Dynamic analysis of a TRIGA reactor

Nuclear energy offers long-term economic and environmental benefits providing a reliable energy source with significant environmental advantages in reducing the effect of human activities on global warming. National governments in countries operating or planning to establish nuclear facilities have instituted regulatory regimes on the use of nuclear materials and facilities to insure a high level of operational safety. Research and Test Reactors (RTRs) play a significant role as research, training, and development facilities providing scientific bases and expertise for nuclear power programs. TRIGA-type reactors play a significant role as one of the most widely used research and training reactors in the world utilized for many diverse fields of applications. TRIGA installations have a unique, pulsing capability allowing the thermal power to reach very high levels for a very short period of time. The paper presents the results of a dynamic analysis of a TRIGA reactor using the coupled PARCS/TRACE code system. A pin-wise PARCS neutronic model was developed coupled to a simplified TRACE thermal-hydraulic representation of the reactor pool. Power pulse analysis from low and operating power level and the consequent peak power and temperature behavior suggest that present Technical Specification limits on fuel temperatures for pulsing is adequate to insure the safe operation of the TRIGA reactors. The study validates presently accepted methodologies and provides further assurances that TRIGA reactors can safely be pulsed and operated as research and training reactors. (author)