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9 Comprehensive Resolution of the Problem of Radioactive Waste Management and Rehabilitation of Contaminated Areas in the Moscow Region* S. A. Dmitriev, Moscow Joint Environmental-Technological Scientific Research Center for Radioactive Waste Decontamination and Environmental Protection (MosNPO Radon) MEASURES TO IMPROVE THE RADIOACTIVE WASTE MANAGEMENT SYSTEM IN RUSSIA Analysis of possible means of achieving the objectives formulated in the document Principles of State Policy on Ensuring Nuclear and Radiation Safety in the Russian Federation through 2010 and Beyond, approved by the President of the Russian Federation, highlights several very significant problems and short- comings associated with state policy on radioactive waste management, and the development and security of the country demand that they be resolved. The complexity and scope of the tasks associated with radioactive waste management are determined by the following 10 circumstances: â 1. Despite certain actions that have been taken to develop and implement specific programs for reprocessing and utilizing radioactive wastes, the countryâs unified policy on radioactive waste management remains in a formative stage. â 2. There is still a prevailing tendency to put off fundamental decisions and actions on long-term state programs that have been developed regarding scientific â *Translated from the Russian by Kelly Robbins. 51
52 CLEANING UP SITES CONTAMINATED WITH RADIOACTIVE MATERIALS research, creation of a modern regulatory base and new technologies, and devel- opment of the technical infrastructure for waste management and isolation. â 3. An increasing number of radiation-hazard facilities in the country need to be removed from operation (nuclear-powered naval and civilian ships, nuclear reactors at atomic power plants built in the 1960s, research and training reactors, irradiation equipment, monitoring devices that use radiation, and other types of radiation-hazard equipment). â 4. The city of Moscow and the Central Region of the Russian Federation require significant attention. Many radioactive waste-producing facilities are concentrated there (representing 70 percent of all wastes from nonnuclear ap- plications produced in Russia), and at the same time it is an area of maximum population density. â 5. Land rehabilitation and reclamation is necessary in areas where ura- nium ore is mined and mine tailings are currently stored, and petroleum drilling enterprise wastes with high concentrations of natural radionuclides must be reprocessed. â 6. Work is required to rehabilitate areas where the radiation situation is unfavorable, formed as a result of radiation accidents. Monitoring of the radiation and environmental status of cities and smaller towns is also necessary, as well as forecasting and prevention of radiation-related extreme events. â 7. The current situation is characterized by the presence of the negative so- called nuclear heritage, including such problems as the accumulation of wastes in the Techa Cascade and Lake Karachai at the Mayak Production Association, and so forth. â 8. Existing regulatory documents on radioactive waste management need improvement. There is a lack of experience in standard solutions and technolo- gies with a high level of reliability and safety. â 9. Work on a nationwide scale to create a unified waste isolation system began in the 1970s-1980s, but lags significantly behind world practice. Indeed, the greatest successes in radioactive waste management have been achieved in countries that have a unified waste management system. These states have specially created governmental organizations: ANDRA in France, ENRESA in Spain, NIREX in Great Britain, and so forth. They operate independently of the radioactive waste producers, are directly subordinate to the countryâs govern- ment, and establish requirements for quality and minimization of radioactive wastes. National radioactive waste repositories with capacities up to hundreds of thousands of cubic meters operate under their auspices. However, foreign experi- ence of countries with unified radioactive waste management systems (Great Brit- ain, France, Spain, Belgium, the Netherlands, and others) is being insufficiently studied and ineffectively used. 10. There is inadequate scientific, organizational, and technological coor- dination of efforts in radioactive waste management. Enterprises that produce
