Cast iron stakeholder engagement on ILW options
Stakeholders representing a range of constituencies and community groups close to the five Magnox Limited sites recently took part in a workshop to consider a possible change in the way operational intermediate level waste (ILW) is managed in respect of decommissioning programmes .
Research has identified a potential opportunity to use shielded ductile cast iron containers as an alternative to the existing strategy. Internal analysis of the option is proving promising. However, while such containers have been used elsewhere in Europe, they are not currently approved for use in the UK.
A work programme to explore the feasibility of the proposal with regulators is under way. As part of this, Magnox Limited has committed to engage with stakeholders and gain feedback. Three Site Stakeholder Group (SSG) chairs were among the 26 attendees, with all SSGs represented. A number of NGOs, council officers and trade unions were also invited, with an excellent turn out on the day.
Issues under discussion included radiological, conventional and environmental safety as well as socio-economic factors. Representatives of the Nuclear Decommissioning Authority, the Environment Agency and the Office for Civil Nuclear Security also acted as observers at the workshop, which was independently facilitated by David Collier and Pete Wilkinson from Golder Associates.
Phil Matthews, project manager, said: "We are very grateful to everyone who attended for their time and their excellent contributions at this critical strategy development stage. The team received a number of valid challenges that will help focus our ongoing work programme."
Magnox Limited has committed significant resource to the project to undertake the large amount of technical work required in a timely manner. The intention is to establish its feasibility before major works are scheduled to begin on the existing strategy.
Phil added: "We want to ensure the earliest possible implementation, should the evaluation prove positive, to maximise what we believe are the significant benefits of the approach. As a result, we are even more grateful to those who attended for working with us inside the tight timescales that we are setting ourselves. We believe the timescale is realistic and will embrace such safeguards, checks and balances and reviews, as are deemed necessary to satisfy all the issues raised by stakeholders. We are committed to continuing to build those relationships and making sure engagement is ongoing as the project progresses."
Golder Associates is now preparing a report for comment by the workshop participants. When finalised, it will be reported back to site stakeholder groups. It is expected to form part of the submission to the regulators, with Magnox Limited seeking concurrence that the strategy could be adopted. If this is achieved, sites will then undertake localised best practicable environmental option studies that are waste stream specific, involving local stakeholders in that process.
The majority of Intermediate Level Waste (ILW) arose during the years of electricity generation at sites. It includes fuel can debris, sludges, resins and some equipment exposed to high levels of surface contamination. Magnox Limited is in the process of reviewing the way it plans to store this waste on sites before a national repository becomes available for final disposal, not expected for a number of decades.
The current plan is to encapsulate ILW in 3m³ stainless steel containers using concrete. A large concrete building would be built at each site to store the boxes and provide radiological shielding.
The potential opportunity to use shielded ductile cast iron containers has been highlighted as an alternative. These weigh 18 tonnes when empty and hold just under 3m³ of waste. Because the robust walls provide adequate integrity, the waste would not need to be encapsulated in concrete. This could mean that more waste can be packaged in each container, reducing the overall number of packages that would require final disposal.
The proposal would also remove the need to build a concrete waste store at each of the five sites, accelerating the hazard reduction process by purchasing containers as and when required rather than waiting for a store to be built.
Magnox Limited is working with regulators including the Nuclear Installations Inspectorate, Environment Agency, Office for Civil Nuclear Security and Department for Transport to explore the feasibility of the proposal and if successful, seek approval to implement the concept. A proposal has also been made to the Radioactive Waste Management Directorate of the Nuclear Decommissioning Authority (NDA) - the body responsible for the future national repository. They will decide if the container can be disposed of in the store. If agreed, it could mean the one box can be used for safe on site storage of waste, transportation and final disposal.