exat fh-ja-i FE0^ya:i¥ B73 <> ?X ■ ?VAA WK> ■v' i J, 5 < G> x NAVAL A:A SYSTEMS COMMAND VAVA7XBA OF IKE NAVY - VAAVAAA7GA, DX. 20362 X~?' ' IX) Report NT-78-1 February 1978 ENVIRONMENTAL MONITORING AND DISPOSAL OF RADIOACTIVE WASTES FROM U. S. NAVAL NUCLEAR-POWERED SHIPS AND THEIR SUPPORT FACILITIES 1977 0 Prepared by M. E. Miles, G. L. Sjoblom, J. D. Eagles I Nuclear Power Directorate Naval Sea Systems Command Department of the Navy Approved by 1 * fj H. G. RICKOVER, ADM USN Deputy Commander for Nuclear Propulsion o ABSTRACT The environmental effect of disposal of radioactive wastes ’ — originating from U. S. Naval nuclear propulsion plants and their support facilities is assessed. The total gamma radioactivity in / liquids, less tritium, discharged to all ports and harbors from the more than one hundred Naval nuclear-powered ships and supporting tenders, Naval bases and shipyards was less than 0.002 curie in 1977. The total tritium released to all ports and harbors was less than 0 one curie in 1977. This report confirms that procedures used by the j Navy to control releases of radioactivity from U. S. Naval nuclear- s powered ships and their support facilities are effective in pro- i * tecting the environment and the health and safety of the general j public. i i ; - oTABLE OF CONTENTS 0 SUMMARY.............................................................1 RADIOACTIVE LIQUID WASTE PROCESSING AND CONTROL ..................... 3 ■ Policy and Procedures Minimizing Release of Radioactivity in Harbors.......................................................3 Source of Radioactivity .......................................... 3 Radioactivity Removal From Liquid Wastes at Shore Facilities ..................................................... 4 Liquid Waste Releases in Harbors ................................. 4 Short-Lived Radionuclides ........................................ 4 Fission Product Radionuclides .................................. 6 Tritium.......................................................... 6 Carbon 14............................................... 7 Liquid Waste Releases at Sea ..................................... 7 Loss of USS THRESHER and USS SCORPION....................... 8 SOLID RADIOACTIVE WASTE TRANSPORTATION AND DISPOSAL ................ 10 ENVIRONMENTAL MONITORING ........................................... 12 Navy Environmental Monitoring Program .............. . .......... 12 ENVIRONMENTAL PATHWAYS ANALYSIS ................................ 19 AUDITS AND REVIEWS ................................................ 24 CONCLUSIONS...................'.................................... . 25 REFERENCES ........................................................ 26 LIST OF TABLES TABLE 1 RADIOACTIVE LIQUID WASTE RELEASED TO HARBORS FROM U. S. NAVAL NUCLEAR-POWERED SHIPS AND THEIR SUPPORT FACILITIES . 1 TABLE 2 TOTAL RADIOACTIVITY IN LIQUID WASTE RELEASED AT SEA ORIGINATING FROM U. S. NAVAL NUCLEAR-POWERED SHIPS .... 8 TABLE 3 RADIOACTIVE SOLID WASTE FROM U. S. NAVAL NUCLEAR-POWERED SHIPS AND THEIR SUPPORT FACILITIES FOR 1973 THROUGH 1977 . 11 In TABLE 4 SUMMARY OF 1977 SURVEYS FOR COBALT 60 IN BOTTOM SEDIMENT OF U. S. HARBORS WHERE U. S. NAVAL NUCLEAR-POWERED SHIPS HAVE BEEN REGULARLY BASED, OVERHAULED OR BUILT .................. 14 TABLE 5 RADIONUCLIDE RELEASES ASSUMED FOR ENVIRONMENTAL PATHWAYS ANALYSIS................................................21 TABLE 6 ENVIRONMENTAL EXPOSURE TIMES, CONSUMPTION AND CONCENTRATION PARAMETERS ASSUMED FOR ENVIRONMENTAL PATHWAYS ANALYSIS.........................................................22 TABLE 7 ESTIMATED MAXIMUM RADIATION EXPOSURE TO AN INDIVIDUAL FOR ASSUMED LIQUID AND AIRBORNE RADIOACTIVITY RELEASES FROM SHIPYARDS ENGAGED IN NAVAL NUCLEAR PROPULSION WORK. 23 TABLE 8 ESTIMATED TOTAL WHOLE BODY RADIATION EXPOSURE TO GENERAL PUBLIC WITHIN 50 MILES FOR ASSUMED LIQUID AND AIRBORNE RADIOACTIVITY RELEASES FROM SHIPYARDS ENGAGED IN NAVAL PROPULSION PLANT WORK ...........................................23 LIST OF ILLUSTRATIONS ILLUSTRATION 1 ILLUSTRATION 2 ILLUSTRATION 3 ILLUSTRATION 4 APPENDIX SIMPLIFIED DIAGRAM OF WASTE PROCESSING SYSTEM . . DREDGE FOR SAMPLING HARBOR SEDIMENT . ........... GAMMA SPECTRA OF HARBOR BOTTOM SEDIMENT SAMPLES . PATHWAYS FOR EXTERNAL AND INTERNAL EXPOSURE OF MAN FROM AIRBORNE AND LIQUID RELEASES OF RADIOACTIVE EFFLUENTS ................................ ENVIRONMENTAL MONITORING SURVEY CHARTS . . . . . 5 13 17 20 30 SUMMARY The radioactivity in wastes discussed in this report originates in the pressurized water reactors of U. S. Naval nuclear-powered ships. As of the end of 1977, the U. S. Navy had 110 nuclear-powered submarines and ten nuclear-powered surface ships in operation. Support facilities involved in construction, maintenance, overhaul and refueling of these nuclear propulsion plants include nine shipyards, thirteen tenders and two submarine bases. This report describes disposal of radioactive liquid wastes, disposal of solid wastes and monitoring of the environment to determine the effect of radioactive releases,and updates reports on this subject issued by the Navy in references 1 through 12.