Re: Pu/Be Source Service Life.

[Al Tschaeche <ant@pmafire.inel.gov>]

When I was transhipping the Pu/Be sources from the then U.S. Nuclear 
Corp. in Burbank, CA. durin the early 1960s, there was no mention of a 
useful life in any of the paperwork from the manufacturer (or anywhere 
else for that matter).  Because the specific activity of the Pu-239 that 
was used in those sources, there didn't seem to be any concern with 
helium buildup inside the sources.  Other that helium buildup, I don't 
know of any other parameter that would limit their lives.  The stainless 
steel capsules were very robust.  I'm not sure that those sources were 
ever assigned a source catetory according to ANSI N43.6-1977(R1989) 
"Classification of Sealed Radioactive Sources".  I don't remember that 
that standard had an "end of life" category in it.  If you think that the 
standard should have such a category, you may wish to contact ANSI and 
suggest it.  Al Tschaeche, INEL, LITCO, ATSCHAEC@INEL.GOV