Experimental and Computational Validation of RAPID

ABSTRACT The RAPID (Real-time Analysis for Particle transport and In-situ Detection) code system utilizes the Multi-stage Response-function Transport (MRT) approach with the Fission Matrix (FM) method for neutronics simulation of nuclear systems. RAPID performs real-time calculations by utilizing pre-calculated databases for different enrichments, burnups, and cooling times. This paper discusses the validation of RAPID using the U.S. Naval Academy’s subcritical reactor (USNA-SCR) facility. Computational validation is performed by detailed comparison with an MCNP reference calculation and experimental validation is performed using both in-core and excore neutron measurements with different He proportional counters. These measurements, and associated calculations have demonstrated that RAPID achieves accurate results in real-time.