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Sellafield – 'an intolerable risk' - Pete Roche

Nuclear Monitor Issue: 
#760
12/04/2013
Article

Pete Roche is an editor of no2nuclearpower.org.uk 

Sellafield in West Cumbria, north-west England, was originally a military site set up immediately post-war to provide plutonium for nuclear bombs. Today it is the site of two reprocessing plants. The first, B205, opened in 1964 to reprocess waste fuel from Britain's oldest reactors, known as Magnox reactors. The last of these reactors will close on 30 September 2014, but B205 isn't expected to complete the reprocessing of spent fuel until sometime between 2017 and 2028 depending on how well it operates.

The second reprocessing plant − THORP (the Thermal Oxide Reprocessing Plant) opened in 1994 to reprocess waste fuel from the UK's newer Advanced Gas-cooled Reactors (AGRs) and overseas Light Water Reactors.

These projects have been overseen by the Nuclear Decommissioning Authority (NDA) since 2005 – a public body set up to replace the widely discredited British Nuclear Fuels (BNFL). The NDA also replaced Nirex – originally the Nuclear Industry Radioactive Waste Executive – which was responsible for developing "safe and environmentally sound options for dealing with radioactive waste in the long term".

A new study commissioned by West Cumbria & North Lakes Friends of the Earth investigates how hazardous nuclear waste at Sellafield has been stored and handled over the past 13 years. The study took place within the context of a decision at the end of January by the local municipality, Cumbria County Council, not to go forward with a search for a Geological Disposal Facility, and a November 2012 National Audit Office (NAO) report on managing risk reduction at Sellafield which clearly demonstrated the need for immediate improvements in the management of major projects at the site.

The NAO report said the site posed a "significant risk to people and the environment" because of the deteriorating conditions of radioactive waste storage facilities. In February 2013 a report from the House of Commons Public Accounts Committee described Sellafield as "an extraordinary accumulation of hazardous waste, much of it stored in outdated nuclear facilities", and chair of the committee, Margaret Hodge MP, said Sellafield posed an "intolerable risk".

Deadlines for cleaning up Sellafield have been missed, while total lifetime costs for dealing with the waste and decommissioning the site continue to rise each year and now stand at £67.5 billion. An enormous amount of public money − some £1.6 billion − is spent at Sellafield each year.

The NAO report didn't look at Sellafield's commercial operations. Cumbrians Opposed to a Radioactive Environment discovered that in the 13-year period between financial years 2000/01 and 2012/13, the site missed 83% of commercial targets and that since the NDA took ownership of Sellafield in 2005 the failure rate has risen to 94%.

The NDA claims it now has a credible plan for decommissioning Sellafield, but given its track record − with only two of the 14 major projects being delivered on or ahead of schedule in 2011-12 – it is small wonder many remain to be convinced that sufficient progress is actually being made.

THORP reprocessing plant
THORP was expected to reprocess 7,000 tonnes of spent fuel in its first decade of operation – two-thirds from overseas customers − but it only managed 5,000 tonnes due to a range of equipment failures and accidents. In April 2005 an internal leak of 22 tonnes of dissolved fuel shut the plant for almost two years. This was followed by another mechanical failure which delayed the slow return to operation until March 2008. Even then a delay in returning to full operation was caused by a lack of high-level waste evaporative capacity.

In 2005, when the NDA took over, THORP was expected to complete its reprocessing contracts by 2010, but this date has now been pushed back to 2018. In June 2012 the NDA announced that it would only reprocess the spent fuel it was contracted to reprocess – in other words it would not attempt to reprocess AGR waste spent fuel for which the contracts allowed for storage or reprocessing. This means the plant will be limping along with a low throughput of around 350 tonnes per year for another five years – less than half the rate it was originally expected to achieve.