* This report concludes that -radioactivity associated with U. S. Naval nuclear-powered ships has had no significant or discernable effect on the quality of the environment. A summary of the radiological information supporting this conclusion follows: From the start of the Naval nuclear propulsion program the policy of the U. S. Navy has been to reduce to the minimum practicable the amounts of radioactivity released into harbors. Navy procedures to accomplish this have been reviewed with the U. S. Department of Energy and the U. S. Environmental Protection Agency. The total gamma radioactivity released within twelve miles from shore from all U. S. Naval nuclear-powered ships and their support facilities in recent years is shown in Table 1; this includes all harbors both U. S. and foreign entered by these ships. TABLE 1 RADIOACTIVE LIQUID WASTE RELEASED TO HARBORS FROM U. S. NAVAL NUCLEAR-POWERED SHIPS AND THEIR SUPPORT FACILITIES Number of Ships Radioactivity-Curies Year In Operation (less tritium) 1971 100 less than 0.002 1972 104 less than 0.002 1973 107 less than 0.002 -w 1974 m less than 0.002 1975 113 less than 0.002 1976 115 less than 0.002 1977 120 less than 0.002 0 ♦References are listed on page 26 As a measure of the significance of these data, if one person were able to drink the entire amount of radioactivity discharged into any harbor in 1977, be would not exceed the annual radiation exposure permitted for an individual worker by the U. S. Nuclear Regulatory Commission Environmental monitoring is conducted by the U. S. Navy in U. S. and foreign harbors frequented by the U. S. Naval nuclear-powered ships. This monitoring consists of analyzing harbor water, sediment and marine life samples for radioactivity associated with Naval nuclear propulsion plants, radiation monitoring around the perimeter of support facilities and effluent monitoring. Environmental samples from each of these harbors are also checked at least annually by a U. S. Department of Energy Laboratory to ensure analytical procedures are correct and standardized. The U. S. Environmental Protection Agency has conducted independent'surveys in U. S. harbors; results have been consistent with Navy results. These surveys have confirmed that U. S. Naval nuclear-powered ships and support facilities have had no significant effect on the radioactivity of the marine environment.i J, RADIOACTIVE LIQUID WASTE PROCESSING AND CONTROL j i Policy and Procedures Minimizing Release of Radioactivity in Harbors The policy of the U. S. Navy is to reduce to the minimum practicable the amounts of radioactivity released to the environment but particularly within twelve miles from shore including into harbors. This policy is consistent with applicable recommendations issued by the Federal Radiation Council (incorporated in Environmental Protection Agency in 1970), U. S. Nuclear Regulatory Commission, National Council on Radiation Protection and Measurements, International Commission on Radiological Protection, International Atomic Energy Agency, and National Academy of Sciences—National Research Council (references 13 through 20). Keeping releases small minimizes the radioactivity available to build up in the environment or to concentrate in marine life. To implement this policy of minimizing releases, the Navy has issued standard instructions defining the radioactive waste disposal limits and procedures to be used by U. S. Naval nuclear-powered ships and their support facilities. These instructions were reviewed by the U. S. Department of Energy and the U. S. Environmental Protection Agency. Source of Radioactivity In the shipboard reactors, pressurized water circulating through the reactor core picks up the heat of nuclear reaction. The Reactor cooling water circulates through a closed piping system to heat exchangers which transfer the heat to water in a secondary steam system isolated from the primary cooling water. The steam is then used as the source of power for the propulsion plant as well as for auxiliary machinery. Releases from the shipboard reactors occur primarily when reactor coolant water expands as a result of being heated to operating temperature; this coolant passes through a purification system ion exchange resin bed prior to being transferred from the ship. The principal source of radioactivity in liquid wastes is from trace amounts of corrosion and wear products from reactor plant metal surfaces in contact with reactor cooling water. Radionuclides with half-lives greater than one day in these corrosion and wear products include tungsten 187, chromium 51, hafnium 181, iron 59, iron 55, nickel 63, zirconium 95, tantalum 182, manganese 54, cobalt 58, and cobalt 60. The most predominant of these is cobalt 60, which has a 5.3 year half-life; cobalt 60 also has the most restrictive concentration limit in water listed by organizations which set radiological standards in references 13, 14, and 15 for these corrosion and wear radionuclides. Therefore, radioactive waste disposal is conservatively controlled by assuming that all the long-lived radioactivity is cobalt 60. ( 1 0 -3- I ‘TRadioactivity Removal From Liquid Wastes at Shore Facilities. Radioactive liquid wastes at shore facilities are collected in stainless steel tanks and processed through a