^^ ^ The Clinch River Study an Investigation of the Fate of Radionuclides Released to a Surface Stream Ml GEOLOGICAL SURVEY CIRCULAR 497 Prepared in cooperation with Oak Ridge National Laboratory and the U.S. Atomic Energy Commission The Clinch River Study an Investigation of the Fate of Radionuclides Released to a Surface Stream By R. J. Pickering, P. H. Carrigan, Jr., and F. L. Parker Prepared in cooperation wifh Oak Ridge National Laboratory and the U.S. Atomic Energy Commission Geological Survey Circular 497 Washington 1965 United States Department of the Interior STEWART L. UDALL, SECRETARY Geological Survey THOMAS B. NOLAN, DIRECTOR Free on application fo the U.S. Geological Survey, Washington, O. C 20242 CONTENTS Page Page A b st ract __________________________ 1 Bottom-sediment sampling and Introduction _______________________ 1 analysis __________________________ 7 Aquatic biology and safety evaluation 2 Status of the Clinch River Study_______ 10 E ydraulic studies __________________ 2 References ________________________ 12 ater sampling and analysis 2 ILLUSTRATIONS Page Figure 1. Map of the lower Clinch River._________________ IV 2. Reduction of maximum concentration of gold-198. 3 6. Cumulative load in the Clinch River water of 3. Ruthenium-106___________________________ 4 4. Cesium-137 _____________________________ 5 5. Cobalt-60 ________________________. 6 6. Strontium-90 _______________________>___. 7 7. Diagram of analysis of bottom-sediment cores--. 9 8. Diagram of core scanner ______________________ 10 9. Cross section at Clinch River mile 7.5_________. 11 TABLES Page Table 1. Water-sampling stations, Clinch River Study. 3 2. Radionuclide loads in Clinch River water___. 5 3. Concentrations of specific radionuclides ___. 8 III 84°37'30" 84°30' 84°22'30" 84°15' 84°07'30" 84°00' Mile 5 upstream from mouth of river Water sampling station (No2) 10 1234567 MILES 84°37'30" 84°30' 84°22'30" 84°15' 84°07'30" 84°00' Figure 1. Water-sampling stations in the lower Clinch River basin. IV The Clinch River Study an Investigation of the Fate of Radionuclides Released to a Surface Stream By R. J. Pickering, P. H. Carrigan, Jr., and F. L. Parker 1 ABSTRACT 4. To evaluate the overall usefulness of this river for radioactive-waste-disposal The Clinch River Study is a multiagency effort to evaluate the physical, chemical, and biological effects of the release to purposes. the Clinch River of low-level radioactive wastes from the Oak 5. To recommend long-term monitoring Ridge National Laboratory. The major radionuclides released procedures. are ruthenium 106, cesium-137, cobalt-60, and strontium-90. t ydrologic and biologic studies have indicated that the radia- t on dosages in the river are well below maximum acceptable The study is under the general supervision levels. Radionuclide concentrations in river water have been measured at seven sampling stations on the Clinch and Ten­ of a steering committee composed of repre­ nessee Rivers. Mass-balance calculations for 44 weeks of sentatives of the Oak Ridge National Labora­ sampling indicate that losses of radionuclides from the water tory (ORNL), the Tennessee State Department phase to the river-bottom sediments represent only a very small part of the total radioactivity released to the river. of Public Health (TDPH), the Tennessee State Game and Fish Commission (TGFC), the A study of the Clinch River bottom-sediment cores collected Tennessee Valley Authority (TVA), the U.S. 1962 has disclosed a recurring pattern of variation in radio- tivity with depth which may reflect past events in waste- Atomic Energy Commission (AEC), the U.S. sposal operations at the laboratory. Current investigations Geological Survey (USGS), and the U.S. Public e expected to provide information about the chemical forms Health Service (USPHS) (Morton, 1961). In­ which the major radionuclides exist and the mechanisms by lich they were incorporated in the sediments. vestigations are carried out by personnel of the various agencies under the direction of four subcommittees of the steering commit­ INTRODUCTION tee, namely: Aquatic Biology, Safety Evalua­ The Clinch River Study is a multiagency tion, Water Sampling and Analysis, and Bot­ effort to evaluate the physical, chemical, and tom Sediment Sampling and Analysis. biological effects caused by the disposal in he Clinch River of low-level radioactive The Clinch River heads in Virginia and vastes from the Oak Ridge National Labora- flows southwestward to join the Tennessee ory 2 at Oak Ridge, Tenn. The study, begun River at Kingston, Tenn. (fig. 1). At its n 1959, has the following objectives: mouth the drainage area of the Clinch River is 4,413 square miles. At the farthest down­ 1. To determine the fate of the radioactive stream gaging station, 39.0 miles upstream from its mouth, the average flow of the Clinch materials currently being discharged to the iver. River is 4,612 cfs (cubic feet per second), based on a 26-year period of measurement. 