- Email: [email protected]
External costs of material recycling strategies for fusion power plants
Fusion Engineering and Design 69 (2003) 699 /703 www.elsevier.com/locate/fusengdes
External costs of material recycling strategies for fusion power plants B. Hallberg a,*, K. Aquilonius a, Y. Lecho´n b, H. Cabal b, R.M. Sa´ez b, T. Schneider c, S. Lepicard c, D. Ward d, T. Hamacher e, R. Korhonen f a
Studsvik Eco and Safety AB (Ass. Euratom/VR), SE-611 82 Nykoping, Sweden b Euratom/Ciemat, Avenida Complutense, 22, E-28040 Madrid, Spain c CEPN (Ass. Euratom/CEA), BP48, F-92263 Fontenay aux Roses Cedex, France d Euratom/UKAEA Fusion Ass., Culham Science Centre, Abingdon, Oxon OX143DB, UK e Euratom/IPP, D-85748 Garching, Germany f VTT Processes, (Ass. Euratom/TEKES), P.O. Box 1606, FIN-2044 VTT, Espoo, Finland
Abstract This paper is based on studies performed within the framework of the project Socio-Economic Research on Fusion (SERF3). Several fusion power plant designs (SEAFP Models 1 /6) were compared focusing on part of the plant’s life cycle: environmental impact of recycling the materials. Recycling was considered for materials replaced during normal operation, as well as materials from decommissioning of the plant. Environmental impact was assessed and expressed as external cost normalised with the total electrical energy output during plant operation. The methodology used for this study has been developed by the Commission of the European Union within the frame of the ExternE project. External costs for recycling, normalised with the energy production during plant operation, are very low compared with those for other energy sources. Results indicate that a high degree of recycling is preferable, at least when considering external costs, because external costs of manufacturing of new materials and disposal costs are higher. # 2003 Elsevier Science B.V. All rights reserved. Keywords: Fusion; External costs; Externalities; ExternE; Recycling; SERF
1. Introduction Fusion power is an option for providing large amounts of energy, and has a virtually inexhaustible supply of fuel and a comparatively low environmental impact. Construction of fusion
* Corresponding author. Tel.: /46-155-22-1600; fax: /46155-22-1616. E-mail address: [email protected] (B. Hallberg).
power plants involves using materials, such as metals, which are in limited supply, however. When introducing new technology, being able to demonstrate a high degree of possibility to recycle materials is becoming important when society is converting to a more sustainable use of natural resources. Furthermore, recycling should have low environmental impact compared to that of using new materials. A way to provide a measure of impact is the concept of external costs [1], which involves
0920-3796/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0920-3796(03)00101-7
B. Hallberg et al. / Fusion Engineering and Design 69 (2003) 699 /703
700
Table 1 Main features of SEAFP plant models Plant model
First wall and blanket structure
Tritium-generating material
Neutron multiplier
First wall and blanket coolant
1 2 3
Vanadium alloy Low activation martensitic steel Low activation martensitic steel
None Li17Pb83 Beryllium
Helium Water Helium
4 5
SiC/SiC Low activation martensitic steel with SiC/SiC insulators SiC/SiC
Li2O ceramic pebble bed Liquid Li17Pb83 Li4SiO4 ceramic pebble bed Liquid Li17Pb83 Liquid Li17Pb83
Liquid Li17Pb83 Li17Pb83
Li4SiO4 ceramic pebble bed
Beryllium
Liquid Li17Pb83 Helium and liquid Li17Pb83 Helium
6
Data for models 1 /3 from [5], and models 4 /6 according to [6].
employing methods of converting effects on health and environment into monetary units. The methods were used in previous studies within the SocioEconomic Research on Fusion (SERF) programme [2]. To our knowledge, there exists no scheme to monetarise the use of a limited supply of natural resources. Only external costs of recycling are therefore treated in this paper. In earlier work [3] external costs of providing building materials to a fusion plant, and disposal of radioactive waste, were reported. Those results are used in this paper to compare with external costs of recycling. This study illustrates differences in environmental impact between several designs of a commercially operated fusion power plant, cf. Section 2. We are concerned with part of its life cycle: replacement of materials while in operation, and decommissioning and waste management after closure, see Section 3.
