Multiple recycling of fuel in prototype fast breeder reactor

Abstract

In a thermal neutron reactor, multiple recycle of U-Pu fuel is not possible due to degradation of fissile content of Pu in just one recycle. In the FBR closed fuel cycle, possibility of multi-recycle has been recognized. In the present study, Pu-239 equivalence approach is used to demonstrate the feasibility of achieving near constant input inventory of Pu and near stable Pu isotopic composition after a few recycles of the same fuel of the prototype fast breeder reactor under construction at Kalpakkam. After about five recycles, the cycle-to-cycle variation in the above parameters is below 1%.

Improved analysis on multiple recycling of fuel in prototype fast breeder reactor in a closed fuel cycle

“…Each of these results was normalized to a total BOC inventory of 1000 kg. In contrast to the previous calculations [1], the present study includes small amounts of Pu-238, U-234 and Am-241 in the BOL inventory, and also considers U recovery and recycling. Though these considerations do not form important outcomes for discussion, the evolution of these nuclides over the operating cycles along with their reaction and decay products like U-232, U-233, U-235 etc., may be of interest.…”

“…[1], the concept of 'Pu-239 equivalence' was employed to judge the quality of the recovered, bred or recycled plutonium. The difference in the Pu-239 equivalents of initial and discharge plutonium indicates the change in the worth.…”

“…The Pu-239 equivalences of various nuclides are given in table 3, and the methods of computation of Pu-239 equivalents for a given composition are as described in ref. [1].…”

“…In the earlier calculations [1], uranium recovery was not considered for recycling. It was assumed that the needed amount of uranium, with its composition as at BOL, was available for every recycling.…”

“…A study on the feasibility of multiple recycling of the Indian prototype fast breeder reactor (PFBR) fuel was done recently wherein the fuel compositions were estimated for 10 refueling cycles involving fuel recovery, cooling and refabrication, taking into account the mandatory requirements on fuel worth and mass [1]. The concept of Pu-239 reactivity equivalence was used for the fuel to assess its quality [2].…”