Digging deep to bury nuclear’s problems

The UK’s search for a deep-disposal site for highly radioactive nuclear wastes is at a major decision point. Alex Marshall asks if a site will ever be found and asks what the implications are for new nuclear

The wolrd's first deep-disposal nuclear waste site being built in Finland. Credit Posiva OyOn the island of Olkiluoto in west Finland, a good three hour’s drive from Helsinki, something is being built that ministers at the UK’s energy and climate department (DECC) can only dream of.

It does not look like much from the surface – a six-metre high tunnel – but it spirals down through granite to reach 450 metres deep. If all goes to plan, by 2020 this will become the world’s first deep disposal facility for nuclear waste.

More tunnels will be built off the main shaft. Developer Posiva will then take spent fuel from nearby nuclear power plants, pack it in copper canisters and put those into holes drilled in the granite.

The canisters will then be surrounded with bentonite, a clay that absorbs radiation and acts as a good water barrier. Each tunnel will then be backfilled. Disposal operations will last 100 years and then the repository will be sealed.

The entire project will cost at least £2.3bn, but it should create a barrier which means no radioactivity will ever reach the environment.

Deep disposal's history and potential future

A similar facility is set to open in Forsmark, Sweden, in 2025, while other countries including France and Switzerland are working on building their own deep-disposal sites, having decided deep disposal is the only long-term solution for the intermediate and high-level radioactive wastes that come from running and decommissioning nuclear power plants. It is unsurprising that the UK also wants such a facility. In fact, it has done so for 36 years. In that time, multiple searches for sites have been undertaken, test drillings started and stopped, and various governments backed the policy, dropped it or run lengthy consultations to try and get public backing (see timeline). In the meantime, the UK’s stocks are stored above ground at 36 sites.

The current push to get a deep disposal site dates from 2008, when the then Labour government published a white paper calling for volunteer communities to host a facility. They would receive a community benefits package in return, as well as jobs, and would have the right to pull out until construction began.

This approach was the one successfully adopted by Finland and Sweden. But so far the UK has had only one volunteer: a partnership of Allerdale and Copeland councils in west Cumbria – those surrounding Sellafield – and Cumbria County Council.

Their involvement will reach a crucial point on 30 January, when the councils are due to decide whether they will commit to desk-based, seismic and underground studies to ascertain whether west Cumbria’s geology is suitable to host a facility.

The councils have said they will not continue until the government gives more legal clarity on the right of withdrawal.

Worryingly for the government, west Cumbria appears to be the only game in town. Shepway council in Kent did consider making an expression of interest for a repository on Romney Marsh to guarantee jobs after the Dungeness nuclear plant closes. However, councillors voted against the idea in September. A proposal by a councillor in Cornwall did not even get to that stage.

January’s vote therefore raises important questions. If Cumbria decides to participate, will a deep disposal site actually be built? If it decides against, what happens then?

The debate about whether deep disposal is needed at all is one that appears to have been played out (ENDS Report 376, p 46).

Environmental groups such as Greenpeace have argued in the past for long-term surface storage. Spent fuel and high-level wastes (a byproduct of fuel reprocessing and defined as materials which increase in temperature significantly due to radioactivity), can in effect be made safe by converting them to a solid glass form, a process known as vitrification. Less radioactive wastes from the operation and maintenance of nuclear plants can be enclosed in cement and stored in stainless steel drums.

However, indefinite surface storage has long been ruled out due to terrorism risks and the sheer timescales involved. It would be needed for thousands of years.

If deep disposal is the only option, can a facility safely be located in west Cumbria? Such a project would not be small. DECC estimates it would be up to 23 square kilometres in size and 200-1,000 metres underground.

The stockpiles of wastes that would go into this plant are vast. There is 1,620 cubic meters of high-level waste in the UK, according to the last inventory conducted by the Nuclear Decommissioning Authority in 2010. There is also 94,300M3 of intermediate-level waste. There are larger volumes of low-level waste, but that can be disposed of at a dedicated facility in Drigg, Cumbria, or at specialist landfills.

