The Techa cascade of water reservoirs is the world’s largest open storage facility for liquid low-level radioactive waste. Its capacity is about 360 mln. m 3 , it occupies an area of more than 65 km 2 , the total activity accumulated in the water and sediments is about 6·10 15 Bq. The major challenge facing the Techa cascade is virtually uncontrollable water level changes. The water level rise can cause significant pollution of the environment. From the late 1990’s onwards, the issue of the Techa cascade safety assurance is considered to be one of the major challenges pertaining to nuclear legacy for «Mayak» and Russia as a whole. Unlike other industrial water reservoirs the Techa cascade liquidation is estimated as highly unrealistic. The main objectives of the paper are: – brief results summary of the practical works on safety improvement at the Techa cascade carried out over the past decade; – introduction the works on the Techa cascade performance assessment; – determination of the existing risks and strategic areas for solving the problem.

The National Radioactive Waste Storage and Disposal Site was established in 1959 in the Faizabad region approximately 50 km east of the capital, Dushanbe. The site is located on the southern flank of the Fan Mountains facing the Gissar Valley in a sparsely populated agricultural area, with the nearest villages located a few km from the site. The site was initially designed to accept a wide range of contaminated materials, including obsolete smoke detectors, sealed radioactive sources, waste from medical institutions, and radioactive liquids. Between 1962 and 1976, 363 tonnes and 1146 litres of material, contaminated with a range of radionuclides were shipped to the site. Between 1972–1980 and 1985–1991, ∼4.8 × 10 14 and 2 × 10 13 Bq, respectively, were shipped to the site. An additional 7 × 10 14 Bq was shipped to the site in 1996. Partly as a result of the dissolution of the former Soviet Union, the disposal site had fallen into disrepair and currently presents both an environmental hazard and a potential for the proliferation of radionuclides that could potentially be used for illicit purposes. Remediation of the disposal site was started in 2005. New security fences were erected and a new superstructure over an in-ground storage site constructed. A central alarm monitoring and observation station has been constructed and is now operational. The geology, flora, and fauna of the region have been documented. Radiation surveys of the buildings and the storage and disposal sites have been carried out. Samples of soil, surface water and vegetation have been taken and analyzed by gamma spectrometry. Results show a slight extent of contamination of soils near the filling ports of the underground liquid storage container where a Cs-137 concentration of 2.3 × 10 4 Bq/kg was obtained. Similar values were obtained for Ra-226. Radiation fields of the in-ground storage site were generally <1 μSv/h with 8% exceeding this value. Neutron radiation levels at the same location were also low with a few readings exceeding 10 μSv/h. The volume of liquid waste is estimated to be ∼140 m 3 . Most of the activity appears to be associated with the sediments in the tank. Suggestions are presented for the immobilization of the liquid wastes and long-term monitoring of the site and the surrounding territory.

The Active Storage Facility for Residuals (Aktives Lager fu¨r Ru¨cksta¨nde – ALfR) — an open-air controlled area — was used for the storage of radioactive waste (liquid and solid waste) at the site of the NPP Rheinsberg in the former GDR. Liquid waste was cemented and dumped for near surface final disposal. During the period of operation of the ALfR some incidents happened. Residues of evaporated cooling water of unknown amount (ca. 1–10 m 3 ), the drop-out from small leakages and the wash-off from contaminated open-air storage barrels contaminated the soil. Since 1997 the buildings of the ALfR have been decommissioned and the site will be remediated. From the beginning of decommissioning up to now the groundwater has been monitored. This paper shows different steps of decommissioning and explains the results of groundwater monitoring. Currently 33 sampling points are being used for sampling groundwater from different layers. The radiological parameters under examination are Cobalt-60, Cesium-137, Strontium-90 and Tritium. Non-radiological parameters like Bore, Potassium, Sodium, Nitrate, pH value and TOC (total organic carbon) are also being investigated. Since 1997 the activity concentration of Cobalt-60 and Tritium in the groundwater has been decreasing. The activity concentration of Strontium-90 had increased from 1997 to 2007. Since 2007 activity concentration of Strontium-90 has been decreasing. 350 m away from the ALfR, in the direction of groundwater flow, the Lake Stechlin is located in a nature protection area. The groundwater beyond the ALfR-site is not used as drinking-water and up to now there has been no detectable contamination of Lake Stechlin. Therefore there is no radiological impact on humans by contaminated groundwater. The hypothetic effective dose of Cobalt-60, Tritium and Strontium-90 resulting from postulated consumption of groundwater was determined using consumption rates according to the German Radiation Protection Ordinance. In case of using the groundwater as drinking-water the annual effective dose is 0,4 mSv/a at a postulated drinking-water well on the ALfR-site and 2,5 μSv/a at a postulated drinking water well in a distance of 142 m. Results of the observations: The observations of direction and velocity of the flow of the ground-water principally confirms the transportation model made at the beginning of decommissioning of ALfR. In vertical direction, the real spread of contamination in the groundwater is smaller than assumed. The dilution of Co-60 is higher than assumed. In contrast to the assumptions of the transportation model, Cesium-137 has a lower mobility.

