Inside rural French site teaching Britain how to dispose of nuclear waste

An underground labyrinth of tunnels being built in the picturesque Champagne countryside of rural France is helping teach British scientists how to dispose of nuclear waste.

Several countries around the world are building geological disposal facilities (GDFs) deep underground to permanently house the radioactive nuclear waste created from power stations, nuclear weapons production, submarines, medical equipment and more.

France has an underground laboratory dedicated to this purpose which is more than 1,600ft beneath the forested border of the regions Meuse and Haute-Marne in a layer of Jurassic clay that dates back more than 160 million years.

Britain is about 20 years behind the French project and is planning to build its own £53 billion version 0.6 miles under either the North or Irish Seas, and about 12 miles off the coast of Cumbria or Lincolnshire.

The project is essential to the long-term viability of nuclear power and is set to be the biggest infrastructure project in British history.

It needs both local community agreement and perfect geology before it can begin.

Amid the vineyards, chateaux and quaint roads of the north-eastern French hinterland is a 740-acre site owned by Andra, the French national radioactive waste management agency, that will in the next few decades be transformed into a GDF named Cigeo, set to open in 2035.

The Telegraph had exclusive access to the lab where hundreds of experiments are being conducted to see how the rock copes with tunnelling and its suitability for concealing thousands of tons of hot and highly radioactive nuclear waste.

In hard hat, steel-toed boots and overalls, Jacques Delay, a scientist at the Cigeo site, revealed the first ever experimental disposal site for intermediate level nuclear waste is almost complete.

The prototype is a 32ft-tall and 262ft-long cavern created with the help of an ex-coal mine excavator that was used in Britain 60 years ago.

The site is the first life-size prototype in clay for this kind of nuclear waste, which is mostly spent fuel from nuclear power stations.

The site also has two dozen 22in-wide boreholes for the disposal of long-lived intermediate-level waste.

The most dangerous waste produced, which will be stored at the site, emits 145 sieverts (Sv) of radiation an hour. Exposure to a few sieverts is lethal to humans.

Cigeo is of particular interest to the UK’s Nuclear Waste Services (NWS) organisation that is tasked with disposing of the UK’s 70-year-old nuclear waste stockpile because it is being built in rocks the same as those seen in Britain.

Prof Neil Hyatt, the chief scientific advisor at NWS, told The Telegraph: “Everything we learn from colleagues in France can really help speed up our own timeline and keep our own costs down, and maximise safety.

“Visits to Cigeo and sharing the data can help us not only understand the geology and science, but also the practicalities of how to build something that will likely become the UK’s biggest ever infrastructure project.”

The French site recently applied for a licence to start building its facility, which will neighbour the current lab in the Champagne region.

A 2.5-mile-long funicular railway will transport waste packages underground in special barrels and subterranean robots will then move the packages around the tunnels.

The highest level waste, which has to spend 70 years cooling to no more than 90C before it can be put underground, will be in 35in-wide tunnels before they are sealed up.

Intermediate level waste will be stored in larger tunnels similar to the prototype currently under construction and the final product will be 32ft across and 1,300ft long.

Hundreds of experiments have been run over the laboratory’s two-decade history, with thousands of holes drilled and tens of thousands of sensors installed.

Investigations have covered everything from ground compression, radiation absorption through the clay, and how heat transfers through the rocks.

The UK GDF is expected to open in the 2050s and it is estimated there will be around 27 million cubic feet of waste – equivalent to 10,000 double decker buses.

It will take 15 years before a site is selected and another 15 years for the endeavour to be completed. It will then be operational for more than a century.

The scale of the project is vast, with timelines being planned out that will span several generations.

For example, scientists and engineers are working on assuring the safety of the site for about 300,000 years – as long as human civilization has existed, which is also the time period required for the radioactivity to safely decay.

A new nuclear power plant is planned in North Wales, as well as Sizewell in Suffolk and Hinkley in Somerset, respectively, and the Government has pledged to triple nuclear power generation by 2050.

A GDF is of paramount importance for the safety and viability of nuclear power, experts say.

Prof Hyatt, who has two decades of experience in industry and academia, told The Telegraph: “Building a safe, secure and permanent disposal facility is absolutely vital for a long-term nuclear strategy and poses one of the biggest challenges in the modern world.

“A GDF is the only viable permanent solution for hazardous waste and it will bring thousands of jobs and millions of pounds into a region every year for several generations.”

Both Conservatives and Labour are understood to be supportive of the project, and scientists say that there is no viable alternative.

High-level and intermediate-level waste that is destined for the GDF is currently mostly stored at Sellafield, but the site is almost full and in need of constant repairs.

Insight from French colleagues is proving invaluable to the British endeavour because the Jurassic clay of the French project is identical to the rocks under the North Sea off the Lincolnshire coast.

“The Lincolnshire prospective GDF site has similar clay to that in which the French site is built in,” said Prof Hyatt.

“The Cumbrian geology is about 100 million years older and we are probing the suitability there too with studies that started last year.”

The two local communities in the French regions affected by the work are being paid more than €25 million each a year by nuclear waste producers, such as EDF, which has been ongoing for more than two decades.

This, as well as extensive community engagement, has seen public sentiment – though still divided – fall largely onto the side of the project which will create thousands of jobs in the area which has seen an economic decline tied to the dwindling fortunes of the local metallurgy industry.

British scientists and policymakers are paying close attention. Unlike in France, the UK state is bankrolling the entire GDF project because it is the main producer of waste.

This means that a UK GDF can only be created if the geology is suitable, but also if the local community agrees.

The candidate communities in the UK are currently given £1 million each year for their participation.

Damien Thieriot, a local politician and forest manager by trade, sees the nuclear project as a lifeline for his ailing hometown, which is haemorrhaging young people to other regions because of a lack of prospects.

“I am not a man of science but I trust Andra. We need to look after the waste, and I wish for us to preserve the environment, improve the area, attract people and save my village.”

“I also want the waste producers to bring more to the region too, such as solar panel farms and more opportunities.

“The money is important, for sure, but it is also about making sure you, as a community, get something back. It is an opportunity, not just an obligation.”