These stocks are likely to have grown by the next assessment in 2013 and will continue to do so until all plants are decommissioned. They also do not include any waste from new plants or the UK’s large plutonium stockpile as that can be treated by other routes (either converting it to mixed oxide fuel or processing it in a fast reactor being pushed by GE Hitachi – a joint venture between two of the world’s largest nuclear companies) (see box, p 33).

Any deep disposal site would start taking intermediate-level wastes in 2040, DECC says, at an average rate of 2,500 containers a year. It would take spent fuel from 2075 at a rate of 200 containers a year and would close in 2175. The estimated cost of all this is £11.5bn, although that is likely to be an underestimate.

 There are many who doubt an area of suitable geology can be found in west Cumbria.

“We’ve spent an awful lot of money over the years looking at the geology of west Cumbria,” says Professor Stuart Haszeldine of Edinburgh University’s School of Geosciences. “We know the geology is very complicated, we know it’s very fractured and we know the water flow is the opposite of what you want to retain uranium for millions of years.” The groundwater flows out to sea and up towards the surface.

The waste that will be deposited in the vaults will also be hot, Haszeldine says, and the heat could potentially fracture the rocks further. “Engineers will say you can engineer anything, but I don’t see any evidence of that.”

The reason for Haszeldine’s certainty comes principally from the fact that the area around Sellafield has been examined for disposal of nuclear waste before. In the 1990s, the government-established company Nirex spent £400m surveying the geology for a potential deep disposal site for intermediate-level waste.

Scientific uncertainties

Nirex tried to build a ‘rock characterisation facility’, the first step to a disposal site, but those efforts stalled at public inquiry, partly “due to concerns over scientific uncertainties” (ENDS Report 266, pp 13-14).

This uncertainty is still seen today in public statements made by the West Cumbrian partnership. In July, it issued a report summing up its research into whether Cumbria should continue to participate in the search for a site.1

“The partnership agrees that it is inherently uncertain whether a suitable site can be found and that more geological work is therefore required,” it says.

The report quotes from a meeting with the planning inspectors from the Nirex inquiry. The inspectors “confirmed that they never said the whole of the geology of west Cumbria was unsuitable [for deep disposal] but also emphasised that in their view the probability of finding a site… is low,” it says.

The main academic countering Haszeldine’s arguments is the councils’ independent geological adviser, Dr Jeremy Dearlove of Durham-based FWS Consultants. The report quotes him as saying: “There remain two potentially suitable rock volumes in west Cumbria, for which insufficient data and no published authoritative reviews are currently available…[but] neither should be regarded at this stage as particularly promising.”

Dearlove told ENDS these areas are the granite incursions in the south-west of the county and the mercia mudstone area around the Solway Firth region in the north. He says the areas should be studied, but insists they should not be developed if the results suggest they are unsuitable. “First and foremost the geology has to be suitable. I do not believe you can engineer a repository. Engineering is meant to last 100s of years; a repository needs to last hundreds of thousands of years.”

Despite the geologists caution, it is well known that the Nuclear Decommissioning Authority (NDA) believes many issues can be dealt with through engineering. It would not comment for this  article.

Haszeldine says there are other parts of England which could be more suitable for a deep disposal site, including the corridor between Cambridge and Norwich and parts of coastal Teesside. “They’re areas of flat-lying and quite uniform rocks, with a natural cap, and where you know the water flow is outwards and downwards and slow and predictable.

“I’m not after the best site. I’m just saying we should find one where we can work with the geology.”

However, Professor Gordon MacKerron, director of the Science and Technology Policy Research Unit at the University of Sussex, and former chair of the government’s Committee on Radioactive Wastes Management (CoRWM), says there are two problems with these alternatives.

