Development of Advanced LWR Fuel Pellet Technology

Nuclear fuel (UO2) pellets play important roles in not only generating heat through fission but also trapping fission products. The fuel burnup tends to increases in order to improve fuel economy. As the burn-up increases, the trapping capacity of pellets decreases and thus the rod internal pressure becomes higher. Accordingly, the performance of fuel rod will be degraded. In order to resolve this problem, it is essential to develop or to ameliorate pellet materials. More specifically, it is important to develop large-grained UO2 pellets. A longer fuel cycle which is needed to enhance the load factor of a nuclear power plant requires new burnable absorber with adequate nuclear performance. Burnable absorber used in our country is having been imported, so the technology related to burnable absorber is behind in our country. It is necessary to develop new burnable absorber for the purpose of reducing the power peaking and residual penalty of the reactor core in longer fuel cycles