IAEA - WATRP REVIEW IN NORWAY
- ITS SCOPE, RECOMMENDATIONS AND USEFULNESS
Anita A. Sørlie
Norwegian Radiation Protection Authority
P.O. Box 55, N-1345 Østerås, Norway
ABSTRACT
The process to select a site for the disposal of low and intermediate level radioactive waste in Norway has been underway since 1989, when a committee was appointed for this purpose.
In 1992, the Directorate of Public Construction and Property (Statsbygg) prepared its impact assessment for a repository for Norway's low and intermediate level waste in accordance with the Planning and Building Act. Three sites, the Killingdal Mine together with Kukollen and Himdalen in the Kjeller vicinity, were evaluated. The steering committee recommended Himdalen as the preferred site. Based on the recommendation the Storting (Parliament) decided in April 1994 that a combined storage and disposal facility should be built in Himdalen. The Storting however recommended that a review of the storage and disposal facility should be made within the Waste management Assessment and Technical Review Programme (WATRP) of the International Atomic Energy Agency (IAEA), before a construction licence could be granted.
In December 1994 the Norwegian Radiation Protection Authority (NRPA) requested a WATRP review from the IAEA. The scope included review of the legal framework, long term safety and the site selection process. The review team consisted of five members with Mr. Zurkinden, Switzerland as the chairman. In September 1995 a review meeting was convened in Oslo where the team and IAEA representatives met with Norwegian experts and also visited the Himdalen site. The chairman presented the team's conclusions and recommendations at a press conference the last day of the meeting. Within the scope of the review the team is satisfied and believes that Himdalen with the technical concept is a suitable site.
The WATRP review was performed at the right time in the process. Some site investigations had been carried out, most of the technical design and part of the safety analyses, but before submission of license applications. At this stage the WATRP team recommendations was an "approval" of the work planned to be done and it was also time enough to take recommendations for additional investigations, calculations and analyses into account.
Statsbygg used the WATRP teams recommendations in their application for a construction license. For NRPA it has been a useful "checklist".
NRPA can highly recommend this service provided by the IAEA, the review process is carried out in a professional way with highly qualified experts.
INTRODUCTION
The Norwegian Radiation Protection Authority (NRPA) is the regulatory body in Norway for both radiation protection and nuclear safety.
In 1989, a committee was appointed by the government to investigate possible solutions for final disposal of all the Norwegian LLW and ILW [1].
In 1992, an impact assessment was performed including three possible disposal sites, with a recommendation for one of them. This was an engineered rock cavity facility in Himdalen, 25 km from the Kjeller waste conditioning plant [2]. During the Parliamentary committee deliberations it was proposed that it should be a combined storage and disposal facility, with storage of the plutonium bearing waste and disposal of the short lived waste.
In April 1994 the Storting (Parliament) decided to go on with investigations at the Himdalen site and that it should be a combined facility, it was also recommended that an IAEA - WATRP review should be performed before the granting of a construction licence. In December 1994 NRPA sent such a request to IAEA.
The Norwegian Nuclear Programme and the Origin of the Norwegian
Radioactive Waste
Norway does not have any nuclear power plants, although there are two research reactors. The Institute for Energy Technology (IFE) operates these two reactors located in Halden, 110 km south-east of Oslo and at Kjeller, 25 km east of Oslo. IFE is an industrial foundation funded from the national budget and from commercial research programmes.
Main research areas at the Halden reactor are reactor safety, technological research and development. Fuel testing, the OECD/Halden project, and research on man-machine interactions are two important tasks. The waste is mainly ion exchange resins. Tested fuel elements are returned to their owners.
The JEEP II reactor at Kjeller is used to produce pharmaceutical products and irradiation services for medicine, industry and research. Neutron beams from the reactor are used to study the fundamental physical characteristics of solids and liquids.
The origin of the Norwegian waste is summarised below:
Waste amount and Radioactivity Content
The low and intermediate level waste in Norway is presently conditioned and stored at IFE, Kjeller. Most of the waste is packed in 210 L steel drums, but also 800 L boxes are being used. An equivalent of about 2400 drums is in store.
