Radiological Surveys of Idaho Phosphate Ore Processing -The Thermal Process Plant.

摘要

In general,the phosphate industry is neither regulated nor monitored for the possession,use,or discharge of radioactive materials associated with phosphate rock and its products and by-products. Recently,the State of Idaho (June 1, 1977) has prohibited the use of phosphate slag material in the construction of habitable structures,but has permitted the continued use of slag for road construction,railroad ballast,and other general purposes. Of immediate concern is the accumulation of a data base which will ultimately lead to an assessment of the impact on public health due to the phosphate industry's activities. This report discussses various radiological surveys conducted in the FMC Corporation's Thermal Process Plant in Pocatello,Idaho. Radiological surveys conducted at the FMC Corporation's Thermal Process Plant in Pocatello,Idaho indicate slightly elevated ambient levels of natural radioactivity within the plant. Compared to an estimated natural background annual dose equivalent rate of about 79mrem,net gamma exposure rates ranged from 42mrem in general plant areas to 182mrem per work year on the slag pile. Stack sampling results also show that appreciable concentrations of the naturally-occurring radionuclides,particularly polonium-210and uranium,are being discharged into the local environs. A general radioactivity balance indicates that the ore is the source of essentially all of the inlet radioactivity. The slag accounts for essentially all of the outgoing uranium and radium-226and up to about 50percent of the lead-210and polonium-210.