根据中国核电发展战略,采用国际原子能机构(IAEA)的核燃料循环软件NFCSS,对未来中国核电发展情景进行了预测,分析了2050年以前中国乏燃料的产生和累积情况。采用NJOY和ENDF/B-VII数据库,计算分析了次锕系核素在热谱、超热谱和快谱中的一群等效截面,分析了237Np、241Am、246Cm等主要次锕系核素的可能嬗变途径,提出了两阶段嬗变MA策略,即将从压水堆中分离出来的MA首先在充分热化的热中子场中嬗变,嬗变后余下的核素再在较硬的中子场中进行嬗变,有望取得较好的嬗变效果。
According to the development plan envisagement for nuclear power plant in China,the development of China's nuclear power in the next decades is predicted with the nuclear fuel cycle software NFCSS provided by IAEA.The amounts of the spent fuel generated and accumulated by the year of 2050 are analyzed.According to the assumption model,the accumulated spent fuel by the year of 2050 will reach at 54791t including 57.89t Minor Actinides(MA)(237Np,42.91t;Am,11.17t;Cm,3.81t) and 2778t FP.One group effective cross section of MA in the thermal,well thermalized,and fast neutron field is calculated based on ENDF/B-VII nuclear evaluation database.The transmutation way for three main MA,i.e.237Np,241Am,and 246Cm is also analyzed.It is more suitable for 237Np transmutation in well thermalized neutron field and for 241Am,the high flux thermalized neutron field is better.But it is difficult for 246Cm transmutation in thermal or fast neutron field due to its little fission cross section.Its transmutation ability can be improved if transmutation occurs in a high fluxes resonance energy area.The two-stage transmutation strategy is presented according to their characteristics in the thermal,well thermalized,and fast neutron field.Based on the two stage transmutation concept,the transmutation is performed in a well thermalized neutron field first.Small amount of residual of the first stage transmutation is transmuted in a thermal field with a spectrum.It is expected to achieve a good result.