A development of nodal transport calculation method for three-dimensional hexagonal geometry

For the detailed analyses of power fast reactor core, the neutron transport calculation is essential. However enormous computation memory and calculation time are generally required to obtain the accurate transport calculation results. In terms of the rationalization of those situation, the nodal transport calculation code for three dimensional hexagonal geometry 'NSHEX' has been developed. The 'NSHEX' code has ever been improved mainly in convergency and calculational accuracy. By treating the angular dependence of flux in detail and applying the new method of the treatment of transverse leakage, the 'NSHEX' code is enabled to reduce the error of multiplication factor by about one sixth as much as that produced by the previous nodal transport calculation method. In future we will furthermore promote the development of the 'NSHEX' code and establish it as the standard transport calculation code to evaluate the power reactor core in detail. (author)