Computational Study on Transmutation of ⁹⁹Tc and ¹²⁹I in Pressurized Water Reactor

The feasibility of transmutation of longlived fission product (LLFP) ⁹⁹Tc and ¹²⁹I in pressurized water reactor (PWR), baesd on Daya Bay PWR, was analyzed. The calculation results show that the maximum transmutation rate is 15.69% for ⁹⁹Tc during one refueling cycle of 18 months, and 9.18% for ¹²⁹I. By analyzing the safety related items of different reactor cores, it is shown that, after introducing LLFPs into PWR, the k_eff gets lower and the range of variation with burnup becomes small, and obvious change of the radial neutron flux density of reactor core is not found, but the radial power peaking factor is declined. And also, there is no safety problems for reactivity coefficient and control after considering fuel temperature coefficient, moderator temperature coefficient, differential soluble boron worth and control rod worth. On the contrary, the above parameters get better. In summary, transmutation of ⁹⁹Tc and ¹²⁹I in PWR is feasible.