processing system to remove most of the radioactivity (exclusive of tritium) prior to collection in a clean tank for reuse. Even after processing to approximately 10-8 microcuries of gamma radioactivity per milliliter, reactor coolant is reused rather than discharged. Illustration 1 shows a simplified block diagram of the waste processing system which consists of particulate filters, activated carbon bed filters, mixed hydrogen hydroxyl resin and colloid removal resin beds. This type of processing system has been developed and used successfully to produce high quality water containing very low radioactivity levels. Liquid Waste Releases in Harbors The total amounts of long-lived gamma radioactivity released into harbors and seas within twelve miles from shore has been less than 0.002 curie during each of the last seven years. This total is for releases from U. S. Naval nuclear-powered ships and from the supporting shipyards, tenders and submarine bases, and at operating bases and home ports in the U. S. and overseas and all other U. S. and foreign ports which were visited by Naval nuclear-powered ships. This quantity is conservatively reported as if it consisted entirely of cobalt 60, which is the predominant long-lived gamma radionuclide and also has the most stringent concentration limits. To put this small quantity of radioactivity into perspective, it is ■ less than the quantity of naturally occurring radioactivity, (reference 21) in the volume of saline harbor water occupied by a single nuclear-powered submarine. Although volumes are of less significance than the amount of radioactivity released, Table 1 of earlier reports has also shown that the total volume of liquids released within twelve miles from shore has been reduced from millions of gallons per year in the 1960's to less than 25 thousand gallons per year beginning in 1973. Thus, the Navy has achieved its policy of reducing releases of radioactive liquids in harbors to the minimum practicable amounts. Therefore, volumes have been deleted from this report. Short Lived Radionuclides Reactor coolant also contains short-lived radionuclides with half-lives of seconds to hours. Their highest concentrations in reactor coolant are from nitrogen 16 (7 second half-life), nitrogen 13 (10 minute half-life), fluorine 18 (1.8 hour half-life), argon 41 (1.8 hour half-life) and manganese 56 (2.6 hour half-life). Total short-lived radioactivity released in water in a year to any harbor has been less than 0.001 curie. -4- WASTE WATER INLET ; ILLUSTRATION 1 SIMPLIFIED DIAGRAM OF WASTE PROCESSING f A SYSTEM -5-For the longest-lived of these, about one day after discharge from an operating reactor the concentration is reduced to one thousandth of the initial concentration and in about two days the concentration is reduced to one millionth. Therefore, since most of the water is transferred to shore facilities for processing and reuse rather than discharged, these short-lived radionuclides are not important for water disposal considerations. Fission Product Radionuclides Fission products produced in the reactor are retained within the fuel elements. The fission gases krypton and xenon are also retained within the fuel elements. However, trace quantities of naturally occurring uranium impurities in reactor structural materials release small amounts of fission products to reactor coolant. The concentrations of fission products and the volumes of reactor coolant released are so low, however, that the total radioactivity attributed to long-lived fission product radionuclides, strontium 90 and cesium 137, in releases from U. S. Naval nuclear-powered ships and their support facilities has been less than 0.001 curie per year for all harbors combined. .Fallout of these same fission products has often been more than this in one rainfall in a single harbor. Tritium Small amounts of tritium are formed in reactor coolant systems as a result of neutron interaction with the approximately 0.015 percent of naturally occurring deuterium present in water, and other nuclear reactions. Although tritium has a 12 year half-life, the radiation produced is of such low energy that the radioactivity concentration guide issued by the International Commission on Radiological Protection, the National Council on Radiation Protection and Measurements, the U. S. Nuclear Regulatory Commission and by other standard-setting organizations is one hundred times higher for tritium than for cobalt 60. This tritium is in the oxide form and chemically indistinguishable from water; therefore it does not concentrate significantly in marine life or collect on sediment as do other radionuclides. Tritium is naturally present in the environment because it is generated by cosmic radiation in the upper atmosphere. Reference 22 reports that the production rate from this source is about six million curies per year, which through rainfall causes a tritium inventory in the oceans of about one hundred million curies. Because of this naturally occurring tritium, much larger releases of tritium than are conceivable from Naval nuclear reactors would be required to make a measurable change in the background tritium concentration. The total amount of tritium released