Category Archives: Radioactive waste management and contaminated site clean-up
R. P OIS S O N, Agence Nationale pour la gestion des Dechets Radioactifs (ANDRA), France
Abstract: This chapter presents the French experiences of contaminated site clean-up and remediation. Radioactive waste management in France is discussed in general terms including the classification of waste. The history of the French waste management organization including site remediation is then discussed, highlighting difficulties encountered and lessons learned.
Key words: site remediation, classification of waste, waste management, waste management organization, orphan polluted sites, conventional risk, radiological risk.
To understand the subject of overall radioactive waste (RAW) management in France, it is important to first describe the sources of waste and the associated classification system, knowing that the latter also has a rationale linked to repository availability. It is then important to describe the waste management organization, its history and its current status. The subject of site remediation can then be addressed, first discussing the waste management organizations, past and present, before describing the site remediation activities.
Between 1949 and 1982 about 33,000 m3 of RAW was disposed of in the North Atlantic and UK coastal waters (NDA and DECC, 2011). The London Convention 1972 prohibited all major nuclear powers from disposing HLW at sea although low level and intermediate level waste disposal continued into the 1980s when a voluntary moratorium came into force. Sea disposal of solid radioactive waste was abandoned by the UK in 1983.
The Rio Declaration on Environment and Development (1992) reaffirmed the voluntary moratorium on sea disposal and the London Convention of 1996 brought into effect the precautionary approach with a ban on all LLW disposals at sea.
Construction was started in 1955 and the DMTR was the first nuclear reactor to operate in Scotland. Its purpose was to test materials under
17.2 Dounreay fast reactor research site. Photograph courtesy of DSRL.
nuclear radiation conditions for the future fast reactor programme. It produced 25 MW thermal but not electricity and was shut down in 1969.
Early decommissioning after shutdown was limited to post-operational clean out (POCO) and removal of non-active support facilities. Decommissioning during the early 2000s has been more comprehensive with cleaning out of the fuel pond and cells and the demolition of inactive buildings. DMTR is now in a care and maintenance period prior to final decommissioning and demolition programmed to start in 2015.
The EPA delegates authorities to states in two areas of RAW management. NESHAPs regulations are based on the requirements of the Clean Air Act, and the authority for delegating compliance responsibility to the individual states is described by law. A state must have emission limits at least as stringent as the federal EPA national standards, although most states have not asked for delegation responsibility of radionuclide NESHAPs. The EPA has a similar process for delegating RCRA hazardous waste requirements to states. The state must have a program at least as stringent as the federal program, and the application for authorization must address specific areas of compatibility. For example, the State of New Mexico is authorized by the
EPA to carry out the base RCRA and mixed waste programs in lieu of equivalent federal programs. The New Mexico Environment Department reviews permit applications for treatment, storage, and disposal facilities for hazardous waste under Subtitle C of RCRA. The WIPP Hazardous Waste Facility Permit is renewed every ten years.
States authorized by the EPA play a significant role in regulation and independent oversight of DOE facilities. Most of the DOE ’s cleanup is performed under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) through Federal Facility Agreements and under RCRA through various consent and compliance orders. These enforceable regulatory agreements and orders with federal and state agencies establish the scope of work to be performed at a given site and the dates by which specific cleanup milestones must be achieved. Failure to comply with these agreements and orders is subject to fines and penalties.
The Canadian regulatory approach to the safety of RAW management is based on three principles: life cycle responsibility and licensing, in-depth defence, and multiple barriers.
The CNSC uses a comprehensive licensing system for the management of radioactive waste, which is regulated during its entire life cycle — from site preparation, construction and operation to decommissioning and, finally, abandonment. It is the licensee’s responsibility to demonstrate that a facility for RAW management can and will be operated safely throughout the lifetime of the facility. This step-wise approach requires a separate licence at each phase. The CNSC also requires early planning, as the application must submit all the relevant information associated with the site operation and decommissioning plans and financial assurance at the first stage. The outcome of the licensing process feeds back into the compliance program — to verify that the licensee fulfills the regulatory requirements.
