Radioactive Waste Dilution in the Clinch River Eastern Tennessee GEOLOGICAL SURVEY PROFESSIONAL PAPER 433-G Prepared in cooperation with the U.S. Atomic Energy Commission and the Oak Ridge National Laboratory Radioactive Waste Dilution in the Clinch River Eastern Tennessee By P. H. CARRIGAN, JR. TRANSPORT OF R AD IONUCL I D E S BY STREAMS GEOLOGICAL SURVEY PROFESSIONAL PAPER 433-G Prepared in cooperation with the U.S. Atomic Energy Commission and the Oak Ridge National Laboratory UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1968 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 25 cents (paper cover) CONTENTS Page Page Abstract ___________________________ Gl Results of statistical analyses G5 Introduction _ _______________________ 1 Minimum, mean, and maximum daily dilution Acknowledgments ______________________ 3 factors 5 Streamflow characteristics of Whiteoak Creek and the Probability of equaling or exceeding Clinch River _______________________ 3 specified dilution factors 5 Dilution factor _______________________ 4 Seasonal variations in dilution _ 6 Computation of dilution factors ____________ 4 Frequency studies of minimum dilution factors 7 Selected period of record ______________ 4 Effects of diffusion in the Clinch River on dilution __ 7 Extension of discharge records for Conclusions ___ _ ___ _ 8 Whiteoak Creek ___________________ 4 References ____ ___ _ 9 ILLUSTRATIONS Page FIGURE 1. Index map of lower Clinch River basin ______________________________ _ G2 2. Graph showing flows in Whiteoak Creek and Clinch River during 1951, indicating variations in the river's dilution of radioactive releases ___________________________________ _ 3 3. Graph showing periods of records available for streamflow stations in Whiteoak Creek basin 4 4. Graph showing relationships between monthly discharges for two streamflow stations in Whiteoak Creek basin __________________________.________________________ ___ 5 5. Graph showing duration curve of daily dilution factors __________ ___ 6 6. Graph showing seasonal variations in dilution factors _________ _ __ 6 7. Graph showing annual minimum dilution factor frequency curves ____ _____ 7 8. Graph showing variation in flow of the Clinch River during a day, due to power releases from Norris Lake ___________________________.___________________________________ 7 9. Graph showing estimate of variation in concentration of radioactivity in the Clinch Raver at the mouth of Whiteoak Creek during a 24-hour period ______________________________-____ 8 10. Graph showing effects of power releases from Norris Lake on the variation in concentration of radioac­ tivity during a 24-hour period __________._______________________ _ 8 III TRANSPORT OF RADIONUCLIDES BY STREAMS RADIOACTIVE WASTE DILUTION IN THE CLINCH RIVER, EASTERN TENNESSEE By P. H. CARRIGAN, JR. Abstract pating agencies (Morton, 1963, p. 1), established A convenient, direct measure of simple volumetric dilution the following objectives: (1) To determine the fate of low-level radioactive liquid wastes released from the Oak of radioactive materials currently being discharged Ridge National Laboratory by waters of the Clinch River has been defined. This measure of dilution is called the to the Clinch River, (2) to determine and understand dilution factor. The dilution factor is the ratio of flow in the the mechanisms of dispersion of radionuclides re­ Clinch River to flow of the radioactive liquid waste stream leased to the river, (3) to evaluate the direct and (Whiteoak Creek) for concurrent periods of time. indirect hazards of current disposal practices in Dilution characteristics of the Clinch River and Whiteoak the river, (4) to evaluate the overall usefulness of Creek have been described by means of several types of statistical analyses: central tendencies, extremes, cumulative the river for radioactive waste disposal purposes, frequency distribution, seasonal trends, and magnitude- and (5) to provide appropriate conclusions regard­ duration-frequency curves of minimum dilution factors. ing long-term monitoring procedures. In order to apply results of these statistical analyses, Work described in this report was part of a co­ complete and steady mixing of the waters of the Clinch operative program with the Health Physics Division, River and Whiteoak Creek must be assumed. Exploratory diffusion tests indicate that complete mixing in the cross Oak Ridge National Laboratory; the Oak Ridge section has occurred within a reasonable distance down­ Operations Office, U.S. Atomic Energy Commission; stream from the mouth of Whiteoak Creek. and the Division of Reactor Development and Flows in the Clinch River in the vicinity of Whiteoak