tional Con U.S. Government Printing Office, Washington, D.C. 23, pp. 26. ARGONNE NATIONAL LABORATORY, Management of Radioactive Wastes utomatic Port HW mental S nalysis h Organi Argonne National Laboratory, in Hearings before the Special Subcommit on Radiation of the Joint Committee on Atomic Energy, Congress of the U. 86th Congress, First Session, on Industrial Radioactive Waste Dispos January 28, 29, 30; February 2 and 3, 1959, Vol. 1, p. 708, Superintende of Documents, U.S. Government Printing Office, Washington, D.C. 1 of Radi 27. F. P. COWAN and L. GEMMELL, Waste Management Operations at Broo ngineer haven National Laboratory, in Hearings before the Special Subcommit on Radiation of the Joint Committee on Atomic Energy, Congress of the U. 86th Congress, First Session, on Industrial Radioactive Waste Dispos January 28, 29, 30; February 2 and 3, 1959, Vol. 1, p. 744, Superintende of Documents, U.S. Government Printing Office, Washington, D.C. Sanitary 28. C. P. STRAUB, A. S. GOLDIN, and A. G. FRIEND, Environmental Implicatio Sanitary of Radioactive Waste Disposal as Related to Stream Environments, Disposal of Radioactive Wastes, Proceedings Conference, Monaco, 195 Vol 2, p. 407, International Atomic Energy Agency, Vienna, Austria, 196 29. S. D. SHEARER, JR., The Leachability of Radium-226 from Uranium M Solids and River Sediments, Ph.D. Thesis, University of Wisconsin, Mad son, Wis., 1962. 59. 1954, Develop Y, A Re onal Labe ence, Bo 5, pp. 24 ary of We ns, in S 30. P. S. WELCH, Limnological Methods, pp. 175-196 and 231-333, Blakist 1954, 32. Develop 5, Public F orks Asso 33. C. V. Davis, Handbook of Applied Hydraulics, McGraw-Hill Book Compan S. Public H 34. H. H. BLACK, Procedures for Sampling and Measuring Industrial Waste Radioche 35. Sewage Ind. Wastes, 24: 45 (1952). H. C. HITE, Primary Devices and Meters for Waste Flow Measurement Conne Nat 36. GRAND JUNCTION OPERATIONS OFFICE, GRAND JUNCTION, COLORADO, Indu on, Radios ry Engine ed by the ineering C -7517 (Pt trial Radioactive Wastes: Mining and Milling of Uranium Ores, in Hearin before the Special Subcommittee on Radiation of the Joint Committee Atomic Energy, Congress of the U.S., 86th Congress, First Session, on I dustrial Radioactive Waste Disposal, January 28, 29, 30; February 2 a 3, 1959, Vol. 1, p. 674, Superintendent of Documents, U.S. Governme Printing Office, Washington, D.C. Health Ser 37. BRAB Conference Report No. 3, Proceedings of a Conference on Laborato l, Conver Design for Handling Radioactive Materials, pp. 27-28, Building Resear tomic Wes 38. C. W. SILL and J. K. FLYGARE, JR., Iodine Monitoring at the National React grs. (Lon Testing Station, USAEC Report AECU-4120, Idaho Operations Offic Thomas, Publisher, Springfield, Ill., 1958. Onne, J. 39. C. B. BRAESTRUP and H. G. WYCKOFF, Radiation Protection, Charles Ridge Nat 40. R. STEPHENSON, Introduction to Nuclear Engineering, McGraw-Hill Bod Chapter 4 DIRECT DISCHARGE TO THE WATER ENVIRONMENT Three concepts are basic in the handling and disposal of radioactive wastes: (1) dilution and dispersion, (2) concentration and confinement, and (3) delay and decay. These three concepts are used to control the direct release of materials to the environment or in processing materials for such release. The next three chapters are concerned with the use of the three major media-hydrosphere, lithosphere, and atmosphere for the disposition of radioactive waste materials. Such use under controlled conditions results in substantial savings when compared with the cost of storage, but the disposal operations must be carried out with the approval of public-health officials. Although the hydrosphere has been used extensively for the disposition of low-level radioactive wastes for periods up to 18 years in some instances, little is known about the capacity of this environment to receive and hold specific radionuclides. Studies now under way, however, should identify the factors responsible for the temporary retention of specific radionuclides. This chapter describes the practices that have developed in the direct discharge of radioactive materials into streams and rivers as well as into the oceans. 4-1 DISPOSAL TO SEWERS Discharge of low-level liquid wastes to an established sewer is both common and convenient. These wastes may be conveyed to sewage-treatment plants or may go directly or indirectly into streams and surface waterways, or, where installations are located along the coast, they may go into the sea or coastal estuaries. Sewer disposal has wide acceptance, particularly in the case of short-lived radionuclides discharged from hospitals and other facilities using radioactive materials. National Bureau of Standards (NBS) Handbooks 491 and 532 provide detailed information for medical personnel concerning the disposal and permissible levels of discharge of P32, [131, and C14 into Handbook 49 states: "It is not realistic to insist on dilution of radioactive waste in sewage to the level established as permissible sewers. 