The CNSC utilizes a harmonized or joint review approach with other federal, or provincial or territorial departments in such areas as health, environment, transport and labour. This approach allows for participation in the CNSC’ s assessment, licensing and compliance programs for waste management facilities.
Conditioning consists of those operations that produce a waste package suitable for handling, transport, storage or disposal. Prior to conditioning RAW for storage or disposal, the pre-disposal management waste acceptance requirements (WAR) and the disposal facility WAC have to be considered to ensure compliance with the storage facility or disposal site requirements, respectively. Where final disposal criteria do not yet exist, disposal criteria assumptions will be defined and incorporated into processing methodologies.
It should be noted that for some waste streams, treatment actions render a waste package that already conforms to the criteria for disposal and that no further conditioning is required. After conditioning, the final characterization will take place in order to ensure that the waste package conforms to the WAC of the disposal facility.
The responsibilities of the ‘generators and operators’ entail the following :
• The technical, financial and administrative management of such wastes within the national regulatory framework and within any applicable co-operative governance arrangements.
• Development and ongoing review of site/industry-specific waste management plans which are to be based on the requirements stipulated in the national radioactive waste management policy and strategy.
• Implementation of waste management plans by the establishment of appropriate waste management and facilities processes and the development of site/industry-specific waste management systems.
• Site/industry waste management in accordance with waste management systems to reflect sustainable development and principles such as continual improvement and best available technology not entailing excessive cost (BATNEEC) and other elements of the national strategy.
At Necsa, the responsibility for the management of solid RAW is documented . This document highlights the responsibilities of the waste generators, the pre-disposal waste operator (NLM), waste disposal operator (National Radioactive Waste Disposal Institute) and the Safety Health and Environmental Quality Department (SHEQ).
The responsibility for the development and maintenance of the NRWMP lies with the Nuclear Liabilities Management (NLM) department of the Nuclear Services Division of Necsa. NLM is also responsible for the submission of the plan to the National Committee on Radioactive Waste Management (NCRWM)  .
The establishment of the NRWMA and the main responsibility of the NRWMA is the final disposal of waste on a national basis at the Vaalputs National Radioactive Waste Disposal Facility, to ensure correct siting and design and to construct and operate new RAW disposal facilities for other waste categories  .
One of the functions of the NRWMA is to assist generators of small quantities of radioactive waste with the management of such waste as well as the management of ownerless waste (e. g., orphan sources) on behalf of the government. These responsibilities are currently being expedited by Necsa (NLM) on behalf of the government. The management of such waste streams are therefore included in the NRWMP.
Korean decommissioning and decontamination (D&D) work on the retired research reactors KRR-1 and 2 and the uranium conversion facility (UCF) at KAERI is under way. Hundreds of tons of metallic and concrete wastes are expected from the D&D of these facilities. Therefore, countermeasures are being taken to deal with the amount of waste generated by dismantling these retired nuclear facilities. Recycling or volume reduction of the large quantities of metallic and concrete wastes are key waste management options due to the difficulty in securing a waste disposal site in Korea and the capacity limitation of the temporary waste storage facility at KAERI. Recycling or volume reduction through application of appropriate treatment technologies has merits from the viewpoint of resource recycling as well as a decrease in the amount of waste to be disposed of resulting in reduced disposal cost and enhanced disposal safety.
Methods of disposal with institutional control include near-surface disposal without artificial barriers, near-surface disposal with artificial barriers and sub-surface disposal with artificial barriers. Near-surface disposal with artificial barriers is already used for LLW generated in commercial nuclear reactor facilities. Near-surface disposal without artificial barriers is being partly implemented while the reactor operators improve safety regulations on the remainder of the wastes. Operating entities are conducting studies and tests on sub-surface disposal with artificial barriers. Based on the results, it will be necessary to discuss the establishment of the framework, including safety regulations.
