SIMODEX, A Fuel Management Program Based on Modal Expansion Method .

Abstract

The simulation of reactor operation using a three dimensional finite difference code such as SORO or FMDP/OHRFSP is quite expensive, even when fairly long time steps are used. There is a need for a fuel management tool which will give approximate power distributions at much lower cost.

Modal methods allow inexpensive calculation of flux distributions. A fuel management program, SIMODEX, is being developed to use modal methods for the flux calculation. Programing is largely complete to the point where the program has been tested on a small sample problem. Additional work is required before the program will be ready to handle real full scale problems.

This paper develops the basic theory behind the method, and outlines the approach that is being followed in the programing.