Abstract:
Burnable poisons play a vital role in long-life pressurized water reactor (PWR) and plate fuel assembly has good application prospects in long-life PWR. In this paper, the selection of burnable poisons and neutronics characteristics of long-life PWR plate fuel assembly were studied. The transportation-burnup calculations of different burnable poison fuel assemblies were carried out and the burnable poison with better neutronics performance was selected. The results show that when the enriched isotopes 157Gd, 167Er and B4C are used as burnable poisons, there is almost no reactivity penalty. When PACS-J and 231Pa are used as burnable poisons, due to their own characteristics, not only does not cause reactivity penalty at the end of the life cycle, but also the fuel assembly life is extended, and the fuel utilization rate is improved. The combination of PACS-J and the slow burn burnable poisons can obtain a better reactivity curve. From results of this article, the plate fuel assemblies can be selected with enriched isotope 157Gd, enriched isotope 167Er, B4C, 231Pa and PACS-J as burnable poisons, and the combinations of burnable poisons can be selected with two combination schemes, PACS-Er and PACS-Pa.