The current status of management of other LLW is described in Section 23.1.2.
In 1996 the first plant built in the US for vitrification of defence-related HLW, the Defence Waste Processing Facility (DWPF) at the Savannah River Laboratory (SRL), commenced operation. Unlike the British and French civil HLW vitrification plants, which operate using Inconel 601-lined induction furnaces, the DWPF operates a Joule-heated ceramic-lined furnace, as will the new facility, the Waste Vitrification Plant (WVP) being built at Hanford. In the DWPF, waste is continually fed into the melter as a wet slurry to minimize dusting of radionuclides along with glass frit and
heated up to 1150°C. The resulting glass is poured into the metal waste canisters at intervals. Borosilicate glasses are used in all of these facilities, but each has its composition tailored to meet the specific requirements of the wastes being processed. Comprehensive tables of glass compositions for both defence and civilian use have been given by Donald (2010) and Jantzen (2011).
Experience gained during the operation of DWPF has led to new glass compositions being developed (Table 25.5) which allow waste loadings to be increased from a nominal 28 mass% to 38 mass% (Marra et al, 2008). These compositions are aimed at the high alumina content wastes to be processed at SRS and Hanford, which are especially problematic due to the refractory nature of alumina which reduces throughput and increases the formation of nepheline (NaAlSiO4) crystals which can be detrimental to the durability of vitreous waste forms by reducing the alumina and silica content of the residual glass. Table 25.5 highlights the variations in composition as glasses are developed for specific waste streams with HAL-17 being developed for Hanford tank sludges containing approximately 53 mass% alumina.
The use of a different furnace technology, the Cold Crucible Induction Melter (CCIM), or skull melter, allows higher vitrification temperatures to be achieved without enhanced corrosion of the refractory liner. Using a small-scale CCIM furnace SIA Radon were able to vitrify SRL Sludge Batch 2 simulated waste at a 50 mass% loading at 1320-1440°C using Frit 320 (Table 25.5) (Stefanovsky et al., 2008). The actual Batch 2 sludge consists primarily of the oxides of Al, Fe, Na and U (Elder et al., 2000).
Table 25.5 Compositions of some borosilicate glasses frits for treating high alumina wastes (mass%)
et al. (2008)
Problems of RAW management in Eastern Europe vary from country to country. The management of RAW systems in both the Czech and Slovak Republics from operation and decommissioning of nuclear facilities was influenced by the Soviet design concept of waste management of WWER reactors, which allowed for the fact that virtually all RAW will be stored until decommissioning of the NPP. A great disadvantage of this design was also the fact that various sources of wastewater were mixed and therefore recycling of separate wastewater is complicated and difficult. The consequence of this design is that usually much higher amounts of waste have to be disposed of at the low — and intermediate- level waste disposal facilities such as at Dukovany or Mochovce, unlike in Western reactor designs. Both in the Czech and Slovak Republics, however, special programmes focusing on reduction of generated waste have been launched.
In the Czech and Slovak Republics the main conditioning technology for operational liquid waste from NPPs selected by the end of the 1980s was bituminisation. This technology is associated with many problems such as maintaining a suitable pH of wastewater concentrates or flammability of bitumen, necessitating conducting fire hazard tests prior to waste conditioning. Another problem in both countries is finding suitable sites for deep geological repositories. In the Czech Republic, the process started by selection of sites only according to geological criteria. It turned out, however, that socio-economic aspects are equally as important as geological criteria for selecting suitable sites. The biggest problem for finding suitable sites is the rejection of these sites by local communities and non-governmental organisations.
In the Czech Republic problems with remediation of sites after uranium mining and milling remain. It may be that the sites will be cleaned up so that they will not significantly endanger people and the environment, but only after spending large amounts of money and it is unlikely that most of these sites will be open for free, unrestricted use in future. They will have to remain under some institutional control, probably indefinitely. They will require constant monitoring and periodic assessment, and, if required, maintenance.