Production of Fission Product Xenon

Abstract

Radioactive Xe isotopes were produced by in-pile melting of irradiated uranyl nitrate hexali yd rate crystals. An aluminum pipe closed at the end was placed adjacent to the reactor core of the TTR-1 (swimming pool type reactor), and uranyl nitrate hexahydrate crystals in a stainless steel capsule were irradiated therein at a neutron flux of 2×1011/cm2-sec. After in-pile cooling for 10–15hr, the capsule was heated to melt the crystals. The rare gas activity released from the crystals was led out of the reactor by helium sweep and collected in a charcoal trap cooled by liquid nitrogen. More than 99% of the rare gas activity was recovered. The composition of the activity at the time of separation, while depending on cooling time and target irradiation history, was in the present case 135Xe(–80%), 133Xe(–10%) and small amounts of Kr isotopes. The remaining uranyl nitrate, crystallizes again upon removal of heat, and can serve for succeeding irradiations. About 30 mCi of radioactive Xe isotopes were produced by 4 hr irradiation using 5 g of 13% enriched U. Radioactive Xe produced in this way is being used for medical purposes.