during each of the last ten years from all U. S. Naval nuclear-powered ships and their supporting tenders, bases and shipyards has been less than 200 curies. Most of this has been into the ocean greater than twelve miles from shore. The total tritium from the entire nuclear Navy is less than single electrical -6-o generating nuclear power stations typically release each year (reference 23). Total tritium released into harbors within twelve miles from shore was less than one curie in 1977. Such releases are too small to increase measurably the tritium concentration in the environment. Therefore, tritium has not been combined with the data on other radionuclides in other sections of this report. Carbon 14 Carbon 14 is also formed in small quantities in reactor coolant systems as a result of neutron interactions with nitrogen and oxygen. Carbon 14 decays with a half-life of 5730 years; however, only low energy beta radiation is emitted as a result of this decay process. As a result, the radioactivity concentration guide for carbon 14 in its chemical form in air issued by the International Commission on Radiological Protection, the National Council on Radiation Protection and Measurements, the U. S. Nuclear Regulatory Commission and by other standard-setting organizations is three thousand times higher than for cobalt 60. Carbon 14 occurs naturally in the environment. It is generated from cosmic radiation interactions with nitrogen and oxygen in the upper atmosphere and oxidized to form carbon dioxide. Carbon 14 is chemically indistinguishable from other radionuclides of carbon. The carbon dioxide diffuses and convects throughout the atmosphere and enters the earth's carbon cycle. Reference 24 states that the earth's carbon 14 inventory is estimated to be about three hundred and ten million curies. The total amount of carbon 14 released during each of the last ten years from the operation of all U. S. Naval nuclear-powered ships and their supporting tenders, bases and shipyards has been l.ess than 100 curies, most of which is released into the atmosphere at sea beyond twelve miles from shore. The total carbon 14 radioactivity released in a year in any harbor has been less than 0.1 curie. Since the inventory of naturally occurring carbon 14 is so large, it is extremely unlikely that releases from Naval nuclear reactors could result in a measurable change in the background concentration of carbon 14. Therefore, carbon 14 has not been combined with the data on other radionuclides in other sections of this report. Liquid Waste Releases at Sea Radioactive liquids incidental to the operation of the nuclear propulsion plants are released at sea under strict controls. These ocean releases are consistent with recommendations the Council on Environmental Quality made in 1970 to the President in reference 25, and consistent with the Marine Protection, Research and Sanctuaries Act, reference 26. Procedures and limits for ocean releases have been consistent with recommendations made by the National Academy of Sciences—National Research Council in reference 17 and by the International Atomic Energy Agency in reference 18. These releases have contained much less radioactivity than these reports considered would be acceptable. Total long-lived radioactivity excluding tritium, released farther than twelve miles from shore by U. S. Navy nuclear-powered ships and supporting tenders is shown in Table 2 for recent years. This is the total amount released from over 100 ships at different times of the year in the open sea at long distances from land in small incremental amounts, and under rapid dispersal -7- conditions due to wave action. The quantity of radioactivity released to the open ocean in 1977 was 0.4 curie, which is less than the naturally occurring radioactivity in a cube of sea water approximately 100 yards on a side. TABLE 2 TOTAL RADIOACTIVITY IN LIQUID WASTE RELEASED AT SEA ORIGINATING FROM U. S. NAVAL NUCLEAR-POWERED SHIPS Radioactivity-Curies (less tritium) 1973 1974 1975 1976 1977 0.4 0.4 0.4 0.4 0.4 Loss of USS THRESHER and USS SCORPION Two U. S. Navy nuclear-powered submarines have been lost at sea in the Atlantic Ocean. The submarine THRESHER sank 10 April 1963, 100 miles from land in water 8,500 feet deep at latitude 41°45'N and longitude 65000'W. The submarine SCORPION sank between 21 and 27 May 1968, 400 miles southwest of the Azores in more than 10,000 feet of water. The . reactors used in all U. S. Naval submarines and surface ships are designed to minimize potential hazards to the’ environment even under the most severe casualty conditions such as actual sinking of the ship. First, the reactor core is so designed that it is physically impossible for it to explode like a bomb. Second, the reactor fuel elements are made of materials that are extremely corrosion resistant, even in sea water. The reactor core could remain submerged in sea water for decades without releases of fission products while the radioactivity decays, since the protective cladding on the fuel elements corrodes only a few millionths of an inch per year. Thus, in the event of a serious accident where the reactor is completely submerged in sea water, the fuel elements will remain