Irradiation characteristics of krypton-85 irradiation facility using pressurization-dissolution method.

Abstract

Experiments in 85Kr irradiation were conducted in a facility devised to oparate on the pressurization-dissolution principle. Unsealed 85Kr gas amounting to 300 Ci was dissolved into 600 ml of liquid reactant-water or methanol, and the effects brought by changing the 85Kr gas pressure and irradiation temperature on the absorbed dose rate in the liquid re-actant were examined from theoretical considerations as well as from the results of β-ray measurements made with thin plate fluoroglass dosimeter.In the case of water reactant, the absorbed dose rate was found to be proportional to the 85Kr gas pressure, at a general level of 103 rad/h in the range of 0.626.2 atm 85Kr gas pressure, and to increase with lowering irradiation temperature. A similar linear relation between absorbed dose rate and 85Kr pressure was observed for methanol reactant, but the general level was one order higher-104 rad/h in the pressure range of 0.595.9 atm, whereas differences in irradiation temperature exerted hardly any influence in this case. These measured values of absorbed dose rate agreed well with the calculated values obtained by input charge method. The efficiency of radiation energy utilization was 37% for water, while with methanol it reached 65%.