Waste strategies compared5 February 2005
The purpose of the ‘Comparison of Alternative Waste Management Strategies for Long-lived Radioactive Wastes’ project was to compare strategies that have been adopted or are being considered for the management of spent nuclear fuel and long-lived radioactive waste. By Mark Dutton and Kathy Hillis
The Comparison of Alternative Waste Management Strategies for Long-lived Radioactive Wastes (Compas) project addressed the policies and strategies for the management of spent nuclear fuel (SNF) and long-lived radioactive wastes – namely high-level waste (HLW) from reprocessing, and long-lived low- and intermediate-level waste (LL-LILW) – that have been developed in many western and central European countries. The comparison reflects the status of the national strategies on 1 September 2003.
The project addressed four aspects:
- The wastes to be managed and ways of changing their properties.
- The issues that have played a major role in influencing the strategies that have been adopted.
- Generic strategies that have been adopted or are being considered.
- The issues that have been important in determining the acceptability of waste management options to stakeholders outside the nuclear industry, and the main elements of the processes associated with options that are being successfully implemented or are being proposed for the future.
HABOG, a storage facility for high-level waste in the Netherlands. The building is recoloured regularly to reflect the temperature of the waste inside
STATUS OF REPROCESSING
The total amount of SNF in the countries participating in the project that will have been discharged from the power plants when they have all come to the end of their operating lives is estimated to be a total of 170,000 tonnes of heavy metal (tHM). Whether this material is managed in the form of fuel elements or not depends on whether it is reprocessed.
Some SNF from many of the participating countries has been reprocessed in the past but, currently, there are no reprocessing contracts in seven of the countries, Germany has announced a date for the end of reprocessing and, in five countries, it is the subject of a government review. There is an assumed date for the end of reprocessing at facilities in the UK. The Netherlands has concluded that the most economical option for the SNF from its commercial nuclear stations is to continue with the existing reprocessing contracts.
The quantity of SNF that is currently planned to be reprocessed is estimated to be 124,000tHM leaving 47,000t to be managed in the form of complete fuel assemblies. The resulting total volume of conditioned vitrified HLW from reprocessing the SNF is about 8000m3.
STRATEGY SELECTION ISSUES
There is a wide range of requirements that must be met in developing a strategy for the long-term management of SNF and long-lived waste. These include international treaties and, for those countries that are, or who will shortly become, members of the EU, there are relevant European Commission (EC) directives. The most important international convention in the present context is the International Atomic Energy Agency Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management, which stipulates the fundamental safety principles in relation to the management of SNF and radioactive waste. It came into force in June 2001 and has been ratified, accepted or approved by all the countries represented in the Compas project.
Other agreements and directives cover important aspects such as: export and import of radioactive waste; disposal at sea and other options; and safeguards.
There are also the requirements to achieve a high level of safety, a low impact on the environment as well as the need to address practical and ethical issues.
Any chosen waste management strategy has to be economically viable and achieving a cost effective solution is an important aspect of managing national liabilities and resources, but it must not preclude achieving an acceptable level of safety and an acceptable approach to the ethical issues. It is generally accepted that there is no single morally correct way to allocate scarce resources or burdens. However, a range of issues associated with the long-term management of radioactive materials generate concern amongst stakeholders. These involve the following important principles:
- Intergenerational equity.
- Intragenerational equity.
- Sustainable development.
- The precautionary principle.
SELECTION OF STRATEGIES
The ways in which the issues identified previously have led to the national strategies that have been selected and are being considered were identified within the project in terms of three decision trees. The decision trees addressed the selection of strategies for:
- The management of SNF.
- The management of LL-LILW.
- Geological disposal.
Node 1: reprocessing of SNF
The main issues that affect the decision on whether or not to reprocess SNF are:
- Maintaining a secure supply of nuclear fuel for energy production.
- Safety and environmental considerations.
- The prospect of a future nuclear power programme that may include advanced nuclear fuel cycles.
- Technical issues.
- Military requirements.
Node 9: long-term management options
The main issues that determine the long-term management option to be adopted are:
- Safety of future generations.
- Preservation of the environment.
- The precautionary principle.
- Intergenerational equity.
The uncertainties or risks associated with some options, notably the disposal of SNF into outer space, disposal in ice sheets and disposal in subduction zones in ocean trenches are considered to be so great that all countries have discounted them. Although such options were previously discounted in the UK, a rigorous and public review by the government of all options (except where they have been ruled out by international agreements) started in 2003.
The options of sea dumping and disposal in deep sea sediments are politically and socially unacceptable in many countries and this has been reflected in international treaties such as the London Dumping and OSPAR conventions, so that the signatories are precluded from these options.
Thus, the long-term (greater than a few hundred years) options that are being considered are land-based geological disposal and indefinite storage. The option that is selected depends on the interpretation that is placed on the above principles and the evaluation of the safety associated with each option.
In Finland and Sweden, it has been concluded that the indefinite storage of SNF is not sustainable and therefore is not in accordance with the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management. In order to fulfil safety requirements it relies on the continued action by future generations and therefore puts an undue burden on them. It has also being argued that safety and security in the case of indefinite storage is highly dependent on societal stability, which cannot be guaranteed. Furthermore, it contravenes the principle of intergenerational equity because the generation that received the benefit from the fuel is not implementing a sustainable solution to its disposal. They are therefore implementing a strategy of selecting a site and constructing a land-based facility for SNF disposal (that is not consigned for reprocessing), vitrified HLW and LL-LILW. The same general view is shared by Germany and Switzerland; and for the Netherlands, Spain and all the EU applicant countries, geological disposal is the preferred option although, in some of these countries, the option of prolonged storage for a few hundred years remains open. The Netherlands has decided to implement a strategy of prolonged storage for at least 100 years.
