Proliferation resistance features of reprocessed uranium in Light Water Reactor fresh fuel

The introduction of reprocessed uranium in fresh Light Water Reactor fuel as a measure against proliferation has been recently put forward in the non-proliferation discussion. In particular, the use of reprocessed uranium implies the presence of the 232U radioisotope, and this can make the possible diversion of the fresh fuel and further uranium re-enrichment more complicated. This work attempts to further evaluate a composition of a proliferation resistant UO2 fuel made of a mixture of fresh and reprocessed uranium, therefore implying, inter alia, the presence of 232U and 236U in the resulting fuel. A new UO2 fuel half-made of fresh uranium with the other half of reprocessed UO2 is proposed and assessed via simulation. 232U/208Tl emits a high energy gamma-ray of 2.6 MeV enhancing its detectability and any attempt to further enrich the mixture to weapon grade using, for example, centrifugation process could be hindered as the enrichment of 232U will rise faster than that of 235U. Moreover, the high-energy gammaparticles emitted by 232U and 236U might tend to dissociate UF6 molecules, potentially complicating the centrifugation process. In terms of radiological emissions, the calculations have shown that the dose rate at 1 m from a fuel assembly made of the proposed mixture is of the same order of magnitude of that of the fuel made of non-reprocessed uranium, though the dose rate doubled.

ABBAS Kamel;  COJAZZI Giacomo;  MERCURIO Giovanni;  PEERANI Paolo;  RENDA Guido; 

2013-11-25

ESARDA and Joint Research Centre

JRC83482

0392-3029,