In 1970 it was decided to bury the waste drums (210 L) that had been generated in Norway until then at the Kjeller site in a 4 m deep trench, stacked in two layers and covered by 2 m of clay. There are no engineered barriers. [3]. This waste will be retrieved, reconditioned and transferred to the new storage and disposal facility when it is available.
About 120 drums of waste are generated per year. About 75 per cent of the waste volume originates from the activities connected to the research reactor programme.
Up to the year 2030 it is estimated that an equivalent of about 10 000 drums of low and intermediate level waste with a total activity of approximately 520 TBq including about 104 g of plutonium will have been generated [4].
DESCRIPTION OF THE COMBINED STORAGE AND DISPOSAL FACILITY
The combined storage and disposal facility will be built into a hillside in crystalline bedrock. The rock formation on the Himdalen site is Precambrian Mylonitised Gneiss.
The facility will have four caverns for the waste packages and one slightly inclining 150 m long access tunnel for vehicles and persons. A service, control and visitors room, will be built along the tunnel inside the facility. The rock caverns will be excavated with about 50 meters of rock covering. The geological covering is for protection against intruders, plane crashes etc. and it is not intended to be taken into account as a main barrier in the long term safety calculations.
In each cavern a solid sarcophagus incorporating the concrete floor and walls will be created. The roof of the sarcophagus will be shaped to shed infiltrating ground water and a waterproof membrane will be fixed to the concrete roof. Three caverns will be used for disposal, the drums will be stacked in four layers, and one cavern for storage.
Operation is planned to start in 1998, the operational period is expected to last until the year 2030, this would take care of all Norwegian low and intermediate level waste, including decommissioning of the research reactors and laboratories at IFE.
Based on the experience during the operational period and safety reports for the closure, it will be decided whether to retrieve or dispose of the waste in the storage part by encasing it with concrete. During operation one does not intended to retrieve any of the waste that has been placed into the storage facility.
The facility will be closed by backfilling the disposal caverns in such a way as to permit functioning of the drainage for a very long time because it is anticipated that the caverns will be maintained in a drained condition after closure of the repository. It is intended to have an institutional control period of 300 -500 years with monitoring the discharges and restrictions on land use.
THE WATRP REVIEW
IAEA's WATRP System
WATRP has been developed by the IAEA to serve Member States through technical assessments and peer reviews of their national policies, programs or facilities related to the management of radioactive waste [5].
Upon the request of a Member State, or an organization within a Member State, the IAEA undertakes the responsibility of convening an international panel of experts to perform such a peer review in accordance with the terms of reference established by the requesting Member State or organization.
The mechanism used for this purpose typically includes a review of source material, an exchange of information with the applicant's experts in a review meeting and a compilation of the findings in a review report.
The advantage of such a peer review for the requesting Member State or organization consists of obtaining independent international expert opinions and advice. The experts perform their reviews in their personal capacities independent of their governments or the IAEA, which means that the final review results present the insight of the experts and not necessarily of their country or organization or the IAEA.
The conclusions and recommendations of the WATRP experts are based on IAEA standards, internationally accepted principles and proven practices taking into account the general consensus on the most viable options for solving particular tasks .
The Scope
A prepatory meeting in Oslo with representatives from IAEA was held to discuss the scope of the review, the time schedule and possible experts (to avoid that IAEA would contact experts that had been involved in the process earlier). In December 1994 NRPA sent the request to IAEA for a WATRP review [6].
The scope of the requested Norwegian review was to evaluate:
The main purpose was to review the safety and radiation protection aspects of the chosen solution as outlined:
Waste management in Norway:
The WATRP Team and its Work
The IAEA accepted the Norwegian request and called in an international expert team consisting of Dr. Auguste Zurkinden (Chairman), Switzerland; Mr. Douglas Metcalfe, Canada; Mr. Dominique Delattre, France; Prof. Dr. Jae-Il Kim, Germany; Dr. Michael Bell, USA; The experts had no former connections to the project or the involved Norwegian organisations.