RESOLUTION OF THE PROBLEM OF RADIOACTIVE WASTE 53 such wastes may be found in such industries as energy, manufacturing, defense, mining, medicine, agriculture, space, and science. REHABILITATION OF LAND AREAS AND DECOMMISSIONING OF RADIATION-HAZARD FACILITIES (THE EXPERIENCE OF MosNPO RADON) In terms of its structure and specialization, the Moscow Joint Environmental- Technological Scientific Research Center for Radioactive Waste Decontamina- tion and Environmental Protection (MosNPO Radon) is the closest in the Russian Federation to the aforementioned types of efforts involved in comprehensively addressing radioactive waste management problems. The enterprise was created as part of a special project, and during the almost half a century since its found- ing, it has developed as a necessary and important part of the cityâs structure for ensuring its technogenic, environmental, informational, and social security and for addressing questions related to centralizing radioactive wastes from organiza- tions in various industries across a significant part of the Russian Federation. The enterpriseâs significance to Moscow and the Central Region is based on the capital being home to more than 20 nuclear- and radiation-hazard enterprises and more than 600 organizations that use ionizing radiation sources in their operations. There are 37 nuclear-hazard facilities of various types within the city limits. The operations of these organizations produce a significant quantity of wastes. Radiation-contaminated areas, a legacy from past decades, are being discovered in the city, and they require constant radiation monitoring. To address this problem, MosNPO Radon has developed and instituted a system of radiation- ecological monitoring (with about 200 sampling points) that ensures the neces- sary radiation safety of the metropolis. Relevant information is also conveyed to the public, creating a favorable moral and psychological climate. Unique tech- nological processes and equipment have been created at the enterprise, and the Moscow radiation monitoring system is the only one in the Russian Federation that covers the territory of an entire major city. MosNPO Radon is currently a multipurpose, multifunctional complex, and its âradioactive waste storage pointâ is in fact one of the numerous systematic elements within its structure that comprehensively ensure the radiation security of Moscow and the countryâs Central Region. A modern scientific research infra- structure has been created, and the enterprise conducts research and experimental design work aimed at improving the safety of radioactive waste management. It has also amassed experience in the development of regulatory documentation and radiation-monitoring systems for use in the technological processes involved in radioactive waste reprocessing. â Technogenic is used to refer to phenomena arising as a result of the development or deployment of technology.
54 CLEANING UP SITES CONTAMINATED WITH RADIOACTIVE MATERIALS The Center for Radioactive Waste Reception and Transport and Radiation Emergency Response was organized in 1999. The center carries out the following work in the decontamination and decommissioning of radiation-hazard facilities: development of decontamination plans, regulations, methods, and methodolo- gies; decontamination of affected areas and facilities; and shipment preparation and transportation of radioactive wastes. The centerâs main tasks include the following: â¢ Removing radioactive wastes from enterprises in Moscow and Russiaâs Central Region â¢ Deactivating radiation-contaminated sites and deactivating and decom- missioning contaminated facilities â¢ Developing regulatory, methodological, and technical documentation â¢ Transporting radioactive wastes â¢ Conducting searches for radioactive sites, radiation monitoring, and other radiation-related studies â¢ Decontaminating individual protective devices and specialized clothing â¢ Developing new methods for deactivating and dismantling various types of structural elements Since its establishment, the center has carried out the following work: â¢ Deactivated more than 1,000 radiation-contaminated sites â¢ Removed more than 23,000 m3 of radioactive wastes on orders from enterprises in Moscow and Moscow Oblast as well as other facilities in Russiaâs Central Region â¢ Handled more than 950 emergencies involving radiation accidents â¢ Removed more than 450 ionizing radiation sources â¢ Decommissioned more than 10 contaminated facilities Moscow Polymetals PlantâOpen Joint-Stock Company A radiation and environmental study was carried out at 32 buildings and structures and adjacent grounds and production space at this industrial enterprise in Moscow, which covers about 165,000 m2. The study uncovered more than 400 radiation hot spots at the site, with a total area of 9,150 m 2. The gamma radia- tion exposure dose rate at the surface of the radiation hot spots reached 4,000 ÂµR per hour with an alpha-particle flow density up to 19 particles per square centimeter per hour. Thorium-232 and radium-226 were the primary radionuclide contaminants. From 1999 through 2002, 17 contaminated buildings and practically the en- tire contaminated grounds at the enterprise were deactivated. Buildings in which
