Russia’s northwest coastline is dotted with hundreds of old and large radioactive sources. Known as RTGs, they mostly power remote lighthouses. Now the power packs are being safely dismantled. Norway is helping Russia do it.
Several hundred radioisotope thermoelectric generators (RTGs) are deployed along the Russian Federation’s Arctic coast to power remote lighthouses and navigation beacons. Similar RTGs were also used as power sources in other remote locations in the Russian Federation and elsewhere in the former Soviet Union. All Russian RTG’s have out-lived their lifespan and are in need of decommissioning. Radioactive incidents involving such sources, such as in Georgia, underscore the urgency of this task.
The RTGs typically contain one or more radionuclide heat sources (RHS) each with an activity of thousands of TBq of strontium-90. This means that they are Category 1 sources as defined in the IAEA international “Code of Conduct on the Safety and Security of Radioactive Sources”. In fact they are among the largest single radioactive sources ever used.
According to the Federal Atomic Energy Agency of the Russian Federation (Rosatom), there are 651 RTGs at various locations in the Russian Federation which are subject to decommissioning or replacement with alternative sources of energy. In 1993, there were almost 200 RTGs in lighthouses in the Murmansk and Arkhangelsk regions of northwest Russia, relatively near the Norwegian border.
Due to the remoteness of these lighthouses, maintenance and security of RTGs is difficult to achieve. Most Russian RTGs are unprotected against intruders and there have been several examples of unauthorised interference. While there is no evidence of any intent to use the radioactive sources for malevolent purposes, there have been incidences of theft of shielding materials, presumably for their value as scrap metal, with the RHS being abandoned.
Naturally, concern has grown about the potential misappropriation of these
radioactive sources as well as the broader issues of continuing maintenance
and safe use of RTGs. This has become a matter of both national and international
concern. The Norwegian Government has played a significant role in international
efforts, fully cooperating with Russian authorities to safely decommission
RTGs and provide alternative power sources.
Norway has actively supported improvement of nuclear safety and security in northwest Russia for more then ten years. Over this period, the Norwegian Government has spent approximately $150 million on a variety of industrial projects, including specific improvements in radioactive waste treatment and storage, physical security, and infrastructure support. The national authority, the Norwegian Radiation Protection Authority (NRPA), takes an active part advising the Government regarding prioritization and quality assurance of all these activities.
In addition, the Plan of Action places great emphasis on adequate regulatory supervision. Accordingly, the NRPA programme includes a variety of regulatory support projects. These are designed to assist the Russian authorities in ensuring that work is properly carried out within the framework of Russian law, taking into account international standards and recommendations from bodies such as the IAEA. The regulatory cooperation between NRPA and various Russian regulatory bodies is critical in maintaining an effective and efficient regulatory process.
The Norwegian Government has been operating an industrial project to support decommissioning of RTGs in northwest Russia since 1997. Since project initiation, more than 60 RTGs have been removed from lighthouses on the Kola Peninsula. They are being replaced with solar panels and nickel-cadmium battery packs.
As part of this project, inspection and preparatory work took place before the RTGs were transferred by helicopter, boat and road to a temporary storage point at ATP “Atomflot” near Murmansk. The RTGs were then transported via road and rail to the dismantling point in the Moscow Region, where the heat sources (RHS) were removed. The RHS were then transported by road and rail to FSUE PA “Mayak”, where they are stored pending final disposal.
While there are important security, environmental and radiological protection incentives for decommissioning RTGs (such as threats to the local environment, public safety, and possible misuse of the source of radioactive material), the decommissioning process is not without risks. Decommissioning itself could result in radiological and other environmental impacts and risks. In addition, the operational and regulatory responsibilities with respect to RTGs have evolved in the last few years, including changes from military to civilian control. It was necessary, therefore, to review the situation in order to weigh the associated risks.
The NRPA, in cooperation with Russian organizations, carried out a study to assess the environmental, health and safety consequences of decommissioning RTGs in northwest Russia. It was concluded that the decommissioning project should continue, since leaving the RTGs in situ, inadequately monitored, could lead to an undesired access to radioactive material.
It was also noted that the relevant authorities and organizations need to clarify their separate responsibilities throughout the entire process of inspecting, collecting, and dismantling RTGs, as well as the storage and disposal of radioactive waste so generated. Additionally, radiation protection guidelines should be reviewed and amended where necessary with correct procedures and checklists to ensure compliance. The need for regulatory support to help achieve this was recognised.
NRPA has provided support to regulators in the Russian Federation. The general goal of regulatory support is to help Russian bodies develop guidelines and requirements for planning, licensing and implementing industry projects.
The NRPA’s main partner in the RTG Regulatory Support Project (RSP) is the Nuclear, Industrial and Environmen-tal Regulatory Authority of the Russian Federation (Rost-echnadzor). However, it is important that all relevant organizations work together — for example, those organizations concerned with transport, operators and regulators from the Russian Federation and Western organizations. This is the “2 plus 2 approach.” Russian and Western operators cooperate on the industry project, and Russian and Western regulators cooperate on licensing/approval of this industry project.
In order to provide the most relevant international inputs to Russian regulators, the NRPA involves regulators and technical support organizations from other countries, including France, Sweden and the UK.
As a first step in the RSP, an Initial Threat Assessment was carried out to clarify the steps in RTG decommissioning and to identify priorities for regulatory action, based on the main radiological threats presented by each step. A series of steps were identified from the operator’s inspection of RTGs at the point of origin through loading them onto the ship, placing them in temporary storage, transporting them via rail and road links to their final processing at FSUE PA “Mayak”.
