/3 as much work to get all the U-235 from a
>batch of natural uranium as it is to enrich it to reactor grade.
>
>Is this the right arithmetic to do?
I think not. It becomes exponentially more difficult to achieve
similar enrichment increases with each pass. It's essentially
impossible to get *pure* U235 from the process, though enrichments
in the 90% range are practical. The primary separation technologies,
gas diffusion and ultra-centrifuge, produce the greatest separation
improvement when the mixtures are roughly 50-50. The enrichment is a
statistical process similar to half lives. As the mixtures approach pure
in either direction, the percentage improvement in separation per pass
declines sharply so that it may take hundreds of passes to get the
same percentage improvement in separation as with one pass when the
mixture was less enriched.
Gary
Michael Zika
>therefore a lower weight is needed. (I recall something like pu239 emits
>an average of 3 neutrons vs U235 having an average of 2, are these numbers
>correct?) Where one is not concerned with weight, a uranium bomb is much
>simpler to design, build, and most importantly, test.
Neutrons emitted from fissile and Fissionable Isotopes
Slow Neutrons Fast Neutrons
Isotope (0.025eV) (2MeV)
U-235 2.43 2.6
Pu-239 2.89 3.1
U-233 2.50 2.6
U-238 0 2.6
Th-232 0 2.2
Source: Evaluated Nuclear Data File ENDF-IV
>
>--
>Kenneth Ng
>Please reply to k...@eies2.njit.edu for now.
>Apple and AT&T lawsuits: Just say NO!
--
|
Michael Zika (zi...@ecn.purdue.edu) | Hey don't ask me "why?",
Purdue University | I'm still working on "how?" !
School of Nuclear Engineering |
Joseph Askew
>"Sellefield is one of the world's largest nuclear processing
>plants, where the spent nuclear fuel from a rector is taken and
>broken down to its constituent parts, including plutonium.
>"The plutonium is being dumped in very large amounts in the
>Irish Sea, and children living there have a very high rate of
>leukemia."
Children living around Sellafield (and often of Plant workers) have
slightly increased risk of one or two rare leukemias. On the other
hand they have a LESSER risk than the general population for all other
types of cancer put together! There is a greater chance of getting
leukemia if you live in Cornwall than if you live right on top of
Sellafield. Noone is proposing we empty Cornwall for health reasons.
I won't even mention the risks of smoking!!
And this is all from the official report by the British Government
based on Official stats - I'll bet noone writing on this has even
read it (including me :-) )
Joseph Askew
--
Joseph Askew, Gauche and Proud Barbarian horns draw out the northern wind;
jas...@spam.maths.adelaide.edu Paler than water lies the Thistle Pass;
Disclaimer? Sue, see if I care Sky swallows up the road to Kokonor;
One China One Korea One Eire32 Moonlight, a thousand miles along the Wall.
Kenneth Ng
:In article <1992Nov28.0...@sugra.uucp> k...@sugra.uucp (Kenneth Ng) writes:
:>In article <1e51ao...@agate.berkeley.edu: j...@mica.berkeley.edu (ACTIV-L via Jym Dyer) writes:
:>:"There is no debate really in the technical community that any
:>:form of plutonium, including the kind that is created in nuclear
:>:power reactors, can be made into weapons. We have among our
:See the comments by Taylor in McPhee's book: 'The Curve of Binding Energy'.
:(Taylor was a major bomb designer for the US for a bunch of years and,
:among other things, has (I THINK!) both the largest and smallest
:fission bombs to his credit. He stated that ANY Pu can be used for
:bombs, that yes, some is better and some is worse but it all works.)
I read that book years ago, my first exposure to amonium tri-iodine, or
whatever it is you call that iodine contact explosive. I don't recall any
real talk about isotope concentrations in that book but its been quite a few
years. He primarily assumed weapons grade material, although I think he did
go into how to extract plutonium from spent fuel rods. Taylor probably could
make 50% Pu240 detonate, but then a real good chemical engineer could use
highway tar in place of gasoline in a car. Point is, make it as difficult
as possible.
:>Um,I kind of doubt it. The former USSR and the United States favored plutonium
:>over uranium for one reason:explosve power / weight. This is because the major
:>means of delivery was with aircraft or ICBM missiles, where weight is at a
:>premium.