However, before a strategy of geological disposal can be pursued there must be an acceptance that the general strategy is adequately safe. Such acceptance has not yet been achieved, for example, in France. Similarly, in the UK, the scientific justification and public acceptability of the disposal of radioactive wastes has been questioned. In these cases, further consultation is underway and a government decision should be made in 2006. A similar situation applies to Italy.
The project identified a number of generic strategies: direct disposal of SNF in a deep geological repository; reprocessing and deep geological disposal of vitrified HLW; partitioning and transmutation of SNF; disposal of LL-LILW in a deep geological repository; surface disposal of uranium tailings with in situ capping; and sub-surface disposal of uranium tailings. The example of the generic strategies for direct disposal of SNF in a deep geological repository is given in Figure 2.
ACCEPTANCE OF LONG-TERM OPTIONS
As illustrated in Figure 3, the construction of a facility for the long-term management of spent nuclear fuel and long-lived radioactive waste is one stage of a multi-step process.
The process starts with the decision on the use of nuclear energy and other related issues, such as the use of reprocessing, since this defines the reference scenario for the volume of spent nuclear fuel and radioactive waste that has to be placed in a facility. At the third and fourth steps a decision has to be made on whether or not to proceed and, if the decision is not to proceed, the process must return to the previous step. If the facility incorporates the concept of retrievability, the management of the spent fuel and the waste may not end with its emplacement since there is the option for its retrieval for further processing before it is re-disposed or another option is employed.
In order to identify the issues that are important in gaining acceptance for a long-term waste management project, it is important to identify the stakeholders and the main decision makers. Not all stakeholders will be decision makers and will therefore need to have the opportunity to communicate the issues that concern them to the decision makers.
Storage pools at CLAB, the Swedish interim storage facility for spent nuclear fuel.
Past experience has shown that there are five levels of decision makers who determine whether or not a long-term management option will be implemented. These levels are the national government, the regional government, special courts, the local municipality and the public. The decision-making role of members of the public depends on national arrangements.
Important aspects in obtaining the acceptance of any long-term radioactive waste management facility have been found to include:
- Acceptance of the overall strategy.
- An appreciation of the nature of the waste and the associated risks.
- A recognition of both the need for a solution and the principle that the generation that has benefited from the activities that have produced the waste has a responsibility to ensure it is managed safely in the long term.
- The facility should result in a net benefit to the local community when its advantages are compared with potential detriments.
- The responsibilities of all the parties – the waste producers, the operator, the regulator(s) and the local, regional and national authorities – must be clear, known and recognised.
- Decision makers must have confidence that the regulator and regulatory process will ensure that risks to the present and future generations are acceptably low.
- Independent expert advisory groups, which could make an important contribution.
- Similarities in approach internationally.
- A stepwise approach to the design of facilities, research and development, siting and the acceptance of facilities.
- Funding must be available.
- A restriction on the waste that will be managed by the facility, for example to the waste from existing facilities, can be a factor.
In addition to recognising and addressing the issues that have been summarised in the previous section, the successful implementation of a long-term waste management strategy requires an open, transparent and staged process. Some of the basic requirements for the implementation of a specific long-term waste management strategy include: the existence of a legal framework; identifying the stakeholders that shall take part in the process; and the definition of the stakeholders’ role in the implementation process.
One of the important aspects of the implementation is that it must include a clear, phased decision-making process that: has been developed in consultation with all stakeholders; has clear decision points; explains how decisions will be taken; and provides opportunities for the stakeholders to contribute meaningfully to the process.
A stepwise approach to developing and implementing waste management strategies is emerging, both in terms of selecting the waste management options and the siting process. The stepwise approach to implementation has been defined as a process that involves discrete and easily monitored steps that facilitates the traceability of decisions, allows feedback from the public and promotes the strengthening of public and political confidence in the safety of a facility, together with trust in the competence of the regulators and implementers of waste management projects. This approach ensures flexibility and the ability to reverse decisions that are subsequently considered to be unacceptable.
Based on a paper presented at the ‘Euradwaste 2004’ conference, held on 29-31 March 2004 in Luxembourg. The two-year Compas project was part of the Fifth Framework Programme of the European Commission. The project was co-ordinated by NNC Ltd and the participants are acknowledged in the Panel on the opposite page. Full results of the project can be found in: EUR 21021 The Comparison of Alternative Waste Management Strategies for Long-lived Radioactive Wastes, 2004, LMC Dutton and Z K Hillis (Eds) et al, European Commission, ISBN 92-894-4986-1. LMC Dutton and ZK Hillis, NNC Ltd, The Renaissance Centre, 601 Faraday St, Birchwood Park, Warrington, Cheshire, WA3 6GN, UKFilesFigure 1. Decision tree for spent nuclear fuel strategy selection Figure 2. Generic strategy for spent nuclear fuel - direct disposal in a deep geological repository Figure 3. The multi-step process of the implementation of a waste management facilityTablesCompas project participants