Study on the Effect of MA Nuclides Transmutation on Safety in Lead-Cooled Fast Reactors

The lead-cooled fast reactor can be used for the post-processing of part of the minor actinides (MA) nuclides contained in the spent fuel. This study designs three modes of adding MA nuclides to analyze and study the effect of the MA nuclides transmutation on the core critical performance, core life cycle and fuel temperature coefficient thus to study the effect of the MA nuclides addition on the reactor safety performance. The results show that the addition of MA nuclides reduces the initial critical performance of the core; that the addition by either coating or mixing with fuel can significantly extend the life cycle of the lead-cooled fast reactor, while the addition of transmutation rod has different effect on the core life cycle depending on the rod location; and that the addition of MA nuclides causes the change of fuel temperature coefficient, which, however, remains negative. All of the three addition modes are feasible. In particular, attention should be paid to the effect of the transmutation rod location on the core life cycle. It is not advisable to distribute the transmutation rods in a concentrated area.