:Doubt it all you want, but it is true. There was a fair quantity of
:U used in bombs too. I don't know which ones (nuclear torpedoes?)
Ok, torpedoes make sense, weight is not a (major) concern, as opposed to
aircraft. But still, do we really have that many torpedoes?
:The weight of the nuclear fuel is irrelevant to the bomb. I'm quite
:sure that other considerations, like how much U refining capacity
:you have and how much Pu production capacity you have, and the
:weight of all the other cruft that goes into each bomb dominate
:the decisions ...
The weight of a bomb is not critical if you plan to put it on a flatbed
truck and drive it to its destination. But it is a major concern when you
want to stuff it into a missile and lob it a couple of thousand miles around
the globe. Hm, but then, that would explain the *HUGE* size of the Soviet
rockets.
:>Last I read, plutonium has a lower critical mass than uranium, and
:>therefore a lower weight is needed.
:Um, the critical mass is dependent on the pressure ... You can make
:ever smaller bombs with ever larger conventional explosives (another
:Taylor trick...).
While I am not a nuclear bomb designer, I would imagine that critical mass
is dependent on: the average number of neutrons emitted per fission, the
speed of the neutrons, the probablility of the neutrons being absorbed and
fissioned by the nuclii, the percentage of neutrons lost to the environment,
and the average number of time for a neutron to reach a nearby nuclii.
Plutonium does better by emitting more neutrons per fission than uranium
does.
:>(I recall something like pu239 emits
:>an average of 3 neutrons vs U235 having an average of 2, are these numbers
:>correct?) Where one is not concerned with weight, a uranium bomb is much
:>simpler to design, build, and most importantly, test.
:This is in exact opposition to what Taylor claimed. He claimed that
:Pu was near ideal from a bomb designers point of view. Why do you
:claim that U is simple to design with? I think you can make any U
:design with Pu if you really want to, but that U is less suited to
:the Pu designs due to the different pressure behaviours.
Um no, the original use of plutonium was almost canceled when Pu240 with its
spontanous neutrons was discovered. Then the implosion mehod was found.
The original atomic bomb plan was a gun device, REAL simple. Take two
pieces, put them together REAL FAST. Remove the other side, and have the
inside piece go into and then out of the outer shell, and you can experiment
to determine exactly how much uranium you need. Plutonium needs an implusion
mechanism, lots of explosives arranged to go off at the same time, real
critical timing problems. Gun device has no such problems.
: (But then
:again, I'm not a bomb designer and will cheerfully yeild to better
:info on this speculative point.) Once you have the device designed and
:built, testing should be no more difficult for one than for the other.
:(How hard is it to push a button, anyway? Oh, you were talking about
:some other aspect of building a test? Then what?)
For starters, you let people know you've got one, usually before your ready
to use them somewhere. Rest assured there is a fair probablity that certain
parties may launch an attack on discovery of such information.
:This is my major complaint with BOTH the 'environmental movement' AND
:the nuclear power industry. The Greenpeace folks want all Pu burried
:rather than (nuclear) burned up. The nuke industry wants to just stuff
:spent fuel rods in a hole in Nevada and call it waste disposal, when
:they should really be reprocessed to remove the fuel. (I know, some
:of the nuclear industry is pro-reprocessing, but most of the power
:structure seems to be Gung-Ho on burial for reasons beyond me...).
Thank President Peanut, otherwise known as Carter for canceling the only
reprocessing plant in the United States.
Kenneth Ng
:In article <JMC.92No...@SAIL.Stanford.EDU> j...@cs.Stanford.EDU writes:
:[edit query on energy to enrich fuel]
:I think not. It becomes exponentially more difficult to achieve
:similar enrichment increases with each pass. It's essentially
:impossible to get *pure* U235 from the process, though enrichments
:in the 90% range are practical. The primary separation technologies,
:gas diffusion and ultra-centrifuge, produce the greatest separation
:improvement when the mixtures are roughly 50-50.
The following is from memory of a book I read a good 20 years ago on the
development of the atomic bomb. The gas diffusion was used at the low end
of the enrichment. The Klaistron like device was used for the final
enrichment. At the time centrifuges were deamed infeasible, and no one
ever heard of laser isotope seperation (my favorite).
