Benchmark Evaluation on Single Core System Composed of 10% Enriched Uranyl Nitrate Solution at STACY

Abstract

Critical experiments on 10% enriched uranyl nitrate solution have been conducted for obtaining benchmark data using a Static Experiment Critical Facility, STACY, in the Nuclear Fuel Cycle Safety Engineering Research Facility, NUCEF. Two cylindrical and one slab tank were used to construct a single core system. Critical solution levels were measured for three core tanks with changing the uranium concentration of uranyl nitrate solution. Fundamental data were obtained for unreflected or water reflected cores. The sensitivities of the fuel composition and tank geometry on the criticality were calculated, and total uncertainty of the experiments are evaluated less than 0.15% Δ k. Calculations of the neutron multiplication factor keff for the critical conditions were performed using a continuous-energy Monte Carlo code MCNP-4B employing JENDL-3.2. This paper presents the core configurations of STACY, their experimental uncertainties and calculation results with above calculation system.