Evaluation of Radiological Conditions in the Vicinity of Hanford for 1963

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1!111111A EC RESEARCH AND IN THE VICINITY OF HANFORD FOR 1963 THE ENWRONMENTAL STUDIES AND EVALUATION STAFF HANFORD ATOMIC PRODUCTS OPERATION

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This report was prepared os an occount of Government sponsored work. Neither the United States, nor the Commission, nor any person acting on beholf of the Commission: A. Mokes ony warranty or representation, expressed ar implied, with respect ro the accuracy, carnpleteness, or usefulness af the information contained in this report, or that the use of ony information, opparatus, method, or process disclosed in this report may not infringe privately owned rights; or E. Assumes any Iiobilities with respect to the use of, or far damages resulting from the use of any information, apparatus, method, or process disclosed in this repart. As used in the above, “persan octing on behalf of the Commission” includes any employee or contractor of the Commission, or employee af such contractor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepares, disseminates, ony information pursuant to his employment or contract with the Commission, or or provides occess to, - his employment with

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UC-41, Health and Safety EVALUATION OF RADIOLOGICAL CONDITIONS IN THE VICINITY OF HANFORD FOR 1963 The Environmental Studies and Evaluation Staff Radiation Protection Operation HANFORD ATOMIC PRODUCTS OPERATION Work performed under Contract No, ‘AT(45- 1)-1350 between the Atomic Energy Commission and General Electric Company Printed in USA. Price $3.00 Available from the Office of Technical Services Department of Commerce

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An evaluation of results obtained from the Hanford environmental surveillance program for 1963 indicates that most of the environmental radiation exposure for the majority of persons in the neighborhood of the Hanford project was due to natural sources and world-wide fallout rather than to Of the low-level wastes released to the environment from the Hanford plants, neutron-induced radionuclides present in reactor cooling water discharged to the Columbia River continued to be the source of greatest potential exposure to the people in the environs. The primary mechanisms of exposure from this source are drinking water derived from the river and consumption of fish and waterfowl which inhabit the river. The city of Richland started using the Columbia River as a source of sanitary water during 1963. In the 4 months following startup of the new plant in August, this source contributed a total exposure amounting to about 570 of the annual permissible limit for populations. - The gastrointestinal tract is the limiting organ for the mixture of nuclides present in drinking water pumped from the Columbia River. In Pasco and Kennewick, which are further downriver, the estimated exposures from drinking water were respectively about 5’70 and 1~0 of the GI tract limit (population at large) for the full 12 months of 1963. The only persons who received radiation exposures attributable to Hanford that were greater than those resulting from the drinking water were the people that ate local fish or waterfowl or who regu - larly consumed produce from nearby farms irrigated with water pumped L from the Columbia River below the reactors. The highly unlikely, but conceivable combination of circumstances ,, that would result in the greatest exposure to an individual from the radionuclides Feleased by the Hanford plants is postulated as; (1) the consumption of some ’200 meals of locally caught fish during the year, (2) the consumption of meat, milk, fruit, and vegetables from irrigated farms of the Riverview district, and (3) the drinking of water from the Pasco system.

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An ind: vidual with such habits could conceivably take in enough radioactive material of Hanford origin (mostly P 32) to supply about 45’% of the annual permissible amount. In this case the bone is the organ that is most restrictive. This same individual could also take in enough Sr 90 of world-wide faU- .) out origin to equal about 570 of the permissible amount-more than twice that estimated for 1962. The exposures from nuclides of Hanford origin and from fallout are not additive in relation to limits, however, since the Radiation Protection Guides recommended by the Federal Radiation Council are not applicable to fallout from weapons tests. The amount of 1131 in the Hanford environs was substantially less than in the previous 2 years when extensive testing of weapons was in pro,g - ress Nevertheless, world-wide fallout continued to be the dominant source of the 1131 found locally, except for the month of September when abnormally large amounts were released from one of the chemical separations plants. For the calendar year 1963, the 1131 in milk from local farms could have resulted in radiation exposures to the thyroids of infants of approximately 10~0 of the Federal Radiation Council Radiation Protection r,uide.

