Assessment of Temperature Reactivity Effect in Compact Plutonium Systems

This work considers the effect of temperature change in plutonium breeder systems (BS) on the reactivity and critical parameters thereof in the course of integral critical experiments conducted at the All-Russian Scientific Research Institute of Technical Physics (VNIITF). The BS temperature reactivity factors (TRF) were assessed according to the multiplier factor Q depending on the BS temperature and according to the change in decay constant α. Experimental and estimated (using Monte Carlo method) TRF values were compared. Extreme gaps in the BS under different temperature values were measured (in an operating mode with a natural heat sink and with the use of an air-cooling system).