长寿期压水堆板状燃料组件可燃毒物选型研究

Burnable Poison Selection of Plate Fuel Assembly for Long-life Pressurized Water Reactor

可燃毒物在长寿期压水堆中起着至关重要的作用,板状燃料组件在长寿期压水堆中具有较好的应用前景。本文开展长寿期压水堆板状燃料组件可燃毒物选型及中子学特性研究,对含不同可燃毒物的板状燃料组件进行输运-燃耗计算,筛选出中子学性能较好的可燃毒物。结果表明,采用富集同位素^(157)Gd、^(167)Er和B_(4)C作为可燃毒物时,几乎无反应性惩罚;当采用PACS-J和^(231)Pa作为可燃毒物时,因其自身特性,在寿期末不仅未造成反应性惩罚,且延长了组件寿期,提高了燃料利用率;PACS-J与慢燃耗可燃毒物组合,可获得更优的反应性曲线。由本文结果可知,板状燃料组件可以选用富集同位素^(157)Gd、富集同位素^(167)Er、B_(4)C、^(231)Pa和PACS-J作为可燃毒物,可燃毒物组合可以选用PACS-Er和PACS-Pa两种组合方案。

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^(157)Gd,^(167)Er and B_(4)C are used as burnable poisons,there is almost no reactivity penalty.When PACS-J and ^(231)Pa 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^(157)Gd,enriched isotope^(167)Er,B_(4)C,^(231)Pa and PACS-J as burnable poisons,and the combinations of burnable poisons can be selected with two combination schemes,PACS-Er and PACS-Pa.