Princeton has Fusion?
Carl J Lydick
=I saw a short piece on ABC News tonight that Princeton had achieved a
=controlled fusion reaction in the laboratory on 9 Dec. Of course,
=they didn't mention anything that _I_ wanted to know, like how much
=energy went in? How much came out?
Energy produced by the reaction was ~1/8 of the energy needed to drive the
reaction. There's still some work to be done.
=So, can someone post the scoop on this? Is it a breakthrough (the
=people at Princeton sure looked happy), or is it "just another" fusion
=experiment?
Depends on what you mean by breakthrough. The power they got out (sorry, I
don't remember the number) was greater than anything that had been previously
achieved, but no, they didn't achieve Q > 1.
=Was there a new technique involved?
Not really. It was a tokamak.
=I'm assuming that
=ANY decent fusion technique would have wide commercial applicability,
=but does this one look especially promising?
Results from tokamaks have been steadily getting better. They're still quite a
way from being commercially useful, though.
--------------------------------------------------------------------------------
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.b.dell
>In article <2eb2u3$j...@usenet.rpi.edu>, roc...@acm.rpi.edu (rocker) writes:
>=I saw a short piece on ABC News tonight that Princeton had achieved a
>=controlled fusion reaction in the laboratory on 9 Dec. Of course,
>=they didn't mention anything that _I_ wanted to know, like how much
>=energy went in? How much came out?
>
>Energy produced by the reaction was ~1/8 of the energy needed to drive the
>reaction. There's still some work to be done.
>
>=So, can someone post the scoop on this? Is it a breakthrough (the
>=people at Princeton sure looked happy), or is it "just another" fusion
>=experiment?
>
>Depends on what you mean by breakthrough. The power they got out (sorry, I
>don't remember the number) was greater than anything that had been previously
>achieved, but no, they didn't achieve Q > 1.
>
I recall a CNN report that said 3 megawatts out for 4 seconds, and another
experiemnt slightly longer (5? 7?) time.
>=Was there a new technique involved?
>
>Not really. It was a tokamak.
>
>=I'm assuming that
>=ANY decent fusion technique would have wide commercial applicability,
>=but does this one look especially promising?
>
>Results from tokamaks have been steadily getting better. They're still quite a
>way from being commercially useful, though.
--
Richard Dell
Matt Austern
> Results from tokamaks have been steadily getting better. They're
> still quite a way from being commercially useful, though.
Note that (1) There are probably some serious physics problems to be
solved before a tokamak can produce, say, a gigawatt at steady state
(plasmas have all sorts of fun instabilities!); and that (2) The
engineering challenge will be just as bad.
There are two reasons why a practical tokamak reactor will be
difficult even if all of the physics had been done. First, all of the
energy comes out in fast neutrons, and converting that to some more
useful kind of energy is not easy. Second, tokamaks burn tritium, so
we need to find some way of making tritium that is cheap, safe, and
that doesn't use more energy than we'll get out of the tritium.
(Some people have suggested that cooling the reactor core with molten
lithium might solve both problems.)
If a pratical tokamak reactor ever can get build, I'm not at all sure
that we'd actually want one. I'm not sure that it would have many
advantages over conventional uranium-burning fission reactors.
Uranium reactors have some practical problems too, but I think they
may turn out to be easier to solve than the problems with tokamak
reactors.
--
Matthew Austern Maybe we can eventually make language a
ma...@physics.berkeley.edu complete impediment to understanding.
rocker
So, can someone post the scoop on this? Is it a breakthrough (the
people at Princeton sure looked happy), or is it "just another" fusion
experiment? Was there a new technique involved? I'm assuming that
ANY decent fusion technique would have wide commercial applicability,
but does this one look especially promising?
Please, someone, post the gory details.
-rocker
Terry Fluche
watts, and on Friday they made some 5.6 million watts. It doesn't say how
many watts they put in.
The article also said they achieved the 'increased efficiency' by usin a
Tritium/Deuterium mix.
Whatever happened with that 'cold fusion' stuff anyway?
--
Those who cannot remember the past are condemned to repeat it.
- George Santayana
:) TJ.
Robert F. Heeter
ma...@physics2.berkeley.edu writes:
>Note that (1) There are probably some serious physics problems
>to be solved before a tokamak can produce, say, a gigawatt at
>steady state (plasmas have all sorts of fun instabilities!);
>and that (2) The engineering challenge will be just as bad.
>
>There are two reasons why a practical tokamak reactor will be
>difficult even if all of the physics had been done. First,
>all of the energy comes out in fast neutrons, and converting
>that to some more useful kind of energy is not easy.
>Second, tokamaks burn tritium, so we need to find some way
>of making tritium that is cheap, safe, and that doesn't use
>more energy than we'll get out of the tritium. (Some people
>have suggested that cooling the reactor core with molten lithium
>might solve both problems.)
>
I'd like to point out that you don't need to use molten lithium,
if you can compound the lithium with something which (a) has a
smaller neutron cross-section (so the Li still absorbs the bulk
of the neutrons) and (b) doesn't become highly radioactive. But
if you use a solid lithium blanket, then you need to use something
else as your coolant, and you need to engineer the blanket so the
tritium will not be trapped inside.
The engineering is definitely going to be tricky - but that's
not to say it will be impossible.
>If a pratical tokamak reactor ever can get build, I'm not at
>all sure that we'd actually want one. I'm not sure that it
>would have many advantages over conventional uranium-burning
>fission reactors. Uranium reactors have some practical problems
>too, but I think they may turn out to be easier to solve than
>the problems with tokamak reactors.
It depends a lot on *how* you get your fusion reactor to work.
A fusion reactor which creates lots of radioactive waste and
costs a lot and doesn't work efficiently is obviously not going
to be competitive. But it may prove possible to develop a fusion
reactor which generates very little radioactive waste, is
inherently safe, generates tritium efficiently so the inventory
of radioactive fuel is small, and costs the same or less than
the alternatives. Fusion may not be able to achieve these ideals,
but if it did, I think it would be very attractive relative to
fission.
*****
Robert F. Heeter
rfhe...@phoenix.princeton.edu
Graduate Student, Princeton Plasma Physics Lab
Disclaimers Apply
Leigh Palmer
<rfhe...@phoenix.princeton.edu> wrote:
> I'd like to point out that you don't need to use molten lithium,
> if you can compound the lithium with something which (a) has a
> smaller neutron cross-section (so the Li still absorbs the bulk
> of the neutrons) and (b) doesn't become highly radioactive. But
> if you use a solid lithium blanket, then you need to use something
> else as your coolant, and you need to engineer the blanket so the
> tritium will not be trapped inside.
>
> The engineering is definitely going to be tricky - but that's
> not to say it will be impossible.
I remember a Scientific American article many years back which suggested
that the molten lithium blanket could be contained in a
palladium-inner-walled-pumped tritium collector jacket (sort of like a
leaky Dewar wall). Hot palladium (and I think some other platinum group
metals) is permeable to hydrogen. All of this was envisioned for a wild
inertial confinement machine, by the way, not a tokamak.
> >If a pratical tokamak reactor ever can get build, I'm not at
> >all sure that we'd actually want one. I'm not sure that it
> >would have many advantages over conventional uranium-burning
> >fission reactors. Uranium reactors have some practical problems
> >too, but I think they may turn out to be easier to solve than
> >the problems with tokamak reactors.
>
> It depends a lot on *how* you get your fusion reactor to work.
> A fusion reactor which creates lots of radioactive waste and
> costs a lot and doesn't work efficiently is obviously not going
> to be competitive. But it may prove possible to develop a fusion
> reactor which generates very little radioactive waste, is
> inherently safe, generates tritium efficiently so the inventory
> of radioactive fuel is small, and costs the same or less than
> the alternatives. Fusion may not be able to achieve these ideals,
> but if it did, I think it would be very attractive relative to
> fission.
Fission has political problems far exceeding any technical barriers to its
use. Sometimes I'm more ashamed of my species's intellectual shortcomings
than others. It is really too bad that there already exists a solution to a
real problem which cannot be used for fear of offending entrenched
"liberal" sensibilities.
Leigh
John De Armond
> According to my local newspaper, on Thursday they made some 3 million
>watts, and on Friday they made some 5.6 million watts. It doesn't say how
>many watts they put in.
