The first task assigned to ANDRA was to operate the surface disposal of SL-LILW that had been created in 1969 at the Centre de la Manche. It also laid down some rules to secure and streamline disposal of waste. For example, the waste had to be packaged in standard packages. In addition,

ANDRA built a collection system to monitor and control the water coming out of the disposal facility, which allowed the impact of the centre on its environment to be monitored.

A new disposal centre in the Aube district

From 1984, ANDRA began looking for a new site for a disposal facility to replace the Centre de la Manche. Geological studies were undertaken in different ‘Departments’ (the ‘Department’ is the main political and admin­istrative subdivision in France). In 1984 and 1985, more than 500 boreholes were drilled in the Aube Department to select a specific location. At this time, ANDRA perfected the technique of using a multi-barrier system consisting of the package, the engineered barrier and the geology to dispose of the waste. Meanwhile, local consultation was carried out through the organization of several visits and meetings with local stakeholders. On 22 July 1987, the Prime Minister signed the Declaration of public interest: the new disposal facility for SL-LILW, the CSFMA, was located in the Aube Department, near the village of Soulaines-Dhuys.

In 1974, due to the oil crisis that followed the Yom Kippur War, France decided to develop a very large nuclear industry, including a number of NPPs and units to recycle spent fuel. The initiation of this significant pro­gramme had the effect of greatly increasing the volume of all categories of RAW: that of high-level and long-lived waste, coming from the recycling of the spent fuel, as well as that of short-lived low — and intermediate-level waste.

To address this situation, the government asked the CEA to create within its ranks an organization to take responsibility for managing all this waste. ANDRA was created inside the CEA in 1979.

Table 15.2 presents each waste category along with the current identified

long-term management solution. For some categories, the corresponding

long-term management solution is still under study and this issue is addressed in the 2013 National Plan for the Management of Radioactive Materials and Waste (‘Plan National pour la Gestion des Matieres et Dechets Radioactifs’ or PNGMDR), which is a three yearly plan stating, for all radioactive materials and waste in France, the chosen long-term management option, either operational or being researched.

There is no simple and single criterion to classify RAW. There is no overall activity level, for instance, to determine whether a given residue belongs to the SL-LILW category. It is necessary to examine the radioactiv­ity of the different radionuclides present in the waste in order to rank it according to the classification. More particularly, in order to be considered as SL-LILW, the specific activity of each radionuclide in the waste must be lower than the prescribed thresholds in the waste acceptance specifications for the SL-LILW disposal facility (‘Centre de Stockage de dechets de Faible et Moyenne Activite’ or CSFMA; see Fig. 15.1 for the different facilities

Centre de stockage FMA

Siege

Centre de stockage TFA

Centre de stockage de la Manche

Centre de

Meuse/Haute-Marne

15.1 Map of French facilities managed by ANDRA.

managed by ANDRA). In that category, the activity of long-lived radionu­clides is particularly limited.

However, it is possible to indicate a range of specific activities within which each waste category generally belongs. It may be that a specific waste pertaining to one of the above-mentioned categories is not acceptable within the corresponding management system due to other chemical, physical or other characteristics. Such is the case for residues containing significant quantities of tritium (a radionuclide that is difficult to confine or retain) or of sealed sources for medical uses.

A special case also concerns the waste generated by uranium enrichment facilities and fabrication plants of nuclear fuel containing uranium oxide. Their waste residues contain uranium and are compatible with the accept­ance criteria of the CSFMA or, if their activity is very low, with those of the VLLW repository (‘Centre de Stockage de dechets de Tres Faible Activite’, or CSTFA). In the first case, the waste is disposed of at the CSFMA and, by convention, registered as SL-LILW, notably in the national inventory. In the second case, the waste is disposed of at the CSTFA and included in the VLLW category.

15.1.1 Waste sources and categories

The various types of RAW are classified according to the half-lives and radioactivity levels of the main radionuclides they contain, to their physical and chemical characteristics, as well as to their origins. Half-lives are divided into very-short (less than 100 days), short (between 100 days and 31 years) and long (over 31 years).

