CANDU堆应用RU的PWR/CANDU联合核燃料循环的研究

Study of RU Utilization in CANDU Reactor- an Advanced Nuclear Fuel Cycle of PWR/CANDU Synergism

对压水堆乏燃料后处理回收铀(RU)在秦山三期CANDU堆中应用的可行性和经济性进行分析。使用ORIGEN2程序,对后处理回收铀在生产后放置不同时间后核素的成份和放射性活度进行了计算。证明RU燃料元件生产的放射性水平是可以接受的。使用DRAGON/DONJON程序对应用RU的秦山三期CANDU堆的时均堆芯和瞬时堆芯校验分析表明:采用简单的2燃耗区,2、4棒束的换料方案能满足最大通道功率、最大棒束功率限制。通过放射性分析和堆芯物理分析可以看出,秦山三期CANDU堆在不改变堆芯结构及运行模式的条件下,从天然铀(NU)燃料过渡到RU燃料是可行的。通过对秦山三期CANDU堆应用RU的经济性分析,可以看出PWR/CANDU联合核燃料循环的策略既可节约铀资源(23%),提高燃料的能量输出(41%),又减少了废燃料的处置量(66%),可大大降低核电成本。

The feasibility and economy of the application of reprocessed uranium(RU) from spent PWR fuel in CANDU reactor of Qinshan Phase III NPP were studied. The composition and activity of RU at dif-ferent time after production were calculated using the code ORIGEN2. It is shown that the radiation level is acceptable when the CANDU fuel elements of RU are fabricated. The time-averaged and instantaneous RU reactor cores of Qinshan Phase III were studied using the code package DRAGON/DONJON. It is shown that when the simple 2 burnup zones are adopted, 2-bundle-shift or 4-bundle-shift refueling schemes will satisfy the license limits of the maximum bundle power and channel power. The transition from the nature uranium (NU) to the reprocessed uranium (RU) can be completed without major modification of the structure of reac-tor core and operation mode. It was estimated that the using of RU in Qinshan Phase III will increase the burnup (41%), save natural uranium resource (23%), decrease the spent fuel to be disposed (66%) and lower the cost of nuclear power.