2. To determine and understand the mech- nisms of dispersion of radionuciides re- eased to the river. During the first 3 years of the Clinch River 3. To evaluate the direct and indirect ha- Study, Norris Dam, at mile 7 9.8 on the Clinch River (CRM 3 79.8) was the only major con­ j;ards of current disposal practices in the iver. trol structure on the river. Releases from 3 The abbreviation "CRM" (Clinch River Mile) followed by a *R. J. Pickering and P. H. Carrigan, Jr., U.S. Geological number has been used in this report to designate distance up­ urvey, and F. L. Parker, Oak Ridge National Laboratory. stream, in miles, from the mouth of the river. This terminology z Operated by Union Carbide Corp. for the U. S. Atomic Energy is consistent with prior usage in the Clinch River Study (Morton, Commission. 1961). CLINCH RIVER STUDY RADIONUCLIDES RELEASED TO A SURFACE STREAM Norris Reservoir are largely made on the AQUATIC BIOLOGY AND SAFETY EVALUATION basis of demand for electric power. In May 196 3 control of flow began at Melton Hill Dam The radionuclide content of plant and ani­ which is at CRM 23.1 on the Clinch River, mal life in the Clinch River has been studied 2.3 miles upstream from the mouth of White- by the Ecology Section, Health Physics Divi­ oak Creek, where radioactive waste from sion, ORNL, and the Radiological Health Re­ ORNL enters the river. The Melton Hill sys­ search Activities Group, Radiological Health tem is to be a "peaking" powerplant, which is Division, USPHS. All preliminary estimates one that is operated mainly during periods of of public consumption of fish, ingestion of peak demand for power and shut down at water, and exposure due to use of the river other times. for recreational purposes indicated radiation dosages that were below maximum permis­ The Clinch River below Whiteoak Creek is sible levels. Calculation of estimated future affected by backwater from Watts Bar Dam, dose rates is continuing. Results of the bio­ which is on the Tennessee River 37.8 miles logical studies were reported by Morton downstream from the mouth of the Clinch (1961, .1962a, 1962b, 1963). River and a total of 58.6 miles downstream from the mouth of Whiteoak Creek. Before HYDRAULIC STUDIES construction of Melton Hill Dam, thermally stratified flow occurred in the lower Clinch The capacity of the Clinch River to dis­ River from spring to fall because the cold perse radioactive materials has been as­ water released from Norris Reservoir flowed sessed through a series of hydraulic testa under the relatively still, warmed backwater Radioactive gold-198 was used as a tracer in of Watts Bar Reservoir. The effect of the the early tests, whereas rhodamine-B and operation of Melton Hill Dam on temperature pontacyl brilliant pink-B fluorescent dyes conditions in the river is not yet known. have been used in more recent tests. In these tests, the longitudinal distance down­ Since 1943, low-level radioactive wastes stream to the cross section of complete lat­ derived from the Laboratory's Process Waste eral diffusion, the variation of peak concen­ Water Treatment Plant, solid-waste burial tration with distance, and the times of travel grounds, liquid-waste seepage pits, and other have been determined. Times of water travel minor sources of radioactivity have entered observed in the tests compare closely with the Clinch River through Whiteoak Creek times computed on the basis of the continuity (fig. 1). The radionuclides in the wastes are equation. Nearly uniform lateral mixing oc­ largely fission products cesium-137, stron- curs within 4 6 miles downstream from the tium-89 and 90, ruthenium-103 and 106, and mouth of Whiteoak Creek. Variation of con­ others but also include some activation centration with distance is shown in figure 2 products, such as cobalt-60 and zinc-65. for two of the tracer tests. Continous monitoring of radionuclide concen­ trations at the point of release to the river WATER SAMPLING AND ANALYSIS and downstream at CRM 4.5 has shown that concentrations are well within the limits rec­ A network of seven water-samp ling sta­ ommended by the National Committee on Ra­ tions on the Clinch and Tennessee Rivers was diation Protection. established under the direction of the Sub­ committee on Water Sampling and Analysis. Whiteoak Creek drains an area of 6 square Samples were collected regularly at the sta­ miles, which includes the Laboratory area. tions for material-balance studies of the Its average discharge is about 10 cfs, most radionuclides released to the river system of which is derived from surface runoff. At and for information on the stable-chemical the present time, its waters are impounded composition of the river water. Station loca­ in Whiteoak Lake by Whiteoak Dam, which is tions are listed in table 1.