John McCarthy
The basic idea of laser separation - to induce a chemical reaction in
a U-235 compound by radiation of the right frequency for the U-235
compound that wouldn't induce it in the corresponding U-238 compound -
occurred to me as soon as I heard of the atomic bomb in 1945. That
is how I supposed the separation was done before I heard of the
methods actually used. I didn't know enough physics to know that
it was infeasible. I would therefore assume that many people thought
of the idea much earlier and were able to do the calculations about
how much light is required and gave the idea up. I would further
assume that the idea was immediately revived when lasers and masers
became available. A mole of light is a lot of photons.
Does anyone know what the problems are with laser separation? It's
a viable technology but evidently not an easy one. For example,
Iraq didn't even try it.
Gary Coffman
>the nuclear power industry. The Greenpeace folks want all Pu burried
>rather than (nuclear) burned up. The nuke industry wants to just stuff
>spent fuel rods in a hole in Nevada and call it waste disposal, when
>they should really be reprocessed to remove the fuel. (I know, some
>of the nuclear industry is pro-reprocessing, but most of the power
>structure seems to be Gung-Ho on burial for reasons beyond me...).
There are two reasons.
(1) Jimmy Carter made it official government policy to discourage
reprocessing for fear of nuclear proliferation.
(2) The economics are against it. A pound of U is about 15 times
cheaper than a pound of Pu. As long as virgin U is cheaper, no
one wants to do commercial reprocessing.
Gary
John De Armond
>This is my major complaint with BOTH the 'environmental movement' AND
>the nuclear power industry. The Greenpeace folks want all Pu burried
>rather than (nuclear) burned up. The nuke industry wants to just stuff
>spent fuel rods in a hole in Nevada and call it waste disposal, when
>they should really be reprocessed to remove the fuel. (I know, some
>of the nuclear industry is pro-reprocessing, but most of the power
>structure seems to be Gung-Ho on burial for reasons beyond me...).
I thought we'd been over this once before. The industry "wants" to put
fuel in holes ONLY because that is the method the goverment has told them
MIGHT be acceptable and thus MIGHT have a stable regulatory environment.
Run your Wayback Machine back to the administration of the Georgia White Trash.
Remember that HE killed reprocessing under the guise of a proliferation
risk. The subsequent 12 years of non-policy did nothing to fix things.
Here is what the utilities want. They want to make power:
* As inexpensively as possible.
* In as stable a regulatory environment as possible.
* Using materials whose acquisition and disposal is well-defined and stable.
* in any manner that does not cause a ruckus and makes a little money
for the stockholders.
In the 60s utilities (and their stockholders) were willing to innovate and take
risks. After the bloody 70s (both nuclear and fossil), that's all gone.
If the government wants them to waste government money on demonstration
projects with no hope of commercialization, so be it. If the government
wants them to burn cow shit and spray the ashes across the sky and they
can make money doing it, so be it. Given that nuclear is a part of the
production scene, if the government wants the utility to store the
spent fuel in a water-filled pit and will let them recover the cost, so be it.
If the government wants them to drill holes in the ground and dump the
fuel in, so be it.
That one method is "right or wrong" doesn't seem to enter into the discussion
anymore. The only concern is whether the government likes it and whether
they can keep the stockholders happy. A real 90s way of doing business.
John
--
John De Armond, WD4OQC |Interested in high performance mobility?
Performance Engineering Magazine (TM) |
Marietta, Ga |Interested in high tech and computers?
j...@dixie.com |Write me about PE Magazine
Need Usenet public Access in Atlanta? Write Me for info on Dixie.com.
E. Michael Smith
>In article <1992Nov28.0...@sugra.uucp> k...@sugra.uucp (Kenneth Ng) writes:
>>Last I read, plutonium has a lower critical mass than uranium, and
>>therefore a lower weight is needed. (I recall something like pu239 emits
>>an average of 3 neutrons vs U235 having an average of 2, are these numbers
>>correct?)
>
>
> Slow Neutrons Fast Neutrons
> Isotope (0.025eV) (2MeV)
>
> U-235 2.43 2.6
> Pu-239 2.89 3.1
> U-233 2.50 2.6
>
> U-238 0 2.6
> Th-232 0 2.2
>
>Source: Evaluated Nuclear Data File ENDF-IV
This implies to me that U-233 is suitable to making bombs, which
implies that a 'short path' to getting weapons grade materials would
be to put some Th-232 rods into a power reactor and then chemically
separate the U-233 that would be created in them. What am I missing?