In France, there are six major waste categories depending on their radio­active content (activity level and half-life), as follows:

• High-level waste (HLW) consists mainly of vitrified-waste packages in the form of stainless-steel containers, which contain the vast majority of radionuclides, whether in the form of fission products or of minor acti­nides. Radionuclides contained in spent fuel are separated from pluto­nium and uranium during fuel reprocessing at the La Hague plant. The activity level of vitrified waste is on the order of several billions of Bec — querels per gram.

• Long-lived intermediate-level waste (LL-ILW) originates mostly from the reprocessing of spent fuel and consists of structural residues from nuclear fuel (i. e., hulls (sheath sections) and ends, which were condi­tioned initially into cemented waste packages, but are now compacted into stainless-steel containers). It also includes technological waste (e. g., used tools, equipment, etc.) and residues resulting from the processing of effluents, such as bituminized sludge. The activity of these residues ranges between 1 million and 1 billion Becquerels per gram. There is either no or a negligible heat release.

• Long-lived low-level waste (LL-LLW) consists mainly of graphite and radium-bearing waste. The activity of graphite waste lies between 10,000 and 100,000 Becquerels per gram. Its long-term activity arises from long-lived beta-emitting radionuclides. Radium-bearing waste contains long-lived alpha-emitting radionuclides and their activity lies between a few tens to a few thousands of Becquerels per gram.

• Short-lived low — and intermediate-level waste (SL-LILW) results mainly from the operation and dismantling of nuclear power plants (NPP), fuel cycle facilities and research establishments, as well as, for a small amount, from activities relating to biological and academic studies. Most residues in this category were disposed of in a surface facility at the Centre de la Manche disposal facility (CSM) up until 1994 and at Centre de l’Aube disposal facility for LILW (CSFMA) since 1992.

• Very-low-level waste (VLLW) is mostly from the operation, mainte­nance and dismantling of NPPs, fuel cycle facilities and research estab­lishments. Its activity level is generally lower than 100 Becquerels per gram. All residues of this category are disposed of at the Centre de l’Aube disposal facility for VLLW (CSTFA).

• Very-short-lived waste includes residues that result notably from medical uses.

For practical purposes, the acronyms listed in Table 15.1 are often used.

R. P OIS S O N, Agence Nationale pour la gestion des Dechets Radioactifs (ANDRA), France

DOI: 10.1533/978085709446.2.489

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.

15.1 Introduction

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.

The Gorleben facility is located in an undisturbed salt dome near the village of Gorleben approximately 100 km southeast of Hamburg, Germany. Fol­lowing the selection of the Gorleben site in 1977 for investigation as a poten­tial repository for heat-generating wastes, and the establishment of DBE in 1979, a comprehensive surface-based investigative programme was initiated to characterize the salt dome and the surrounding area of the site. Based on the positive indications from the surface investigations, an underground exploratory facility was designed and constructed by DBE in 1986 on behalf of the BfS. The Gorleben exploratory facility was intentionally designed to facilitate conversion to a repository, assuming subsequent investigations would continue to support the site’s suitability. From 2000 to 2010, site char­acterization activities at Gorleben were suspended by the federal govern­ment as part of a moratorium agreement negotiated between the previous government and the nuclear industry. In October 2010 the moratorium expired and site characterization and licensing activities were restarted.

In the 1980s and 1990s, considerable effort was invested in investigating the Gorleben salt dome as a potential site for hosting a nuclear waste repository. The investigations supported the concept of rock salt as a host environment based on its very low inherent permeability and the self­healing nature of fractures due to the plastic response behaviour of the rock type. In addition to the subsurface research facility, many of the surface installations were also completed prior to the imposition of the ten-year moratorium. In the framework of research, development and demonstra­tion activities, significant advances have been made with respect to proto­type equipment development, including development of a shaft hoist system with a capacity to lift 85 tonnes, emplacement machines for both drift and borehole disposal, and equipment for backfilling disposal drifts. For these reasons, the facility at Gorleben is unique when compared to other inter­national repositories in that much of the site characterization and surface infrastructure work was actually completed in the 1980s and 1990s. As a result, despite the moratorium, Gorleben remains one of the most techni­cally advanced potential high-level RAW repository sites currently under consideration both in a national and international sense. Figure 14.7 shows the potential Gorleben repository concept and existing prototype equipment.