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TABLE OF CONTENTS the Columbia River ..,..., 11 Fish and Waterfowl ...,.,. 21 Milk and Agricultural Produce .... 30 H. Radioactive Particulate in the Atmosphere J. Radioactive Wastes Released to Ground . RIVER AND RELATED SAMPLE RESULTS . . 58 ATMOSPHERIC AND REEF THYROID SAMPLE RESULTS ...... 116 FARM PRODUCE AND ‘,

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LIST OF FIGURES 1 Geographical Relationship of Hanford Works 2 Features of Hanford Project and Vicinity. ..... 3 Relative Abundance of Radionuclides in Columbia River Water at Several Locations. Annual Averages 1963, 13 Concentrations of Radionuclides in Columbia River Water at Pasco, Washington ....... 16Rate of Transport of Radionuclides at Pasco, Washington . Relative Contribution of Radionuclides to GI Tract Dose - Pasco Sanitary Water - 1963 ......... 22 Calculated Dose to GI Tract from Pasco Sanitary Water . ~32 in Whitefish Caught in Columbia River Between Ringold and Richland. ........... 25 Release of 1131 to the Atmosphere; 1963. ..... 1131 in Locally Produced Milk ......... .13 Average Concentrations of 1131 in Beef Cattle Thyroids, 1963 .,....... Activity on Filters from Several Northwestern United States Sampling Stations ........ External Dose Rate as Measured at Hanford External Dose Test Location .........

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LIST OF FIGURES (Contd) 19 Probable Extent of Beta Emitters in Ground Water, 1963 . 45 --- 20 Probable Extent of Tritium in Ground Water, 1963 . . . 46 Calculated Dose to the GI Tract, 1963. ...... 49 22 Calculated Dose to Bone, 1963 ......... 50 23 Calculated Dose to Thyroid, 1963 ......., 51 24 Calculated Dose to Total Body, 1963 ....... 52

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EVALUATION OF RADIOLOGICAL CONDITIONS IN THE VICINITY OF HANFORD FOR 1963 The Hanford project* (Figure 1) is located in a semiarid region of southeastern Washington having an average annual rainfall of about” 7 inches. Natural vegetation in this section of the state is sparse, primarily suited for grazing although large areas near the project perimeter have gradually been put under irrigation during the past few years, The plant site, shown in Figure 2, comprises an area of about 500 square miles. The Columbia River flows through the project and forms part of the eastern boundary. The meteorology of the region is typical of a desert area with frequent strong inversions occurring at night and breaking during the day to provide unstable and turbulent conditions. Near the plant production sites the prevailing winds are from the northwest with strong drainage and cross winds. causing distorted flow patterns. The populated areas of primary interest near the plant perimeter are Richland, Pasco, and Kennewick. Smaller communities in the vicinity are Benton City, West Richland, Mesa, and Othello. All together about 80, 000 people live in the vicinity of the project. Protection of these people from undue radiation exposure attributable to Hanford sources is one of the attendant responsibilities in the operation of the Hanford facilities. During the tours e of operation, various radioactive wastes are generated by. the several plant facilities. High level wastes are concentrated ‘and retained in storage within the project area. Controlled releases of lows level wastes, for which concentration and retention are not feasible, are made to the ground. The Hanford practices governing radioactive waste disposal are described in the Hearings on Industrial Radioactive Waste Disposal held by the Joint Congressional Committee on Atomic Energy in * Operated for the Atomic Energy Commission by the General Electric Company under Contract Number AT(45-1)-1350.

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The AEC .Manual Chapters (2) and the recommendations of the National Committee on Radiation Protection and lMeasurement (NCRF), (3) the International Commission on Radiological Protection (ICRP), ‘4) the Federal Radiation Council (FRC), ‘5) and the results of Hanford research .! programs form the basis of radiation protection practices at Hanford. The recommendations of these organizations in the form of permissible rates of intake of specific nuclides and guides for radiation exposure constitute criteria against which radiation exposures estimated from measurements of the Hanford environmental surveillance program are compared. The results of this comparison indicate the effectiveness of Hanford waste control and radiation protection practices and point out any conditions requiring This report estimates the annual exposure received by the individuals who are expected to receive the greatest amount of radiation from environmental sources, and the exposure received by people who are more typical residents of this region. These exposures are compared with the recoinform of maximum permissible exposures for individuals that are not employed in radiation work are 1500 mrems per year to the GI tract, 500 mrems per year to the total body, and 3000 mrems to the thyroid. The limits for bone-seekers are calculated with reference to biological effects observed from deposition of radium and are most readily applied in the form of maximum permissible rates of intake ( MPRI). * Similar evaluations for previous years have also been reported. (1,6,7) The Radiation Protection Guides established by the FRC for individuals are 1500 mrems per year to the thyroid, 1500 mrems per year to the bone, and 500 mrems to the whole body. The Radiation Protection Guides for the “average of a suitable sample, of an exposed population group” are one -third of those for individuals. * The MPR1’is taken as the maximum permissible concentration in water for a given radionuclide, as recommended by the NTCRP for persons in the neighborhood of controlled areas, multiplied by the “rate of water intake as defined for the standard man. This amounts to one-tenth of the MPC’s for continuous exposure of occupational workers multiplied by 2200 cc per day, or by 800 liters per year in the case of annual estimates.

