23 Apr (NucNet): There is no regulatory reason a radioactive waste repository in northwest England should not continue to perform its function, despite the possibility of coastal erosion, an Environmental Agency document says.
The internal document seen by NucNet says the Drigg low-level radioactive waste (LLRW) facility in Cumbria is expected “in the absence of intervention” to be subject to coastal erosion beginning within a timeframe of a few hundred to a few thousand years from now.
But the document notes that providing a suitable environmental safety case can be made and providing Drigg can be operated safely in future, there is no regulatory reason to close it.
The document suggests that in retrospect it was a mistake to site the Drigg repository on the Cumbrian coast because of its vulnerability to flooding. “It is doubtful whether the location of the LLRW site would be chosen for a new facility for near-surface radioactive waste disposal if the choice were being made now,” it says.
The Environmental Agency document, dated 9 January 2014, sets out the agency’s latest assessment of the risks of coastal erosion at Drigg. It was released by the agency in response to a request from The Guardian newspaper.
Erosion from storms and rising sea levels caused by climate change has “emerged as the expected evolution scenario” for Drigg, the document says.
The Environmental Agency proposes “an optimised approach” to disposal at Drigg that would probably entail preventing items individually carrying “a significant burden of radioactivity” from being disposed of at the site. Equally, an optimised approach is likely to entail preventing any processes within the LLWR site or as a result of coastal erosion that might lead to the production of high dose particles, the document says.
“These considerations may require improvements to waste characterisation and segregation, but we consider such improvements themselves to be part of the optimised approach,” the document says. “They are judged to be desirable in view of the expected scenario of coastal erosion.”
The Drigg site, which covers about 110 hectares, is between five and 20 metres above sea level. It is run by a consortium led by the US engineering company URS, the French state-owned nuclear company Areva, and the Swedish nuclear firm Studsvik. The consortium has already been asked by the Environmental Agency to look at options for improved flood defences.
In a stress test carried out at Drigg following the March 2011 Fukushima-Daiichi accident, the facility’s operator LLW Repository Ltd said “consideration of extreme external events produces no new hazards or risks from the LLWR site”.