Paper said 12 MW for the first shot. I've not heard about the second.
Don't start making any power plant plans. Kinda meaningless in any
event. They didn't tell us how much energy was produced vs used, only
the rates. The interesting numbers would be the number of watt-seconds
(or joules if you insist) consumes vs produced. I'll bet the ratio
is 5:1.
> The article also said they achieved the 'increased efficiency' by usin a
>Tritium/Deuterium mix.
This is non-news. It has been known for quite some time that D-T would
improve things at the expense of crapping up the thing with tritium.
Hmm. Press releases from the fusion community? Must again be time to go
begging for more scientific welfare money.
John
--
John De Armond, WD4OQC | For a free sample magazine, send
Performance Engineering Magazine(TM) | a digest-size 52 cent SASE
Marietta, Ga "Love America" | (Domestic) to PO Box 669728
j...@dixie.com "Hate its government" | Marietta, GA 30066
Email to me may be published at my sole discretion.
Jarle Brinchmann
|>Fission has political problems far exceeding any technical barriers to its
|>use. Sometimes I'm more ashamed of my species's intellectual shortcomings
|>than others. It is really too bad that there already exists a solution to a
|>real problem which cannot be used for fear of offending entrenched
|>"liberal" sensibilities.
Oh, what, solar energy? :-)
I'm not quite sure if you mean that fission is a _real_ solution to anything.
If you do so, I would strongly oppose to the view, but I'll drop it here.
Jarle.
---------------------------------------------------------------------
Nuke the Whales ! | Jarle Brinchmann,
| Email: Jarle.Br...@astro.uio.no
International Krill Union. | or : jar...@astro.uio.no
Cameron Randale Bass
>
>Hmm. Press releases from the fusion community? Must again be time to go
>begging for more scientific welfare money.
I'm waiting for the outraged screams about 'science by press
conference' from PPPL.
'What? It was PPPL's press release?', he said as he feigned shock
at the stunning display of hypocrisy.
dale bass
Thomas D. Orth
|>
|> In article <palmer-12...@rs14-annex3.sfu.ca>, pal...@sfu.ca (Leigh Palmer) writes:
|>
|> |>Fission has political problems far exceeding any technical barriers to its
|> |>use. Sometimes I'm more ashamed of my species's intellectual shortcomings
|> |>than others. It is really too bad that there already exists a solution to a
|> |>real problem which cannot be used for fear of offending entrenched
|> |>"liberal" sensibilities.
|>
|> Oh, what, solar energy? :-)
|>
|> I'm not quite sure if you mean that fission is a _real_ solution to anything.
|> If you do so, I would strongly oppose to the view, but I'll drop it here.
|>
|> Jarle.
|>
|> Nuke the Whales ! | Jarle Brinchmann,
|> | Email: Jarle.Br...@astro.uio.no
|> International Krill Union. | or : jar...@astro.uio.no
|>
Argonne National Laboratory
or...@dublin.aps1.anl.gov
Speaking for myself
Carl J Lydick
=ter...@wyvern.wyvern.com (Terry Fluche) writes:
=
=> According to my local newspaper, on Thursday they made some 3 million
=>watts, and on Friday they made some 5.6 million watts. It doesn't say how
=>many watts they put in.
=
=Paper said 12 MW for the first shot. I've not heard about the second.
=Don't start making any power plant plans. Kinda meaningless in any
=event. They didn't tell us how much energy was produced vs used, only
=the rates. The interesting numbers would be the number of watt-seconds
=(or joules if you insist) consumes vs produced. I'll bet the ratio
=is 5:1.
8:1, actually.
Jarle Brinchmann
In article <CI01n...@spk.hp.com>, boro...@spk.hp.com (Don T. Borowski) writes:
|>Newsgroups: sci.physics,sci.energy
|>: If a pratical tokamak reactor ever can get build, I'm not at all sure
|>: that we'd actually want one. I'm not sure that it would have many
|>: advantages over conventional uranium-burning fission reactors.
|>: Uranium reactors have some practical problems too, but I think they
|>: may turn out to be easier to solve than the problems with tokamak
|>: reactors.
|>
|>Uranium reactors have the the advantage of being out there actually
|>powering the generation of electricity.
|>
Yes, but they do have a couple of problems too.
a) They are considered a health treath by a non-negligible part of the
population, and I'm rather sceptical that this is easy to change.
This would be an advantage for fusion, _if_ the radioctivity could
be made small.
b) The supply of radioactive material is limited, though this might not
be a large problem at the moment.
c) Fission reactors gives waste with extrememly long half-lives. Unless some-
one has a really fantastic idea I consider this a rather big problem,
although in my opinion nuclear energy is better than coal and oil.
At the moment I think the best option would be to make better solar-energy
systems and indirect solar-energy systems like using rivers, sea-waves, wind
etc. Since these probably have fewer factors of uncertainty, always an advantage.
Jarle.
Paul Dietz
>
>In article <CI01n...@spk.hp.com>, boro...@spk.hp.com (Don T. Borowski) writes:
>|>: that we'd actually want one. I'm not sure that it would have many
>|>: advantages over conventional uranium-burning fission reactors.
>
>b) The supply of radioactive material is limited, though this might not
> be a large problem at the moment.
With fission breeder reactors, fuel supplies are not a problem for
millions or billions of years. Supplying the entire current world
primary energy demand would use several thousand tonnes of uranium per
year; the ocean contains 4 *billion* tonnes of uranium extractable at
less than $1000/kg. And *trillions* of tonnes of uranium (and
thorium, about three times as much as uranium) is available in
dispersed form in rocks.
So, if one is willing to live with some variety of fission breeder
reactor, one does not need fusion. Ever.
Paul F. Dietz
di...@cs.rochester.edu
Jim Carr
>>
>>Hmm. Press releases from the fusion community? Must again be time to go
>>begging for more scientific welfare money.
In article <CHz9F...@murdoch.acc.Virginia.EDU>
cr...@watt.seas.Virginia.EDU (Cameron Randale Bass) writes:
>
> I'm waiting for the outraged screams about 'science by press
> conference' from PPPL.
Chuckle <grin>.
Of course, what this points out is that they are doing technology and
not science, since they did not wait to write a Phys. Rev. Letter
and then hold a press conference after it had been reviewed and
accepted -- on the Monday publication day according to tradition.
(It must be remembered that P&F were much maligned for their press
conference, and they had an article accepted and in press. Some of
the complaints came from PPPL. It is more normal to wait for the
article to be printed or until a talk is given at a conference, but
"in press" is acceptable since the refereeing is complete.)
According to the rules of PRL, this work is not eligible for rapid
publication since it has appeared in another place, namely the New
York Times. It will be interesting to see what transpires. I should
drop a note to Bob Park and have him monitor this in What's News.
--
J. A. Carr <j...@scri.fsu.edu> | "The New Frontier of which I
Florida State University B-186 | speak is not a set of promises
Supercomputer Computations Research Institute | -- it is a set of challenges."
Tallahassee, FL 32306-4052 | John F. Kennedy (15 July 60)
Goran Olsson, Plasma Physics, KTH
>
>With fission breeder reactors, fuel supplies are not a problem for
>millions or billions of years. Supplying the entire current world
>primary energy demand would use several thousand tonnes of uranium per
>year; the ocean contains 4 *billion* tonnes of uranium extractable at
>less than $1000/kg. And *trillions* of tonnes of uranium (and
>thorium, about three times as much as uranium) is available in
>dispersed form in rocks.
>
>So, if one is willing to live with some variety of fission breeder
>reactor, one does not need fusion. Ever.
>
Fission breeders presupposes the processing of spent fuel to separate the
fission products from U, Pu & Th to regenerate fuel. When this is done the
long-lived fission products that are inert gases, Xe & Kr nuclides, are
inevitably liberated into the atmosphere, since it is virtually impossible
to contain them due to their inertness. If fission breeders are to be used
on the scale you suggest, the radiation from these isotopes alone will be
many times the natural background.
I'm not willing to live with that. Ever.
Right now a sizable fraction of the radiation you receive comes from
Xe & Kr liberated from the military Pu reprocessing over the last five
decades.
The reprocessing of nuclear waste as well as fission power as a whole have
lots of other hazards that make the business questionable, but none as
inevitable as the inert gas problem.
(Sorry if you got multiple copies of this post, my newsreader had hiccups.)