Low and intermediate level radioactive waste must be sorted and treated before it can be sent to radioactive waste storage. The waste must fulfil an extensive amount of acceptance criteria (WAC) to guarantee a safe storage period. NUKEM Technologies has a broad experience with the building and management of radioactive waste treatment facilities and has developed methods and equipment to produce the waste packages and to gather all the required information.

DFD is an acronym for the “Decontamination for Decommissioning” process developed in 1996 by the Electric Power Research Institute (EPRI). The process was designed to remove radioactivity from the surfaces of metallic components to allow these components to be recycled or free-released for disposal as non-radioactive. DFD is a cyclic process consisting of fluoroboric acid, potassium permanganate and oxalic acid. The process continues to uniformly remove base metal once oxide dissolution is complete. The DFD process has been applied on numerous components, sub-systems and systems including the reactor systems at Big Rock Point and Maine Yankee in the United States, and the Jose Cabrera (Zorita) Nuclear Power Plant (NPP) in Spain. The Big Rock Point site has been returned to Greenfield and at Maine Yankee the land under the license was reduced for an Independent Spent Fuel Storage Installation (ISFSI). In the upcoming months the Zorita NPP in Spain will initiate dismantlement and decommissioning activities to return the site to a non-nuclear facility. The development of the EPRI DFD process has been an ongoing evolution and much has been learned from its use in the past. It is effective in attaining very high decontamination factors; however, DFD also produces secondary waste in the form of ion exchange resins. This secondary waste generation adds to the decommissioning quota but this can be improved upon at a time when radioactive waste storage at nuclear facilities and waste disposal sites is limited. To reduce the amount of secondary waste, EPRI has developed the DFDX process. This new process is an enhancement to the DFD process and produces a smaller amount of metallic waste rather than resin waste; this reduction in volume being a factor of ten or greater. Electrochemical ion exchange cells are the heart of the DFDX system and contain electrodes and cation ion exchange resin. It has been used very successfully in small system applications and the next evolution is to design, build and implement a system for the chemical decontamination for decommissioning of larger reactor systems and components, and Full System Decontamination (FSD). The purpose of this paper is to provide a reference point for those planning future chemical decontaminations for plant decommissioning. It is based on actual experience from the work already performed to date and the planned development of the DFDX process.

