Research on an alternative pin power reconstruction method in core simulator of COSINE code package - 15154

Nodal method is widely adopted by core analysis codes. Some nodal method employs transverse integral to discretize space variables, such as node expansion method (NEM). The main defect of these methods is that they cannot provide pin-wise power distribution that is very important in nuclear design and safety analysis. One classical remedy is to use functions to fit the fluxes with certain constraint conditions and then multiply the form factor to get heterogeneous pin power. However, this kind of method normally needs corner fluxes or currents as extra constraint conditions that cannot be provided by nodal method directly. In this paper, an iteration method of pin power reconstruction is elaborated. The numerical testing shows that such methods can achieve better accuracy. (authors)