========================================================================
Goran Olsson, Plasma Physics, KTH, Stockholm, Sweden
(I'm not involved in fusion research)
ols...@plasma.kth.se
========================================================================
Jeremy Whitlock
>
>[...] Second, tokamaks burn tritium, so
>we need to find some way of making tritium that is cheap, safe, and
>that doesn't use more energy than we'll get out of the tritium.
Run a CANDU next to the tokamak and extract tritium from its used heavy water!
(Ontario Hydro has supplied tritium from this source and for this purpose).
Jeremy.
--
Jeremy Whitlock e-mail: whit...@mcmaster.ca
Department of Engineering Physics phone: 905-525-9140 ext.27140
McMaster University, 1280 Main West
Hamilton, Ontario, Canada, L8S 4L7 "My thoughts are mine, not Mac's"
Lawrence R. Mead
: Paul F. Dietz
: di...@cs.rochester.edu
What do you propose to do with 4 billion tons of dangerous waste???
--
Lawrence R. Mead (lrm...@whale.st.usm.edu) | ESCHEW OBFUSCATION !
Associate Professor of Physics
Paul Dietz
>Paul Dietz (di...@cs.rochester.edu) wrote:
>: millions or billions of years. Supplying the entire current world
>: primary energy demand would use several thousand tonnes of uranium per
>: year; the ocean contains 4 *billion* tonnes of uranium extractable at
>: less than $1000/kg.
>
>What do you propose to do with 4 billion tons of dangerous waste???
These 4 billion tons of uranium would be fissioned over a period of on
the order of a million years. So it would be more like 5000 tons/year
of fission products. Most of the fission products are stable or decay
quickly, and so would not accumulate to 4 billion tons. The fraction
with very long halflives is actually quite small, if actinides are
efficiently recycled.
Paul
Jim Carr
>
>a) They are considered a health treath by a non-negligible part of the
> population, and I'm rather sceptical that this is easy to change.
> This would be an advantage for fusion, _if_ the radioctivity could
> be made small.
TFTR uses tritium in kCi amounts. This is not small, and it is not
a commercially sized machine. It would require a lot of education
to get people to accept this as a minor risk.
>c) Fission reactors gives waste with extrememly long half-lives. Unless some-
> one has a really fantastic idea I consider this a rather big problem,
> although in my opinion nuclear energy is better than coal and oil.
Perhaps because the "half-life" of CO2 is so long?
A clear understanding of the effects of CO2 is certainly a high priority
if we are to understand the tradeoffs when developing suitable energy
technologies.
>At the moment I think the best option would be to make better solar-energy
>systems and indirect solar-energy systems like using rivers, sea-waves, wind
Getting power from rivers and oceans (tides or waves) are known to have
significant environmental effects. Production of solar-energy systems
is not environmentally benign either.
Jim Carr
>
>Right now a sizable fraction of the radiation you receive comes from
>Xe & Kr liberated from the military Pu reprocessing over the last five
>decades.
Hmm. My "book" says Xe has no radioactive isotopes with lifetimes of
more than a few days to a month. As a consequence, it is not flagged
as a major fission product and I cannot imagine how it could be a
problem in normal breeder operation or a long-term hazard from Hanford.
It would be present in fuel rods that were exposed and immediately
processed for extraction of weapon's grade Pu, but no commercial
breeder would operate this way.
Kr is an issue. Kr-85 with a 10.72 year half-life is produced at the
level of a kg or so per 1000 MW(e) years. It appears to be more common
in U-233 reactors (from Th breeding) than in Pu or U-235 mixed oxide
reactors according to the limited information I have available. However,
as an inert gas that beta decays with a low energy gamma ray, I cannot
imagine how it would be a sizable fraction of the radiation I receive.
I do know that standard monitoring methods had no trouble seeing the I
from Chernobyl here, and that the Cs was buried under the remnants of
the fallout from atmospheric testing. I do not recall Kr being an
issue in the BEIR reports. What is a "sizable" fraction? I am
curious how it compares to Radon, for example, or annual dental X-rays.
It is true that skyshine from Kr was a major radiation source from the
TMI accident.
Douglas A. Harrell
For those of you who are not familiar with Dr. Stacey, he is the head of
the US division of ITER. For those of you not familiar with ITER, it is
the foremost international effort to solve the fusion problem.
According to my notes from the class, the inventory of radioactive
materials in a fusion reactor, due to activation of structural materials,
is approx 2 to 5*10^9 curies. This is of course for a projected typical
reactor after ~2 years operation, at ~2000MWt. Now, this number is
within an order of magnitude or so of the active inventory of a typical
fission reactor. If anything, it is higher than the fission reactor's
inventory. There are two major differences between the two:
1. The fission reactor's inventory is virtually all spent fuel.
The fusion reactor's inventory is primarily structural materials
activated by the high-energy (14MeV) neutrons produced in fusion.
Of course, the fuel is much more readily dealt with, i.e.
removed, reprocessed, stored, etc. The innermost (read: hardest
to get to) structure of a fusion reactor must be replaced every
couple of years or so due to radiation damage. Also, the tritium
breeding blanket must be replenished in order to assure self-
sufficiency.
2. The effective half-life of the fusion reactor materials is
much shorter than for a typical LWR's spent fuel. This is the
usual arguement of fusion proponents. Of course, most of the
time they fail to mention that there are fission reactors, such
as the IFR, that produce only a fission product waste stream, with
the actinides remaining in the reactor fuel cycle until they are
burned (fissioned). With this type of reactor, the effective half-
life of the waste stream is very comparable to that for a fusion
reactor, without the problem of having to completely disassemble
and rebuild the reactor every couple of years.
The point is, fusion has its tons of waste material as well, and it is in
many ways harder to deal with than fission reator wastes. Why do people
think that fusion is the end-all, solve-all answer to our energy problem?
I used to think that way myself until I entered the field and learned.
Just remember, Enrico Fermi and some of his cohorts did some chalkboard
calculations, stacked some uranium with some graphite bricks and a few
cadmium rods in a squash court, and made a *working* fission reactor.
It is, as John DeArmond says, almost unbelievable.
Just my two cents worth.
--
Douglas Alan Harrell
Georgia Institute of Technology, Atlanta Georgia, 30332
Internet: gt0...@prism.gatech.edu
--------------------------------------------------------------------------------
Matt Austern
> : So, if one is willing to live with some variety of fission breeder
> : reactor, one does not need fusion. Ever.
> What do you propose to do with 4 billion tons of dangerous waste???
That's a good question, isn't it? There really are practical problems
with fission, and that's one of them. (I think there are solutions,
but not necessarily easy solutions.)
There are practical problems with fusion, though, too---and radioactive
waste disposal is one of them. I'm not sure that the problems with
fusion are more tractable than the problems with fission.
--
Matthew Austern Never express yourself more clearly
ma...@physics.berkeley.edu than you think. ---N. Bohr
John De Armond
>Fission breeders presupposes the processing of spent fuel to separate the
>fission products from U, Pu & Th to regenerate fuel. When this is done the
>long-lived fission products that are inert gases, Xe & Kr nuclides, are
>inevitably liberated into the atmosphere, since it is virtually impossible
>to contain them due to their inertness.
You continue to demonstrate your ignorance of these substances. Kr, in
particular, is heavy enough that it sits nicely in a beaker just like
an invisible liquid and can be poured with equal ease. Activated charcoal
has a voracious appetite for Kr and Xe. Both are easily liquified
and stored as liquids. And after decay, both are very valuable
commercial substances.
>The reprocessing of nuclear waste as well as fission power as a whole have
>lots of other hazards that make the business questionable, but none as
>inevitable as the inert gas problem.
>(Sorry if you got multiple copies of this post, my newsreader had hiccups.)
>========================================================================
> Goran Olsson, Plasma Physics, KTH, Stockholm, Sweden
> (I'm not involved in fusion research)
> ols...@plasma.kth.se
>========================================================================
You'd think someone with a physics background would know better.
Marc Brett
: I saw a short piece on ABC News tonight that Princeton had achieved a
: controlled fusion reaction in the laboratory on 9 Dec. Of course,
: they didn't mention anything that _I_ wanted to know, like how much
: energy went in? How much came out?
Numbers I heard were: 20MW went in, 5MW came out.