In 2006, Atomic Energy of Canada Limited (AECL) and Natural Resources Canada (NRCan) began implementing a $7B CDN, 70-year Nuclear Legacy Liabilities Program (NLLP) to deal with legacy decommissioning and environmental issues at AECL nuclear sites. The objective of the NLLP is to safely and cost-effectively reduce the nuclear legacy liabilities and associated risks based on sound waste management and environmental principles in the best interest of Canadians. The liabilities include shutdown research and prototype power reactors, fuel handling facilities, radiochemical laboratories, support buildings, radioactive waste storage facilities, and contaminated lands at several sites located across eastern Canada from Quebec to Manitoba. The largest site, Chalk River Laboratories (CRL) in Ontario, will continue as an operational nuclear site for the foreseeable future. Planning and delivery of the Program is managed by the Liability Management Unit (LMU), a group that was formed within AECL for the purpose. The composition and progress of the NLLP has been reported in recent conferences [1, 2]. The NLLP comprises a number of interlinked decommissioning, waste management and environmental restoration activities that are being executed at different sites, and by various technical groups as suppliers to the LMU. Many lessons about planning and executing such a large, diverse Program have been learned in planning the initial five-year “start-up” phase (which will conclude 2011 March), in planning the five-year second phase (which is currently being finalized), and in planning individual and interacting activities within the Program. The activities to be undertaken in the start-up phase were planned by a small group of AECL technical experts using the currently available information on the liabilities. Progress in executing the Program was slower than anticipated due to less than ideal alignment between some planned technical solutions and the actual requirements, as well as the limited available resources of the suppliers to execute the work. Several internal and external reviews of the Program during the start-up phase examined progress and identified several improvements to planning. These improvements included strengthening communications among the groups within the Program, conducting more detailed advance planning of the interlinked activities, and being cautious about making detailed commitments for activities for which major decisions had yet to be made. The second phase was planned using a dedicated core team, and involved much more involvement of the suppliers to ensure feasibility of the proposed program of work and more detailed specification of the required resources. Priorities for executing the diverse activities in the Program were originally set using criteria based on the risks that the liabilities presented to health and safety, to the environment and to AECL’s ability to meet its obligations as the owner-operator of licensed nuclear sites. The LMU later recognized that the decision criteria should also explicitly include the value gained in reducing the risks and liabilities for expended funds. Greater consideration should be given to mitigating risks to the execution of the Program that might materialize. In addition, licensing strategies and processes should be better-defined, and waste characterization methods and disposition pathways would have to be put in place, or clearly identified, to deal with the wastes the Program would generate before many of the planned activities could be initiated. The NLLP has developed several processes to assist in the detailed planning of the numerous projects and activities. These include developing a more formal procedure for setting priorities of the different parts of the Program, preparing an Integrated Waste Plan to identify the optimal suite of support facilities to be constructed, the creation of a series of “pre-project initiation” procedures and documents to guide the development of well-founded projects, and the use of staged decision-making to incorporate more flexibility to adjust Program strategy and the details of implementation at planned decision points. Several Case Studies are outlined to illustrate examples of the application of these planning techniques.

The management of radioactive waste in Belgium is undertaken by the national agency for radioactive waste and enriched fissile materials, ONDRAF/NIRAS, and its industrial partner Belgoprocess. ONDRAF/NIRAS has set up a management system designed to guarantee that the general public and the environment are protected against the potential hazards arising from radioactive waste. Belgoprocess is a private company, founded in 1984 and located in Dessel, Belgium. It is a subsidiary of ONDRAF/NIRAS and its activities focus on the safe processing and storage of radioactive waste. The management system of ONDRAF/NIRAS includes two aspects: a) an integrated system and b) an acceptance system. The integrated system covers all aspects of management ranging from the origin of waste to its transport, processing, interim storage and long-term management. The safety of radioactive waste management not only depends on the quality of the design and construction of the processing, temporary storage or disposal infrastructure, but also on the quality of the waste accepted by ONDRAF/NIRAS. In order to be managed safely, both in the short and the long term, the waste transferred to ONDRAF/NIRAS must meet certain specific requirements. To that end, ONDRAF/NIRAS has developed an acceptance system.