First, the volunteer-led approach is the only one that has proven successful in getting deep disposal facilities approved on the continent. None of these areas has volunteered. Second, selecting a site outside Cumbria would involve transporting all the nuclear waste from Sellafield across the UK. “You’d suddenly have to engage a lot of other communities,” he says.

Haszeldine disagrees with both points. “Radioactive waste is transported around the UK already and we don’t know about it because it’s very successful.”

However, he’s unable to provide an answer on how to engage areas that have not volunteered. “That’s for politicians to sort out,” he says. “Other countries have started by making a survey of geology and then discussed with communities who may be suitable. But you have to go deep to build confidence. You can’t just turn up and run a two-year hearts and minds campaign. It might take five years, ten years.”

No plan B

One thing is clear beneath all the debate: the government really should have a plan B to west Cumbria, not least because there is no guarantee a facility will be built there even if the geology is suitable. Any site would still need planning permission.

The government can argue that the planning regime is now weighted towards approval. The nuclear national policy statement, which is meant to inform all such planning decisions, says there is a need for a facility (ENDS Report 438, pp 50-51).

However, that does not mean it will be exempt from challenges at EU level. Under the Environmental Impact Assessment Directive, developers must show they have considered alternative sites to the one proposed or explain why others were not investigated.

The European Commission launched a major overhaul of the directive in October and it is not yet clear if that requirement will be tightened or loosened (see p 41). It is also likely that the directive will be changed again before 2029, the most likely date for a Cumbrian planning application (see timeline, above).

But if the government has not properly examined alternatives it could be open to challenge, says Angus Evers, head of the environmental group at law firm SJ Berwin LLP and co-convenor of the UK Environmental Law Association’s waste group.

When contacted about these dilemmas, DECC was far from effusive. ENDS asked the department what would happen if the Cumbrian partnership withdraws in January. “In that event, we would work with the councils to understand the reasons for their decision and what could be done to overcome them,” DECC said. “We will continue to work to obtain further interest from other communities around the country.”

DECC added it was not wedded to the idea of Cumbria. “Our approach is to look for an interested community with geology that meets the necessary technical and regulatory requirements for safety and environmental protection,” it said.

There have been doubts about the sincerity of this view over the past couple of years due to the government’s need to provide certainty to developers of new nuclear plants.

Those doubts increased last year when DECC asked the NDA to review ways to speed-up development of a deep-disposal site so it could open in 2029, rather than 2041. The NDA’s final report pushed against this idea pointing out that speeding up disposal could “threaten confidence in the [voluntary] process”.2 DECC insists the new nuclear programme is not dependent on having a Cumbrian site.

Any firm that wants to build a new plant will need a “funded decommissioning programme” approved by government, it points out. This requires the developer to set aside funds to fully deal with any waste created. The government will set a fee for accepting waste at an assumed deep-disposal facility, set at three-times expected costs and featuring a risk premium in case actual costs turn out to be higher (ENDS Report 443, p 42).

Jean McSorley, an independent consultant who was formerly Greenpeace’s lead nuclear campaigner, said there should be no cap on costs because it is an artificial subsidy and there is no guarantee it will cover the expense, especially if storage needs to increase. But it appears that such views are being ignored.

Certainly, the new nuclear developers do not seem bothered by slow progress in Cumbria. EDF is already negotiating with DECC over its funded decommissioning programme for a new nuclear plant at Hinkley Point, Somerset. In a statement it said: “Our programme allows for all the intermediate-level waste and spent fuel to be stored at the power station. That waste will therefore not need to be disposed of in a repository until about 2080.

“We continue to have confidence that a repository will be developed well before this date, not least because existing radioactive wastes will require permanent disposal.”

That optimistic attitude is shared by MacKerron. “The reason for optimism that a site will happen is that 4-5 years ago, no one [in the world] had even chosen a site for a facility and then Finland did and Sweden did, so we now know that finding a site isn’t a problem.

“The question then is: If they can, why can’t we? And the answer is: it’s hard, but they used a participatory process and it can work given time. It can’t be rushed.”