Some cruft that is also formed that makes separation difficult?
Foxvog Douglas
>Apparently the amount of bomb grade U-235 possessed by the U.S. and
>the Soviet Union is considerably larger than the amount of plutonium
>they have. This is from a publication of the National Resources
>Defense Council, and is thought to be correct. I suppose that once
>uranium is enriched to reactor grade, the amount of material that
>has to be handled to enrich some of it to bomb grade is not so much.
There is a big difference between bomb grade and reactor grade Uranium.
The enrichment facilities to convert reactor grade uranium to bomb grade
would be basically the same as what is necessary when starting from
natural uranium. Just the first couple of passes through the cycle
could be skipped.
>I am quite sure that Greenpeace is entirely insincere in their
>recommendation that the Japanese buy Russian enriched uranium.
>If the Japanese were doing that, Greenpeace would invent a reason
>why they shouldn't.
Why are you "sure" of this? Can you read minds? You seem to be in the
juvenile stage in which anything done by someone you oppose must be
evil, so if it something you consider good, it must be for neferous(sp?)
purposes. Talk issues, not slander.
>John McCarthy, Computer Science Department, Stanford, CA 94305
--
doug foxvog
d...@tko.vtt.fi
Foxvog Douglas
>.7 percent U-235 to 2.8 percent U-235. To start the next level of
>enrichment you have only 1/4 the amount of material to handle and
>therefore the next factor of 4 enrichment is only 1/4 the work.
This does not follow unless the next factor of 4 can be achieved in the
same manner (as well as the subsequent ones). Low levels of enrichment
can be achieved using techniques that cannot achieve high levels of
enrichment so this and the following calculation don't follow.
>Getting the cost of enriching it indefinitely involves summing the
>series 1 + 1/4 + (1/4)^2 + ... , and the sum of this series is 4/3.
>Thus it is less than 4/3 as much work to get all the U-235 from a
>batch of natural uranium as it is to enrich it to reactor grade.
>Is this the right arithmetic to do?
Your arithmetic is correct, but since the assumptions that it is
based upon are invalid, therefore it is NOT the right arithmetic to do.
>John McCarthy, Computer Science Department, Stanford, CA 94305
>He who refuses to do arithmetic is doomed to talk nonsense.
But you must beware of the simplifications you make before you turn a
problem into arithmetic.
--
doug foxvog
d...@tko.vtt.fi
Russ Brown
>In article <1992Nov29....@gn.ecn.purdue.edu> zi...@gn.ecn.purdue.edu (Michael Zika) writes:
>>In article <1992Nov28.0...@sugra.uucp> k...@sugra.uucp (Kenneth Ng) writes:
>>>Last I read, plutonium has a lower critical mass than uranium, and
>>>therefore a lower weight is needed. (I recall something like pu239 emits
>>>an average of 3 neutrons vs U235 having an average of 2, are these numbers
>>>correct?)
>>
>> Neutrons emitted from fissile and Fissionable Isotopes
>>
>> Slow Neutrons Fast Neutrons
>> Isotope (0.025eV) (2MeV)
>>
>> U-235 2.43 2.6
>> Pu-239 2.89 3.1
>> U-233 2.50 2.6
>>
>> U-238 0 2.6
>> Th-232 0 2.2
>>
>>Source: Evaluated Nuclear Data File ENDF-IV
>
>This implies to me that U-233 is suitable to making bombs, which
>implies that a 'short path' to getting weapons grade materials would
>be to put some Th-232 rods into a power reactor and then chemically
>separate the U-233 that would be created in them. What am I missing?
>Some cruft that is also formed that makes separation difficult?
>
uranium or plutonium cycles. They involve high-energy gamma emitters.
Lots of extra shielding and probably process steps involved.
Don Goodeve
>>of the nuclear industry is pro-reprocessing, but most of the power
>>structure seems to be Gung-Ho on burial for reasons beyond me...).
>There are two reasons.
>(1) Jimmy Carter made it official government policy to discourage
> reprocessing for fear of nuclear proliferation.
>(2) The economics are against it. A pound of U is about 15 times
> cheaper than a pound of Pu. As long as virgin U is cheaper, no
> one wants to do commercial reprocessing.
