石墨-熔盐反应堆堆芯中子通量与钍铀转换比

Neutron Flux and Th-U Conversion Ratio for Graphite-Molten Salt Reactor

作为获国际认可的第四代核电站反应堆堆型之一的熔盐堆(Molten salt reactor,MSR),具有固有安全性高、经济性好、核资源可持续发展以及易于防止核扩散等优点。针对石墨-熔盐零功率堆的几何参数,利用蒙特卡罗计算程序MCNP5建立了物理计算模型,计算临界情况下堆芯径向、轴向中子通量及增殖区厚度与Th-U转换比(Conversion ratio,CR)的关系。结果表明,(1)石墨-熔盐零功率堆堆芯中子通量密度分布较为平坦;(2)石墨-熔盐零功率堆反射层厚度和增殖区厚度在一定范围内,CR随反射层厚度或增殖区厚度的增加而增加,当超出该范围,CR不再随反射层厚度或增殖区厚度的增加而明显增加。

The molten salt reactor （MSR） is the only one liquid-fuel reactor in six candidates of Genera- tion IV advanced nuclear reactor, which is characterized by remarkable advantages in safety, economics and sustainable development of the fissile resource and proliferation resistance of nuclear energy. A de- tailed computational model using the Monte Carlo code MCNP5 is set up, in order to study about radi- cal/axis neutron flux and the influences of the reflect thickness or blanket thickness on the conversion ratio （CR） of the Th-U fuel cycle. Main results obtained in this calculation show that： （1） The neutron flux distribution of the graphite-molten zero power reactor core is relatively smooth. （2） CR will in- crease with the increasing of the thickness of reflector and/or the thickness of breeding region in a cer- tain range and when it exceeds this range CR cannot get increased significantly.