Decommissioning is the final phase in the lifecycle of a nuclear installation and is to be considered part of a general strategy of environmental restoration after the final suspension of the industrial activities. At present, over 110 nuclear facilities within the Union are at various stages in the decommissioning process and it is forecast that at least a further 160 facilities will need to be decommissioned over the next 20 years (within the present 15 Member States). Enlargement of the Union would contribute to a rapid increase in the number of nuclear facilities to be decommissioned (at least 50 facilities).
Since 1979, the European Commission’s DG Research has conducted four successive five-year research and development programmes on the decommissioning of nuclear installations performed under cost-sharing contracts with organisations within the European Union. The main objective of these programmes was, and still is, to establish a scientific and technological basis for the safe, socially acceptable and economically affordable decommissioning of obsolete nuclear installations.
These programmes were carried out by public organisations, research institutes and private companies in the Member States under shared-cost contracts and concerted actions. The main objectives of these activities were to strengthen the scientific and technical knowledge in this field, with a particular view to enhance safety and environmental protection aspects, minimising the occupational exposures and dismantling costs as well as the radioactive waste arisings.

Since 1979, more than 60 Mio € have been spent on :

•  the development of decontamination and dismantling techniques for different kinds of nuclear installations
•  technologies for waste minimisation, such as melting of steel components
•  the development of decommissioning strategies and management tools
•  the development of remote handling systems for high activated components (TELEMAN programme)
•  development of planning and management tools for decommissioning projects

In the beginning of the 90s, four pilot decommissioning projects were chosen to compare the differences in the approach of :

•  a fuel processing plant (AT1 in La Hague)
•  a gas-cooled reactor (WAGR in Windscale)
•  a boiling water reactor (KRB-A Gundremmingen in Germany) and
•  a pressurised water reactor (BR-3 in Belgium)

Five years ago, a VVER type reactor (Greifswald in Germany) has been added to this list of pilot decommissioning sites.

The WAGR dismantling, for instance, served as a bridgehead for the future dismantling of graphite gas-cooled reactors. It was an extremely important textbook case, which rightly used the most modern techniques, thus enabling the choice of the scenario which is best suited to lower, the doses received by the operators, the costs, and the volumes of the wastes.
Operations to remove the reactor internals were undertaken with the use of innovative dismantling techniques involving amongst others :

•  Computer-controlled Remote Dismantling Machine using stereoscopic television cameras to assist in the dismantling process;
•  Acoustic-cleaning of electrostatic pre-filters;
•  Ultra-violet laser to decontaminate vital parts of the machine before maintenance;
•  Video-gamma-camera to identify and sort radioactive materials and hot spots.

The dismantling of the BR3 in Belgium concentrated successfully on developing dry and underwater cutting techniques for the highly activated core internals.
The Greifswald decommissioning project, one of the largest in the world, started the stage 3 dismantling of five commercial VVER-440 reactors in Greifswald and one VVER-70 reactor in Rheinsberg. The remote-controlled dismantling of the first reactor pressure vessel and reactor internals, using a new developed robotic system, has been started in 2001.
In the KRB-A (Germany), a 250 MWe Boiling Water Reactor, the dismantling of the core internals, the heat exchanger, the activated concrete bio-shield and the reactor pressure vessel was finished.
The AT1 reprocessing plant in France has successfully completed its decommissioning period and the site is currently being cleaned up for further use.

Within the EC programme, two databases on decommissioning have been created :

•  EC DB TOOL for collecting technical performance data and
•  EC DB COST for collecting data on waste arising, doses etc ...

Both are now being merged into one database, EC DB NET, which will be available on the internet (so far only, in first instance, for members of the project group).
The interest from the IAEA and the OECD/NEA and EC in the development of a common understanding of the decommissioning process led to the creation of a list of Standardised Decommissioning Cost Item Definitions (INCOSIT), another project under FP-4, to ease a world-wide comparability and transferability of data on decommissioning.
With this set of standardised decommissioning cost items it should be possible to create a common tool for the calculation of whole decommissioning projects, regardless of the type of reactor or the chosen method of dismantling.
Under FP-5, a first benchmark exercise on decommissioning costs of VVER reactors is being executed. Similar activities, using the same list, are currently under work in the IAEA and OECD/NEA.

With the support of the EC, conferences, workshops and seminars were held on :

•  Melting of dismantling steel;
•  Decommissioning strategies;
•  The use of databases and
•  Dismantling techniques.