2. Plant models The fusion power plant designs under study were those of the safety and environmental assessment of fusion plants (SEAFP), see [4]. These are called models 1/6, cf. [5,6]. The models differ mainly by the type of materials used for core reactor components and type of cooling medium, see Table 1.
Fig. 1. Flow of materials exchanged during normal operation and after decommissioning.
3. Description of decommissioning and waste management Decommissioning and waste management involves exchange of materials during operation of a fusion plant, as well as after shutdown. Activities are mainly waste handling and decontamination and demolishing of buildings. Handling of radioactive waste and conventional waste was divided into main activities: segmentation, packaging, intermediate storage, transport to repositories and recycling plants, and recycling. Two waste handling scenarios were considered, one according to present practice (PP), and another according to a future prospective scenario (RZ) in which a large part of the activated waste is assumed to be recycled and used to produce new
B. Hallberg et al. / Fusion Engineering and Design 69 (2003) 699 /703
701
Table 2 Activated recyclable waste and cleared recyclable waste according to PP and a future prospective scenario (RZ) Plant model Activated recyclable waste (PP) tonnes Activated recyclable waste (RZ) tonnes Non-activated recyclable waste tonnes 1 2 3 4 5 6
15 800 22 000 15 800 18 519 18 508 18 519
34 300 59 800 32 500 46 522 65 232 33 270
179 400 168 700 179 400 216 500 216 500 216 500
Data regarding activated waste were taken from [8] (Models 1 /3), and [9] (Models 4 /6).
fusion power plant components [7]. The latter has been devised to minimise the amount of waste for final disposal. Different material streams were considered for activated recyclable parts and conventional recyclable parts, see Fig. 1. Regulations regarding transport and handling of radioactive materials will govern how they are treated. It will be possible to recycle some components only up to 100 years of storage, which was assumed to take place at the plant site. Some parts have to be taken to final repositories. This amount varies between designs, see Table 2. A comparatively small amount of radioactive slag remains after recycling and must be transferred to a repository.
4. Methods and data for estimation of external costs The site chosen for the fusion power plant was, in this and earlier SERF studies, Lauffen-amNeckar north of Stuttgart in the province Baden/Wu¨rttemberg in Germany. A bedrock repository for high level waste and long-lived intermediate or low level waste was assumed to be located at Gorleben, and the repository for low and intermediate level waste at Konrad, an abandoned iron mine. Both sites are in the province Niedersachsen. In the PP scenario, recycling of conventional materials and materials with a low level of radioactivity was presumed to take place at different present-day recycling facilities. In the future prospective scenario, much of the waste was assumed to be transported to a combined
recycling and fusion reactor component production plant. This will be a very specialised plant, and we postulated that there would be only one such in Europe. Therefore, it was assumed to be further away (/1500 km) from Lauffen-amNeckar than the recycling plants considered in the PP scenario (200 km). ExternE methods have been used. These are bottom-up and have a site-specific and marginal approach, i.e. they consider the extra impact of the studied activities at the presumed site. An example is release of effluents from vehicles used for transports. This contributes to e.g. diminished public health and acidification effects on crops. The impacts were translated into costs, e.g. cost for health care and diminished harvests, using impact-cost factors from ExternE. No discounting for future costs was applied. Altogether, impacts were considered on a local scale, regional scale and in one case also global scale. External costs were normalised with the produced electrical energy. The assumption for plant models 1/3 was a reactor with an electrical power output of 1000 MW, in operation for 35 years with 75% availability, yielding a total electricity production of 2.3 /1011 kW h. The corresponding value for the 1500 MW models 4/6 was 3.45 /1011 kW h. Uncertainty analysis was made using the PRISM code system, described in Ref. [10]. After specification of model parameters and their distribution, an ensemble of input data files was generated. Running the external cost calculation model with these produced a set of output data files, the results of which were distributions of result variables. The median of each variable was taken as
702
B. Hallberg et al. / Fusion Engineering and Design 69 (2003) 699 /703
Fig. 2. External cost for recycling (mt/kW he), according to PP (a) and a future prospective scenario (b).
mid estimate, while the 5 and 95% percentile were used as minimum and maximum estimates, respectively. Transport of radioactive waste to final repositories and transport of conventional and radioactive materials to recycling plants were considered for the two waste handling scenarios. The model takes into account amount of materials, distance to disposal site and recycling plant, external costs due to emissions from vehicles and increased
number of accidents due to increased traffic. External costs include impacts on public health, crop yields etc. A straight-line gaussian atmospheric dispersion model [11] was employed to calculate yearly average concentrations of dust and radioactivity around a recycling plant. Meteorological data representative for the Lauffen-am-Neckar site was used. Impacts due to particle releases and radiological exposure were calculated on a local scale.