--
Marc....@london.waii.com
Western Geophysical
Erik Max Francis
> Getting power from rivers and oceans (tides or waves) are known to have
> significant environmental effects. Production of solar-energy systems
> is not environmentally benign either.
Naturally. _No_ energy production scheme is totally without
environmental effects, even theoretically. There's a little something
called entropy.
The idea is to find something which is a good tradeoff.
Erik Max Francis, &tSftDotIotE ...!apple!uuwest!max m...@west.darkside.com __
USMail: 1070 Oakmont Dr. #1 San Jose, CA 95117 ICBM: 37 20 N 121 53 W / \
-)(- Omnia quia sunt, lumina sunt. All things that are, are lights. -)(- \__/
Robert Franklin Heeter
>In article <MATT.93De...@physics2.berkeley.edu> ma...@physics.berkeley.edu writes:
>>
>>[...] Second, tokamaks burn tritium, so
>>we need to find some way of making tritium that is cheap, safe, and
>>that doesn't use more energy than we'll get out of the tritium.
>
>Run a CANDU next to the tokamak and extract tritium from its used heavy water!
>(Ontario Hydro has supplied tritium from this source and for this purpose).
No need, just put a bunch of Lithium around your reactor. You
absorb the neutrons (and prevent induced radioactivity) and generate
more tritium at the same time. Doesn't cost much energetically
to reduce the D-T fuel cycle to (effectively) a D-Li fuel cycle
with neutron and T intermediates. With two different isotopes
of Li to choose from, you can balance tritium in = tritium out,
so you don't have surplus T running around. This is because
Li-6 sponges up a N and gives T&He-4, while Li-7 takes the
n, and gives you a T, and He-4, and another n.
>
Followups set to sci.physics.fusion where the rest of the discussion
is. As usual, I encourage interested people to read the group there.
*****************
Robert F. Heeter
rfhe...@phoenix.princeton.edu
Graduate Student, Princeton Plasma Physics Lab
*Disclaimers Apply
Jigs
>Getting power from rivers and oceans (tides or waves) are known to have
>significant environmental effects. Production of solar-energy systems
>is not environmentally benign either.
Just ask the people in France who have that tidal wave thing going. They
made their beautiful bay into an ugly smelly disgustin, wouldn't want to
live there, kinda place.
JIgar Shah
js...@ux4.cso.uiuc.edu
Jigs
>That's a good question, isn't it? There really are practical problems
>with fission, and that's one of them. (I think there are solutions,
>but not necessarily easy solutions.)
>There are practical problems with fusion, though, too---and radioactive
>waste disposal is one of them. I'm not sure that the problems with
>fusion are more tractable than the problems with fission.
I really don't know a lot about fusion, but I thought that a majority of the
"waste" in fusion was Helium isotopes that were either very short-likved
or not radioactive.
Living in ignorance
JIgar Shah
js...@ux4.cso.uiuc.edu
Don T. Borowski
spent fuel, but in the structures and breeding blanket.
Donald Borowski WA6OMI Hewlett-Packard, Spokane Division
"Angels are able to fly because they take themselves so lightly."
-G.K. Chesterton
Andy Holland
>fission products from U, Pu & Th to regenerate fuel. When this is done the
>long-lived fission products that are inert gases, Xe & Kr nuclides, are
>inevitably liberated into the atmosphere, since it is virtually impossible
>to contain them due to their inertness. If fission breeders are to be used
>on the scale you suggest, the radiation from these isotopes alone will be
>many times the natural background.
Xenon fission products are short lived, and will be virtually decayed away
prior to fuel re-processing. This leaves Kr85 which decays to a stable
Rb85. Zero release plants have been designed, and containing the small volume
of inert Krypton is not difficult. Because Kr is inert, its biological affect
is quite small, even if it does escape.
Your conjecture that a sizable fraction of the background radiation is from
weapons program reactors is absolute bologna.
Contrast Kr85 with tritium. Hydrogen can migrate through metal pipes, and
tritium is no different. Tritium water is not chemically inert, and is
a definite biological hazard. Practical fusion plants will not be clean.
Hot fusion (probably the only kind), is not anymore a panacea than breeders,
but breeders can be designed with today's technology, while a fusion power
plant is a good 75+ years away.
Utility companies can barely handle LWR technology. Imagine trying to maintain
and operate a fusion reactor. While severe accidents are not as serious a problem
with fusion for the general public, the potential to completely screw up a
multi-billion dollar fusion reactor investment is not trivial. Additionally, unlike
fission, it is very difficult to design a small hot fusion reactor, so the first
multi-billion dollar plant better work right, or you'll never see another one.
Fusion power, if it ever comes, will be strictly baseload, and huge (5000+ MWe).
Small proto-type fission reactors (50 MWe), including breeders, can be designed,
built and tested before increasing the scale. This is a significant engineering
and investment advantage. By the close of the 21st century, if we haven't totally
blown, fusion might be an option, but I'd bet on something better coming along
before that ever happens.
| Andy Holland | "Why do the nations so furiously rage together,
| Westinghouse NMD | and why do the people imagine a vain thing?"
| zc...@ncstate.pgh.wec.com |
| Views Expressed here are soley my |
| own and are not representitive of |
| Westinghouse Electric Corporation |
| etc... |
Robert F. Heeter
Douglas A. Harrell <gt0...@prism.gatech.EDU> wrote:
>I have just completed an 'Intro to Fusion' course under Dr. Weston Stacey.
>For those of you who are not familiar with Dr. Stacey, he is the head of
>the US division of ITER. For those of you not familiar with ITER, it is
>the foremost international effort to solve the fusion problem.
One would think he would do a good job...
> According to my notes from the class, the inventory of radioactive
>materials in a fusion reactor, due to activation of structural materials,
>is approx 2 to 5*10^9 curies. This is of course for a projected typical
>reactor after ~2 years operation, at ~2000MWt. Now, this number is
>within an order of magnitude or so of the active inventory of a typical
>fission reactor. If anything, it is higher than the fission reactor's
>inventory.
But then again, maybe not. The ESECOM study in the mid-late 80s
developed several reactor designs for fusion plants and compared them
with fission (breeder and non-breeder) plants. These designs
run 0.2 to 2.4 x10^9 curies for fusion, and >5 x 10^9 curies
for fission (fission core only, but whole plant for fusion). These
are 1200MW electric or 3500-4000MW thermal designs - bigger than
yours, but this shouldn't be enough to cause fusion plants to
suddenly drop to a factor of 2-20 less than the fission plants.
In any case fusion will have *less* radioactive inventory than
fission. The ESECOM study is perhpas the single most comprehensive
study of the subject...
>There are two major differences between the two:
>
> 1. The fission reactor's inventory is virtually all spent fuel.
> The fusion reactor's inventory is primarily structural materials
> activated by the high-energy (14MeV) neutrons produced in fusion.
> Of course, the fuel is much more readily dealt with, i.e.
> removed, reprocessed, stored, etc. The innermost (read: hardest
> to get to) structure of a fusion reactor must be replaced every
> couple of years or so due to radiation damage. Also, the tritium
> breeding blanket must be replenished in order to assure self-
> sufficiency.
On the other hand, you might also mention that far less of the fusion
radioactive inventory is likely to escape to the environment in any
conceivable accident. Also, the biological hazard of the fusion
isotopes is much less than that of the fission isotopes. And that
"every couple years" is given as every 6 years of full-power operation,
or every 7-8 years assuming the plant does not run full-time and full
power. And the blanket can be replenished at the same time, although
a liquid blanket could just be recirculated and replenished as needed.
>
> 2. The effective half-life of the fusion reactor materials is
> much shorter than for a typical LWR's spent fuel. This is the
> usual arguement of fusion proponents. Of course, most of the
> time they fail to mention that there are fission reactors, such
> as the IFR, that produce only a fission product waste stream, with
> the actinides remaining in the reactor fuel cycle until they are
> burned (fissioned). With this type of reactor, the effective half-
> life of the waste stream is very comparable to that for a fusion
> reactor, without the problem of having to completely disassemble
> and rebuild the reactor every couple of years.
I haven'tt seen a breeder design that has radioactivity reducing
to the level of natural uranium ore in just a day, but such a proposal
(though not feasible with current technology) does exist for fusion.