Under the 4^th Research Framework Programme of the EC (1994–98), a 20-year period of EC funded research activities in the decommissioning field was concluded, which has been qualified as essential in that sector. It can be stated that most of the dismantling techniques and technologies involved in the decommissioning process have reached industrial stage.
A large number of Final Reports and publications on various aspects of decommissioning are available (most of the time) at the EC service or from the relevant authors.
The activities in the decommissioning which are supported in FP-5 are clearly shifting from research on technology to :

•  dissemination of results from former research activities
•  exchange of experience and provision of training
•  collection of relevant data from decommissioning projects as well as
•  development of decision-supporting and management tools
•  integration of the needs of the candidate countries.

The current Work programme in Nuclear Fission Research supports the creation of networks to :

•  " exchange of information between national and Community sponsored research;
•   promote exchange and feedback between the research and user communities;
•   achieve consensus or a common understanding on key technical/scientific issues;
•   identify research needs and develop strategies for how they can be addressed, promote training activities within a specific area, etc ..."

And in the Communication of the Commission on the European Research Area (Oct.2000), which will be created within the period of FP-6 (2002-2006), the Commission proposes European Networks of Excellence around special areas of interest.
For this purpose the Commission decided to support the creation of a "Thematic Network on Decommissioning" (www.ec-tnd.net) as an effective instrument for facilitating these objectives. This network is in line with the Commission’s current and future intentions of interconnecting individual, national and European initiatives in a certain field and has the ability to serve as a forum for extended exchange of experience and the integration of future members from the Eastern Europe. It shall involve research facilities, the decommissioning industry, ongoing and future decommissioning projects as well as authorities and regulators.
It is foreseen to provide free access to the database EC DB NET for the members of the network, with the objective, on one side, to disseminate collected experience from different decommissioning projects, but also to receive more data to improve the usability of the database. An extended set of data and a large number of clients are an indispensable condition for a longstanding existence of a database.

Besides the Thematic Network and the database, there are 3 more projects, which received substantial financial support from the Commission under FP-5 :

•   The IRDIT project (Innovative Remote Dismantling Techniques) is dealing with a special aspect of the dismantling process – the remote dismantling of the high-activated reactor pressure vessel (RPV) and its internals. For this aim, two projects were chosen :
  •  The remote cutting of the Russian-type VVER reactor pressure vessels of unit 1 and 2 of the NPP Greifswald (Germany) and
  •  The cutting of the RPV and internals of the BR3 pressurised water reactor in Mol (Belgium).
•   The Standardised Decommissioning Cost Estimation of VVER NPP is a benchmark exercise which is based on the Standardised Decommissioning Cost Item List and shall comprise the real and the planning data of several VVER plants in Germany, Eastern Europe and NIS.
•   The Compendium on the state-of-the-art in Decommissioning shall provide the practical to date experience and knowledge in all aspects of decommissioning - starting with the planning and licensing and finishing with waste management and site release for further use - which has been collected during the last 20 years of the EC research in this field. It is intended to serve as a handbook on decommissioning and shall give practical guidance on all the questions future decommissioning projects might face.

As a result of the latest call under the EC research programme, two consecutive "Training Courses in Nuclear Decommissioning" will be organised by a consortium of experienced decommissioners. These courses shall comprise all main aspects of decommissioning and will also give the possibility to extend the theoretical part with a practical course in one of the partners facilities. The first course will start most probably in the second half of 2002.
With these projects, supported under the current research programme of the Commission, it is intended to create a network of excellence in nuclear decommissioning and to keep and enhance the high level of European expertise and competitiveness in this field.
In recent times a number of decommissioning activities have been started by other international organisations like IAEA or OECD/NEA, as well as in other services of the EC, like DG Environment or DG Enlargement (cost studies, Environmental Impact Assessments etc.). The Commission supports the idea of a close co-operation with the different international bodies in this field and a complementary approach to solve open questions.
As an example could serve the co-operation in the field of cost estimation methodologies, where the NEA (Liaison Committee on Decommissioning), the IAEA (cost studies on VVER) and the EC/DG Environment (decommissioning cost handbook) have recently initiated complementary investigations focusing on different cost aspects of decommissioning.

Where does the Commission still see issues to discuss and to work on during the oncoming years in the decommissioning field ?