>Gary
I beleive I am right in asserting that one of the biggest
reprocessing plants in the world is on the coast of cumbria (about
120 miles from where I type). We are in the unenviable position
on this island that much of the Nuclear industry in Europe can
look to us to solve their waste problems. However, this has
not been exactly well thought out (minor understatement).
As Gary stated, the economics do not seem right. However, if you
want Pu for weapons - its your only option. The only trouble
is now that we have too much of the damn stuff. I recall reading
recently that U supplies (ore) are due to run down within the
next 20 years.
The result?? Fast breeder technology. Throw in low-grade U (plenty
about (relatively)) and Pu and what do you get? - As I understand
it more Pu. Unless you have some reprocessing technology this
is going to cause a lot of hassle. Reprocessing in general
is a lot of hassle. BNFL (bless their *window-test bluey-white
cotton sox*) have managed to lose a quater of a ton of Pu in
the Irish sea (now the most radioactive in the world). Carelessness?
Quite literally yes.
My conclusion (if there be one) is that the Nuc. industry needs
reprocessing to continue in the future. Therefore:
i) Pu is going to get easier to come by (goody!)
ii) Reprocessing will have to get bigger (yum yum)
iii) Some stupid git is going to lose some more somewhere - or
throw a large pile together in a hole. Wont that be fun
kiddies??
Isn't it good to be alive in the late 20th century?
Cheers
Don
--
---------------------------------------------
| Don --- Well why not? Someone has got to be!|
---------------------------------------------
Paul Dietz
>is now that we have too much of the damn stuff. I recall reading
>recently that U supplies (ore) are due to run down within the
>next 20 years.
I believe you are wrong. The uranium market is quite glutted.
Mines have been closing due to the low price.
Note that it is a typical situation for the proven reserves of a
mineral to be about 30 years. This is because the exploration needed
to prove the size of a deposit, and the development of the technology
needed to exploit new kinds of deposits, is not free, and if
sufficient reserves have already been found, it's uneconomical to find
more. "Resources", the unknown reserves we can expect to be present
if we look for them, are typically much larger.
Example for some other minerals (world, in million metric tons metal
content):
Mineral Reserves 1950 Production 1950-80 Reserves 1980
Copper 100 156 494
Iron 19,000 11,040 93,464
Aluminum 1,400 1,346 5,200
Lead 40 85 127
--------------------
Paul F. Dietz
di...@cs.rochester.edu
Michael Zika
>
>>(1) Jimmy Carter made it official government policy to discourage
>> reprocessing for fear of nuclear proliferation.
>
>>(2) The economics are against it. A pound of U is about 15 times
>> cheaper than a pound of Pu. As long as virgin U is cheaper, no
>> one wants to do commercial reprocessing.
>
>>Gary
>
Kinda curious, reprocessing _nuclear_ fuel _must_ be economical, but
many people suggest that recycling most everything should be subsidised
to make it economical...
>The only trouble is now that we have too much of the damn stuff.
"Too much" of a potential resource?
>I recall reading recently that U supplies (ore) are due to run down within the
>next 20 years.
>
>The result?? Fast breeder technology. Throw in low-grade U (plenty
>about (relatively)) and Pu and what do you get? - As I understand
>it more Pu.
Depends on the fuel cycle and the design of the reactor. There is quite a
bit of work going on to design both Plutonium burning and minor actinide
burning fast reactors.
>Unless you have some reprocessing technology this
>is going to cause a lot of hassle. Reprocessing in general
>is a lot of hassle.
If you want to recover the resource, you _have_ to reprocess. The good news
is that once the LWR fuel is reprocessed once, the ANL designs have it
going into a pyrometallurgical reprocessing cycle which is _much_ smaller
than the purex process required for oxide fuels (LWR fuels)
>i) Pu is going to get easier to come by (goody!)
Not necessarily -- the pyroprocess carries all of the higher actinides with
the Pu, so the Pu is, in fact, harder to come by (much to radioacitively hot
for a quick steal/proliferation)
>ii) Reprocessing will have to get bigger (yum yum)
Once again, not necessarily. If the LWR reprocessing is centralized, then
the pyroprocess can take over from there...
>Isn't it good to be alive in the late 20th century?
I think so...
>Cheers
> Don
>
>
>--
> ---------------------------------------------
>| Don --- Well why not? Someone has got to be!|
> ---------------------------------------------