Fusion plants are also expected to generate far less waste requiring
deep disposal than any fission plant. And whereas fusion plants will
require dissasembly of major reactor components (but not the whole
reactor), fission breeders require a lot of handling and reprocessing
of the waste stream, which means a *lot* of radioactive-materials
handling, with corresponding hazards.
>
>The point is, fusion has its tons of waste material as well, and it is in
>many ways harder to deal with than fission reator wastes. Why do people
>think that fusion is the end-all, solve-all answer to our energy problem?
>I used to think that way myself until I entered the field and learned.
>
The point is, fusion has far less waste, and the waste that it has is in
fact far easier to deal with. I'm not claiming that fusion is the
holy grail of energy research, but it irks me that people are giving
it such a bad rap when in fact it has the potential to be a valuable
component of our energy infrastructure.
>Just remember, Enrico Fermi and some of his cohorts did some chalkboard
>calculations, stacked some uranium with some graphite bricks and a few
>cadmium rods in a squash court, and made a *working* fission reactor.
>It is, as John DeArmond says, almost unbelievable.
>
Unfortunately, the easy way is not always the best way.
>Just my two cents worth.
>
Same for me...
Note: Followups set to sci.physics.fusion, where everyone
else is discussing this. (There is a group for discussing
fusion energy, why not use it?
**************
Robert F. Heeter
rfhe...@phoenix.princeton.edu
Graduate Student, Princeton Plasma Physics Lab
Disclaimers apply.
Carl J Lydick
=I really don't know a lot about fusion, but I thought that a majority of the
="waste" in fusion was Helium isotopes that were either very short-likved
=or not radioactive.
You're forgetting about neutron activation of the material from which the
reactor's built.
John De Armond
>It is true that skyshine from Kr was a major radiation source from the
>TMI accident.
There wasn't any skyshine as it is normally defined. That is,
scattered radiation detected against the normal fluence direction.
There WAS a beam of gamma through the roof of the containment
building but it was not significant except in the beam.
At some long interval after shutdown, long enough that the short
lived isotopes are gone, the predominent radiations are from
Kr-85, Ba-133 and Cs-137. As you've already determined, the
gamma from Kr-85 is very low abundance and low energy. In contact
wtih high Z materials (steel, etc), there is some Bremsstrahlung
radiation but it is also very low energy with a short range.
The spectrum of radiation from such an environment is overwhelmingly
dominated by the 0.661 MeV gamma from Cs-137. The gammas from
Ba-133 can be seen but they are minor in comparison.
What you may be thinking of is several years after the accident,
immediately before the first manned entries, the containment was
vented of (so sue me if my memory is foggy) about 47,000 Ci of
Kr-85. The concentration of Kr-85 was very slight, considering
the several million cu ft volume of the containment, but
the media whipped the populace into a frenzy over it. During
the actual venting, Kr could be detected at the mouth of
the vent but none was detectable at ground level immediately
under the stack nor anywhere else, for that matter.
Knut Lekvam
An interesting calculation. You assume that there will be a
constant consumption of energy over the next million years!!!
To me it looks like you are not aware of that most places on this
earth are getting more and more dependent of market economy.
Take a look in the newspapers and read about the GATT for
instance.
If this system is supposed to work you need a constant annual
growth. A flat no-growth/no-decrease equilibrium economy is so far
not compatible with keeping the wheels rolling on all those
highways. It wont keep those bluehairs in Florida alive either,
what a petty.
As an experiment we assume that you are annually consuming
5000 tonnes of uranium each year.
If you increase the amount of energy consumption with as little
as 1% each year. I think most main-stream economists of
today would say that that was a very small growth rate.
(But I am making a conservative calculation here.)
Then after only 1000 years you have passed the amount of
uranium possibly existing on earth. The last of these years you
produced 105 million tonnes of nuclear waste annually.
Then it is over.
If you on the other hand developed an economy which did not have
this growth. Well I saw some other letters in this newsgroup who
warned about what happened in the USSR supposedly because they had
tax on the gasoline. I would certainly not buy that kind of shit.
But It seems like there are a few persons out here who would.
Just for fun, lets assume that we have to flatten out the
growth and the nukes-only guys have right in all their
assumptions. Wouldn't we then risk a hell of a lot of new
Chernobyles all around, when all the workers start getting lacy.
Or look what is happening in Bulgaria right now when they are
solving their energy problems. No I forgot they are not
restarting the plant because they are communists they are
capitalists now. But Chernobyl happend in Soviet,
damn I cant work this out!!
---------------------------------------------------------------------------
Knut Lekvam | "You turn now to drink and
kle...@acs.ucalgary.ca | show your foreskin"
University of Calgary | -Habbakuk 2:16
----------------------------------------------------------------------------
Arthur Carlson
(Andy Holland) writes:
|> Fusion power, if it ever comes, will be strictly baseload, and huge
|> (5000+ MWe).
This may be true, just as it may be true that fusion will never work, but
it cannot be stated as a fact. What's your source? The studies I remember
generally talk about 1 to 1.5 GWe, but can go as low as 0.5 GWe. The only
source I could put my hands on right away* has a figure (19) showing cost
of electricity as a function of net electric power ranging from 6 cents/kWhr
at 900 MWe down to about 4.5 cents/kWhr at 1800 MWe, which is a strong
incentive to get bigger, but not an imperative.
Art Carlson
Max Planck Institute for Plasma Physics
Garching, Germany
a...@ipp-garching.mpg.de
Jigs
>If you increase the amount of energy consumption with as little
>as 1% each year. I think most main-stream economists of
>today would say that that was a very small growth rate.
>(But I am making a conservative calculation here.)
>Then after only 1000 years you have passed the amount of
>uranium possibly existing on earth. The last of these years you
>produced 105 million tonnes of nuclear waste annually.
>Then it is over.
You also have to consider that within the next 1000 years, we will
probably have fusion. In which case, we will be using deutrium and
tritium (maybe something else). In the case for deutrium, there is
enough of that in the oceans to power the world forever. I will get
you numbers in a few minutes (I have to look them up). You are
right, the previous poster did not include comnsumption rises in his
estimate, but I think that we are arguing a moot point.
Jigar Shah
js...@ux4.cso.uiuc.edu
Don T. Borowski
: In article <2ec80e$e...@gap.cco.caltech.edu> ca...@SOL1.GPS.CALTECH.EDU (Carl J Lydick) writes:
[stuff deleted]
: If a pratical tokamak reactor ever can get build, I'm not at all sure
: advantages over conventional uranium-burning fission reactors.
: may turn out to be easier to solve than the problems with tokamak
: reactors.
Uranium reactors have the the advantage of being out there actually
powering the generation of electricity.
Paul Dietz
> If you increase the amount of energy consumption with as little
> as 1% each year. I think most main-stream economists of
> today would say that that was a very small growth rate.
> (But I am making a conservative calculation here.)
> Then after only 1000 years you have passed the amount of
> uranium possibly existing on earth. The last of these years you
> produced 105 million tonnes of nuclear waste annually.
> Then it is over.
This is wrong in at least two ways.
First: the amount of uranium available on earth is far larger than you
have claimed. The crust is about 3 ppm uranium. The continents, to a
depth of 10 km, contain about 10 trillion tons of uranium. Even at
the dubious rate of 100 million tons/year, this still can last for
100,000 years.
Second: your assumption of 1000 years of exponential growth in
terrestrial energy use is absurd. At this rate, the rate of energy
use at the end comfortably exceeds the total global insolation. The
earth is roasted by waste heat. In reality, demand would saturate at
some point before this (probably at a per capita level not enormously
higher than today's western consumption).
Finally: if you really are positing such continued exponential
economic growth, then why the hell are *we*, their impoverished
ancestors, trying to solve our descendants problems? Their economic
resources will (in this scenario) exceed ours by many orders of
magnitude.
Paul F. Dietz
di...@cs.rochester.edu
Jim Carr
>j...@ds8.scri.fsu.edu (Jim Carr) writes:
>
>>It is true that skyshine from Kr was a major radiation source from the
>>TMI accident.
>
>There wasn't any skyshine as it is normally defined. That is,
>scattered radiation detected against the normal fluence direction.
Thanks for correcting me, John. I know better. I think I said
it that way because I was remembering that (improper) use of
terminology to describe gamma radiation from a cloud of Kr passing
overhead.
>There WAS a beam of gamma through the roof of the containment
>building but it was not significant except in the beam.