B. Hallberg et al. / Fusion Engineering and Design 69 (2003) 699 /703
The nuclide C-14 deserves special attention because it enters the global carbon exchange, and thus may cause global exposure. The global collective effective dose commitment, integrated over 100 000 years, was calculated according to the methodology used in ExternE [12], see [13].
5. Results and discussion External costs for the present practice scenario and the future prospective scenario are found in Fig. 2a and b, respectively. Results for models 1/3 were taken from [13]. The external costs of recycling are quite low, and do not differ much between scenarios and models. This is because the main contributor to the results is release of dust from recycling plants, and the amount of conventional materials is larger than the amount of activated materials, cf. Table 2. Costs are dominated by acute and chronic public health impacts. Models 2 and 5 have more materials, and therefore higher costs. External costs for manufacturing materials and disposal pertaining to models 1/3 are found in Ref. [3]. They are about 0.1 and 0.5 / 0.8 mt/kWhy e, respectively, which is rather small, but larger than costs for recycling. This indicates that a high degree of recycling is preferable, at least when considering external costs, even though external costs for using limited natural resources were not taken into account.
References [1] European Commission, ExternE. Externalities of Energy. vol. 2. Methodology, EC, DG XII, Report EUR 16521 EN, 1995.
703
[2] Externalities of fusion. SERF2 (1999 /2000), Ciemat, Spain, 2001. [3] Y. Lecho´n, H. Cabal, R.M. Sa´ez, D. Ward, B. Hallberg, K. Aquilonius, R. Korhonen, T. Hamacher, T. Schneider, S. Lepicard, Exploitation and improvement of the external costs assessment of fusion power, Fusion Eng. Des. 58 /59 (2001) 1027 /1032. [4] I. Cook, G. Marbach, W. Gulden, L. Di Pace, P. Rocco, C. Girard, N. Taylor, Safety and Environmental Assessment of Fusion Power. Report of the SEAL and SEAFP-2 Projects. EC, DG XII, Report EUR 16524 EN, 1995. [5] N.P. Taylor, I. Cook, Description of Plant Models, Blankets and Structural Materials, SEAFP2/5.1/UKAEA/ 1 (Rev. 0), UKAEA Fusion, Culham, UK, March 1997. [6] D.J. Ward, Technical Inputs on Additional Models of Conceptual Fusion Power Plants, UKAEA, Great Britain, 2001. [7] P. Rocco, M. Zucchetti, Recycling and clearance possibilities. Final report of task 4.2. Safety and Environmental Assessment of Fusion Power-2 (SEAFP-2). SEAFP2/ 2.47JRC/4 (Rev.0), August 1998. [8] K. Brode´n, M. Lindberg, G. Olsson, Repository analysis for fusion reactor waste. Studsvik RadWaste AB, RW-98/ 46, Sweden, 1998. [9] K. Brode´n, G. Olsson, Evaluation of possibilities for clearance or repository disposal of tritiated and activated components of the SEAFP-99 plant models. Studsvik RadWaste AB, RW-01/57, Sweden, 2001. [10] D. Hofman, U. Bergstro¨m, PRISM/WINDOWS 4.0 */User’s Manual. Studsvik Eco and Safety AB, STUDSVIK/ES-00/ 31, Sweden, 2000. [11] F. Pasquill, F.B. Smith, Atmospheric Diffusion, Study of the Dispersion of Windborne Material from Industrial and Other Sources, third ed., Ellis Horwood Ltd, Chichester, 1983. [12] European Commission, ExternE. Externalities of Energy. vol. 5., Nuclear, EC, DG XII, Report EUR 16524 EN, 1995. [13] K. Aquilonius, B. Hallberg, Socio-economic research on Fusion 2. Externalities of Fusion. Task 1: Analysis of key variables influencing external costs. 1.1.5. Recalculation of externalities considering new activated materials. 1.1.5.2. Decommissioning and site restoration, Studsvik Eco and Safety AB, Sweden, 2000.
