[ RadSafe ] Re: Spent Fuel and Decay

[Leo M. Lowe]

Hi Mike,

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Does anybody know of any calculations as to how long it takes spent fuel
to decay to the activity level it had before going into the reactor?  I
realize it is highly dependant on factors such as level of enrichment,
amount of burn-up, activation of cladding, etc, and breeding of Pu.
Still I would be interested in knowing what the numbers look like.

From: "Brennan, Mike  (DOH)" <Mike.Brennan at DOH.WA.GOV>
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The World Nuclear Association at http://www.world-nuclear.org/info/inf04.html
shows a graph of the decay of the radioactivity of spent 
fuel.  Apparently, the total activity of the spent fuel is less than 
the activity of the original ore before 10,000 years of decay.  An 
OECD NEA 1996 report (Radioactive Waste Management in Perspective) is 
cited as the source of the graph.

A similar graph was in an issue of Nuclear News a few years ago, but 
I can't place the exact volume/date at the moment.

Regards,

Leo M. Lowe, Ph.D., P.Phys.

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