Study on the Calculation Methods for the Spiral Surface in the Monte Carlo Program
With the development of reactor,the fuel elements in nuclear reactor design tend to be diversified.Spiral cross fuel elements are one of them.Compared with fuel elements of the traditional pressurized water reactor,the helical cross structure element can enhance the heat transfer capacity while maintaining the material strength and structural integrity under operating conditions[1],thereby greatly improving the safety and economy of the reactor.In order to describe the distribution of neutrons in different regions of the reactor,it is necessary to solve the neutron transport equation.Common methods for solving the neutron transport equation include the deterministic method and the Monte Carlo method.Compared with the deterministic method,the Monte Carlo method use fewer approximations,and the Monte Carlo method can basically describe arbitrary geometric shapes.For the cross-spiral fuel element,the cross-spiral geometry unable to be effectively described in these common Monte Carlo programs.A description method of the helical surface was developed in a Monte Carlo program.And two different solutions are proposed to solve the distance between the neutron and the thread surface,which are the approximation method and the approximation method optimization-fixed step adjustment strategy.Through comparison of simulation experiments,it is found that the latter can effectively improve the calculation efficiency.
Spiral surfaceMonte Carlo methodReactor fuel element
NETL
NSTL
万方数据
