J
Jon Kirwan
Guest
On Wed, 4 Mar 2009 07:31:51 -0800 (PST), bill.sloman@ieee.org wrote:
to "burn" more of the available radioactive materials -- fast neutron
reactors being one (liquid sodium being used, I think, as the coolant)
and, if my vague memory is correct, breeder reactors, too. I have NO
detailed knowledge about them, but I have read that they can be
designed with very much lower volumes of waste to store. From what I
read, fast neutron reactors burn existing long-lived nuclear waste,
producing a small volume of waste with half-life of a few decades --
which makes finding very long-term storage far less important. (I've
read that thorium can be used to also nearly eliminate the buildup of
long-lived nuclear waste.)
To examples to look up on the above are: (1) the Integral Fast Reactor
(IFR), the concept having been developed at Argonne National
Laboratory and built and tested at the Idaho National Laboratory; (2)
Liquid-Fluoride Thorium Reactor (LFTR), with early development taking
place at Oak Ridge National Laboratory. Both the IFR and LFTR operate
at low pressure and high temperatures. Both probably need a decade of
substantial, further engineering from what I've read. But South Korea
has a sizeable research program going on in these areas, I think. So
maybe it is closer than I imagine.
A serious problem is the carbon dioxide and other atmospheric wastes
being produced in China and India, with no real end in sight unless
they are offered some viable solution in the short term. That may
have to be nuclear, if it is to happen in time.
A general concern I have about proliferating fission power based on
uranium is the production of plutonium, which can be more easily
separated through chemical means instead of needing thousands of gas
centrifuges. I recall reading that 120 tons of 239-Pu are produced
each year by existing plants. It takes only a very few kg per bomb. I
kind of worry about expanding production. People start looking for
things to do with the stuff that is laying about.
Even __natural__ uranium fueled systems, those not using enriched
235-U, make 239-Pu. North Korea's Yongbyon Reactor I is a natural
uranium/graphite power reactor that was activated in 1987 and uses a
1950 MAGNOX design (graphite moderator, aluminum-magnesium clad
natural uranium fuel, and CO2 gas cooling.) It took a few years to
get working, but by 1990 it was operating at somewhere between 20 and
30 MW. But before it got operating like this, I read that they
extracted some 14kg of 239-Pu in 1988! Just after a year of fitful
operation. Over the next three years reports I read claimed that they
had extracted another 27 kg of 239-Pu. And that's just one reactor in
North Korea. Their Yongbyon Reactor II is another MAGNOX design and
started running at 50 MW in 1992 and is producing some 60 kg of 239-Pu
per year.
There are other considerations. Electrical energy is a subset of
total energy consumption. In the USA, electrical usage in 2002 was
13.1 quads out of about 98 quads total. Of that, nuclear represented
that 2.66 quads figure and hydro power was about 4 quads, memory
serving. Converting over to nuclear power as a replacement for coal
generation of electricity (most of the remainder) would require some
(13.1-2.66-4)/2.66 or almost 2 and a half times more nuclear power
plants of size similar to what we have now (around 103 or 104 times
2.4, or roughly 250 more sites added.) If looking to replace a
substantial part of the fossil fuels used for other than electrical
generation (oil heat, natural gas heat, propane, vehicle fuels, etc.),
that multiplier really starts to climb up very fast.
Imagine this scenario of fission power replacement, then, across the
world's current mix of uses. Yet, it may be the only way to consider
replacement of fossil fuels in the face of a world with increasing
populations (exponentially rising) and despite (linear) improvements
in efficiency of use.
There are some very serious problems ahead and it's likely that if we
don't substantially reduce world requirements, which is unlikely even
with strong efforts to improve efficiencies (the low hanging "fruit"
has already been picked to improve profits), fission power is probably
the only surer answer towards mitigating carbon releases in the nearer
term. I'm interested in seeing a realizable fusion reactor, but it is
hard to imagine it becoming viable on the grand scales required in
short order.
No one solution seems anywhere close to the convenience and prevalence
that fossil fuels represent. We've benefitted from near-free energy
for a century and more and whole societies have grown up in response.
It's going to be hard work controlling the continued temptation that
fossil fuel represents while finding alternatives that somehow need to
be suddenly snapped into place as replacements for a growing capacity
we've developed over a period of more than a century's time. All the
while the population grows, pressure on the environment continues, and
the desire for refrigeration and computer use expands.