Technology, U.S. Atomic Energy Commission. Creek have been affected considerably by releases from The release of low-level radioactive liquid waste Morris Lake for peak-demand hydroelectric power. Other to the basin of Whiteoak Creek, which drains the exploratory tests indicate that the effects of the variation in flow of the Clinch River were almost completely evened Oak Ridge National Laboratory (ORNL) area, was out through processes of turbulent diffusion. begun soon after establishment of ORNL in 1943 for the processing of radioactive materials. INTRODUCTION Radioactive liquids have entered Whiteoak Creek This report describes a contribution of the U.S. as a result of direct releases of processed waste Geological Survey to the Clinch River Study. The water from ORNL, seepage from liquid-waste Clinch River Study was a multiagency effort to eval­ holdup pits, and drainage from solid-waste disposal uate the past, present, and future use of the Clinch trenches (Browder, 1959). River for disposal of low-level radioactive liquid Throughout most of ORNL's history, the waters waste from the Oak Ridge National Laboratory, of Whiteoak Creek have been impounded in White- operated by Union Carbide Corp. for the U.S. oak Lake by Whiteoak Dam, which is located 0.6 Atomic Energy Commission, in eastern Tennessee mile upstream from the mouth of the creek. The (Morton, 1961, 1962, 1963). The agencies that par­ lake was created as a holdup facility for the radio­ ticipated in the study are: Oak Ridge National active waste carried in the creek water. Radioactive Laboratory; Tennessee Game and Fish Commission; waste waters in Whiteoak Creek flow into the Clinch Tennessee State Department of Public Health, River at a point 3.3 miles downstream from the Stream Pollution Control Board; Tennessee Valley ORNL area. The diluted wastes in the Clinch River Authority; U.S. Atomic Energy Commission; U.S. flow into the Tennessee River 20.8 miles downstream Geological Survey; and U.S. Public Health Service. from the entry of Whiteoak Creek. When the study was begun in 1960, the Clinch The continuous release of radioactivity to the River Study Steering Committee, an advisory group Clinch River during nearly 20 years of ORNL opera­ composed of representatives of each of the partici­ tions has provided a unique opportunity for studying Gl G2 TRANSPORT OF RADIONUCLIDES BY STREAMS the effects of such releases on the river and the Various estimates of average dilution afforded by effects of the physical, chemical, hydrologic, and the river have been made; estimated dilution has biological characteristics of the river on the fate of ranged from 450 to 1,000 times the average dis­ the radioactivity. charge in Whiteoak Creek (for example, see Morton, Dilution of radioactive waters, which are released 1962, p. 106, and Feige and others, 1960, p. 25). to the Clinch River through Whiteoak Dam (fig. 1, Variations in estimates stem from using different inset), by flow in the river has been an integral part bases of flow comparisons: different periods of rec­ of waste water treatment at ORNL. Concentrations of low-level radioactivity in these releases have been ord, different streamflow measuring sites. greater than desirable levels in the creek. Through Other statistical measures of available dilution dilution afforded by the river, concentrations have such as the median and the frequency of occurrence been reduced to very acceptable levels in the river of minimums had not been estimated until this work (see Morgan, 1959a, p. 447). was undertaken. 7'30" 84-00' TENNESSEE --^NORTH J CAROLINA S SOUTH ^CAROLINA A Streamflow stations 1 Clinch River near Scarboro, Tenn. 2 Whiteoak Creek at Whiteoak Dam, near Oak Ridge Tenn. 3 Whiteoak Creek below ORNL, near Oak Ridge, Tenn. 4 Whiteoak Creek at ORNL, near Oak Ridge, Tenn. O Water-sampling station at mile 5.5 Enlargement at right MELTON HILL DAM 5 0 10 MILES I I I FIGURE 1. Lower Clinch River basin from Norris Lake to river mouth. RADIOACTIVE WASTE DILUTION, CLINCH RIVER, EASTERN TENNESSEE G3 Three of the principal radionuclides, strontium-90, STREAMFLOW CHARACTERISTICS OF WHITEOAK ruthenium-106, and cobalt-60, released continuously CREEK AND THE CLINCH RIVER into the river, are transported downstream into the Variations in flow of Whiteoak Creek reflect, al­ Tennessee River without substantial uptake by bot­ most completely, variations in natural runoff in its tom sediments or biota. (See Churchill and others, basin. Flows through Whiteoak Dam normally are 1965; Carrigan and Pickering, 1967, p. 63.) These uncontrolled, the lake serving only for emergency radionuclides are moving in the water as solutes storage needs. or as finely