Reactivity effect measurement of neutron interaction between two slab cores containing 10% enriched uranyl nitrate solution without neutron isolater

Tonoike, Kotaro ; Miyoshi, Yoshinori; Okubo, Kiyoshi

The reactivity effect of neutron interaction between two identical units containing low enriched (10% enrichment) uranyl nitrate solution was measured in the STACY. The unit has 350mm of thickness and 690mm of width and distance between those two units was adjustable from 0mm to 1450mm. Condition of the solution was about 290gU/L in uranium concentration, about 0.8N in free nitric acid molarity, 2427C in temperature and about 1.4g/cm in solution density. The reactivity effect was estimated from variation of critical solution level from 495mm to 763mm depending on the core distance. The reactivity effect was also evaluated by the solid angle method and a computational method using the continuous energy Monte Carlo code MCNP-4C and the nuclear data library JENDL3.2. Comparison of those estimations is presented.