9873210 wrote:The Tc99 in the waste has a yield of about 6% and a half life of 200,000 years. Ignore every other isotope and the claim is still false.
The idea of background radiation level in thousands of year (with implications of safe after 50 years) is as far off as the idea of absolutely deadly forever.
For every complex problem there is an answer that is clear, simple, and wrong.
Are you sure about your figures? I understand that, resulting from the fission of U235, there is generated Tc99 with a yield of about 6%. Now this Tc99 is confined within the fuel rod, which is bombarded with an intense flux of neutrons. And there is a significant cross section (a few barns) for the capture of these neutrons by Tc99, so producing Tc100 which decays with a half-life of 16 seconds into stable (non-radioactive) Ru100. Now the fuel rods remain in a reactor for typically about a year. So when they are taken out for reprocessing, what is the Tc99 yield in the waste? I find it difficult to believe that it remains the 6% which you have quoted - but you may be correct. Can you clarify where you obtain this figure on which your pronouncements are based?