Malgorzata Sneve

Regulatory supervision of sites for spent fuel and radioactive waste storage in the Russian Northwest

In the 1960s two technical bases for the Northern Fleet were created in the Russian northwest at Andreeva Bay in the Kola Peninsula and Gremikha village on the coast of the Barents Sea. They maintained nuclear submarines, receiving and storing radioactive waste and spent nuclear fuel. No further waste was received after 1985, and the technical bases have since been re-categorised as temporary storage sites. The handling of these materials to put them into a safe condition is especially hazardous because of their degraded state. This paper describes regulatory activities which have been carried out to support the supervision of radiological protection during recovery of waste and spent fuel, and to support regulatory decisions on overall site remediation. The work described includes: an assessment of the radiation situation on-site; the development of necessary additional regulatory rules and standards for radiation protection assurance for workers and the public during remediation; and the completion of an initial threat assessment to identify regulatory priorities. Detailed consideration of measures for the control of radiation exposure of workers and radiation exposure of the public during and after operations and emergency preparedness and response are complete and provided in sister papers. The continuing requirements for regulatory activities relevant to the development and implementation of on-going and future remediation activities are also outlined. The Norwegian Radiation Protection Authority supports the work, as part of the Norwegian Governments plan of action to promote improvements in radiation protection and nuclear safety in northwest Russia.

Radiological criteria for the remediation of sites for spent fuel and radioactive waste storage in the Russian Northwest.

In the 1960s, two technical bases of the Northern Fleet were created in Northwest Russia, at Andreeva Bay in the Kola Peninsula and Gremikha village on the coast of the Barents Sea. They maintained nuclear submarines, performing receipt and storage of radioactive waste and spent nuclear fuel, and are now designated sites of temporary storage (STSs). An analysis of the radiation situation at these sites demonstrates that substantial long-term remediation work will be required after the removal of the waste and spent nuclear fuel. Regulatory guidance is under development to support this work. Having in mind modern approaches to guaranteeing radiation safety, the primary regulatory focus is on a justification of dose constraints for determining acceptable residual contamination which might lead to exposure to workers and the public. For these sites, four principal options for remediation have been considered-renovation, conversion, conservation and liquidation. This paper describes a system of recommended dose constraints and derived control levels formulated for each option. The unconditional guarantee of long-term radioecological protection provides the basis for criteria development. Non-exceedance of these dose constraints and control levels implies compliance with radiological protection objectives related to the residual contamination. Dose reduction below proposed dose constraint values must also be carried out according to the optimisation principle. The developed criteria relate to the condition of the facilities and the STS areas after the termination of remediation activities. The proposed criteria for renovation, conversion, conservation and liquidation are entirely within the dose limits adopted in Russia for the management of man-made radiation sources, and are consistent with ICRP recommendations and national practice in other countries. The proposed criteria for STS remediation and new industrial (non-radiation-hazardous) facilities and buildings on the remedied sites had, until now, no analogues in the Russian system of regulation of radiation-hygienic standardisation. The proposals made here may serve as a basis for corresponding standards at other sites.

Medical and radiological aspects of emergency preparedness and response at SevRAO facilities.

Regulatory cooperation between the Norwegian Radiation Protection Authority and the Federal Medical Biological Agency (FMBA) of the Russian Federation has the overall goal of promoting improvements in radiation protection in Northwest Russia. One of the projects in this programme has the objectives to review and improve the existing medical emergency preparedness capabilities at the sites for temporary storage of spent nuclear fuel and radioactive waste. These are operated by SevRAO at Andreeva Bay and in Gremikha village on the Kola Peninsula. The work is also intended to provide a better basis for regulation of emergency response and medical emergency preparedness at similar facilities elsewhere in Russia. The purpose of this paper is to present the main results of that project, implemented by the Burnasyan Federal Medical Biophysical Centre. The first task was an analysis of the regulatory requirements and the current state of preparedness for medical emergency response at the SevRAO facilities. Although Russian regulatory documents are mostly consistent with international recommendations, some distinctions lead to numerical differences in operational intervention criteria under otherwise similar conditions. Radiological threats relating to possible accidents, and related gaps in the regulation of SevRAO facilities, were also identified. As part of the project, a special exercise on emergency medical response on-site at Andreeva Bay was prepared and carried out, and recommendations were proposed after the exercise. Following fruitful dialogue among regulators, designers and operators, special regulatory guidance has been issued by FMBA to account for the specific and unusual features of the SevRAO facilities. Detailed sections relate to the prevention of accidents, and emergency preparedness and response, supplementing the basic Russian regulatory requirements. Overall it is concluded that (a) the provision of medical and sanitary components of emergency response at SevRAO facilities is a priority task within the general system of emergency preparedness; (b) there is an effective and improving interaction between SevRAO and the local medical institutions of FMBA and other territorial medical units; (c) the infrastructure of emergency response at SevRAO facilities has been created and operates within the framework of Russian legal and normative requirements. Further proposals have been made aimed at increasing the effectiveness of the available system of emergency preparedness and response, and to promote interagency cooperation.