I thought there was some Kr released a few days into the accident.
Detectable, but not dangerous.
>What you may be thinking of is several years after the accident,
>immediately before the first manned entries, the containment was
>vented of (so sue me if my memory is foggy) about 47,000 Ci of
>Kr-85.
Numbers are interesting. That 47 kCi of Kr-85 gets people excited,
but no comment at all about that canister of 8 kCi (?) used up in the
TFTR experiments.
benjamin franz
: kle...@acs.ucalgary.ca (Knut Lekvam) writes:
: > If you increase the amount of energy consumption with as little
: > as 1% each year. I think most main-stream economists of
: > today would say that that was a very small growth rate.
: > (But I am making a conservative calculation here.)
: > Then after only 1000 years you have passed the amount of
: > uranium possibly existing on earth. The last of these years you
: > produced 105 million tonnes of nuclear waste annually.
: > Then it is over.
: This is wrong in at least two ways.
: First: the amount of uranium available on earth is far larger than you
: have claimed. The crust is about 3 ppm uranium. The continents, to a
: depth of 10 km, contain about 10 trillion tons of uranium. Even at
: the dubious rate of 100 million tons/year, this still can last for
: 100,000 years.
Not to get too deeply involved in this, but that 3 ppm would have to be
extracted almost atom by atom (an exaggeration - but not that much of one).
I haven't ran the numbers, but I rather suspect you would spend many times
the energy obtained from "burning" the uranium in mining and extraction.
Net loss energy cycles are no good. You must distinguish between
extractable and *economically* extractable. Mining at 10km depths is not
trivial either. The cost of mining increases dramatically with depth.
: Second: your assumption of 1000 years of exponential growth in
: terrestrial energy use is absurd. At this rate, the rate of energy
: use at the end comfortably exceeds the total global insolation. The
: earth is roasted by waste heat. In reality, demand would saturate at
: some point before this (probably at a per capita level not enormously
: higher than today's western consumption).
Impossible to judge. Too many technological possiblities exist. For
example: if a significant population moves into space the limitations of
energy exploitation caused by living on a planet are eliminated. You can
use anything up to a large fraction of the total output of the local star.
Or even higher if you start scoop mining hydrogen from say Jupiter. A rate of
energy usage that would deplete your ten trillion tons of uranium in a
matter of days (if someone were silly enough to use uranium for an energy
source under those conditions rather than solar or fusion power).
A thousand years is much too long for general predictions about energy
usage levels. We can't make good predictions as far a century into the
future. Our current energy usage levels are not particularly high. I can
think of many projects that would require many times the energy we use now
(smelting entire asteroids for metals and oxygen, for example).
: Finally: if you really are positing such continued exponential
: economic growth, then why the hell are *we*, their impoverished
: ancestors, trying to solve our descendants problems? Their economic
: resources will (in this scenario) exceed ours by many orders of
: magnitude.
You deserve a real slap on the wrist for that remark. "Not our problem -
*we* won't have to clean it up." This kind of thinking has *always* led to
disaster in the long term. It is much more expensive to cleanup a mess
than to prevent it from happening in the first place.
: Paul F. Dietz
: di...@cs.rochester.edu
--
benjami...@m.cc.utah.edu
Sometimes you've just gotta pull down your pants and slide on the ice.
Steinn Sigurdsson
Paul Dietz (di...@cs.rochester.edu) wrote:
: kle...@acs.ucalgary.ca (Knut Lekvam) writes:
: > If you increase the amount of energy consumption with as little
: > as 1% each year. I think most main-stream economists of
: > today would say that that was a very small growth rate.
: > (But I am making a conservative calculation here.)
: > Then after only 1000 years you have passed the amount of
: > uranium possibly existing on earth. The last of these years you
: > produced 105 million tonnes of nuclear waste annually.
: > Then it is over.
: This is wrong in at least two ways.
: First: the amount of uranium available on earth is far larger than you
: have claimed. The crust is about 3 ppm uranium. The continents, to a
: depth of 10 km, contain about 10 trillion tons of uranium. Even at
: the dubious rate of 100 million tons/year, this still can last for
: 100,000 years.
Not to get too deeply involved in this, but that 3 ppm would have to be
extracted almost atom by atom (an exaggeration - but not that much of one).
I haven't ran the numbers, but I rather suspect you would spend many times
the energy obtained from "burning" the uranium in mining and extraction.
Run the numbers, you are wrong. Extraction costs are logarithmic
in concentration.
: Second: your assumption of 1000 years of exponential growth in
: terrestrial energy use is absurd. At this rate, the rate of energy
: use at the end comfortably exceeds the total global insolation. The
: earth is roasted by waste heat. In reality, demand would saturate at
: some point before this (probably at a per capita level not enormously
: higher than today's western consumption).
Impossible to judge. Too many technological possiblities exist. For
example: if a significant population moves into space the limitations of
Human energy use on the Earth's surface is absolutely limited to
about 1000 TW. Insolation is about 10^5 TW and generating more
than about 1% of that on the surface would directly force climate
changes - in practise 10,000 TW might be safely generated but
in reality you want to leave a little bit of leeway before worrying
about direct climate forcing.
energy exploitation caused by living on a planet are eliminated. You can
use anything up to a large fraction of the total output of the local star.
Or even higher if you start scoop mining hydrogen from say Jupiter. A rate of
energy usage that would deplete your ten trillion tons of uranium in a
matter of days (if someone were silly enough to use uranium for an energy
source under those conditions rather than solar or fusion power).
Like you said, who would be that silly.
A thousand years is much too long for general predictions about energy
usage levels. We can't make good predictions as far a century into the
future. Our current energy usage levels are not particularly high. I can
think of many projects that would require many times the energy we use now
(smelting entire asteroids for metals and oxygen, for example).
They do not require mining the Earth's crust for Uranium or Thorium.
Energy usage is hard to predict, putting absolute physically
attainable levels on what can happen on Earth is not hard.
: Finally: if you really are positing such continued exponential
: economic growth, then why the hell are *we*, their impoverished
: ancestors, trying to solve our descendants problems? Their economic
: resources will (in this scenario) exceed ours by many orders of
: magnitude.
You deserve a real slap on the wrist for that remark. "Not our problem -
*we* won't have to clean it up." This kind of thinking has *always* led to
disaster in the long term. It is much more expensive to cleanup a mess
than to prevent it from happening in the first place.
No it isn't. It is sometimes much cheaper for all concerned to
cleanup a mess later. You are completely discounting what creating
the mess may have gained us in knowledge, capability and
infrastructure.
* Steinn Sigurdsson Lick Observatory *
* ste...@lick.ucsc.edu "standard disclaimer" *
* I know people whose idea of fun *
* Is throwing stones in the river in the afternoon sun *
* Oh let me be as free as them *
* - BB 1986 *
Paul Dietz
> Not to get too deeply involved in this, but that 3 ppm would have to be
> extracted almost atom by atom (an exaggeration - but not that much of one).
> I haven't ran the numbers, but I rather suspect you would spend many times
> the energy obtained from "burning" the uranium in mining and extraction.
> Net loss energy cycles are no good. You must distinguish between
> extractable and *economically* extractable. Mining at 10km depths is not
> trivial either. The cost of mining increases dramatically with depth.
No, you haven't run the numbers. At 3 ppm U, a kilogram of rock has
about 200 megajoules of fission energy (nearer a gigajoule if thorium
is included); this is about an order of magnitude greater than the
heat of combustion of a similar quantity of coal. This is far more
than the energy needed to completely melt the rock, let alone
do more mundane chemical extrations.
The cost of mining increases dramatically with depth if one cannot
exploit the overburden, and have to drill deep shafts. In this case,
however, the mines would resemble enormous holes with shallow sloped
walls.
If uranium gets consumed at lower rates (say, a few times the current
rate of primary energy use) then mining at great depths is never needed,
since global erosion exposes the rock quickly enough.
>: Second: your assumption of 1000 years of exponential growth in
>: terrestrial energy use is absurd. At this rate, the rate of energy
>
>Impossible to judge. Too many technological possiblities exist. For
>example: if a significant population moves into space the limitations of
>energy exploitation caused by living on a planet are eliminated. You can
>use anything up to a large fraction of the total output of the local star.
Yes. We were discussing fission vs. fusion, however. If one
has a space-based civilization, fusion reactors burning deuterium
seem a silly idea -- solar energy is more convenient for most
applications.
