Research of reflector optimum design of a lead cooled fast reactor

Taking SEALER as the research object, from the point of view of the effect of reflector materials on the core neutronics physics, this paper evaluates the effect of various reflector materials on the core life, core energy spectrum and core power distribution. The results show that without considering the increasing of the number of cycles of the reflector assembly and the changing of the structure of the reflector assembly, the energy spectrum of the reflector area is the softest, and the power of the outer ring assembly is the largest when BeO is used as the reflecting material. Compared with the original design, the core life is effectively prolonged, the radial power distribution of the core is more flat, and the core economy is better. In view of the effect of the thickness on the life of the core, the sensitivity analysis was carried out. It was found that the sensitivity of Y₃Al₅O₁₂ reflector to the thickness was the highest. Increasing the number of cycles of Y₃Al₅O₁₂ reflector can greatly prolong the life of the core. For the structure of reflector assembly, the effect of different assembly structures on core life and radial power is small under the premise of constant total volume of the reflector. Considering all factors, it is recommended to use BeO as the reflecting material and independent reflector rod in the optimal design scheme. (authors)