3D simulation as a tool for improving the safety culture during remediation work at Andreeva Bay

Andreeva Bay in northwest Russia hosts one of the former coastal technical bases of the Northern Fleet. Currently, this base is designated as the Andreeva Bay branch of Northwest Center for Radioactive Waste Management (SevRAO) and is a site of temporary storage (STS) for spent nuclear fuel (SNF) and other radiological waste generated during the operation and decommissioning of nuclear submarines and ships. According to an integrated expert evaluation, this site is the most dangerous nuclear facility in northwest Russia. Environmental rehabilitation of the site is currently in progress and is supported by strong international collaboration. This paper describes how the optimization principle (ALARA) has been adopted during the planning of remediation work at the Andreeva Bay STS and how Russian-Norwegian collaboration greatly contributed to ensuring the development and maintenance of a high level safety culture during this process. More specifically, this paper describes how integration of a system, specifically designed for improving the radiological safety of workers during the remediation work at Andreeva Bay, was developed in Russia. It also outlines the 3D radiological simulation and virtual reality based systems developed in Norway that have greatly facilitated effective implementation of the ALARA principle, through supporting radiological characterisation, work planning and optimization, decision making, communication between teams and with the authorities and training of field operators.

Environmental, health and safety assessment of decommissioning radioisotope thermoelectric generators (RTGs) in northwest Russia

This paper presents findings from public health and environmental assessment work that has been conducted as part of a joint Norwegian-Russian project to decommission radioisotope thermoelectric generators (RTG) in northwest Russia. RTGs utilise heat energy from radioactive isotopes, in this case 90Sr and its daughter nuclide 90Y, to generate electricity as a power source. Different accident scenarios based on the decommissioning process for RTGs are assessed in terms of possible radiation effects to humans and the environment. Doses to humans and biota under the worst-case scenario were lower than threshold limits given in ICRP and IAEA literature.

Protection of the environment in existing exposure situations

The International Commission on Radiological Protection (ICRP) described its approach to the protection of the environment and how it should be applied in Publication 124. The report expanded on the Commission’s objectives for environmental protection, and how the Derived Consideration Reference Levels (DCRLs) apply within different exposure situations. DCRLs relate radiation effects to doses over and above their normal local background radiation levels, and consider different potential pathways of exposure for animals and plants. This paper will describe how the DCRLs may be used within existing exposure situations to better understand the potential impacts on animals and plants. In these circumstances, the Commission recommends that the aim be to reduce exposures to levels that are within the DCRL bands (or even below, depending upon the potential cost/benefits), but with full consideration of the radiological and non-radiological consequences of doing so. Using examples, this paper will demonstrate how this may be achieved in practice, bearing in mind the potential exposure of humans, animals and plants during and following any remediation attempted.

Radiation Protection of the Public and Environment Near Location of SevRAO Facilities

This work presents the results of original investigations of radiation-hygienic situation, existing near location of SevRAO Facilities — STS of SNF and RW in Andreeva bay and Gremikha village. The obtained data permits to conclude that hard and long-term remedial work will be initiated after SNF removal. Having in mind modern approaches to guaranteeing radiation safety, the primary attention at remediation scenarios development was paid to justification of dose constraints of the residual contamination exposure to workers and the public. Four principal options of STS remediation were considered – renovation, conversion, conservation, and liquidation. Primary and derived quantitative radiation-hygienic criteria were formulated for each option.

Radiological protection regulation during spent nuclear fuel and radioactive waste management in the Western Branch of the Federal State Unitary Enterprise ‘SevRAO’

The site of temporary storage of spent nuclear fuel and radioactive waste, situated at Andreeva Bay in Northwest Russia, was developed in the 1960s, and it has carried out receipt and storage of fresh and spent nuclear fuel, and solid and liquid radioactive waste generated during the operation of nuclear submarines and nuclear-powered icebreakers. The site is now operated as the western branch of the Federal State Unitary Enterprise, SevRAO. In the course of operation over several decades, the containment barriers in the Spent Nuclear Fuel and Radioactive Waste storage facilities partially lost their containment effectiveness, so workshop facilities and parts of the site became contaminated with radioactive substances. This paper describes work being undertaken to provide an updated regulatory basis for the protection of workers during especially hazardous remediation activities, necessary because of the unusual radiation conditions at the site. It describes the results of recent survey work carried out by the Burnasyan Federal Medical Biophysical Centre, within a programme of regulatory cooperation between the Norwegian Radiation Protection Authority and the Federal Medical-Biological Agency of Russia. The survey work and subsequent analyses have contributed to the development of special regulations setting out radiological protection requirements for operations planned at the site. Within these requirements, and taking account of a variety of other factors, a continuing need arises for the implementation of optimisation of remediation at Andreeva Bay.