The risks associated with the steps must be addressed for each RTG. This is done through the preparation of a decommissioning plan, a safety analysis, and an environmental impact assessment (EIA), which should be developed for each RTG before work starts on decommissioning.
While there will be common features in the plans and assessments between different RTGs, plans should be tailored to take account of the specific characteristics of each RTG (location, history, condition, etc.) and the specifics of the decommissioning process for that RTG.
The physical form of the RHS is intended to make it very unlikely that significant dispersion or leaking of activity could occur—even under extreme conditions such as severe impact, intense fire, long-term immersion in water (e.g. in the sea) or explosion (presumably deliberate).
The primary radiological threat is direct exposure to radiation from the source in the event that shielding is removed or is no longer effective. The key operator must take actions to reduce the threats. These actions need to be systematically planned for all steps in the process and addressed in the decommissioning plan and in the safety and environmental assessments.
Rostechnadzor has recognised that there is a need to upgrade the regulatory framework for the safe decommissioning and disposal of RTGs in the Russian Federation, taking account of the magnitude of the problem and the associated high hazards, as well as the lack of experience in this area.
The aim of the RSP is to upgrade the existing regulatory framework of the Russian Federation for the safe decommissioning and disposal of RTGs. The focus is on the following priority areas:
• Regulatory requirements based on the Initial Threat Assessment;
• Requirements for data, safety assessment and quality assurance;
• Supervision over radiological safety and security, including physical protection; and
• Requirements for emergency preparedness and response, based on environmental impact assessments made for each stage of RTG decommissioning.
Other areas of interest include preparation of an inspection handbook,
training and certification of personnel, compliance monitoring; and providing
information for the public.
The first task is to clarify the roles and responsibilities of the different organizations involved—particularly operators and regulators—with respect to the safety and security of RTGs. The aim is to ensure that there is clear allocation of responsibilities, consistent coordination of regulatory control and compliance requirements, effective transfer of responsibility at each stage in the overall management process and transparency within the Russian regulatory regime. There are gaps in these areas.
This task needs to address both the roles and responsibilities relating to RTGs in situ, but also those relating to the other stages involved in decommissioning. They include the transport of complete RTGs and RHS, the dismantling of RTGs, and the storage and ultimate disposal of RHS.
In addition, Rostechnadzor has responsibility for the regulation, control and supervision of all RTGs in Russian Federation, but the Defence Ministry is responsible for radiation and nuclear safety in military units. The Defence Ministry therefore has its own military nuclear regulatory body, and Rostechnadzor often does not have access to military sites with RTGs.
In line with the Code of Conduct requirement for a natio-nal register
of Category 1 and 2 sources, the operating organizations are developing—through
a parallel industrial project—a database containing comprehensive
information related to each RTG. This includes their location, description,
key characteristics (including size of radioactive source) and associated
potential hazards. The database will also provide an assessment of vulnerability
specific to each RTG. Based on analysis of information from this database,
Rostechnadzor considers whether the types of data held are adequate for
all locations and RTGs, and thus identifies gaps in information to be filled
through the industrial project.
Another major task is to identify Russian Federation regulations relevant to the control of RTGs and to consider—taking into account international standards and recommendations and best practice in other countries—whether existing regulations need to be supplemented or modified and/or whether new regulations need to be developed. Again, this review needs to consider safety and security measures at the various stages of the RTG life cycle: use, recovery, transport, decommissioning, storage and disposal. Regulations identified through this process as ‘missing’ or requiring modification (and which fall within the remit of Rostechnadzor) will then be developed or modified.
Once the basic regulatory infrastructure has been updated, it is proposed that further assistance will be provided in relation to some specific aspects of Rostechnadzor’s role within the infrastructure.
Accordingly, support can be provided to Rostechnadzor in developing an assessment capability, independent of the operators, sufficient to perform its two main assessment functions for the various activities involving RTGs, namely:
• developing regulatory guidance for operators on conducting assessments that satisfy regulatory requirements for each stage of the RTG life cycle; and
• critically reviewing and evaluating safety and security assessments and EIAs submitted by operators in support of licensing and authorization applications at different stages, as a basis for regulatory decision-making.
Support is also provided to adapt inspection procedures, or develop new ones, to be applied to the various stages of an RTG’s life cycle in accordance with the updated regulatory requirements. In addition an inspection handbook focusing on safety and security of RTGs is under development. This will provide a system for tracking and recording inspection findings and monitoring of the risks. The audit trail would ensure compliance with regulation and help promptly identify any irregularities, or potential problems.
Finally, support is provided for the development of regulatory guidance on requirements for emergency planning in relation to accidents or unauthorized actions involving RTGs at any stage of their life cycle, and to improve the capabilities of Rostechnadzor and technical support organizations to fulfil their functions in the event of such an emergency.
The Government of Norway continues to support the safe decommissioning of RTGs in northwest Russia. This involves close cooperation with Russian authorities and other countries supporting the wider programme on RTG decommissioning. So far about a third of the RTGs in the region have been removed with Norwegian support, and without incidents.
One lesson is clear: regulatory support is a vital adjunct to carrying out such industrial projects so that the whole process is safe and efficient for everyone involved.
Malgorzata Sneve is a Senior Adviser at Norwegian Radiation Protection Authority in Østerås, Norway. E-mail: Malgorzata.K.Sneve@nrpa.no
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