Around one-fifth of the electricity used in UK homes and businesses today is generated by nuclear power. Nuclear technologies are also part of the national defence strategy, cancer treatments, academic research, industrial applications and even space travel. But of course, where there is nuclear power, there is nuclear waste. Here, Radioactive Waste Management (RWM) discusses the global progress of nuclear waste disposal and what we plan to do with ours.
An inevitable consequence of nuclear power is an accumulated legacy of radioactive by-products that needs to be addressed, both here in the UK and overseas.
For waste that is short-lived and at the lower end of the radioactivity spectrum, treatment and disposal options are already well established. These range from re-use, recycling, combustion and compaction to disposal at specialised landfill sites or, for the UK, the national Low Level Waste Repository (LLWR) in Cumbria. This low-level material accounts for the overwhelming bulk of radioactive waste globally and is likely to consist of items such as redundant equipment, tools, protective clothing, concrete, steel or demolition rubble.
For the smaller proportion of longer-lived, more hazardous waste, more than 20 countries with a nuclear programme are already working towards the solution endorsed by the global scientific community: geological disposal. This involves building a repository in stable rocks deep underground to ensure the waste, housed inside robust containers, remains safely beyond reach while the radioactivity reduces naturally over time.
International progress
Every country that has settled its long-term waste strategy has opted for geological disposal. A number have already made significant progress, with some of the most advanced programmes in Finland, Sweden, France, Canada and Switzerland. Three rock types are considered suitable and all are abundant in the UK: higher-strength rock such as granite, lower-strength sedimentary rock such as clays, and evaporite such as rock salt. Each would require a bespoke engineering approach, depending on the location.
In Finland, construction is under way at Olkiluoto, following a search that began in 1983 and included screening of the entire country, with early identification of more than 100 possible locations. Olkiluoto was selected in 2001 following a decade of surface-based investigations and support expressed by the local community, who also had a right of veto. Finnish waste organisation Posiva aims to begin disposal of spent fuel in the 2020s.
Sweden has identified a GDF (geological disposal facility) site at Forsmark in Östhammar, which will take spent fuel. The site selection process began in 1992, based from the outset on working with communities. Forsmark was selected in 2009 following comprehensive investigations over a period of years. A repository for shorter-lived intermediate level waste has already been operating in this locality since the 1980s, extending under the Baltic seabed to a depth of around 50 metres.
France has explored 30 expressions of interest since the 1980s, narrowed down to 10. An underground rock lab was developed at Bure in Alsace during the 1990s, and the chosen final repository site is around 5 km away.
Meanwhile, 22 communities entered into the Canadian process, which started in 2010 and has now been reduced to two sites. Borehole drilling to test rock samples is under way.
In Switzerland, federal authorities identified six regions with potentially suitable geology and three are now being investigated in detail.
The UK programme
In the UK, a maximum of around 750,000 cubic metres, or some 10% of the estimated total radioactive waste volume, is destined for geological disposal. This figure is kept under review to take account of any developments, such as the extent of the new nuclear programme, packaging adjustments or other changes.
Much of the higher activity radioactive waste is already safely stored in secure, purpose-built surface facilities at around 20 UK locations, with the bulk at Sellafield in Cumbria. These stores will be safe for many decades but must be continually monitored, maintained, repaired and eventually replaced.
Deep geological disposal avoids passing on the burden to future generations and requiring them to carry on handling this waste for thousands of years to keep themselves safe. The need for a GDF is indisputable: Passing the buck to our children and grandchildren should no longer be an option.
Radioactive Waste Management (RWM) is the UK government organisation tasked with finding a willing community and a suitable site. RWM is part of the Nuclear Decommissioning Authority group which is responsible for dismantling and cleaning up the country’s earliest nuclear sites. RWM collaborates closely with partner organisations overseas to learn from their experience, share lessons, carry out joint research projects and promote understanding.
The UK’s GDF will comprise a series of tunnels and vaults up to 1,000 metres underground, where the waste, treated and encased in robust packages then surrounded by protective backfill material, will remain safe and secure for many thousands of years while levels of radioactivity decay naturally.
Search based on consent
Here in the UK, the search for a site is based firmly on consent, with a requirement for a clear vote of public support from residents who would be directly affected. Equally, withdrawal from the process is an option but must be a collective decision agreed by the local authorities involved (district, county and/or unitary councils).
A desk-based screening exercise covering the whole of England and Wales has provided information about known geological formations, concluding that many regions have potentially suitable rock formations. This is valuable early guidance but cannot provide sufficient information on the deeper rock formations where a GDF would actually be built. At depths of up to 1,000 metres, there is currently limited understanding – the Channel Tunnel is 40 metres below the seabed, the deepest underground station is 60 metres underground.
More detailed investigations, including non-intrusive seismic surveys and deep borehole drilling, would be required over a period of years to confirm actual suitability. This is subject to community willingness.
Long-term community benefits
The west Cumbrian boroughs of Allerdale and Copeland, which hosts the Sellafield and LLWR sites, have established working groups and are already engaged in early discussions.
The offer remains open for any individual or organisation to hold discussions with RWM on an exploratory basis and without commitment, and more discussions are expected to open in other parts of the country over the course of the coming year.
The UK Government’s 2018 ‘Working with Communities’ policy lays out a flexible process which includes the establishment of Community Partnerships that will see RWM, local authorities and other groups working together to engage with people, address questions, deliver community investment funding and build a long-term vision that could underpin future significant investment in the area.
Benefits for a community that eventually hosts a facility are numerous. This nationally significant infrastructure project represents an investment of many billions of pounds, requiring a construction workforce of up to 2,000 during peak periods and a permanent staff of several hundred, lasting throughout a GDF’s operational life of 100-plus years.
Training opportunities, upskilling, contracts for local businesses and further inward investment will follow, while improvements to infrastructure such as roads, rail lines or port facilities may be required. The surface facilities will occupy one square kilometre, perhaps the size of a small business park, while most of the repository will be deep underground.
There is also short-term investment in local communities participating in the process. Once a Community Partnership is formed, one million pounds a year will be available for local projects, rising to £2.5 million a year in areas proceeding to physical site investigations.
A number of years will be required for the detailed work required to satisfy RWM, and the independent safety, security and environmental regulators that a site will be suitable. That time will be used to work with communities to ensure they can take an informed decision, when ready, on whether they wish to host a GDF. Radioactive waste is a fact of life in the UK: it exists and has to be dealt with. The final part of the journey to deliver the solution is now firmly under way.