intact for an indefinite period of time, and the radioactive material contained in these fuel elements should not be released. The maximum rate of release and dispersal of the radioactivity in the ocean, even if the protective cladding on the fuel were destroyed, would be so low as to be insignificant. Radioactive material could be released from this type of reactor only if the fuel elements were actually to melt and,in addition,the high-strength, all-welded reactor system boundary were to rupture. The reactor's many protective devices and inherent self-regulating features are designed to prevent any melting of the fuel elements. Flooding of a reactor with sea water furnishes additional cooling for the fuel elements and so provides added protection against the release of radioactive fission products. -8-Radiation measurements, water samples, bottom sediment-samples and debris collected from the area where THRESHER sank were analyzed for radioactivity shortly after the sinking and again in 1965 by various laboratories with highly sensitive equipment. Similarly, sea water and bottom sediment samples taken near SCORPION'S hull were analyzed for radioactivity. None of these samples showed radioactivity above naturally occurring background levels and none showed evidence of radioactivity released from either THRESHER or SCORPION. In 1977 followup samples of water, sediment, marine life and debris were collected from the immediate THRESHER debris areas. None of these samples showed any evidence of release of radioactivity from the reactor fuel elements. However, cobalt 60 released from THRESHER coolant systems was detectable at low levels in sediment samples from a localized area which was not sampled during previous surveys. The cobalt 60 radioactivity in these sediment samples was small compared to naturally occurring radioactivity. Cobalt 60 was not detectable in the samples of water, marine life or debris. Thus, the THRESHER and SCORPION have not had a significant effect on the radioactivity in the environment. o -9-SOLID RADIOACTIVE WASTE TRANSPORTATION AND DISPOSAL During maintenance and overhaul operations, solid low-level radioactive wastes consisting of contaminated rags, plastic bags, paper, filters, ion exchange resin and scrap materials are collected by nuclear-powered ships and their support facilities. Transfers of these low level radioactive materials from nuclear-powered ships to support facilities are required to be strictly controlled in accordance with Naval accountability procedures to prevent loss, including serialized tagging and marking and signatures required by radiologically trained personnel. Solid radioactive waste materials are packaged in strong tight containers, shielded as necessary and shipped to burial sites licensed by the U. S. Nuclear Regulatory Commission or a State under agreement with the U. S. Nuclear Regulatory Commission. Shipments are made in accordance with U. S. Department of Transportation regulations in containers approved for the specific quantity, type, and form of radioactivity. Shipments of radioactive waste material associated with the Naval nuclear propulsion program have not resulted in any measurable release of radioactivity to the environment. Solid radioactive materials from Naval nuclear-powered ships have not been dumped at sea since 1970 when the Navy issued procedures prohibiting 1 sea disposal of solid radioactive materials. Shipyards and other shore facilities are not permitted to dispose of radioactive solid wastes by burial on their own sites. Table 3 summarizes total radioactivity and volumes of radioactive solid waste disposal for the last five years. Table 3 includes all waste generated at the listed facilities because any radioactive waste generated by U. S. nuclear-powered ships is transferred to the ,listed facilities. The quantity of solid radioactive waste in any one year from a particular facility depends on the amount and type of support work performed that year. On the average, one waste shipment per month is made from each facility. Table 3 does not include expended fuel or high level radioactive material associated with expended fuel. Expended fuel is shipped from the refueling shipyard by the U. S. Department of Energy to its facilities in Idaho for processing in the same manner as other expended nuclear fuel. It is required to be shipped in accordance with the requirements of the Department of Transportation, the Nuclear Regulatory Commission, and the Department of Energy. Each shipment is escorted by a specially trained U. S. Government representative. Each shipping container is specifically designed to withstand extreme accident impacts, fire, or water immersion, and to prevent releases of the material to the environment in the event of accident. The cargo is non-explosive and non-flammable. Because of efforts to minimize solid waste and the utilization of compaction equipment, total volumes have remained nearly constant in spite of increasing work caused by increasing numbers of ships. The average annual volume for the entire Naval nuclear propulsion program could be contained in a cube measuring fifteen yards on a side. The total annual volumes of solid radioactive waste