•   Cost aspects of decommissioning
  The cost of decommissioning should reflect all activities of the decommissioning process, starting with the planning and licensing and post-operation and finishing with radioactive waste management and site clearance.
  If the decommissioning is deferred for an extended period of time, also surveillance and security of the facility should be taken into account. According to the legal framework, a mechanism has to be established before operation in order to secure the funds needed for the decommissioning of each facility.
  However, for plants that were constructed in earlier nuclear programmes, i.e. in the 50s and 60s or under different legal frameworks as in the Eastern European Countries, funds are often limited, which may have impact on the chosen decommissioning strategy. The decommissioning projects have demonstrated that costs can be managed. Comparisons of individual cost estimates for specific facilities have shown relatively high variations, however, which result mainly from the use of different cost estimation methodologies, using different data requirements. This could be one field for comparison, analysis and discussion.

A second issue in the decommissioning field is the :

•   Radiation safety during decommissioning
  In 1996 the European Commission has issued the Directive on Basic Safety Standards (Directive 96/29/EURATOM).
  It has introduced a series of new measures to improve the protection of the health of workers and the general public. For this purpose, the Directive reduced the dose limits and contains explicit provisions for intervention situations. It also structures the concept of clearance and exemption for materials containing radioactivity.
  To advise the Member States on the implementation of the Directive, DG Environment has issued several publications, i.e.
  
  •   definition of clearance levels
  •   the ALARA concept in Decommissioning
  •   radiological protection criteria for the clearance of buildings
  •   calculation of individual and collective doses from the recycling of metals from
    •  the dismantling of nuclear installations
    •  practical use of the concepts of clearance and exemption.
  There are a number of Final Reports from EC-funded research projects, which deal with radiological aspects in decommissioning as well. There is however a need for clarification and coherence of the current system with aspects such as optimisation, dose limits, triviality, public and environmental protection.
  With respect to operator safety during interventions in hazardous environments, such as areas with alpha contamination, development of safe and comfortable and, in the same time, cost-effective protective clothing equipment is needed. That concerns also the efficiency of protective clothing as well as the biological and physical monitoring of the operator.

Another important aspect is the investigation of

•   Environmental Impact of Decommissioning
  In January, a workshop was organised by the Commission on "Current Regulatory Status on the EU Member States and Applicant Countries" concerning "Environmental Impact Assessment for Decommissioning of Nuclear Installations" (EIA).
  The study, which was initiated and financed by DG Environment, aimed at reviewing the requirements of the relevant EIA Directive of the European Commission (97/11/EC) and to provide guidelines for their application to the specific issue of decommissioning. Special consideration has been given to public involvement in this process.
  As there is presently limited experience in applying EIA to the decommissioning of nuclear power plants in either the EU or in the applicant countries, it is believed that there is a need for discussion and exchange of experience on this item.
  In this context should be stressed the extended work in environmental questions of decommissioning which has been done by DG Environment during recent years.

One of the main issues in decommissioning is

•   Waste treatment and unconditional release of dismantling waste
  The management of large volumes of materials arising from the decommissioning of nuclear facilities represents one of the major tasks to be undertaken and one of the most substantial cost fractions. According to existing experience, less than 1% of the materials produced will be managed as low and intermediate level radioactive wastes.
  Various international organisations, as the IAEA and the EU, have issued a number of release recommendations, relating to exemption and clearance criteria, i.e. the present EC recommendation on unconditional clearance of scrap metal (EC Radiation Protection 89, Recommended radiological protection criteria for the recycling of metals from the dismantling of nuclear installations, 1998).
  In addition, each Member State has its own strategies and policies about waste management, including the material release criteria. Harmonisation of the waste management practices and of the clearance levels among the member states or rather world-wide would be beneficial not only in terms of equivalent levels of safety in waste management and disposal, but also in the minimisation of wastes through release and recycling.
  The newly created Thematic Network could promote the creation of a broadly accepted and coherent system of release criteria and associated regulations for recycling and reuse of materials from decommissioning, considering all aspects of global optimisation.

•   Socio-economical, political and public perception issues are the major non-technical problems influencing decommissioning projects. They should be addressed as early as possible in the conceptual phase of a decommissioning project.
  In case of an early shut down of a plant, the questions will gain even higher importance. As some of the Eastern European operators will have to face the challenges of an early shut down, it is most valuable to have the possibility to gain from outside experience to build a strategy on employment of redundant staff, educational and training programmes and site development and reuse.
  In this respect should be mentioned the successful strategy on the reuse of the Greifswald decommissioning site where currently 1.5 Billion DM (about 745 Mio €) foreign investments are under negotiation (which, by the way, supports the strategy of immediate dismantling and site clearance).
  
