The failure of a fuel element cladding in one of the water-cooled plutonium production reactors permits the erosion of irradiated uranium metal by the cooling water which is normally disposed to the Columbia River. Monitoring systems at both the reactors and at their effluent basin outlets to the river continuously monitor these streams, and if major fission-products release occurs the coolant can be held in retention basins. In addition to these monitoring systems, a river monitor is located at the 300 area which continuously monitors the gross gamma activity of the Columbia River; however, its sensitivity to rupture debris is limited because of the relatively high background'' from the short-lived (n, {gamma}) produced radionuclides in the river. In making hazard assessments and in providing adequate monitoring techniques and equipment at down-river locations, it is essential to know what changes occur in fission and (n, {gamma}) produced radionuclides following release of rupture products to the river.

This brief report (December, 1962) discusses the effect of effluents from the Hanford Production reactors on the water temperature of the Columbia River.