[ RadSafe ] Plutonium from Power Reactors

[Peter Bossew]

In the classical PUREX process, as used in La Hague and (to my 
knowledge) also in THORP and Mayak (and don't know about India), Am goes 
with fission products. There are efforts to separate the so-called minor 
actinides (Am, Np, Cm) because some isotopes are very long-lived (in 
particular 237Np, which is furthermore very tricky in the environment 
due to its complicated chemical properties). Chemically, Am and Cm go 
together (3+) (which is why they are normally analysed together in 
environmental alpha assay). The separation is technically feasible with 
a kind of annex to the PUREX process (there is ample literature about 
this), but expensive. - A related point is the separation of other 
long-lived stuff, notably 129I and 99Tc. Also this is possible, 
currently most of it goes into the waste fraction, but some is released 
into the environment: this is one reason why the La Hague and Sellafield 
plants are located right on the gulf stream which carries that waste 
away and disperses & dilutes it (hopefully). Its trace can be followed 
far into the polar ocean, and there is increasing concern about that 
matter (there is plenty of literature about the subject). Again, 
near-complete separation from both HLW and the release stream is 
technically possible, but expensive. The same is true for 14C and 85Kr, 
medium long lived, which are basically released through the stacks (La 
Hague is also a very windy place, conveniently) in current practice.
If one chooses to reprocess in large scale, it will probably be 
necessary to retain also these effluents (the feasibility has been 
demonstrated), but it will probably make reprocessing much more 
expensive; I don't know figures, if somebody knows details this would be 
very interesting information, because I think that the economical + 
ecological future of nuclear power depends on this to some extent.
In summary, radiochemical separation of long-lived radionuclides and 
undesirable components of MOX is possible, also to some extent their 
transmutation into short-lived waste which can then be added to the HLW 
fraction, as well as retention of the volatile effluents; however I am 
not sure about the economical impact of such measures. But if the 
renaissance of nuclear power takes place, as it appears, which would 
quite logically (I think) imply reprocessing, this problem should be 
discussed in time, otherwise the public will eventually ask questions; 
rightly so.

An overview can be found in IAEA TECDOC-1467 (2005)(& lots of 
references) and ORNL/M-1822 (1992), among other sources. Also the 
Wikipedia entry "Nuclear reprocessing" is informative, and 
www.uic.com.au/nip72.htm of the Australian uranium association.

pb


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Peter Bossew 

European Commission (EC) 
Joint Research Centre (JRC) 
Institute for Environment and Sustainability (IES) 

TP 441, Via Fermi 1 
21020 Ispra (VA) 
ITALY 
  
Tel. +39 0332 78 9109 
Fax. +39 0332 78 5466 
Email: peter.bossew at jrc.it 

WWW: http://rem.jrc.cec.eu.int 
  
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