Numerical model of MIT research reactor

A numerical model of the MIT nuclear research reactor has been developed to support studies on automated control and diagnostics. The model replicates the reactor´s kinetic response as well as its thermal hydraulic behavior. The latter includes forced convection heat transfer within the primary, reflector, and shield systems, gamma heating of both the reflector and shield, and conduction to the reflector from both the primary and shield regions. Issues in the code´s development are delineated including the modeling of time delays using lagged temperatures, the selection of appropriate time steps given the stiff nature of the kinetics equations and the need to avoid computational time delays when modeling heat exchangers, the numerical stability of the code (which is a function of power level because of the interaction of the multiple heat sources to the reflector), the initialization procedure including the derivation of the recurrence relation needed to resolve the numerical stability issue, and the method whereby the code was calibrated against the actual reactor. The results of benchmarking studies are presented