[geeks] Global warming, was Mr Bill?

[Sridhar Ayengar]

Sandwich Maker wrote:
> " so it isn't going to be at lethal levels for millions of years.
> 
> while the half life of pu-239 is only 24Ky, u-238 [unfissionable in
> current reactors] is 4.5Gy.  even u-235 half life is 0.71Gy.  and high
> level 'waste' is essentially pure oxide, and while i admit i don't
> know the analysis a large percentage has to be u-238; afaik even after
> enrichment the bulk of the fuel load is u-238.

But it's the isotopes with low half-lives that make the waste dangerous. 
  The longer the half-life, the less radioactive.

Peace...  Sridhar