regent said:
I believe that if nuclear power is taken to be the ONLY source of power, natural uranium will run out in 50 years.
Reprocessing usually gets a lot of what the input amount of fuel was. 96% of spent uranium is still fissile,
Also, it makes sense that congress would ban it because it is costly. I would agree that they are 'stupid' from taking advice from anti-nuke activists.
regent,
I'm afraid you are INCORRECT in virtually EVERYTHING you said above.
For example, spent fuel is NOT 96% fissile. Nuclear reactor fuel starts out fresh as
about 4% U-235 and 96% U-238; which is probably where you got the 96% number.
After 3 years in the reactor, virtually ALL the fissile U-235 has been burned up. However,
some of the "fertile" U-238 has been transmuted into Pu-239 which is fissile. Some of
that Pu-239 is fissioned in the reactor. In fact, in the 3 years that a fuel assembly
spends in a reactor, about 40% of the energy you get from that assembly comes from
fissioning Pu-239 that was created in situ. At the end of 3 years, there is still some
Pu-239 left in the fuel; about 2% or so.
So spent fuel consists of about 2% fissile Pu-239, about 4% fission products, and
about 94% U-238. So only about 2% of the spent fuel is fissile; NOT 96%.
NO - it DOESN'T make sense for Congress to ban reprocessing because it is costly.
Reprocessing IS economical; and that is what the British, the French, and the
Japanese do with their fuel cycle. Reprocessing IS economical.
Reprocessing let's you recover the fissile Plutonium so that it can be recycled back to
the reactor - so you get more energy out of a given amount of Uranium. Additionally,
because the Plutonium is recycled back to the reactor; you don't have Plutonium in the
waste stream. One of the reasons for the high cost of the USA's spent fuel disposal
repository at Yucca Mountain is because it is being built to survive thousands of years;
which is the lifetime of the Plutonium that will be entombed there.
If you get the Plutonium out of the waste stream, and recycle it back to the reactor to
be burned; then the repository doesn't have to survive for thousands of years. That's
because the longest lived fission product of any consequence is Cesium-137 which has
a half-life of 30 years compared to the 24,000 year half life of Plutonium-239.
In a time span much, much less than that required to store Plutonium, ALL the
radioisotopes in the nuclear waste will have decayed to a level of radioactivity LESS
than the Uranium that was mined from the ground. If you aren't concerned about the
Uranium in the ground naturally, and its level of radioactivity; then you shouldn't be
concerned with fission products that are several hundered years old either.
Reprocessing is an EXCELLENT, and COST EFFECTIVE technology; and the USA
would use it just like the other countries, Britain, France, Japan,... but Congress made
reprocessing
ILLEGAL in the USA.
Dr. Gregory Greenman
Physicist