from the Naval nuclear propulsion program listed in Table 3 are less than one tenth of the total volumes of radioactive solid-waste buried in all U. S. cormiercial burial grounds each year (reference 27). -10-TABLE 3 RADIOACTIVE SOLID WASTE FROM U. S. NAVAL NUCLEAR-POWERED SHIPS AND THEIR SUPPORT FACILITIES FOR 1973 THROUGH 1977 1973 1974 1975 1976 1977 Facility Thousand Cubic Thousand Cubic Thousand Cubic Thousand Cubic Thousand Cubic Feet Curies Feet Curies Feet Curies Feet Curies Feet Curies Portsmouth, New Hampshire Naval Shipyard 7 3 7 4 14 6 ’ 6 7 9 6 Groton, New London, Conn. Electric Boat Div., Tender at StatePier, & Sub Base 12 2 7 4 5 3 7 4 8 14 Newport News, Virginia Newport News Shipbuilding 6 5 4 4 2 2 2 5 2 5 Norfolk, Virginia Naval Shipyard and Tenders 4 2 3 5 4 4 11 5 6 1 Charleston, South Carolina Naval Shipyard and Tenders 6 19 4 22 3 13 4 20 7 13 Pascagoula, Mississippi Ingalls Shipbuilding Div 1 4 3 5 2 6 3 1 3 10 San Diego, California Tenders <1 <1 <1 <1 <1 2 1 <1 1 4 Long Beach, California Naval Shipyard and Base <1 <1 <1 <1 1 <1 <1 <1 <1 <1 Vallejo, California Mare Island Naval Shipyard 6 23 7 34 11 19 8 10 7 27 Bremerton, Washington Puget Sound Naval Shipyard 10 21 20 306 14 7 8 34 6 10 Pearl Harbor, Hawaii Naval Shipyard & Sub Base 7 143 6 3 2 1 Q 6 4 1 TOTALS 59 222 62 53 63 53 92 53 91 NOTES: (1) This table includes all radioactive waste from tenders and nuclear-powered ships. This radioactivity is primarily cobalt 60. This radioactive waste is shipped to burial facilities licensed by the U. S. Nuclear Regulatory Commission or State. (2) Volumes less than 500 cubic feet are reported <1 thousand and less than 0.5 curie is reported <1.ENVIRONMENTAL MONITORING To provide additional assurance that procedures used by the U. S. Navy to control- radioactivity are adequate to protect the environment, the Navy conducts environmental monitoring in harbors frequented by its nuclear-powered ships. Environmental monitoring surveys for radioactivity are periodically performed in harbors where U. S. Naval nuclear-powered ships are built or overhauled and where these ships have home ports or operating bases. Samples from each harbor monitored are also checked at least annually by a U. S. Department of Energy laboratory to ensure analytical procedures are correct and standardized. The Department of Energy laboratory results have been consistent with shipyard and operating base results. Navy Environmental Monitoring Program The .current Navy environmental monitoring program consists of analyzing’ samples of harbor water and sediment, supplemented by shoreline surveys, posted dosimeters and effluent monitoring. Sampling harbor water and sediment each quarter year is emphasized since these materials would be the most likely affected by releases of radioactivity. Marine life samples have also been collected from some harbors. Five water samples are taken in each harbor once each quarter year in areas where nuclear-powered ships berth and from upstream and downstream locations. These samples are analyzed for gross gamma radioactivity and for cobalt 60 content. A sodium iodide or germanium lithium scintillation detector with a multichannel analyzer is used to measure gross gamma activity in an energy range frosh 0.1 MeV to 2.1 MeV expressed in terms of cobalt 60 equivalent and to analyze the resulting gamma data for the presence of cobalt 60. Procedures for analysis will detect cobalt 60 if its concentration exceeds one three hundredth of the U. S. Nuclear Regulatory Commission limit of reference 13. No cobalt 60 has been detected in any of the water samples from all harbors monitored. A radiological laboratory of the Environmental Protection Agency has analyzed samples from harbors to identify radionuclides present in sediment These analyses showed cobalt 60 was the predominant radionuclide added to sediment from Naval nuclear reactor operations. Therefore, Navy monitoring procedures require collecting in each harbor approximately 20 to 120 sediment samples once each quarter year for cobalt 60 and gross gamma analyses. Locations and numbers of sediment samples for a particular harbor depend on the size of the harbor and the number and separation of locations where nuclear-powered ships berth. Sampling points are selected to form a pattern around ship berthing locations and to provide points in areas away from these berthing locations. The sampling locations are selected individually for each harbor considering characteristics of the harbor. Sediment samples are collected using the dredge shown in Illustration 2. The dredge samples a surface area of 36 square inches and has -12-been modified to collect only the top one-half to one inch of sediment. The top layer was selected because it should be more mobile and more accessible to marine life than deeper layers. After the dredge is lowered to the harbor bottom the messenger weight lowered on the support from the surface causes the spring-loaded jaws on the dredge to close and trap the sediment. The samples are placed directly into a one quart container lined with a plastic bag. Each sediment sample is analyzed for gamma activity in the container in which collected using the scintil lation detector with a multichannel analyzer. Gross gamma activity in an energy range from 0.1 MeV to 2.1 MeV is expressed in terms of equivalent cobalt 60 and the resulting gamma data is analyzed for the presence of cobalt 60 activity. Results of the sediment samples from harbors monitored by the Navy in the U. S. and possessions for 1977 are summarized in Table 4. -a.