Re: So, is reprocessing in America's future?

[AndrewsJP@AOL.COM]

Regards to all.



This is out of my immediate area of expertise, but I have to add to this 

discussion.



Almost everybody in this discussion seems to disregard the formation of 

Pu-238 in the reactor fuel reprocessing end.  This comes from activation of 

U-235 to U-236, then activation from U-236 to U-237, beta decay quickly to 

Np-237, then activation to Np-238 and beta decay of Np to Pu-238.  Pu-238 has 

a relative short long half-life of about 90 years which makes it an energetic 

alpha fraction of any Pu mixture containing it.  Since its source is U-235, 

not U-238, the fraction of Pu-238 in any Pu mixture is dependent on the 

enrichment of the original fuel.  Highly enriched fuel such as navy reactor 

fuel when reprocessed will have a lot of this material.  Candu fuel which is 

not enriched will have less than that from BWR and PWR reactors.  The 

importance of this material is that it is a heat source for any potential 

weapon made from non-weapons grade material. Large pieces of Pu containing 

significant activity from Pu-238 get very hot! and I don't mean radioactive 

"hot."  This heat as well as the added intense alpha radiation makes it 

difficult to handle and manage.  It makes it difficult to make into bombs of 

any kind.



Pu-238 also spontaneously fissions much more than Pu-239, thus producing 

unwanted neutrons that will interfere with the controlled fission explosion 

desired for a weapon.



Note that the short burn time used to produce weapons grade Pu will limit the 

amount of Pu-238 produced.  On the other hand, the longer burn time for 

reactor fuel will enhance this nuclide in the reprocessed Pu mix.



Just my thoughts.  By the way, my reference for this is the Trilinear Chart 

of the Nuclides, by William H. Sullivan, dated January 1957 when I first got 

into this business.  I kept it up as long as the producers kept sending out 

new nuclide stamps.  I still find it useful.



John Andrews

Knoxville, Tennessee

************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.