Spent fuel analysis of material test research reactor using ORIGEN2 computer code

Abstract

The main uses of the research reactor includes research and education, isotope production, neutron activation analysis, neutron physics experiments and fundamental research. Fuel loading in these reactors is smaller than the Nuclear Power Reactors. The spent fuel is usually stored on-site for about ten years. During the storage their activity and decay heat die down. The knowledge of spent fuel activity and decay heat is essential for designing the spent fuel storage, its shielding, transportation and heat load analysis. The decay heat and activity of spent fuel dictate the requirements for reprocessing and disposal of generated radioactive waste. This paper presents the radioactivity analysis of Pakistan Research Reactor-I (PARR-I) spent fuel. PARR-I is MTR type research reactor utilizing 19.99% enriched Uranium Silicide (U3S2-Al) fuel. It operates at 10 MW design power. It highlights the activity and decay heat profiles of actinides and fission products. The core inventory calculations were carried out using depletion computer code ORIGEN2. The decay heat and activity profiles show that the fission products dominate for initial period of decay as fuel is removed from the core. The actinides activity and decay heat is smaller but they survive for a longer time than fission products. The variation of decay heat with the passage of time follow the same pattern as the activity.