External costs of material recycling strategies for fusion power plants B. Hallberg a,*, K. Aquilonius a, Y. Lecho´n b, H. Cabal b, R.M. Sa´ez b, T. Schneider c, S. Lepicard c, D. Ward d, T. Hamacher e, R. Korhonen f a
Studsvik Eco and Safety AB (Ass. Euratom/VR), SE-611 82 Nykoping, Sweden b Euratom/Ciemat, Avenida Complutense, 22, E-28040 Madrid, Spain c CEPN (Ass. Euratom/CEA), BP48, F-92263 Fontenay aux Roses Cedex, France d Euratom/UKAEA Fusion Ass., Culham Science Centre, Abingdon, Oxon OX143DB, UK e Euratom/IPP, D-85748 Garching, Germany f VTT Processes, (Ass. Euratom/TEKES), P.O. Box 1606, FIN-2044 VTT, Espoo, Finland
Abstract This paper is based on studies performed within the framework of the project Socio-Economic Research on Fusion (SERF3). Several fusion power plant designs (SEAFP Models 1 /6) were compared focusing on part of the plant’s life cycle: environmental impact of recycling the materials. Recycling was considered for materials replaced during normal operation, as well as materials from decommissioning of the plant. Environmental impact was assessed and expressed as external cost normalised with the total electrical energy output during plant operation. The methodology used for this study has been developed by the Commission of the European Union within the frame of the ExternE project. External costs for recycling, normalised with the energy production during plant operation, are very low compared with those for other energy sources. Results indicate that a high degree of recycling is preferable, at least when considering external costs, because external costs of manufacturing of new materials and disposal costs are higher. # 2003 Elsevier Science B.V. All rights reserved. Keywords: Fusion; External costs; Externalities; ExternE; Recycling; SERF
1. Introduction Fusion power is an option for providing large amounts of energy, and has a virtually inexhaustible supply of fuel and a comparatively low environmental impact. Construction of fusion
* Corresponding author. Tel.: /46-155-22-1600; fax: /46155-22-1616. E-mail address: [email protected] (B. Hallberg).
power plants involves using materials, such as metals, which are in limited supply, however. When introducing new technology, being able to demonstrate a high degree of possibility to recycle materials is becoming important when society is converting to a more sustainable use of natural resources. Furthermore, recycling should have low environmental impact compared to that of using new materials. A way to provide a measure of impact is the concept of external costs [1], which involves
0920-3796/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0920-3796(03)00101-7
B. Hallberg et al. / Fusion Engineering and Design 69 (2003) 699 /703
700
Table 1 Main features of SEAFP plant models Plant model
First wall and blanket structure
Tritium-generating material
Neutron multiplier
First wall and blanket coolant
1 2 3
Vanadium alloy Low activation martensitic steel Low activation martensitic steel
None Li17Pb83 Beryllium
Helium Water Helium
4 5
SiC/SiC Low activation martensitic steel with SiC/SiC insulators SiC/SiC
Li2O ceramic pebble bed Liquid Li17Pb83 Li4SiO4 ceramic pebble bed Liquid Li17Pb83 Liquid Li17Pb83
Liquid Li17Pb83 Li17Pb83
Li4SiO4 ceramic pebble bed
Beryllium
Liquid Li17Pb83 Helium and liquid Li17Pb83 Helium
6
Data for models 1 /3 from [5], and models 4 /6 according to [6].
employing methods of converting effects on health and environment into monetary units. The methods were used in previous studies within the SocioEconomic Research on Fusion (SERF) programme [2]. To our knowledge, there exists no scheme to monetarise the use of a limited supply of natural resources. Only external costs of recycling are therefore treated in this paper. In earlier work [3] external costs of providing building materials to a fusion plant, and disposal of radioactive waste, were reported. Those results are used in this paper to compare with external costs of recycling. This study illustrates differences in environmental impact between several designs of a commercially operated fusion power plant, cf. Section 2. We are concerned with part of its life cycle: replacement of materials while in operation, and decommissioning and waste management after closure, see Section 3.
2. Plant models The fusion power plant designs under study were those of the safety and environmental assessment of fusion plants (SEAFP), see [4]. These are called models 1/6, cf. [5,6]. The models differ mainly by the type of materials used for core reactor components and type of cooling medium, see Table 1.
