Transmutations of Long-Lived and Medium-Lived Fission Products Extracted from CANDU and PWR Spent Fuels in an Accelerator-Driven System

Abstract

This study presents the time-dependent analyses of transmutations of long-lived fission products (LLFPs) and medium-lived fission products (MLFPs) occurring in thermal reactors in a conceptual helium gas-cooled accelerator-driven system (ADS). In accordance with this purpose, the CANDU-37 and PWR 15 × 15 spent fuels are separately considered. The ADS consists of LBE-spallation neutron target, subcritical fuel zone, and graphite reflector zone. While the considered ADS is fueled with the spent nuclear fuels extracted from each thermal reactor without the use of additional fuel, fission products extracted from same thermal reactor are also placed into transmutation zone in graphite reflector zone. The LLFP transmutation performance of the modified ADS is analyzed by considering three different spent fuels extracted from the thermal reactors. Spent fuels are extracted from CANDU-37 in case A, from PWR-15 × 15 in case B, and from CANDU-37 fueled with mixture of PWR 15 × 15 spent fuel and 46% ThO2 in case C. The LBE target is bombard with protons of 1000 MeV. The proton beam power is assumed as 20 MW, which corresponds to 1.24828·1017 protons per second. MCNPX 2.7 and CINDER 90 computer codes are used for the time-dependent burn calculations. The ADS is operated under subcritical mode until the value of keff increases to 0.984, and the maximum operation times are obtained as 3400, 3270, and 5040 days according to the spent fuel cases of A, B, and C, respectively. The calculations bring out that in the modified ADS, LLFPs and MLFPs, which are extracted from thermal reactors, can be transformed to stable isotopes in significant amounts along with energy production.

Analysis of thorium and transuranium utilization in a small modular reactor

“…In our pre vi ous stud ies [14][15][16][17][18], the uti li za tion of var i ous nu clear-spent fu els and tho rium fer tile fu els were an a lyzed in sev eral subcritical nu clear re ac tors to re ju ve nate or en rich them. As for the pres ent study, unlike them, the ef fec tive us abil ity of PWR-MOX spent fuel and tho rium fer tile fuel in an SMR op er at ing under crit i cal mode is in ves ti gated in terms of en ergy gen er a tion.…”

Analysis of PbBi eutectic after matrix separation by acid induced dispersive liquid–liquid microextraction followed by HR-CS-ETAAS determination

“…It is also used effectively for the transmutation of long-lived radioisotopes and to provide sustainable generation of power. 6,7 The quality and compatibility of the liquid metal coolants with stainless steel structural materials ensure safe and uninterrupted plant operations. The reactivity of structural components with a lead bismuth eutectic (LBE) coolant enhances corrosion, which necessitates strict quality control of the purity of the coolant (LBE) to ensure safer operation of the reactor.…”