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A discussion and interpretation of the results of the various Hanford environmental sampling programs are presented in the following text and figures. The raw data for many of the programs and brief descriptions of analytical methods used in determining the amounts of radionuclides in various samples are presented in the appendices. A. Raciionuclides in the Columbia River Hanford’s eight production reactors are cooled with Columbia River water. This water goes through filtration processes and then passes once through the reactors as a coolant before being returned to the river. Stable elements present in the cooling water are transformed ‘into radionuclides during passage through the reactors, and radioactive materials formed oti the surfaces of the fuel elements and channels are washed away by the The relative abundance of the radionuclides found in the cooling water, as adjusted to 4 hours past irradiation, is shown in Table 1. RELATIVE ABUNDANCE OF REACTOR EFFLUFIVT R.ADIONUCLIDES Reference Time - 4 Hours Postmradiatlon (Trace nuclide composition based on analyses by the Radiological Chemistry Operat~on made in 1958. )

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the radionuclides formed in reactor cooling water are shortrapidl~- after formation. In addition to radioactive decay, some portion of the radionuclides is removed from the water by sedimentation and uptake by aquatic organisms. The radionuclides in the river also include some contribution of “fallout” from weapons tests. Samples of river water were obtained every 2 weeks from Vernita Ferry, Hanford Ferry, 300 Area, the inlet to the Pasco municipal water plant, and Vancouver. Some samples of river water were also collected at Richland, particularly during the latter part of the year when the new water plant was in operation. River water samples were analyzed for several radionuclides and the results of the anal~-ses are presented in Appendix A, The relative abundance Ferry, Pasco, and Vancouver circles are proportional to the The average concentrations of. of the significant radionuclides at Hanford is illustrated in Figure 3. The areas of the total activity measured at the three locations. radionuclides measured routinely at the four river sampling stations are shown in Table II. ANNUAL AVERAGE CONCENTRATIONS OF SEVERAL RADIONUCLIDES IN COLUMBIA RIVER WATER - 1963 Hanford Ferry Richland

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Total Activity Represented Total Activity Represented Relative Abundance of Radionuclides in Columbia River Water at Several Locations. Annual Averages 1963

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The Hanford Ferry monitoring station is about 7 miles downstream from the closest production reactor and about 6 miles upstream from the point where the project boundary crosses the Columbia River. Studies of effluent distribution at the Hanford Ferry indicate nonuniformity which causes sample results to show higher concentrations of most radionuclides than the average of the cross section at this location. .Measurements on a traverse across the river at Richland indicated a fairly uniform distribution of the longer-liver radioisotopes throughout the river at this point. At Pasco, the distribution of radioisotopes in the river is slightly nonuniform because of the entry of the Yakima River some 10 miles upstream. Vancouver, about 260 miles from the reactors, is the farthest downstream location where river water is routinely sampled for’ Hanford’s sur - veillance program. Further downstream the intrusion of sea water into the Columbia River complicates quantitative measurement of the radionuclides. Seasonal variation in the flow rate of the Columbia River markedly affects the quantity of water available for dilution of the reactor effluent. Also affected is the time required for a specific volume of water to move from one location to another. The flow rate of the Columbia River at Pasco and Vancouver for 1959 through 1963 is shown in Figure 4. The variation in concentration of several radionuclides in the river water at Pasco for the same period is shown in Figure 5. The rate of transport of these same radionuclides past Pasco is shown in Figure 6, and in Table 8 of .4ppendix .4. The rate of transport of certain radionuclides passing Vancouver may be used, as an index of the quantities entering the Pacific Ocean from the Columbia River. The annual average rate of transport of selected radionuclides is given in Table IH and detailed measurements are tabulated in Appendix A, ANNUAL AVERAGE RATE OF TRANSPORT OF SELECTED RADIONUCLIDES PAST VANCOUVER..-

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The inventory of each of these nuclides which exists in the ocean can be calculated by assuming an equilibrium between the rate of addition through the river and the rate of decay in the ocean. A constant rate of entry into the ocean equivalent to that indicated by the 1963 Vancouver measurements, implies inventories of about 250 curies of P 32, 30, 000 Radiation exposure that results from the drinking of water pumped from the river and sent through treatment plants is discussed in the next section of this report. There is no known instance of untreated river water being consumed routinely by humans. For comparative purposes, however, the relationship between …