NRPA provided the expert team with an overview report of the siting procedure, the legal framework, the site and the concept (Feb. 95) in order to make them acquainted with the situation in Norway.
All reports and documentation were originally written in Norwegian and therefore had to be translated into English for the purpose of this review. The team got a list over the material that was going to be translated and also an overview of all available /produced documentation and the team members were free to request any material they wanted. They were also provided with all documents that were produced during the review period (site investigations and design work was going on).
In August 1995 the chairman sent a set of questions from the team to NRPA. These questions were to be answered and discussed at the review meeting in Oslo in September 1995.
Particular one group of concerned citizens kept sending letters to IAEA requesting different aspects to be covered in the review. IAEA forwarded these letters to NRPA. NRPA summarised the questions raised and included also questions that had been raised from other concerned groups during the work. This summary was presented and discussed with the WATRP team and included into the team's evaluation of the storage and disposal facility.
All relevant Norwegian experts currently working on the project and also those that had been involved earlier participated at the review meeting. Two days of the meeting were used for discussions, one day for an excursion to the Himdalen site and to the waste conditioning facility at IFE and two days for drafting the review report. On the third day the team presented their preliminary conclusions for a discussion with the Norwegian experts and then started to write the report. The review meeting ended with a press conference and a press release.
The main findings, views, conclusions and recommendations of the team are summarised in the review report. The report was printed in a limited number and confidential. IAEA submitted the report to the team members and NRPA. The report was translated and declassified and published as a two language document, the original received from the IAEA and the Norwegian version, by NRPA [6].
After the press conference five representatives from groups of concerned citizens had a long discussion with the chairman Mr. Zurkinden and the IAEA scientific secretary Mr. Warnecke. The members of the groups claimed that the team had not been provided with a complete documentation. It was of course a big disappointment for them that the team approved the site and the technical concept chosen.
The WATRP press release was covered by TV (short announcement at the news and text-TV) and the main newspapers. They were not present at the press conference. The local press (small communities) has been following the process closely, especially the initiatives of the groups of concerned citizens.
WATRP TEAM RECOMMENDATIONS
Within the scope of the review, the team was satisfied with the overall approach taken by the responsible Norwegian organisations in the development of the storage and disposal facility for low and intermediate level waste. Based on the existing information the review team believed that the Himdalen site, in combination with the engineering concept (sarcophagus), can be suitable for the storage and disposal of the relatively small amounts of Norwegian low and intermediate level waste. The review team emphasised that it is only necessary to find a suitable site, and in fact it is not necessarily possible to find the best site. The team encouraged the responsible Norwegian organisations:
The main findings, views, conclusions and recommendations of the team are summarised in the review report. Recommendations have been highlighted in the text to make them clearly visible. I will now give some examples of the teams recommendations.
Legal Framework
"Progress in site characterisation and in definition of the project have modified the project. The modifications appear to be improvements, but as a matter of precaution, however, the team recommends to verify whether the modifications to the project require the submission of an updated version of the impact assessment and the initiation of a new procedure according to the Planning and Building act".
"Since both Statsbygg and NRPA are governmental organisations, the team is satisfied that the funding for possible post-construction actions will not be particularly difficult. The team recommends that the legal system clearly identifies the body responsible for the post-construction phase."
"The team is satisfied with the regulatory control by NRPA of the operating organisations. Quality assurance systems is one important point. The team recommends that NRPA strengthens its technical oversight by conducting on-site inspections and verifications".
Approach to the Selection of Site
"The team considers the choice of the Himdalen site as sensible. The choice was based on a level of information which is typical at this stage of a repository project. The team recommends that the suitability of the site be confirmed by considering additional site specific data gathered during the construction period".
Proposed Site and Disposal Concept
"Additional investigations will be carried out during the construction of the facility. In order not to unduly disturb the site, the team recommends that additional boreholes be kept to the minimum required for site characterisation and confirmation and all boreholes be suitably sealed at the end of their planned use".