Dynamics of body burdens and doses due to internal irradiation from intakes of long-lived radionuclides by residents of Ozyorsk situated near Mayak PA.

This paper presents and discusses new autopsy results and other historic data from earlier autopsies and environmental monitoring linked to releases from the Mayak PA facilities in the Chelyabinsk oblast in the southern Urals. The focus is on residents of the town of Ozyorsk located near to Mayak PA and the dynamics of body burdens and radiation doses from inhalation of plutonium alpha and americium-241, and ingestion of strontium-90 and caesium-137. It is demonstrated that accumulation and exposure from these radionuclides was mainly due to unplanned releases in the 1950s and 60s. The mean content of plutonium alpha at the time of autopsy of people commencing residence in Ozyorsk from 1949 to 1959 was about 3.5 Bq, falling to 0.2 Bq in those arriving after 1990. A reducing trend was also seen for (241)Am. The highest (90)Sr content in Ozyorsk residents was measured in 1967. The (137)Cs body content of residents arriving in Ozyorsk at any time was in almost all cases below the limit of detection. The committed effective dose from internal exposure to these long-lived radionuclides which would have been accumulated in Ozyorsk residents if present from 1949 to 2013 is estimated to be 13 mSv. This dose is primarily attributed to intakes during 1949 to 1959 when the annual effective dose rate was approximately 1 mSv y(-1). The current value is about 0.1 mSv y(-1). This dose is about 20 times higher than the dose from global man-made fallout, which is about 0.005 mSv y(-1) at present, but much lower than that from natural background radiation, i.e. about 2 mSv y(-1). The experience gained from this work and continuing activities can contribute to the development of improved international guidance in legacy situations, particularly as regards the provision and use of monitoring data to test and thereby build confidence in prognostic models for radiation conditions and potential future exposures. The scope includes evidence for the rate of reduction in radionuclide concentrations in environmental media and in their bioavailability, resuspension of long-lived alpha radionuclides, uptake of (90)Sr and (137)Cs in the food-chain, and confirmation of cumulative uptake via autopsy and whole body counting measurements. Continuing investigations will thus support decisions on future planned releases and contribute to planning of remediation of other areas affected by historic releases.

Radio-ecological characterization and radiological assessment in support of regulatory supervision of legacy sites in northwest Russia.

The Norwegian Radiation Protection Authority has been implementing a regulatory cooperation program in the Russian Federation for over 10 years, as part of the Norwegian governments Plan of Action for enhancing nuclear and radiation safety in northwest Russia. The overall long-term objective has been the enhancement of safety culture and includes a special focus on regulatory supervision of nuclear legacy sites. The initial project outputs included appropriate regulatory threat assessments, to determine the hazardous situations and activities which are most in need of enhanced regulatory supervision. In turn, this has led to the development of new and updated norms and standards, and related regulatory procedures, necessary to address the often abnormal conditions at legacy sites. This paper presents the experience gained within the above program with regard to radio-ecological characterization of Sites of Temporary Storage for spent nuclear fuel and radioactive waste at Andreeva Bay and Gremikha in the Kola Peninsula in northwest Russia. Such characterization is necessary to support assessments of the current radiological situation and to support prospective assessments of its evolution. Both types of assessments contribute to regulatory supervision of the sites. Accordingly, they include assessments to support development of regulatory standards and guidance concerning: control of radiation exposures to workers during remediation operations; emergency preparedness and response; planned radionuclide releases to the environment; development of site restoration plans, and waste treatment and disposal. Examples of characterization work are presented which relate to terrestrial and marine environments at Andreeva Bay. The use of this data in assessments is illustrated by means of the visualization and assessment tool (DATAMAP) developed as part of the regulatory cooperation program, specifically to help control radiation exposure in operations and to support regulatory analysis of management options. For assessments of the current radiological situation, the types of data needed include information about the distribution of radionuclides in environmental media. For prognostic assessments, additional data are needed about the landscape features, on-shore and off-shore hydrology, geochemical properties of soils and sediments, and possible continuing source terms from continuing operations and on-site disposal. It is anticipated that shared international experience in legacy site characterization can be useful in the next steps. Although the output has been designed to support regulatory evaluation of these particular sites in northwest Russia, the methods and techniques are considered useful examples for application elsewhere, as well as providing relevant input to the International Atomic Energy Agencys international Working Forum for the Regulatory Supervision of Legacy Sites.