>: Finally: if you really are positing such continued exponential
>: economic growth, then why the hell are *we*, their impoverished
>: ancestors, trying to solve our descendants problems?
> You deserve a real slap on the wrist for that remark. "Not our problem -
> *we* won't have to clean it up." This kind of thinking has *always* led to
> disaster in the long term. It is much more expensive to cleanup a mess
> than to prevent it from happening in the first place.
Harrumph. Perhaps an analogy would be better put: having *us* worry
about problems that only arise if energy demand increases by four
orders of magnitude would be about as sensible as having our ancestors
of 20,000 years ago worry about nuclear waste disposal. Problems of
our descendants, caused by our descendants, are properly the concern
of our descendants. Especially when they will (in that scenario) be
far better able to solve those problems than ourselves.
Paul F. Dietz
di...@cs.rochester.edu
Knut Lekvam
After having read sci.energy for a few weeks I have here pointed
out a single lie/myth which has been repeated to the
most boring extent by fission lovers:
"Fission will last forever, why bother finding alternatives?"
I think that is a great point!
-----------------------------------------------------------------------------
Knut Lekvam | "A long habit of not thinking a thing wrong, gives
kle...@acs.ucalgary.ca | it the superficial appearance of being right."
University of Calgary | -Thomas Paine
-----------------------------------------------------------------------------
Knut Lekvam
Paul Dietz (di...@cs.rochester.edu) wrote:
: kle...@acs.ucalgary.ca (Knut Lekvam) writes:
: > If you increase the amount of energy consumption with as little
: > as 1% each year. I think most main-stream economists of
: > today would say that that was a very small growth rate.
: > (But I am making a conservative calculation here.)
: > Then after only 1000 years you have passed the amount of
: > uranium possibly existing on earth. The last of these years you
: > produced 105 million tonnes of nuclear waste annually.
: > Then it is over.
: This is wrong in at least two ways.
: First: the amount of uranium available on earth is far larger than you
: have claimed. The crust is about 3 ppm uranium. The continents, to a
: depth of 10 km, contain about 10 trillion tons of uranium. Even at
: the dubious rate of 100 million tons/year, this still can last for
: 100,000 years.
I was referring to YOUR own numbers of what was available on earth at a
CHEAP price! I repeat once again the same quotes which I referred to
in my last letter:
In article <1993Dec16....@cs.rochester.edu> di...@cs.rochester.edu (Paul Dietz) writes:
>In article <2epts8$f...@server.st.usm.edu> lrm...@whale.st.usm.edu (Lawrence R. Mead) writes:
>>Paul Dietz (di...@cs.rochester.edu) wrote:
>>: millions or billions of years. Supplying the entire current world
>>: primary energy demand would use several thousand tonnes of uranium per
>>: year; the ocean contains 4 *billion* tonnes of uranium extractable at
>>: less than $1000/kg.
>>
>>What do you propose to do with 4 billion tons of dangerous waste???>
>
>These 4 billion tons of uranium would be fissioned over a period of on
>the order of a million years. So it would be more like 5000 tons/year
>of fission products. Most of the fission products are stable or decay
>quickly, and so would not accumulate to 4 billion tons. The fraction
>with very long halflives is actually quite small, if actinides are
>efficiently recycled.
Reading all this again it puzzles me wheather there are some hidden agenda
behind using only small numbers when talking about waste, pollution
and other negative aspects of nuclear power. And when you are
referring to the positive aspects, you are using vast numbers again?
I have some new larger numbers here! I started running my growth programme
again. (It is always easier the second time!) The result was that you have
used up more than 28 trillion tonnes of uranium after only 1100 years, and
in the last year, there was produced 286 million tonnes of waste. As you
can see, the time estimat was within 10 % of what I stipulated in the
previous letter. Hence it is pretty irrelevant what kind of tremendous
amounts of uranium there are on the earth.
My point which should be pretty clear, is that as long as you base your
support of nuclear power on the assumption that there is a *free* market
economy (the safety aspect) there are not enough uranium!!
: Second: your assumption of 1000 years of exponential growth in
: terrestrial energy use is absurd. At this rate, the rate of energy
: use at the end comfortably exceeds the total global insolation. The
: earth is roasted by waste heat. In reality, demand would saturate at
: some point before this (probably at a per capita level not enormously
: higher than today's western consumption).
It seems that you are getting at least some of the point here!
: Finally: if you really are positing such continued exponential
: economic growth, then why the hell are *we*, their impoverished
: ancestors, trying to solve our descendants problems? Their economic
: resources will (in this scenario) exceed ours by many orders of
: magnitude.
Another aspect with the liberalism is that you don't have governments
that interfere with the economics. Hence all investments are up to the
individuals. I don't see why they should anyhow become more willing to
join efforts to get rid of environmental hazards and overconsumption
than you 'impoverished' americans are.
Paul Dietz
> I was referring to YOUR own numbers of what was available on earth at a
> CHEAP price!
Mr. Lekvam, you said "available on earth". My figures were for
uranium available "in the oceans". Do note that these are different.
Did I say this was the only uranium available on earth? Did I say
that these other sources would be too expensive? No -- and, indeed,
at the projected < $500/lb cost of uranium from seawater, the
contribution of this cost to the cost of electrical power is only
about $.0001/kWh. One could easily afford more expensive uranium.
>My point which should be pretty clear, is that as long as you base your
>support of nuclear power on the assumption that there is a *free* market
>economy (the safety aspect) there are not enough uranium!!
Um, where did I say "free market?" I think you should respond
to what I write, not what you hallucinate.
Look, I can make a stupid extrapolation of an exponential curve as
well as the next guy. I would not pretend that activity is other than
mental masturbation.
>Another aspect with the liberalism is that you don't have governments
>that interfere with the economics.
[ additional deleted ]
Ah. Before your leap into political non sequiturs, I had thought this
was a technical discussion about fission vs. fusion. Are you saying
that there is something peculiar about fission that causes liberal
governments to allow energy demand to increase without bound? Your
reasoning is getting rather hard to understand.
Paul F. Dietz
di...@cs.rochester.edu
Andy Holland
>at the projected < $500/lb cost of uranium from seawater, the
>contribution of this cost to the cost of electrical power is only
>about $.0001/kWh. One could easily afford more expensive uranium.
I am as pro-fission as they come, but you have your facts wrong.
I believe you'll find that at $500/lb, the nuclear cost would be about $0.036/kwh - minimum.
(includes SWU, Fab, Uranium, conversion, losses, LWR fuel cycle etc...). Even with breeders,
the cost will be significantly higher than $.0001/kWh. At that point however, you'll find
its cheaper to extract Thorium from the sands of the beaches, and breed U233.
For fuel, that's pretty hefty, keeping everything constant. I don't believe that seawater
extraction will ever be economical, but you never know.
| Andy Holland |
| Westinghouse NMD |
| zc...@ncstate.pgh.wec.com | For unto us a child is born, unto us a son is
| Views Expressed here are soley my | given, and the government shall be upon his shoulder
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| etc...
Paul Dietz
> I believe you'll find that at $500/lb, the nuclear cost would be about
> $0.036/kwh - minimum. (includes SWU, Fab, Uranium, conversion,
> losses, LWR fuel cycle etc...). Even with breeders, the cost will be
> significantly higher than $.0001/kWh.
You're a bit confused here. I am talking about breeder reactors, not
LWRs, so SWUs are irrelevant.
Moreover, I was only talking about the contribution of the ore-related
costs to the cost of electricity; the cost of subsequent steps (once
the uranium has been extracted from the ore) is clearly independent of
the cost, or concentration, of the ore. Clearly the cost of the power
itself will be higher -- but this cost will be nearly independent of
the cost of raw uranium itself.
One could, as you note, also breed from thorium. The contribution
of the cost of thorium ore to the cost of power would also be
very small.
Paul F. Dietz
di...@cs.rochester.edu
Andy Holland
>You're a bit confused here. I am talking about breeder reactors, not
>LWRs, so SWUs are irrelevant.
Why would you pay $500/lb for breeding material, when you can obtain thorium
or tails U3O8 at less than $10/lb? Do you own shares in seawater extraction
or something? I remember Edward Teller talking about the fact that we several
thousand years worth of breeding material in the form of tails is siting in canisters.