>7 ILLUSTRATION 2 DREDGE FOR SAMPLING HARBOR SEDIMENT -13-TABLE 4 SUMMARY OF 1977 SURVEYS FOR COBALT 60 IN BOTTOM SEDIMENT OF U. S. HARBORS WHERE U. S. NAVAL NUCLEAR-POWERED SHIPS HAVE BEEN REGULARLY BASED, OVERHAULED OR BUILT Number of Samples with Cobalt 60 less than 3 to 30 greater than Total Bottom Area with. Cobalt 60 over 3 pCi/g** (Square Kilometers) Estimated Total*** Cobalt 60 in Top Layer of Sediment (Curies) 3 pCi/g* pCi/g 30 pCi/g Portsmouth, New Hampshire 176 0 0 0 ND Naval Shipyard Groton, New London, Conn. 537 4 0 0.1 0.02 Electric Boat Division, State Pier and Submarine Base Newport News, Virginia 141 0 0 0 ND Newport News Shipbuilding Norfolk, Virginia 231 0 0 0 ND Naval Shipyard and Base Charleston, South Carolina 210 1 0 0 ND Naval Shipyard and Bases Pascagoula, Mississippi 80 0 0 0 ND Ingalls Shipbuilding Division San Diego, California 245 0 0 0 ND Navy Piers Long Beach, California 156 0 0 0 ND Naval Shipyard and Base Vallejo, California 224 0 0 0 ND Mare Island Naval Shipyard Bremerton, Washington 248 0 0 0 ND Naval Shipyard and Base Pearl Harbor, Hawaii 172 0 0 0 ND Naval Shipyard and Sub Base Apra Harbor, Guam 124 0 0 0 ND Port Canaveral, Florida 73 0 0 0 ND NOTE: *Minimum detectable radioactivity is of pCi/crrn range from two to four times the approximately 1 pCi/g (picocurie per gram). Results in units value of pCi/g. lpCi = 1 x 10-12ci **0ne square kilometer is approximately eaual to 0.4 square mile. Areas with cobalt 60 over 3 pCi/g were in immediate vicinity of piers used for berthing nuclear-powered ships. ***Where total cobalt 60 in the surface sediment layer is less than 0.01 curie, ND is reported. Samples more than one foot deep from several harbors show that total cobalt 60 present may be two to five times that measured in the surface layer.Evaluation of the data summarized in Table 4 shows that low-level cobalt 60 radioactivity in harbor bottom sediment is detected around a few piers at.operating bases and shipyards where nuclear-powered ship maintenance and overhauls have been conducted over a period of several years. The activity detected is from operations in the early 1960's since releases such as shown earlier in Table 1 are too small to be detectable in the harbors. Cobalt 60 is not detectable above background levels in general harbor bottom areas away from these piers. Maximum total radioactivity observed in a U. S. harbor is less than 0.1 curie of cobalt 60. This radioactivity is small compared to background; based" on the typical concentrations of naturally occurring radioactivity such as potassium 40, radium, uranium and thorium which are described in reference 21 for marine sediment, the natural radioactivity in the sediment of a typical harbor amounts to hundreds of curies. Comparison to previous environmental monitoring data in references 1 through 12 shows that these environmental cobalt 60 levels have been steadily decreasing. The first data column in Table 4 includes all samples with less than three picocuries of cobalt 60 per gram of sediment. Most of the sediment samples did not contain detectable cobalt 60 and are tabulated in this range. In this range cobalt 60 is difficult to distinguish from the levels of naturally occurring radioactivity such as potassium, radium, uranium and thorium. Cobalt 60 in sediment in this low range may also be detectable as a result of world wide dispersion from atmospheric nuclear weapons testing. The value of 30 picocuries per gram was selected for the top of the second range of data in Table 4. A measure of the significance of this range is that if a person's food consumption were to contain cobalt 60 in this range of activity throughout the year, he would not exceed radiation exposure levels permitted in references 13, 14, and 15 for members of the general public. Only a small fraction of the sediment samples are in this second range and none of the samples exceeded this range in 1977. Data on uptake of this cobalt 60 by marine life obtained to date show that in the salt water harbor bottom environments, no significant buildup of cobalt 60 occurs in marine life. EPA evaluation in reference 28 shows that the cobalt 60 from Naval nuclear propulsion plants is in the form of metallic corrosion product particles which do not appear to be concentrated in the food chain. Because of the nature of the radioactivity and low concentrations noted in Table 4, extensive monitoring of radioactivity in marine life has not been necessary as part of routine environmental monitoring programs in these harbors. In addition to Navy analysis of environmental samples at least two sediment samples from each harbor monitored have been sent each year to a U. S. Department of Energy laboratory, as a check of Navy results. This Department of Energy laboratory provides a further check on the quality of environmental sample analyses by