Fig. 1. Flow of materials exchanged during normal operation and after decommissioning.
3. Description of decommissioning and waste management Decommissioning and waste management involves exchange of materials during operation of a fusion plant, as well as after shutdown. Activities are mainly waste handling and decontamination and demolishing of buildings. Handling of radioactive waste and conventional waste was divided into main activities: segmentation, packaging, intermediate storage, transport to repositories and recycling plants, and recycling. Two waste handling scenarios were considered, one according to present practice (PP), and another according to a future prospective scenario (RZ) in which a large part of the activated waste is assumed to be recycled and used to produce new
B. Hallberg et al. / Fusion Engineering and Design 69 (2003) 699 /703
701
Table 2 Activated recyclable waste and cleared recyclable waste according to PP and a future prospective scenario (RZ) Plant model Activated recyclable waste (PP) tonnes Activated recyclable waste (RZ) tonnes Non-activated recyclable waste tonnes 1 2 3 4 5 6
15 800 22 000 15 800 18 519 18 508 18 519
34 300 59 800 32 500 46 522 65 232 33 270
179 400 168 700 179 400 216 500 216 500 216 500
Data regarding activated waste were taken from [8] (Models 1 /3), and [9] (Models 4 /6).
fusion power plant components [7]. The latter has been devised to minimise the amount of waste for final disposal. Different material streams were considered for activated recyclable parts and conventional recyclable parts, see Fig. 1. Regulations regarding transport and handling of radioactive materials will govern how they are treated. It will be possible to recycle some components only up to 100 years of storage, which was assumed to take place at the plant site. Some parts have to be taken to final repositories. This amount varies between designs, see Table 2. A comparatively small amount of radioactive slag remains after recycling and must be transferred to a repository.
4. Methods and data for estimation of external costs The site chosen for the fusion power plant was, in this and earlier SERF studies, Lauffen-amNeckar north of Stuttgart in the province Baden/Wu¨rttemberg in Germany. A bedrock repository for high level waste and long-lived intermediate or low level waste was assumed to be located at Gorleben, and the repository for low and intermediate level waste at Konrad, an abandoned iron mine. Both sites are in the province Niedersachsen. In the PP scenario, recycling of conventional materials and materials with a low level of radioactivity was presumed to take place at different present-day recycling facilities. In the future prospective scenario, much of the waste was assumed to be transported to a combined
recycling and fusion reactor component production plant. This will be a very specialised plant, and we postulated that there would be only one such in Europe. Therefore, it was assumed to be further away (/1500 km) from Lauffen-amNeckar than the recycling plants considered in the PP scenario (200 km). ExternE methods have been used. These are bottom-up and have a site-specific and marginal approach, i.e. they consider the extra impact of the studied activities at the presumed site. An example is release of effluents from vehicles used for transports. This contributes to e.g. diminished public health and acidification effects on crops. The impacts were translated into costs, e.g. cost for health care and diminished harvests, using impact-cost factors from ExternE. No discounting for future costs was applied. Altogether, impacts were considered on a local scale, regional scale and in one case also global scale. External costs were normalised with the produced electrical energy. The assumption for plant models 1/3 was a reactor with an electrical power output of 1000 MW, in operation for 35 years with 75% availability, yielding a total electricity production of 2.3 /1011 kW h. The corresponding value for the 1500 MW models 4/6 was 3.45 /1011 kW h. Uncertainty analysis was made using the PRISM code system, described in Ref. [10]. After specification of model parameters and their distribution, an ensemble of input data files was generated. Running the external cost calculation model with these produced a set of output data files, the results of which were distributions of result variables. The median of each variable was taken as
702
B. Hallberg et al. / Fusion Engineering and Design 69 (2003) 699 /703
Fig. 2. External cost for recycling (mt/kW he), according to PP (a) and a future prospective scenario (b).
mid estimate, while the 5 and 95% percentile were used as minimum and maximum estimates, respectively. Transport of radioactive waste to final repositories and transport of conventional and radioactive materials to recycling plants were considered for the two waste handling scenarios. The model takes into account amount of materials, distance to disposal site and recycling plant, external costs due to emissions from vehicles and increased
number of accidents due to increased traffic. External costs include impacts on public health, crop yields etc. A straight-line gaussian atmospheric dispersion model [11] was employed to calculate yearly average concentrations of dust and radioactivity around a recycling plant. Meteorological data representative for the Lauffen-am-Neckar site was used. Impacts due to particle releases and radiological exposure were calculated on a local scale.