Since the very beginning of the nuclear activities in Belgium, the incineration of radioactive waste was chosen as a suitable technique for achieving an optimal volume reduction of the produced waste quantities. Based on the 35 years experience gained by the operation of the old incinerator, a new industrial incineration plant started nuclear operation in May 1995, as a part of the Belgian Centralized Treatment/Conditioning Facility named CILVA. Up to the end of 2006, the CILVA incinerator has burnt 1660 tonne of solid waste and 419 tonne of liquid waste. This paper describes the type and allowable radioactivity of the waste, the incineration process, heat recovery and the air pollution control devices. Special attention is given to the treatment of several hundreds of tonne historical waste from former reprocessing activities such as alpha suspected solid waste, aqueous and organic liquid waste and spent ion exchange resins. The capacity, volume reduction, chemical and radiological emissions are also evaluated. BELGOPROCESS, a company set up in 1984 at Dessel (Belgium) where a number of nuclear facilities were already installed is specialized in the processing of radioactive waste. It is a subsidiary of ONDRAF/NIRAS, the Belgian Nuclear Waste Management Agency. According to its mission statement, the activities of BELGOPROCESS focus on three areas: treatment, conditioning and interim storage of radioactive waste; decommissioning of shut-down nuclear facilities and cleaning of contaminated buildings and land; operating of storage sites for conditioned radioactive waste.

Remote monitoring of radiological conditions on large areas is important task during large-scale activity with radioactive contamination/materials. We present results of application of an automatic system for remote measurements of radiological conditions at territory of rehabilitation activity. The system is scanning collimated spectrometric detector, its construction and main performance characteristics are shortly described. System, including two different measurement heads was used during three years for radiological monitoring of area rehabilitation works at temporal radwaste storage area of RRC Kurchatov Institute. The results of its application for exposure dose rate monitoring at particular control points from separate strong sources located in the territory of activity are presented and special cases are studies in details. The method of EDR calculation in 3-D space around territory of activity and analysis of relative input of main gamma-sources into EDR are presented. The results of application of the system during rehabilitation activity at territory of temporal storage of radioactive wastes of RRC Kurchatov Institute have shown high efficiency of this system for such operations.

Geological disposal is an essential component of the long-term management of spent fuel and high-level radioactive waste. Implementation of a suitable deep repository may, however, be difficult or impossible in some (especially small) countries because of challenging geological conditions or restricted siting options, or because of the high costs involved. For these countries, shared regional or international storage and disposal facilities are a necessity. The European Parliament and the EC have both expressed support for concepts that could lead to regional shared facilities being implemented in the EU. The EC, therefore, funded two projects that form the first two steps of a staged process towards the implementation of shared regional or international storage and disposal facilities. In the period 2003 to 2005, the EC funded SAPIERR I, a project devoted to pilot studies on the feasibility of shared regional storage facilities and geological repositories, for use by European countries. The studies showed that shared regional repositories are feasible, but also that, if they are to be implemented, even some decades ahead, efforts must already be increased now. The first step would be to establish a structured framework for the work on regional repositories. This is the goal of SAPIERR II (2006–2008): to develop possible practical implementation strategies and organisational structures. These will enable a formalised, structured European Development Organisation (EDO) to be established in 2008 or afterwards for working on shared EU radioactive waste storage and disposal activities. The EDO can work in parallel with national waste programmes. Participating EU Member States will be able to use the structures developed as, when and if needed for the furtherance of their individual national policies.

Storage is a necessary step in the overall management of radioactive waste. In recent years, due to the unavailability of disposal facilities, storage facilities intended originally as temporary, have had their lifetimes extended and consideration has been given, in some countries, to the use of long term storage (LTS) as a management option. In 2003, the IAEA published a position paper titled “The Long Term Storage of Radioactive Waste: Safety and Sustainability”. The position paper, which written for a non-specialist audience, focused on seven key factors for safety and sustainability of LTS, namely: safety, maintenance/institutional control, retrieval, security, costs, community attitudes and retention of information. The Agency is preparing a follow-up report to the position paper that elaborates in a more technical manner upon the issues raised in the position paper and issues important for implementation of LTS. It also provides some discussion of the reasons for implementing a LTS option and contrasts LTS with aspects of other management options. The present paper provides an overview of the draft follow-up report.

