MA以IMF燃料靶组件形式在大型钠冷快堆中的非均匀嬗变研究

MA heterogeneous transmutation in large sodium cooled fast reactor as IMF fueled target subassembly

针对次量锕系核素(MA)的嬗变问题,以中国示范快堆(CDFR)为基本堆芯,研究了MA以靶组件形式在大型钠冷快堆中非均匀嬗变的问题。为增加嬗变的效果,靶组件的燃料选择了不含铀的惰性基体燃料(IMF)。结果表明:少量IMF燃料靶组件的插入对堆芯会产生一定的影响,主要是钠空泡反应性正反馈增强较明显,同时与MA均匀嬗变不同的是堆芯功率峰因子有所增加,其他参数影响相对较小;IMF燃料靶组件中MA的嬗变效果较好,尤其是MA焚毁效率比燃料均匀添加MA时增加了约1/3,IMF燃料中由MA转变的238Pu的次级裂变对MA的焚毁贡献显著增加。在大型钠冷快堆中使用含MA靶组件进行非均匀嬗变时,需要合理选择靶组件的数量和布置位置,以便实现在MA高效嬗变的同时对堆芯性能不会产生非常显著的影响。

Based on China Demonstration Fast Reactor（CDFR）,the issues about Minor Actinides（MA） transmuted heterogeneously in large sodium cooled fast reactor as IMF（Inert Matrix Fuel） fueled target subassembly are studied in the paper.The results indicate that loading few targets into CDFR will introduce certain influences on core performance,mainly on obviously increased sodium void worth and differed from homogeneous transmutation,slightly increased power peak factor,while on other parameters there are relatively small impacts.High MA transmutation efficiency is obtained by IMF fueled target subassembly,especially for MA incineration efficiency,which is increased by about 1/3 compared with MA homogeneous transmutation in sodium cooled fast reactor.Additionally,for MA incineration,in IMF fuel the contribution of secondary fission of MA converted 238Pu becomes more important.In conclusion,the high MA incineration efficiency and small impacts on core performance will be achieved if the number and the loading position of target are optimized when MA is transmuted heterogeneously in large sodium cooled fast reactor.