Re:uranium supply

[Jacques.Read@eh.doe.gov]

Light water reactors get a substantial fraction of their energy from the fission
of bred-in plutonium, and burn only a small fraction of the 235U.  The fuel is
"used-up" and discharged not because the fissionable isotopes are depleted so
much as because there are a variety of  fission products that have enormous
capture cross-sections that "poison' the core. This is why there's a "recycled
uranium" problem in the DOE gaseous diffusion plants GDPs). During the late
fifties and sixties, the cold war demand for weapons was so great that the
discharged fuel and targets from the plutonium production reactors was taken
back and fed into the GDPs, even though the chemical separtation of the uranium
from the neptunium and plutonium wasn't complete.  In practice, the fissionable
materials left over from weapons dismantlement could be combined with the
700,000 tonnes of depleted uranium left over in tanks behind the three GDPs and
supply whole bunches of nuclear power plants for centuries.  With fuel recycling
and breeders we probably don't have to mine any uranium for centuries.  And, of
course, there's more thorium around than uranium, and it breeds as well.

Jacques Read



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