The anticipated doubling of world demand for electricity over the next fifty years requires that the gift of nuclear energy that has served developed nations over the past half century must not be abandoned. However, the absence of a clear and unequivocal policy regarding the storage and disposal of radioactive waste is seen by a significant section of the public as a threat to their rights and the non-existence of dedicated regulation of radioactive waste based on law has become an obstacle to the development of nuclear energy in Europe and the USA. A European survey of public opinion carried out at the request of the European Commission revealed that three-quarters of the respondents to sixteen thousand interviews believed that ‘all radioactive waste is very dangerous’. The public perception of threat has been fostered by the general lack of appreciation of the cautious system of radiation protection that has evolved from scientific observation and prediction of the risk of cancer from exposure to low level radiation. The concept of collective dose based on the system of radiation protection and applied to accident scenarios with remote possibilities, but in the absence of scientific assessment of the balance afforded by the pragmatism that man applies to everyday risks including the risk of cancer from the ever-present background of natural radiation, has added a measure of dread to the public sense of threat. That dread has been exacerbated by the emergence since September 2001 of the possibility of the use of radioactive waste as a terrorist weapon and for radioactive waste storage facilities to be seen as terrorist targets. International policy has moved from the comprehensive coverage of nuclear regulation with radioactive waste as an integral, but minor player, in the nuclear energy process to particular consideration with radioactive waste requiring specific regulation. This paper identifies the vectors that determine the direction of the policy governing radioactive waste, the moves toward consolidation of international policy separate from the body of existing nuclear law and future direction that will clear the way for a sustained, appropriate use of nuclear energy.

Storage and disposal of radioactive waste are complementary rather than competing activities, and both are required for the safe management of wastes. Storage has been carried out safely within the past few decades, and there is a high degree of confidence that it can be continued safely for limited periods of time. However, as the amounts of radioactive waste in surface storage have increased, concern has grown over the sustainability of storage in the long term and the associated safety and security implications. In response to these concerns, the IAEA has prepared a position paper [1] that is intended for general readership. This presentation will provide a summary of the position paper, and a discussion of some safety issues for further consideration. A key theme is the contrast of the safety and sustainability implications of long term storage with those of early disposal. A number of factors are examined from different points of view, factors such as safety and security, need of maintenance, institutional control and information transfer, community attitudes and availability of funding. The timing and duration of the process of moving from storage to disposal, which are influenced by factors such as the long timeframes required to implement disposal and changing public attitudes, will also be discussed. The position paper focuses on the storage of three main types of waste: high level waste from the reprocessing of nuclear fuel, spent nuclear fuel that is regarded as waste and long-lived intermediate level radioactive waste. Long term storage of mining and milling waste, and other large volumes of waste from processes involving the use of naturally occurring radioactive materials are not discussed. Specialist meetings were held last year by the IAEA on the sustainability and safety of long-term storage to establish and discuss the issues where a broad consensus exists, and to investigate areas where issues remain unresolved. Within the technical community, it is widely agreed that perpetual storage is not considered to be either feasible or acceptable because of the impossibility of assuring active control over the time periods for which these wastes remain potentially hazardous. For high-level and long-lived radioactive waste, the consensus of the waste management experts is that disposal in deep underground engineered facilities — geological disposal — is the best option that is currently available, or likely to be available in the foreseeable future.

There is only one nuclear power plant in Lithuania — Ignalina NPP (INPP). The INPP operates two similar units with present power level of about 1250 MW(e) each. They were commissioned (first grid connection) in 1983 and 1987 respectively and provide approximately 70–80 per cent of the electricity produced in Lithuania. From the beginning of INPP operation all power plant generated solid radwaste is collected and stored in the solid radwaste facility that is located in INPP sanitary protected area. The storage facility for solid radwaste at INPP consists of four above ground buildings, namely buildings No. 155, No. 155/1, No. 157 and No. 157/1. This facility is Soviet type facility designed for the interim storage of low and intermediate level radwaste arising as a consequence of operation of NPP. The institutional waste from industry, hospitals etc., including sealed sources as well, has been stored in this facility from 1990. At present this radioactive waste storage facility is still not licensed but SAR is prepared and licensing process is going on. The paper provides information on INPP solid radwaste storage facility and discusses problems met during the safety assessment of this facility: lack of the information on the inventory data, lack of design data for the buildings etc. Modeling results of the structural analysis, radiological data, shielding analysis and proposals to improve the safety of the facility also are discussed.