RESOLUTION OF THE PROBLEM OF RADIOACTIVE WASTE 55 work had been done with radioactive substances were also dismantled. During the deactivation process, the radioactive wastes were prepared for transport into long-term storage, a process that included fragmentation of large pieces, condi- tioning, and packing of wastes into metal or plastic containers. Some 425 m 3 of radioactive wastes were prepared and shipped off for long-term storage. Deactivation work at radiation-contaminated sites proceeded to a depth of up to 1 m by means of manual sorting of extracted soil. Excavated areas were filled in with clean soil or paved with concrete topped with asphalt. As a result of the decontamination of these sites, the gamma radiation exposure dose rate was reduced to background levels (11-18 ÂµR per hour). Decontamination of the buildings was highly effective, also reducing the gamma radiation exposure dose rate to background levels, an average of 15 ÂµR per hour (0.15 ÂµSv per hour), reaching maximum levels of 27 ÂµR per hour (0.27 ÂµSv per hour) in certain points. Following completion of the rehabilitation efforts, the individual effective dose from external exposure for plant workers will not exceed 0.3 mSv annually. Carrying out this decontamination work has made it possible to develop a methodology, organizational approaches, and forms of cooperation among vari- ous organizations involved in radiation accident response efforts at enterprises in the nuclear complex. In the course of the work, new deactivation technologies have been improved and developed, and much experience has been gained in addressing the problem of rehabilitating a major contaminated Russian Federal Atomic Energy Agency (Rosatom) facility. The Radiochemical Laboratory of the Vernadsky Institute of Geochemistry and Analytical Chemistry This laboratory operated in Moscow from 1966 through the end of the 1980s. It included 7 hot rooms and associated control rooms with an area up to 240 m 2, 15 auxiliary rooms, a ventilation system, and so forth. The project had to take into account that the laboratory building had to be rehabilitated without changing the structure of the first floor and without dismantling the technical equipment, special structures, and utility lines. The decontamination work proceeded at the same time that the building was being renovated. While work was under way, an analysis of the situation indicated that the requirement to dismantle the equip- ment contradicted the demand to preserve the buildingâs structure, which led to the need to carry out additional deactivation cycles and to apply treatments to preserve the building structure for 50 years. Experience was acquired in working in radiochemical laboratory facilities with high levels of contamination. As a re- sult of the intensive deactivation effort and in accordance with the requirements of the client, maximum dose levels were reduced to 20 Î¼R per hour as opposed to maximum initial readings of up to 68,000 Î¼R per hour.
56 CLEANING UP SITES CONTAMINATED WITH RADIOACTIVE MATERIALS Open Joint-Stock Company Kolchugtsvetmet [S. Ordzhonikidze Kolchugino Plant for Ferrous Metals Processing] Located in Vladimir Oblast, the Kolchugtsvetmet plant was contaminated with natural radionuclides (radium-226). The contaminated area included a two- story, 1,200 m2 production building. The first floor measured 898 m2 and the second, 317 m2. The production building was constructed and put into service in the early 1950s to manufacture phosphorescent substances using a radium-226 bromide solution. Radioactive materials were involved in the production process in both solid and solute form and were used in dust separation operations. A ra- dioecological study of the laboratory facilities revealed radiation-contaminated areas of more than 200 m2, with a gamma-irradiation exposure dose intensity from 45 to 28,000 Î¼R per hour. Removal of weakly attached contaminants and treatment of the surfaces of equipment, walls, and floors to reduce the risk of per- sonnel contamination were accomplished using Optimist-type deep-penetrating primer. The walls were then treated with acrylic faÃ§ade paint. The floors, walls, and equipment were treated in areas with surface-fixed alpha contamination of more than 5 alpha-particles per minute per square centimeter. Some 500 m3 of radioactive wastes were removed from the facility. At this site, the center gained experience in working under high-level con- tamination conditions. A brick building was completely cleaned, and after ra- diometric monitoring it was dismantled, along with its autonomous ventilation system and pipes. The site where the dismantled building once stood was then rehabilitated along with adjacent areas. The Kurchatov Institute Wastes with a total activity of several thousand curies and a volume up to several thousand cubic meters are present on the grounds of this institute or could be created there as a result of decommissioning efforts, and this situation requires significant time for waste reprocessing. MosNPO Radon is carrying out this work rather successfully. Given the urgency of the problem of reducing the volume of radioactive wastes subject to long-term storage, a technology for reagent-based decontamination of soil and related materials has been developed from research and lab tests. This technology will make it possible to reduce by dozens of times the volume of radioactive soil that must be stored. It includes a complete cycle for leaching radionuclides from the soil at increased temperature in an agitation regime using a mixed reagent solution with subsequent repro- cessing of the resulting technological solutions. The soil is thus cleaned to meet regulatory standards and can be removed from the enterpriseâs production zone. The radioactive concentrate that formed as a result of the cleaning process is sent away for long-term storage. Specially created units with simultaneous processing capacities of 12, 60, and