Shaft transport

Borehole emplacement

Backfilling slinger truck in a disposal drift

Drift emplacement

14.7 Gorleben repository concept with prototype shaft hoist, borehole emplacement machine, backfilling slinger truck and drift emplacement machine. Source: Provided by the German Company for the Construction and Operation of Waste Repositories (DBE), Peine, Germany.

Since the moratorium was lifted and research was recommenced, new safety requirements for the disposal of heat-generating waste, as well as requirements for retrievability have been published and are expected to be enacted. The performance criteria include the evaluation of repository safety for a one million-year period (referred to as the period of geological stability) at an annual effective exposure not to exceed 10 pSv for likely event scenarios and 100 pSv for less likely events (BMU, 2010). However, recent legal actions challenging key aspects of the operating licence for the Gorleben site investigation, submitted to the Upper Administrative Court of Luneburg, have resulted in the suspension of on-going subsurface research activities at Gorleben with immediate effect pending further judi­cial review.

A preliminary safety assessment (vorlaufige Sicherheitsanalyse fur den Standort Gorleben, VSG) that will provide a detailed evaluation of the potential suitability of the Gorleben salt dome as a repository host formation for the disposal of heat generating waste is currently being com­pleted. The Gesellschaft fur Anlagen — und Reaktorsicherheit (GRS) is responsible for developing the VSG in collaboration with a team of con­tributing organizations, and is scheduled to be completed in 2013.

In 1976 investigative efforts commenced at the former iron ore mine Konrad to assess its suitability as a repository for LLW and ILW. The original facility, consisting of two shafts, excavated in 1957 and 1960, respectively, was used to mine iron ore from an iron-rich very low permeable oolitic limestone formation between 1965 and 1976. A total of 6.7 million tonnes of ore were mined during this period.

The geological situation at Konrad offers favourable conditions for the disposal of RAW. The repository horizon is hydraulically isolated from overlying groundwater bearing formations. A more than 400 m thick and regionally widespread series of impervious clay, marl and mudstone layers cover the repository host rock and provide a geological barrier that, in conjunction with geotechnical barriers, will prevent radionuclides escaping into the biosphere (Fig. 14.6). Based on the favourable hydraulic conditions, considerations for repurposing the facility as a RAW repository were already initiated in 1975. In 1982 an application for the commencement of planning approval procedures was submitted.

After an almost 20-year licensing process, the Konrad facility was approved as a final repository in 2002. On 26 March 2007, the licence for Konrad was confirmed by the Federal Administrative Court. The ruling brought to a close all outstanding legal considerations and related judicial processes. Work on conversion of the mine began in May 2007 under the operational management of the BfS. The BfS is the licence holder and formal operator and manager of the facility, while DBE is assigned the responsibility for operating the facility and for the planning and construc­tion of the repository.

The Konrad repository is the first final repository approved in Germany in accordance with the AtG. The facility is approved for the disposal of waste with negligible heat generation and has a licensed capacity for 303,000 m3 of waste. Based on current waste forecasts, it is anticipated that a total of 290,000 m3 of waste will be emplaced in the repository by 2050 (BfS, 2011d).

JHI Up to 400-m-thick layer of different clays as natural geological barrier.

ШШ

Iron ore horizoi (host rock)

Old working chambers which are not to be used for disposal Model of the deep geological underground in the area of the Konrad repository.

14.6 Three-dimensional representation of the Konrad Repository. Source: Provided by the German Federal Office for Radiation Protection (BfS), Salzgitter, Germany.

A total of 11 storage fields have been approved for the Konrad repository, although it is not anticipated that all of the available volume will be required. These fields will be constructed in the upper 800 m level of the repository. Refitting work is currently scheduled to be completed by 2019 after which waste acceptance operations will begin (BfS, 2011d).

