One other thing that might be worth keeping in mind -- the usual practice with fast neutron (breeder) reactors is to run the fuel to much higher burnups than ordinary LWRs - twice as high or more.
This is significant from the proliferation point of view because weapons-grade Pu production requires just the opposite - very low burnup (weeks to months, versus years), in order to minimise the content of Pu-240, 241, 242 & 238, as well as Am-241 & 243.
While the long burnup in a fast reactor will produce (breed) a lot more Pu per kg of U, that Pu will be useless for weapons by the time the spent fuel is taken out of the reactor for reprocessing.
Jaro
-----Original Message-----
From: Dr Christoph Hofmeyr [mailto:chofmeyr@nnr.co.za]
Sent: Tuesday February 04, 2003 2:08 AM
To: Emil
Cc: radsafe@list.vanderbilt.edu
Subject: RE: Quiz: RE(2): Power Plant was declared bankrupt.[Scanned]
Emil, Jaro,
A few thoughts came to mind. U-238 contributes to fission, but only at
quite high neutron energies. This and some fission of the Pu-239 in the
blanket will contribute to fission products. The blanket material would
be highly active, although less active than used fuel. In a normal
thermal reactor the conversion ratio C (the number of fissile nuclei
resulting from one fission)is typically 0.6, while in a breeder it must
by definition be >1.0 (in practice >1.02 or so to allow for reprocessing
losses). Anyway, thermal reactor used fuel contains Pu-239 accompanied
by some of the higher isotopes (which makes it less suitable for nuclear
weapons), and some of it is recycled together with uranium in MOX fuel,
which is used in thermal reactors.
A Pu breeder could in principle initially start off on U-235 in stead of
Pu-239. However,the world is faced with a stockpile of weapons grade
Pu-239 and U-235 and the problem seems to be how to dilute this material
down practically 'irretrievably' to reactor fuel to thwart
proliferation.
Personal musings.
Chris Hofmeyr
chofmeyr@nnr.co.za
-----Original Message-----
From: Emil [mailto:kerrembaev@YAHOO.COM]
Sent: 01 February 2003 08:37
To: Franta, Jaroslav; radsafe
Subject: Quiz: RE(2): Power Plant was declared bankrupt.[Scanned]
Jaro,
>>>>>>>>>> the quantity of Pu from a small
350 MW breeder reactor would not be anywhere near
"hundreds of tons." Such large quantities would
>>etc.
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