"The team agrees that the hydraulic cage design for the sarcophagus is an appropriate approach to isolating the disposed waste from flowing ground water and keep the repository in a drained stage. The team recommends that the drainage system should be designed in such a way that it will effectively remove groundwater inflows into the facility for a suitably long period of time even under the occurrence of future adverse events and processes".
"The team paid special interest to the seismic situation of the site and expressed its view that a nuclear facility has to be designed in accordance with a design earthquake. Therefore the team recommends a design earthquake should be established for the storage and disposal facility and the potential impacts of such an earthquake on the integrity of the sarcophagus, the groundwater inflow conditions, rockfall and other relevant aspects and components of the disposal facility should be assessed".
"The team acknowledges that the drainage system and the concrete barrier of the sarcophagus are very important features of the proposed concept. It agrees with the NRPA criteria and recommends that the performance requirements for the concrete and the time frames over which those requirements need to be met should be met and that the space provided for the hydraulic cage between the sarcophagus and the cavern walls be kept to a minimum, taking into account operational and radiation protection needs".
Safety Assessment
"Since the inventory of long lived waste is fundamental to the long term safety of the facility, the team paid special attention to this matter. The team recommends that all long lived radionuclides which may be present in the waste be considered, unless it has been demonstrated that they are not significant and acceptable limits for the total inventory of long lived radionuclides in the facility be determined on the basis of safety assessments".
"The team agrees that mostly conservative assumptions have been made in the development of the scenarios described. The team recommends that a thorough analysis of all creditable processes and events influencing the future evolution of the repository system be made, from which scenarios covering the range of possibilities should be derived".
"As a matter of confirmation the team recommends that the gas generation in the storage and disposal facility and the consequences for the facility should be evaluated".
FOLLOW UP
The WATRP review was performed at the right time in the process of building a disposal facility. The team evaluations and recommendations was a support to Norwegian organisations involved, that the siting process had been well performed and that the work planned to be done was suitable. It was also early enough to have time to do more calculations, analyses and examinations. The recommendations could be followed up before all the safety analyses was done and the application for construction license was sent. As examples an earthquake design was done by NORSAR [7] and calculations by the Norwegian Geotechnical Institute [8]. Gas generation scenarios and consequences for the facility was performed by AEA Technology (UK), a subcontractor to Statsbygg [9].
Statsbygg has used the recommendations from the team when making the license application and the safety analyses. In the application they have listed all recommendations relevant for them and showed in which way they have been taken into account.
The team reviewed the legal framework and the requirements set by the authorities for the applications and the safety reports. In its report the team discussed these aspects and agrees with the NRPA criteria. This is a help for the NRPA when handling the license applications and safety reports. The review report can also be used as a "check list".
The IAEA-WATRP review is a support for the Norwegian organisations involved but it is also helpful for other organisations and concerned citizens that a group of external experts have evaluated the work done in Norway.
The WATRP report was published as a two language document. The layout of the report is very good and it has been a useful information material to send to persons contacting NRPA. The WATRP report also provides an important support when it is necessary to answer questions raised by politicians and the media.
CONCLUSION
The WATRP review contributes to improving the confidence in the planned waste management systems, and helps to ensure that those systems perform in a safe and reliable manner. The review also helps improve public acceptance of the planned storage and disposal facility.
The review report is written in short, numbered paragraphs and the recommendations are highlighted. This ensures its easy use and easy reference.
The WATRP review is a useful assessment of the work done during the siting activities, legal framework and the technical concept. The review report from IAEA, written in the personal capacity of five international experts, presents its self as an objective report that Norwegian authorities and others can use in assessing waste management practises in Norway now and in the future.
The NRPA can highly recommend this service provided by the IAEA, the review process is carried out in a professional way with highly qualified experts. To use experts from different countries and from different parts of the world adds an (extra) international weight to the report. Norwegian authorities would consider the use of the service again whenever a waste management project is developed.
REFERENCES