LLW and ILW originating from the operation of nuclear power plants, as well as from basic research, nuclear medicine and industrial applications in the former GDR was disposed of in the repurposed salt mine Bartensleben in Morsleben: the Morsleben Repository for Radioactive Wastes (Endlager fur radioaktive Abfalle Morsleben, ERAM) from 1971 until German reuni­fication (Fig. 14.5). The BfS became the licence holder upon reunification and DBE took over the operation of the facility as well as the task of designing any improvements and modifications through repository closure. After reunification, except for the period from 1991 to 1994 when emplace­ment operations were temporarily halted, disposal of low-level and medium — level radioactive waste with short-lived radionuclides continued until the Higher Administrative Court of Magdeburg issued an injunction on 25 September 1998 halting further disposal. On 12 April 2001, BfS committed to the permanent closure of the facility with no additional waste emplace­ment. During its period of operation from 1971 through 1998, a total of about 37,000 m3 of RAW, including about 6,621 spent sealed radiation sources, was disposed of in the facility (BfS, 2011g).

The licence application for permanent closure, including the closure plan and the associated environmental impact statement, was initially submitted to the licensing authority, the Ministry of Agriculture and Environment of Saxony-Anhalt (Ministerium fur Landwirtschaft und Umwelt Sachsen — Anhalt, MLU) on 13 September 2005. Revised documentation was resub­mitted for review to the MLU in January 2009. The MLU completed its

review in July 2009 and the documents were submitted for public comment from 21 October 2009 to 21 December 2009.

Pending completion of the closure licensing process, work is ongoing to stabilize non-repository portions of the former mine. Specifically, extensive former mining activities in the central portion of the salt body raised sig­nificant concerns regarding the long-term stability of the subsurface open­ings. To address these concerns, backfilling of 27 former mine chambers with saltcrete was initiated on 8 October 2003. These operations were completed in February 2011. A total of approximately 935,000 m3 of void volume have been filled in this manner. Final closure of the repository portions will com­mence after issuance of the closure licence (BfS, 2011h).

14.4.1 Asse II

At the same time that Germany was constructing its first NPPs, the govern­ment recognized that methods and technologies would need to be devel­oped for the final geological disposal of related heat-generating wastes. The permanent disposal of these wastes in salt domes was seen as providing a promising option for the development of a HLW repository. To further investigate the ability of a salt-rock formation to serve as a potential reposi­tory host rock, the German Federal Ministry of Education and Research (Bundesministerium fur Bildung und Forschung, BMBF) acquired the former Asse potash and rock salt mine in 1965 as a prototype facility for LLW and ILW disposal with strong emphasis on research and disposal technologies (BfS, 2011e). The facility was managed at the time by the GSF (Gesellschaft fur Strahlen — und Umweltforschung mbH), a major research centre in Germany, which later became the Helmholtz Zentrum Munchen (HZM). Management and operations of the Asse facility were conducted by the Helmholtz Zentrum Munchen (HZM) until the facility was trans­ferred to the BfS in 2009. From its initiation until 2009, Asse was regulated under German mining laws.

Research and experimental work on remotely handled ILW disposal started in the summer of 1972 and continued until waste disposal practices ended in 1978. From 1971 until 1978 the facility was also used to store a major part of the LLW and ILW produced in the Federal Republic of Germany. Altogether 125,787 drums and waste packages containing RAW were emplaced in the mine (BfS, 2011f). The layout of the Asse facility including chambers containing RAW is shown in Fig. 14.4.

The AtG was amended in 1976. The amendment implemented a licensing (i. e., plan approval) process for RAW storage and as a result waste storage practices were discontinued in 1978. At the time, as no additional RAW was being transferred to the site, German mining law continued to provide the legal basis for the operation of the facility as an underground research labo­ratory (URL). After phasing out of the disposal practices in 1978, the facil­ity continued to be used as an underground research laboratory with a major focus on the development of disposal technologies for heat­generating waste.

In 1995, after research and development came to an official end, backfill­ing of the former mining chambers in the southern flank of facility was initi­ated along with efforts to evaluate the long-term safety of the former mine. However, research was allowed to continue as long as related activities did not interfere with mine closure operations (Kappei, 2006).