Jon
On the radioactive waste, there are some alternative designs that tend
to "burn" more of the available radioactive materials -- fast neutron
reactors being one (liquid sodium being used, I think, as the coolant)
and, if my vague memory is correct, breeder reactors, too. I have NO
detailed knowledge about them, but I have read that they can be
designed with very much lower volumes of waste to store. From what I
read, fast neutron reactors burn existing long-lived nuclear waste,
producing a small volume of waste with half-life of a few decades --
which makes finding very long-term storage far less important. (I've
read that thorium can be used to also nearly eliminate the buildup of
long-lived nuclear waste.)
To examples to look up on the above are: (1) the Integral Fast Reactor
(IFR), the concept having been developed at Argonne National
Laboratory and built and tested at the Idaho National Laboratory; (2)
Liquid-Fluoride Thorium Reactor (LFTR), with early development taking
place at Oak Ridge National Laboratory. Both the IFR and LFTR operate
at low pressure and high temperatures. Both probably need a decade of
substantial, further engineering from what I've read. But South Korea
has a sizeable research program going on in these areas, I think. So
maybe it is closer than I imagine.
A serious problem is the carbon dioxide and other atmospheric wastes
being produced in China and India, with no real end in sight unless
they are offered some viable solution in the short term. That may
have to be nuclear, if it is to happen in time.
A general concern I have about proliferating fission power based on
uranium is the production of plutonium, which can be more easily
separated through chemical means instead of needing thousands of gas
centrifuges. I recall reading that 120 tons of 239-Pu are produced
each year by existing plants. It takes only a very few kg per bomb. I
kind of worry about expanding production. People start looking for
things to do with the stuff that is laying about.
Even __natural__ uranium fueled systems, those not using enriched
235-U, make 239-Pu. North Korea's Yongbyon Reactor I is a natural
uranium/graphite power reactor that was activated in 1987 and uses a
1950 MAGNOX design (graphite moderator, aluminum-magnesium clad
natural uranium fuel, and CO2 gas cooling.) It took a few years to
get working, but by 1990 it was operating at somewhere between 20 and
30 MW. But before it got operating like this, I read that they
extracted some 14kg of 239-Pu in 1988! Just after a year of fitful
operation. Over the next three years reports I read claimed that they
had extracted another 27 kg of 239-Pu. And that's just one reactor in
North Korea. Their Yongbyon Reactor II is another MAGNOX design and
started running at 50 MW in 1992 and is producing some 60 kg of 239-Pu
per year.
There are other considerations. Electrical energy is a subset of
total energy consumption. In the USA, electrical usage in 2002 was
13.1 quads out of about 98 quads total. Of that, nuclear represented
that 2.66 quads figure and hydro power was about 4 quads, memory
serving. Converting over to nuclear power as a replacement for coal
generation of electricity (most of the remainder) would require some
(13.1-2.66-4)/2.66 or almost 2 and a half times more nuclear power
plants of size similar to what we have now (around 103 or 104 times
2.4, or roughly 250 more sites added.) If looking to replace a
substantial part of the fossil fuels used for other than electrical
generation (oil heat, natural gas heat, propane, vehicle fuels, etc.),
that multiplier really starts to climb up very fast.
Imagine this scenario of fission power replacement, then, across the
world's current mix of uses. Yet, it may be the only way to consider
replacement of fossil fuels in the face of a world with increasing
populations (exponentially rising) and despite (linear) improvements
in efficiency of use.
There are some very serious problems ahead and it's likely that if we
don't substantially reduce world requirements, which is unlikely even
with strong efforts to improve efficiencies (the low hanging "fruit"
has already been picked to improve profits), fission power is probably
the only surer answer towards mitigating carbon releases in the nearer
term. I'm interested in seeing a realizable fusion reactor, but it is
hard to imagine it becoming viable on the grand scales required in
short order.
No one solution seems anywhere close to the convenience and prevalence
that fossil fuels represent. We've benefitted from near-free energy
for a century and more and whole societies have grown up in response.
It's going to be hard work controlling the continued temptation that
fossil fuel represents while finding alternatives that somehow need to
be suddenly snapped into place as replacements for a growing capacity
we've developed over a period of more than a century's time. All the
while the population grows, pressure on the environment continues, and
the desire for refrigeration and computer use expands.
Jon