Britain looks to Sweden for a solution to nuclear waste
In deep, startlingly clear, blue-lit ponds some 40m (130ft) below the Swedish countryside, lies decades worth of high-level nuclear waste.
It’s a strangely beautiful and quite disturbing sight. Row upon row of long metal containers, filled with spent nuclear fuel from the country’s reactors, lie beneath the surface near Oskarshamn, on Sweden’s Baltic coast.
It is both highly lethal and completely safe.
Lethal, as this material is intensely radioactive; safe, as it sits under 8m of water, a very effective barrier against radiation.
Waste can be stored like this for decades. In fact, it has to be.
Intense radioactivity generates a lot of heat, and this type of material must be cooled for long periods before it can be removed for storage.
However, the question of what to do with it afterwards is one that many governments, including that of the UK, have wrestled with for years.
The problem is not the quantity.
Even after some 60 years of commercial and military programmes, the UK’s stockpile of the most dangerous high-level waste amounts to a few thousand tonnes, although there are also several hundred thousand tonnes of intermediate-level waste that must also be managed.
The real issue is time.
“Spent fuel assemblies are intensely radioactive and that radioactivity takes a long time to decay,” explains Professor Neil Hyatt, chief scientific adviser to the UK’s Nuclear Waste Services.
“After about 1,000 years, about 10% of the original radioactivity remains, and it will slowly decay over about 100,000 years or so.”
This creates unique difficulties.
“We cannot rely on institutional control for time scales much longer than a few centuries,” says Prof Hyatt.
“The Roman Empire lasted about 500 years. The last ice age ended about 10,000 years ago.
“So the Earth’s surface and human civilizations are changing much faster than the rate at which the radioactivity in this spent nuclear fuel can decay.”
Sweden has already reached its own conclusions. It plans to bury its waste in rock deep underground and leave it there for good.
This is a process known as geological disposal, and the country’s scientists have spent decades studying various ways in which it could be accomplished.
Much of the research has been carried out in Aspo Hårdbergslaboratorium, a facility built near Oskarshamn in the south of the country.
Hundreds of meters below the surface, a network of huge man-made caves has been drilled into the rock.
It is used for experiments, looking at how waste can be packaged and buried, and how the materials used can degrade over time.
The bedrock here is cracked and flowing with salt water – ancient brine that has migrated from the Baltic Sea over thousands of years.
Such a humid environment would not be suitable for a real disposal facility. But according to Ylva Stenqvist, project director at the country’s nuclear power operator SKB, it is perfect for testing.
“This location was chosen because it’s quite wet,” she explains.
“Because if we try our experiments in an area that’s really dry, we have to wait forever for any kind of results.
“So we deliberately chose this location to speed up some of the experiments, to really stress our materials and our methods and see how they fare in this pretty aggressive environment.”
Earlier this year, the Swedish government approved plans for an actual geological disposal facility (GDF), to be built in Forsmark, about 15 miles north of Stockholm.
The project is expected to cost around 19 billion Swedish kronor (£1.5 billion; $1.8 billion) and create 1,500 jobs, although construction will take decades. Work on a similar system, across the Baltic Sea in Finland, began in 2015.
This development is being closely monitored from the UK, which also intends to build a GDF, although repeated attempts to find a suitable site have been hampered by political intransigence, as well as intense opposition from local protesters and environmentalists.
Ongoing efforts to find a site and a population willing to host it now follow a “consent-based” approach, under which the government agency Nuclear Waste Services establishes partnerships with local communities to engage them in the process.
As an incentive, these communities are offered £1 million in investment for local initiatives when they sign up, with that figure rising to £2.5 million if deep drilling operations take place.
Since this process started in 2018, four such partnerships have been established.
Three are in Cumbria. They include the part of the coastline that is already home to the Sellafield nuclear power station and many of its workers. The fourth, and most recent, was established in Theddlethorpe, Lincolnshire.
Scotland is not part of this process, and the Scottish Government does not currently support deep geological disposal.
Even in those areas where partnerships have been established, strong resistance remains.
“We are strongly opposed to geological disposal of hot, heat-generating nuclear waste,” said Marianne Birkby of Cumbria protest group Radiation Free Lakeland.
“The waste should remain where it can be monitored, where it can be repackaged and where it can be retrieved if something goes horribly wrong,” she insists. “Underground, there would be absolutely no chance of containment if a leak occurred.”
A site for a UK GDF is unlikely to be decided for at least another 15 years. But some experts question whether it should ever be built at all.
Among them is Dr Paul Dorfman, Assistant Fellow in the Science Policy Research Unit at the University of Sussex and Chair of the Nuclear Consulting Group.
“Geological disposal is a concept, not a reality,” he explains. “There is significant scientific uncertainty as to whether the materials that would be used can survive the ravages of time.”
He believes the government’s enthusiasm for new nuclear power plants is why it is pushing to build a GDF.
“If you can’t get rid of the waste, you can’t produce more, which means that the USP of nuclear power – being climate friendly and so on – is entirely dependent on the notion that you can get rid of this waste.” he says.
“Geologic disposal is actually, unfortunately, a nuclear fig leaf.”