85 result of an accident, and the hazard should be considered from th point of view." On this basis the recommended permissible level P32 and I131 in sewage for maximum short-period contamination is 0.1μ ml (0.1 mc/liter) This concentration of activity in sewage migh result in some external radiation hazard in the case of accident. immersion, but calculations show this to be in the order of 0.1 to O rep from immersion for 1 hr. NBS Handbook 49 also states: "The simplest way to dispose radioactive wastes encountered in connection with the administratio of the material to the patient is, of course, to allow the patient t use the toilet without restriction." Where samples are needed fo analysis, they can be collected in bottles, and the residual can b disposed of via the toilet or waste sink. The concentrations corr sponding to the specific disposal practices suggested in Handbook 49 and 53 have been calculated by Straub, and numerical example applicable to specific radionuclides have been presented by Straub Kittrell, and Kenny.6.7 3 The concentration of radioactive material in sewage can be ca culated by dividing the amount of radioactive material released b the actual volume of sewage flow during the same period of time: Sewage concentration Amount of radionuclide discharged in time t (4 The amount of dilution possible is a function of the time required fo disposal of the waste and of the actual volume of sewage available fo dilution during the time of discharge. Various devices have bee developed which release the waste over a period of time to obtai the maximum benefit from dilution. Most radionuclides discharged into sewer systems originate i hospitals. Problems that may require examination include (1 occasional discharges of 70 mc or more of radioiodine, largely in urine by patients treated for cancer of the thyroid; (2) occasional discharge of 10 to 30 me of radiobromine and radiosodium; and (3) a more o less continuous discharge, usually no more than 1 to 2 mc/day from each patient treated, of these and other radionuclides, principall radiophosphorus, radiosulfur, and radiosodium. Much smalle amounts of radioactivity are discharged from industrial establish ments that use radioactive materials. Where sewer disposal is practiced, traps and pipes should be moni tored prior to disassembly for repairs to avoid radiation exposure o maintenance personnel by radioactive materials that have bee precipitated, adsorbed, or plated on exposed surfaces. The externa hazard to the sewer worker is minimal; to receive 0.03 rad (one-thir 8 tion is wager sible le phosphorus per liter and for about 18 min in a like concentration radioiodine. 16 Similar calculations and estimates can be made f other radionuclides. of acc of 0.1 to disp Iminist he pate e neede idual c ations Hand cal ex by St can be release of time timet required available Share e to ob originate include ely in ur l dischar a more ne/day f* princip ld be r exposur have be he exter (one-t The effect of radioactive materials on sewage-purifying organism and on sewage-treatment processes is discussed in detail in Chap. 4-2 DIRECT DISCHARGE TO STREAMS AND RIVERS Perhaps the greatest use of river water in the atomic energy industr is in the direct cooling of nuclear reactor facilities, as at Hanfor where Columbia River water is used to cool the reactors and is returne to the river after a single pass through the reactor (see Chap. 2). A the water passes through the reactor, radionuclides are produced the water through neutron activation. These radionuclides a released to the Columbia River after decay in hold-up tanks of som of the short-lived constituents. The radionuclides encountered a listed in Table 2.6. Other atomic energy installations, such as Oak Ridge Nation Laboratory (ORNL), Knolls Atomic Power Laboratory (KAPL and the Savannah River Plant, discharge. small amounts of fissio products to the streams on which they are located. The liquid wast from Harwell, Aldermaston, and Amersham, England, go to th Thames River, in the last case via the River Colne. Low-lev wastes at Mol, Belgium, are discharged to the River Mol Nêthe 4-2.1 Permissible Levels of Activity for Direct Discharge 9 When radioactive materials have been released into streams, th practice has been to discharge amounts below the maximum permi sible concentrations indicated for specific radionuclides in water wit these amounts modified as a result of downstream studies.11-16 Foster and Davis 15 report that gross-activity concentrations plankton (mainly diatoms) is about 2000 times that of the Columb River. In spite of the large variety of nuclides present in the Hanfor effluent, 30 to 50% of the radioactivity in the plankton is from På 25 to 50% is from Cu64, 5 to 15% is from Na24, and less than 10% from mixtures of the rare earths and iron groups. During the summe months, when aquatic life is most radioactive, the P32 content small fish, Richardsonius balteatus (Richardson), is about 150,00 times that of water; in caddis fly larvae, Hydropsyche cockerel (Banks), the concentration factor is 350,000 times that of water. Although P32 is responsible for less than 1% of the radioactivity i waste, it makes up 70 to 95% of the radioactivity in most invertebrate and fish. The great biological reconcentration of radiophosphorus |