participating in the quality control programs sponsored by the Department of Energy and the Environmental Protection Agency. -15-J The check samples were analyzed for gamma radionuclides in a manner similar to Navy procedures but with greater sensitivity. Illustration 3 depicts the gamma spectra for two such samples. Both spectra show the presence of abundant naturally occurring radionuclides which contribute to measured radioactivity even if cobalt 60 were not present. The upper spectrum is for a sample to which cobalt 60 has been added to an activity of approximately 3 picocuries per gram and shows recognizable energy peaks due to the presence of this small activity of cobalt 60. The lower spectrum depicts the appearance of most of the sediment samples in the first column in Table 4. In addition to the extensive routine monitoring of harbor water and sediment, selected samples of marine life such as mollusks, bottom-feeding fish, barnacles and starfish have been collected in 1977 from most harbors monitored. Marine life samples are also analyzed using a sodium iodide or germanium lithium detector with a multi-channel analyzer. No cobalt 60 associated with U. S. Naval nuclear-powered ships has been detected in these samples of marine life. For comparison, references 29 and 30 contain evaluations by laboratories of the Environmental Protection Agency and of the Department of Energy of the effects on the environment from the accumulation near points-of discharge of radionuclides from several nuclear facilities. 3 The referenced reports conclude for these other facilities that radioactivity levels much greater than shown in Table 4 have caused no significant radiation exposure to the general public. In all monitored harbors, twice per year shoreline areas uncovered at low tide are surveyed for radiation levels with sensitive scintillation detectors to determine if any radioactivity from bottom sediment washed ashore. All results were the same as background radiation levels in these regions, approximately 0.01 mi 11irem per hour. Thus, there is no evidence in these ports that radioactivity from sediment is washing ashore. Ambient radiation levels are measured using sensitive thermoluminescent dosimeters continuously posted at locations outside the boundaries of areas where radioactive work is performed. These dosimeters are also posted at locations remote from support facilities to measure background radiation from natural radioactivity. Results of dosimeters posted at support facilities between radiologically controlled areas and the general public are compared with dosimeters posted at remote background locations up to several miles away. These results showed that radiation exposure to the general public from radioactive work on Naval nuclear propulsion plants was not increased above that received from natural background radiation. -16- □0 Id z Z < X CJ cc Id CL CO I- z o o o 30 27 24 21 18 15 I2f~ 4' U -t-Th (X-RAY) r-Rd-226 (U) Pb-212 {Th) ---Pb-214 (U) Th-208 (Th ) ,---Bi-214 (U) ii I!!! iii! ■I 'if , ,. !B,i, I n1’!; ■’* Hwih I; ifii..... »J! h, i ,,I, 0.3 0.6 0 UJ X o cc UJ a. cn h~ o o 100 “ U + Th (X-RAY) Ra-226 (U) Pb-212 (Th) Pb-214 (U) W'H, wma 0 SAMPLE WEIGHT: 338 grams COUNTING TIME : 200 MINUTES 1024 CHANNELS: 0-2.4 MEV U 1 NATURAL URANIUM DAUGHTER Th=NATURAL THORIUM DAUGHTER ■Ac-228 (Th) -Co-60 T’Wg,- 0.9 Co-60 M ‘i, rK'40 y ”s fiy''1 ± 1.2 nr 1.5 1.8 T SAMPLE WEIGHT: 1468 grams COUNTING TIME: 200 MINUTES 1024 CHANNELS: 0-2.4 MEV U=NATURAL URANIUM DAUGHTER Th=NATURAL THORIUM DAUGHTER Th - 208 (Th) Bi-214 (U) ---Ac -228 (Th) 0.3 0.6 0.9 1.2 1.5 GAMMA ENERGY IN MEV K-40 . 1.8 yrV y O &LR^. 4 ^TRUETUREA NAVAL PROPERTY SUNDRY COSTCO P^AIMEW PSVILE o $e.piMbnt “SAMPLE FblNf' A WATER SAMPLE f’tflNT vku ShbRSENE SURVEY WATER 0 Carqljinez 5trait~~~'Y7 EWiOJMENTM, MOMlTORl AS ' LAWATRVINS AT TH el mare islanp naval sRfY/W VALLEJO; CALI FCAYA figure 1 JANUARY \^18V DRY DOCK KIO. 7 DRY DOCK WO. 6 DRY DOCK WO. 5 Y San.Francisco &av ENVIRONMENTAL MoNI~R?RIHg LoQATioHS AT the. Hunters point naval shipyard SAN pPANSlS^OALIPORNIA SOUTH gate STM &OL6 □ BLRSS. 4 STFHJcpJR.B~> — NAVAL PTOpERfY ftXlNC^Y o PO-STCD. DOSIVETPY PE.VICE o 5EDIMEWT SAMPLE R?lNf a water, sample, point Uii shoreline survey WATER. januajry ms 0 FIGURE. 2.0 San Francisco Bay — JSC ALC IN FEET Si^Tsoojpi^] O |QZ> ihoo FIGURE 3 S/M g€U> □ &LP^B4^TKU^TU(IE$> — NA7AU FWfEgTY l>Pt!.NP^ □ posted ^M^rpeY Psvi^e o -SEDIMENT WFU2 ©INT A WAW $AMf==t-S POINT “ WA#N5 ^UfCVeT EMVI ROMMeHTAL- McN ITdM^ U.6. NAVAL. AllC ^lATiAH ALAMECA ,AAL| F=k?^N IA JANU/^Y i^ia 0o o ENVIRONMENTAL MONITORING SURVEY CHART LONG BEACH HARBOR, CALIFORNIA ENVIRONMENTAL MONITORING SURVEY CHART LONGo BEACH,CALIFORNIA—ANAHEIM BAY AREA*. * NORTH . FIGURE 6 ENVIRONMENTAL MONITORING SURVEY CHART SAN DIEGO BAY, CALIFORNIA ■jYTYVVirrr 4 LEGEND A HARBOR WATER SAMPLE POINT OHARBOR SEDIMENT SAMPLE POINT , □ PERIMETER DOSIMETRY DEVICE nrn. SHORELINE SURVEY AREAo ENVIRONMENTAL MONITORING SURVEY CHART BALLAST POINT; SAN DIEGO HARBOR M iY <$A Ao Co v'- H x.,-UY m. O O A O LEGEND A Harbor Water Sample Point o Harbor Sediment Sample, Poin □ Film Badge Location mi Shoreline Survey Area o o ,, A Y D D6O o •■■w-iifK ft a IL;;A-LHYfVV;t A'AV