B. Hallberg et al. / Fusion Engineering and Design 69 (2003) 699 /703
The nuclide C-14 deserves special attention because it enters the global carbon exchange, and thus may cause global exposure. The global collective effective dose commitment, integrated over 100 000 years, was calculated according to the methodology used in ExternE [12], see [13].
5. Results and discussion External costs for the present practice scenario and the future prospective scenario are found in Fig. 2a and b, respectively. Results for models 1/3 were taken from [13]. The external costs of recycling are quite low, and do not differ much between scenarios and models. This is because the main contributor to the results is release of dust from recycling plants, and the amount of conventional materials is larger than the amount of activated materials, cf. Table 2. Costs are dominated by acute and chronic public health impacts. Models 2 and 5 have more materials, and therefore higher costs. External costs for manufacturing materials and disposal pertaining to models 1/3 are found in Ref. [3]. They are about 0.1 and 0.5 / 0.8 mt/kWhy e, respectively, which is rather small, but larger than costs for recycling. This indicates that a high degree of recycling is preferable, at least when considering external costs, even though external costs for using limited natural resources were not taken into account.
References [1] European Commission, ExternE. Externalities of Energy. vol. 2. Methodology, EC, DG XII, Report EUR 16521 EN, 1995.
703
[2] Externalities of fusion. SERF2 (1999 /2000), Ciemat, Spain, 2001. [3] Y. Lecho´n, H. Cabal, R.M. Sa´ez, D. Ward, B. Hallberg, K. Aquilonius, R. Korhonen, T. Hamacher, T. Schneider, S. Lepicard, Exploitation and improvement of the external costs assessment of fusion power, Fusion Eng. Des. 58 /59 (2001) 1027 /1032. [4] I. Cook, G. Marbach, W. Gulden, L. Di Pace, P. Rocco, C. Girard, N. Taylor, Safety and Environmental Assessment of Fusion Power. Report of the SEAL and SEAFP-2 Projects. EC, DG XII, Report EUR 16524 EN, 1995. [5] N.P. Taylor, I. Cook, Description of Plant Models, Blankets and Structural Materials, SEAFP2/5.1/UKAEA/ 1 (Rev. 0), UKAEA Fusion, Culham, UK, March 1997. [6] D.J. Ward, Technical Inputs on Additional Models of Conceptual Fusion Power Plants, UKAEA, Great Britain, 2001. [7] P. Rocco, M. Zucchetti, Recycling and clearance possibilities. Final report of task 4.2. Safety and Environmental Assessment of Fusion Power-2 (SEAFP-2). SEAFP2/ 2.47JRC/4 (Rev.0), August 1998. [8] K. Brode´n, M. Lindberg, G. Olsson, Repository analysis for fusion reactor waste. Studsvik RadWaste AB, RW-98/ 46, Sweden, 1998. [9] K. Brode´n, G. Olsson, Evaluation of possibilities for clearance or repository disposal of tritiated and activated components of the SEAFP-99 plant models. Studsvik RadWaste AB, RW-01/57, Sweden, 2001. [10] D. Hofman, U. Bergstro¨m, PRISM/WINDOWS 4.0 */User’s Manual. Studsvik Eco and Safety AB, STUDSVIK/ES-00/ 31, Sweden, 2000. [11] F. Pasquill, F.B. Smith, Atmospheric Diffusion, Study of the Dispersion of Windborne Material from Industrial and Other Sources, third ed., Ellis Horwood Ltd, Chichester, 1983. [12] European Commission, ExternE. Externalities of Energy. vol. 5., Nuclear, EC, DG XII, Report EUR 16524 EN, 1995. [13] K. Aquilonius, B. Hallberg, Socio-economic research on Fusion 2. Externalities of Fusion. Task 1: Analysis of key variables influencing external costs. 1.1.5. Recalculation of externalities considering new activated materials. 1.1.5.2. Decommissioning and site restoration, Studsvik Eco and Safety AB, Sweden, 2000.