  Public perception is one of the main issues related to nearly all activities in the nuclear field, and there is room for strong improvement. Therefore the current co-operation projects under FP-5 should provide a forum for the exchange of experience and the start of new initiatives.
  In this respect, the EC supported Decommissioning web-site (http://www.ec-decom.be) should be mentioned, which provides an opportunity for all interested parties working in the nuclear decommissioning to provide data and information and make it an interactive forum to communicate with the public.

Conclusion

The European Commission recognised very early the need for research, development and demonstration of an effective and safe decommissioning of nuclear installations after completing operation.
With more than 140 nuclear power plants and almost the same amount of research reactors within the Member States there was a clear need for a programme on decommissioning and dismantling of those installations.
Relating to the results of a 20-year research and development programme, comprising all aspects of a decommissioning project including the management and treatment of dismantling waste, this programme contributed significantly to the fact that the European nuclear industry currently is probably one of the few industries that has demonstrated to be able to manage successfully the end-of-life of their installations.
It can be stated that Decommissioning and Dismantling of nuclear installations have reached industrial stage and is a mature technology.
In order to disseminate the accumulated know-how and improve the exchange of information within the participating organisations, databases have been set up, a thematic network, which is open for all interested parties, has been created and a compendium on the state-of-the-art knowledge in Decommissioning and Dismantling is under way.
This wide dissemination of knowledge and best practice in the decommissioning through international co-operation, networking, training activities, conferences and workshops integrating future Member States of the European Union should provide the basis to keep and enhance the existing high level of expertise in this field.
However, there is still room for discussion and improvement, especially in strategy and management, reduction of waste arising, harmonisation in recycling and reuse of materials, free release levels as well as on assessment of environmental impacts and public perception issues.
Despite the common opinion that the EC should further decrease the funding of research activities in the nuclear decommissioning, there is also a common attitude to continue the support for dissemination of best practice and accumulation of knowledge within networks of excellence and through co-operation with international organisation which are active in this field.

References

1.	Research and Training Programme in the Field of Nuclear Energy , 1998 to 2002, Official Journal, L 26, Febr. 1999
2.	Remote Dismantling Operations – WAGR Decommissioning , T Benest et al., UKAEA Windscale, Final Report to EC contract n°FI4D-CT95-0006
3.	A Proposed Standardised List of Items for Costing Purposes in the Decommissioning of Nuclear Installations , Interim Technical Document, OECD/NEA-IAEA-EC 1999
4.	The BR3 Pressurised Water Reactor Pilot Dismantling Project , Final Report, V Massaut et al., EUR 18229, 1998
5.	Study into the Development of a Decommissioning Planning Tool , Final Report to contract FI4D-CT96-0008, Garner/Colquhoun/Elder, NLM Co Ltd., 1999
6.	Decommissioning of Nuclear Plants and Related Waste , Euroelectric, June 2000
7.	Recycling and Reuse of Radioactive Material in the Controlled Nuclear Sector , Hopkinson/Bishop/Cross/Harrison, AEA Technology, EUR 18041, 1998
8.	IAEA TECDOC-1032, Factors for formulating strategies for environmental restauration , July 1998
9.	IAEA-TECDOC-1133, The decommissioning of VVER type nuclear power plants , January 2000
10.	IAEA-TECDOC-855, Clearance levels for radionuclides in solid materials – Application of exemption principles , 1996
11.	Decommissioning experience in the European Union to date , V Massaut et al., paper presented at the EURADWASTE’99 conference, 15-18 Nov. 1999 in Luxembourg
12.	Proceedings of the second workshop "Decommissioning of Nuclear Installations – Technical Aspects" , Mol 8 –10 June 1999, EC Doc. XII-217-99
13.	Proceedings of the first workshop "Decommissioning of Nuclear Installations – Strategy and Planning" , Heringsdorf, 21-22 September 1998, EC Doc.XII-25-99
14.	Proceedings of the joint NEA/IAEA/EC workshop on "Regulatory Aspects of Decommissioning" , Rome, 19 –21 May 1999, ISBN 8-448-0033-0
15.	Managing Radioactive Waste in the European Union , Publication of the EC, DG Research, 1999

   © European Commission, DG RTD, J/4