Routine samples of ground water, river water, and bottom sediment were collected from the Clinch River in 1983 in the preconstruction-construction phase of the CRBRP environmental radiological monitoring program. The water samples analyzed for iodine-131 yielded only a slight indication of the presence of I-131 at levels below the nominal lower limit of detection of 0.5 pCi/L. The only significant radioisotopes identified in sediment samples were /sup 137/Cs, /sup 60/Co, and the naturally occurring /sup 40/K. The results for /sup 137/Cs vary from 2.2 to 10.1 pCi/g (dry weight), while the results for /sup 60/Co range from 0.35 to 1.2 pCi/g (dry weight). With the exception of tritium, no significant radioactivity was detected in ground or surface water at the CRBRP site. Tritium concentrations ranging from 12,667 to 12,823 pCi/L were found in samples of surface water taken from the Clinch River below Melton Hill Dam while samples taken at the dam exhibited tritium levels from 28 to 942 pCi/L. These elevated tritium levels in the Clinch River below Melton Hill Dam are attributable to DOE operations at Oak Ridge. The external gamma radiation levels measured at the CRBRP site averaged 17.4 +- 3.2 mR/quarter for 1983. This is consistent with levels measured at TVA's nonoperating nuclear power plant construction sites. 3 figures, 8 tables.