Although the facility was initiated as a URL, because of the disposal practices that were conducted concurrent with research, the facility became

by default a repository. It has since been recognized that the operation and regulation of Asse under mining law did not provide an adequate regula­tory framework to manage and close the facility. On 4 September 2008, the BMBF, the BMU and the Lower Saxony Ministry for the Environment and Climate Protection (Niedersachsisches Ministerium fur Umwelt und Kli — maschutz, NMU) jointly agreed that the facility would be closed under the Atomic Energy Act. On 1 January 2009, transfer of the facility to the BMU under management of the BfS was completed.

Despite legal and political issues surrounding the Asse facility today, considerable experience and information was gained during the period of its operation. This experience and the tests that were conducted at Asse resulted in improved waste handling practices and technologies, as well as an improved understanding of salt as a host rock and engineered barrier system behaviour. Several national and international research studies were conducted at the URL. Examples include the following:

• a cooperative research programme with the US Department of Energy examined brine moisture migration, thermal mechanical response of salt, and material corrosion studies;

• drilling optimization studies were conducted as part of the Commission of European Communities COSA Project;

• the longest running drift-scale thermal simulation study was initiated by the Karlsruhe Institute of Technology (KIT) and later expanded and finalized under the European Union sponsored multi-national BAMBUS I and BAMBUS II projects, which included dismantling and retrieval exercises.

The BAMBUS projects were the last significant research conducted at the facility (Bechtold et al, 2004). Upon assuming operational responsibility for the Asse repository in January 2009, the BfS conducted a comparative study to assess the effectiveness of the various closure options. The options investigated included:

• retrieval: removal of waste from the mine for emplacement in another disposal facility

• relocation: construct and license a repository in deeper sections of the salt dome.

• complete backfilling: complete backfilling of all of the subsurface cavi­ties with concrete and installation of sealing systems in shafts and drifts at appropriate geological intersections.

After evaluation of the result of the comparative assessment, published in January 2010 (BFS, 2010), the BfS selected retrieval as the preferred option for final closure of the facility and is currently in the process of elaborating technical processes and requirements to achieve this goal.

While many countries have opted for near-surface or surface disposal for LLW and ILW, Germany has pursued deep geological disposal for all RAW subject to the controls of the AtG. Additionally, it has been German federal policy since the early 1960s that deep geological disposal offers the best possible isolation of the wastes. Deep geological disposal is seen as particu­larly beneficial over surface or near-surface disposal with respect to the avoidance of inadvertent human intrusion. To this end, even wastes with no or only negligible heat-generating capacity are, and will continue to be, disposed of in deep geological repositories.

Approximately 98.5% by volume of the nuclear waste generated in Germany is classified as waste with negligible heat-generating capacity. Because Germany has selected deep geological disposal for these wastes, it is necessary that sufficient underground volumes are located and that the costs associated with deep disposal are manageable without adversely affecting safety. The conversion of existing underground mines, assuming the facility can be determined to provide adequate isolation and safety, offers an alternative to the development of new purpose-built facilities for disposal of these wastes. As a result, Germany pursues two separate strate­gies for radioactive wastes disposal. For wastes with negligible heat­generating capacity (i. e., short-lived LLW and ILW), former mines, which have been extensively studied and retrofitted, are used for disposal pur­poses. However, before an existing mine can be used for geological disposal purposes, the facility must be thoroughly evaluated and appropriately designed to provide engineering alternatives where the original purpose of a mining facility may diverge from the safety and isolation requirements of a repository. For heat-generating waste, only a purpose-built facility in pre­viously undisturbed geological formations is seen as appropriate.

Currently, Germany operates an underground exploratory facility in the Gorleben salt dome. The exploratory facility is specifically tasked with studying the suitability of the Gorleben salt dome as a potential repository host formation for heat-generating wastes. However, the site has not yet been selected as a potential repository and a final decision on the site ’s suitability will depend on the results of additional investigations and posi­tive findings from future safety assessments.

Germany currently has three existing facilities which are classified as geological repositories for the disposal of nuclear wastes with negligible heat-generating capacity: Asse, Morsleben and Konrad. Asse and Morsle — ben will both undergo closure as repositories in accordance with the AtG, but only Konrad was licensed for disposal under the AtG.