PHITS calculation of gamma doses in the PRR-1 SATER facility
A computational model of the Philippine Research Reactor-1 (PRR-1) Subcritical Assembly for Training, Education, and Research (SATER) was developed using the Particle and Heavy Ion Transport code System (PHITS). Photon transport of 0.6617 MeV gamma rays was then simulated using PHITS to calculate gamma doses at specific locations in the PRR-1 SATER tank. Simulations were performed with 108 particles. The results of the PHITS simulations were compared to the measured doses in the facility to evaluate the accuracy of the computational model in predicting the gamma radiation levels of the PRR-1 SATER. On average, gamma doses calculated from the PHITS model are higher by a factor of 1.07 ± 0.22 compared to measured values. These results provide a slightly conservative but closer estimate of gamma doses in the facility compared to calculation results that were obtained prior to the commissioning of the facility, which overestimated the doses by a factor of ~200.