RESOLUTION OF THE PROBLEM OF RADIOACTIVE WASTE 57 1,000 kg of contaminated soil were used to work out this technology for reagent- based soil decontamination in a rotary reactor-mixer and to test its capabilities in various operating regimes and output capacities. While these tests were being conducted, work was simultaneously under way to develop means of decontami- nating technological solutions and neutralizing water used in washing operations. The tests were conducted on real batches of cesium-137âcontaminated soil taken from the grounds of the Kurchatov Institute. The following values for the basic technological parameters involved in reagent-based soil decontamination were determined during the tests: the composition and concentration of the sulphuric acid-based reagent solution; the process temperature, 95Â°C; and the liquid-solid phase coefficient, L:S = (1:1.5)/1. Under these parameters, 95-98 percent of the contaminants are removed from the soil. Decontamination of the technological solutions is achieved by means of ferrocyanide precipitation of cesium. After adjustment of its composition, the cleansed solution has a sufficiently low specific activity level and may be reused for processing the next batch of soil. Organizing the soil deactivation process so as to utilize the technological solution in a closed cycle makes it possible to reduce reagent requirements significantly to 50 kg per metric ton of soil. As a result of lab-based and field testing, the technological process for re- agent-based removal of cesium-137 from soil was developed. The main apparatus used is a rotary electric-heated reactor-mixer used for processing the soil with reagents. This equipment is currently being tested for use in removing radionu- clides from soil. The tests involve checking the technical features included in the design of the apparatus and the operating capacity of this nonstandard equipment. Various deactivation procedures are also being worked out. Two batches of soil actually contaminated with cesium-137 have been pro- cessed. Processing of the first batch of 535 kg of soil reduced the equivalent dose level by 72 times to 10 Î¼R per hour, which corresponds to the background level, while specific activity was reduced by 40 times to 0.51 kBq/kg. DISCUSSION OF WORK EXPERIENCE As a result of the activities of MosNPO Radon, practically all points of surface contamination discovered in Moscow have been eliminated. At the same time, substantial characteristic problems require attention. At almost all facilities that were in operation in the 1940s-1950s, there is no reliable information on the structure of the buildings, their condition, and the location and condition of utility lines and pipes. At practically all old enterprises still in operation, there is also no information on the presence of hot spots due to accidental spills of radioac- tive substances or unauthorized radioactive waste burial sites on their grounds. Therefore, any project must begin with a search for any information that has been maintained and a full-scale radiation study of the facility. The experience amassed by MosNPO Radon attests to the city having
58 CLEANING UP SITES CONTAMINATED WITH RADIOACTIVE MATERIALS radiation-contaminated sites that have been concealed by new construction, erosion of riverbanks and other slopes, and other construction-related activities. Ensuring radiation safety for the public demands that such hot spots be discov- ered and eliminated. In preparing for work aimed at rehabilitating sites in the city of Moscow, it must be kept in mind that ignorance of what awaits construction workers carry- ing out site preparation work, especially at locations formerly used as industrial dump sites, not only could lead to significant expense but also could be a potential source of radioactive contamination for the surrounding area. Moscow currently has about 2,000 facilities in operation that work with ionizing radiation sources and radioactive substances. However, the city has no comprehensive database about enterprises that previously worked with ionizing radiation sources but closed or changed orientation as a result of economy policy changes during the past 15 years. From the above-mentioned points, we may conclude that systematic data are needed on a citywide scale regarding the locations of potentially hazardous radiation-contaminated sites. Therefore, it is proposed that a program be devel- oped to conduct a comprehensive radiation study of facilities where work with radioactive substances has been carried out since the late 1980s. Such a program should also include studies of known and suspected sites of soil contamination at specific facilities and other areas of the city.