Given the amount of enriched material utilized over the years for weapons, naval,
and commercial reactors, it kind of makes sense to use the huge amount of tails material
from these processes first.
>
>Moreover, I was only talking about the contribution of the ore-related
>costs to the cost of electricity; the cost of subsequent steps (once
>the uranium has been extracted from the ore) is clearly independent of
>the cost, or concentration, of the ore. Clearly the cost of the power
>itself will be higher -- but this cost will be nearly independent of
>the cost of raw uranium itself.
True, my point was, however, that the cost of the ore under these circumstances
is prohibitively high. Your post seemed a bit misleading, because those other
costs are very real. Your still off by a couple of orders of magnitude, because
the ore price is over 90% of the total I quoted, the SWU and fab prices remained
the same.
Even with breeders, ore only, your number is incorrect by a couple of orders
of magnitude.
I showed a realistic price, which is nearly $.036 /Kwhr (OK, we'll be generous and
say $0.03/Kwhr ore only). This is quite large for generation fuel cost, and at these
prices fusion becomes a possible alternative. So do alot of other energy forms, which
could kill off both fusion and nuclear. For example, I pay a little less than $0.07 /Kwhr
for residential electricity. Commercial-Idustrial costs are around $.04/Kwhr, for my
local producer, West-Penn Power.
This is the total cost of electricity, and for nuclear baseload, its the Commercial-Idustrial
price you are competing with. If my local power producer, using fossil fuels, can deliver
electricity to my door at those prices, its hard to justify a fuel cost at $.03/Kwhr.
^^^^
Fortunately, the total cost of nuclear fuel is less than $0.004/Kwhr, (current spot $10/lb
Uranium, large LWR, an 40x higher than the price you quoted at $0.0001/Kwhr, and believe me,
breeder fuel with re-processing, inevitably regulation ridden, will do well
to be $0.001/Kwhr!). What has killed nuclear, is not the fuel, but rather the O&M costs as
well as the huge capital costs associated with building a plant. These plagues are shared by fusion,
and with government regulators eager to control everything and generate as much work-fare as
possible, these prices will probably go in only one direction; up.
>
>One could, as you note, also breed from thorium. The contribution
>of the cost of thorium ore to the cost of power would also be
>very small.
I am sure not going to pay $500/lb for something that I can get for less than $10/lb.
There is a alot of tails out there which is good breeding material, and its cheap. There
is alot of cheap thorium available as well. It does not make any sense to purchase
a breeding material at those high prices.
Andy Holland |
Westinghouse Electric Corporation | Nuclear Engineer, Reactor Core Designer
zc...@trumpet.pgh.wec.com |
Not a spokesman for Westinghouse |
Paul Dietz
>>You're a bit confused here. I am talking about breeder reactors, not
>>LWRs, so SWUs are irrelevant.
>
> Why would you pay $500/lb for breeding material, when you can obtain thorium
> or tails U3O8 at less than $10/lb? Do you own shares in seawater extraction
> or something?
Because we were discussing very long term prospects. Seawater extraction
is an existence proof that very large amounts of uranium are available
at an affordable cost. Of course you are right, that one would go for
the depleted uranium currently on hand before doing something like this.
The Japanese were looking into the technology because they hoped to
get the cost down to $100/lb or so, in which case it could make sense
to use a once-through cycle without breeding for much longer than
would be possible with existing uranium reserves.
> True, my point was, however, that the cost of the ore under these circumstances
> is prohibitively high. Your post seemed a bit misleading, because those other
> costs are very real. Your still off by a couple of orders of magnitude, because
> the ore price is over 90% of the total I quoted, the SWU and fab prices remained
> the same.
>
> Even with breeders, ore only, your number is incorrect by a couple of orders
> of magnitude.
You're just plain wrong. Let's do the elementary arithmetic, shall
we?
A pound of uranium contains about 1.15e24 atoms. At 180 MeV/fission
(and remember, this is with breeding, so we are fissioning all that
U238), this is 3.3e13 joules per pound. In a thermal cycle with an
efficiency of 40%, this produces 3.6 million kWh per pound of uranium.
At $500/lb, the contribution of the ore price to the cost of energy is
a shade over $.0001/kWh. This cost is not prohibitively high; it is,
in fact, nearly trivial.
Perhaps your mistake was in using the energy content of just the U235
when computing the fuel requirements of breeder reactors? Note that
breeders will get roughly 100x as much energy out of a given quantity
of ore as today's commercial reactors, and that $500/lb is only 50x
today's spot market uranium price (a price at which the cost of ore is
not a large part of the cost of operating a reactor).
Paul F. Dietz
di...@cs.rochester.edu
Knut Lekvam
>>My point which should be pretty clear, is that as long as you base your
>>support of nuclear power on the assumption that there is a *free* market
>>economy (the safety aspect) there are not enough uranium!!
>Um, where did I say "free market?" I think you should respond
>to what I write, not what you hallucinate.
*I* said FREE MARKET ECONOMY in my previous posting which you responded to!
And based on that, I calculated the exponential growth. I have
never accused you of saying 'free market', but now I may!
(And If I did I would at least use a nicer language!)
>>Another aspect with the liberalism is that you don't have governments
>>that interfere with the economics.
[ additional deleted ]
>Ah. Before your leap into political non sequiturs, I had thought this
>was a technical discussion about fission vs. fusion. Are you saying
>that there is something peculiar about fission that causes liberal
>governments to allow energy demand to increase without bound? Your
>reasoning is getting rather hard to understand.
I wrote 'liberalism' which is the theory of the free market forces. It is
tought by liberalists, which should NOT be mixed with liberals. In the
US the latter has been used (by others) as a term for socialists, I believe.
This would of course have the opposite meaning! (I admit that liberal
and all the derived words and theories may be difficult to separate
from each other, but some people have a certain affection to whatever
might be *free*).
Returning to the question:
NO, There is hopefully? nothing about fission that causes liberalist
governments to allow the energy demand to increase without bound. Rather
on the contrary. (The depletion of resources!).
YES, there are something about liberalism that causes the energy demand
to increase without bound!
Regarding this being a technical discussion:
Extrapolating into the future with no thoughts of anything but
nuclear theory does unfortunately bring up only the most negative
scenarios from science fiction. And science fiction is what that
is!
(By the way have anyone read "The Gods Themselves" by Isaac Asimov;
They have a new sort of free nuclear energy which almost
everybody think is perfect? No maybe we should leave that for a
more appropriate forum.)
Andy Holland
> > Even with breeders, ore only, your number is incorrect by a couple of orders
> > of magnitude.
>
>You're just plain wrong. Let's do the elementary arithmetic, shall
>we?
>
>A pound of uranium contains about 1.15e24 atoms. At 180 MeV/fission
>(and remember, this is with breeding, so we are fissioning all that
Yes and no. You don't create the energy all at once. The ore price goes away if your breeding
doubling time is sufficient to match the interest on money. However, the costs of breeders are
incurred in the front end, and recovered on the back end, when you sell the fuel to the
'new breeder' coming on line.
>U238), this is 3.3e13 joules per pound. In a thermal cycle with an
>efficiency of 40%, this produces 3.6 million kWh per pound of uranium.
>
>At $500/lb, the contribution of the ore price to the cost of energy is
>a shade over $.0001/kWh. This cost is not prohibitively high; it is,
>in fact, nearly trivial.
>
My point about breeders was that breeding material is alot cheaper than $500/lb. The
only place where you would use high cost material is in a once through cycle, as
you mentioned in your response about the Japanese. (Part of their motivation has to
do with long term security).
If you consider only ore as the cost in breeding, don't go to a banker to borrow
the money. Assuming that the breeding ratio is high enough to overcome the interest
charges, in the long run, it is possible that the only effective cost will be
the re-processing of the fuel. In that case, the ore cost is trivial. However,
the costs of re-processing the fuel, fabricating the fuel, and their associated capital charges,
the charges for disposal of radioactive bi-products are very real, and are high. A fuel cost of
$.0001/Kwhr is not reasonable. ^^^^ ^^^^
Furthermore, the real economic cost of breeders must consider plant capitalization, O&M
etc, etc etc.... In the "long run", breeders will do well to out-perform LWRs at current
uranium prices, which are very low right now.
Breeders are no more a panacea than fusion, or any other energy alternative.
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