TRU management by fast reactor toward sustainability and flexibility

This paper presents transuranics (TRU) management by fast reactor changing TRU conversion ratio (CR). A closed nuclear fuel cycle consisting of Advanced Recycling Reactor (ARR) and Consolidated Recycling Facility (CRF) is investigated so as to consume TRU from used nuclear fuel from light water reactor (LWR) by sodium cooled fast reactor (SFR) and reduce the amount of TRU and the decay heat of nuclear waste disposed in repository. On the other hands, self-sustainability is one of strong points in SFR and it is preferable and possible that the ARR is able to change the conversion ratio. The design targets are set as follows: - TRU CR will be 0.5-0.6 in TRU burning core of the ARR and the breeding ratio of TRU self- supply core will be 1.0 or more.And these characteristics will maintain after multi recycling. The TRU CR is defined by INL as follows. 1 TRU CR. = (RHM -RTRU)/RHM (1) RHM: mass consumption of HM between beginning of life and end of life, RTRU: mass consumption of TRU between beginning of life and end of life. TRU burning capability is defined as follows. TRU burning capability = (TRU-B-TRU-P)/EL-P (2) TRU-B: burnt TRU (kg), TRU-P: produced TRU (kg), EL-P: produced electricity (TWeh) - The outer dimension of subassembys are the same between the the TRU burning core and the TRU self-supply core, taking the replacement of core into account. It is assumed as follows. - The ARR is a 500 MWe of SFR (thermal power:1180MW), with oxide fuel and burnup of 150 GWd/t. - The TRU composition of fresh fuel is Np-237 5.3%/Pu-238 3.1%/Pu-239 45.7%/Pu-240 21.3%/Pu-241 7.2%/Pu-242 3.9%/Am-241 3.9%//Am-243 2.1%/Cm-244 0.8% (wt.). According to the nuclear calculation, it is found that the TRU burning core can consume TRU and the TRU self-supply has an appropriate breeding characteristics, as shown. There is no doubt that the provided ARR can change the TRU consuming and breeding characteristics from TRU CR. of 0.5-0.6 to B.R. of 1.0.