High level liquid waste treatment facilities
HLW liquids are so radioactive that they generate their own heat, and are stored at Sellafield in special cooling tanks which prevent the liquid from boiling. The consequences of a prolonged cooling failure could be 'very severe' leading to boiling after 12 hours, and to the tanks drying out after three days. Consequently the HLW facility at Sellafield is probably one of the most dangerous nuclear facilities in the world. Following the 9/11 terrorist attacks in 2001, a review found that a terrorist attack on the tanks could require the evacuation of an area between Glasgow and Liverpool, and cause around two million fatalities.

Thirteen years ago the Nuclear Installations Inspectorate (NII) warned that the HLW liquid storage tanks needed to be emptied and the waste solidified "as soon as reasonably practicable", and levels reduced from approximately 1,600 cubic metres to a buffer level of 200 cubic metres by 2015. Any shortfall would be "publicly unacceptable". By 2011, even though stocks had only been reduced to 900 cubic metres, the Office for Nuclear Regulation (ONR) (which now incorporates the NII) decided to increase the permitted level of highly active liquid stocks to almost three times the limits defined under the earlier legal requirement. The ONR appears to have sanctioned something which 12 years ago it deemed "publicly unacceptable", because it is not prepared to use its regulatory powers to end reprocessing early.

In 1998 the liquid HLW was stored in 21 stainless steel tanks, the eight oldest of which were built between 1955 and 1968. Even the 13 newest tanks were causing concern because of leaks in the cooling system. In 2008 the NII declared that Sellafield needed new liquid HLW storage tanks "with utmost urgency". The NDA estimated the cost of six new replacement tanks to be £83m with delivery expected in March 2013. But by 2011 the cost had shot up to £474m and delivery was not expected until March 2018. Then in June 2012 the NDA abandoned the project. The ONR simply said the information it had been given suggests that replacement tanks "may no longer represent the 'as low as reasonably practicable' position with regard to hazard reduction activities on the site".

So failure by the NDA has been responded to by the ONR changing its recommendations, rather than using its regulatory powers to ensure action. ONR appears to be sanctioning a cost-cutting exercise rather than insisting on maximum safety.

The highly active liquid wastes that come out of the two plutonium separation plants operating at Sellafield are evaporated to reduce their bulk. A range of problems with the evaporation facility at Sellafield over the years has meant that plans to reduce liquid HLW stocks, whilst continuing with reprocessing and plutonium separation operations which produce the waste, have not gone according to plan. There are three evaporators at Sellafield, and the NDA gave approval for the construction of a fourth to start in 2009. The construction project is the biggest single nuclear project in the UK. It was originally estimated to cost £90m and was due to be completed as early as 2010. But the cost has now jumped up to £673m, and it won't be ready until at least 2016.

Treatment of solid wastes
In 2002 The Observer newspaper, reporting on a document from Nirex, declared that "almost 90 per cent of Britain's hazardous nuclear waste stockpile is so badly stored it could explode or leak with devastating results at any time".

A decade later, the description by the NAO makes the situation sound very similar: "Some of the older facilities at Sellafield containing highly hazardous radioactive waste have deteriorated so much that their contents pose significant risks to people and the environment."

The recent NAO report says a quarter of Sellafield Limited's annual spending − £381m in 2011-12 − is on waste retrieval and clean-up of high hazard legacy ponds and silos containing spent fuel, spent fuel cladding, and intermediate-level waste sludges, etc. But limited progress has been made on starting some key waste retrieval projects, and completing waste retrieval from legacy ponds and silos has been postponed by seven years until 2036.

Conclusions
Despite a focus which should have been "squarely on the nuclear legacy" the NDA, since taking over Sellafield in 2005, has continued with operations which produce yet more waste because of short-term income generation. We are now told it is too late to come up with an alternative used waste fuel management process so the two reprocessing plants must limp on another five years or so before decommissioning can begin.

Between 2000 and 2008 the nuclear regulator said that the liquid HLW needed to be solidified "as soon as reasonably practicable", that new storage tanks "should be progressed with the utmost urgency", and that further evaporator capacity was "essential for the longer term safe management of highly active liquor".

But despite the NDA's failure to urgently replace old tanks containing highly radioactive liquid waste and build new evaporator capacity to reduce the bulk of dangerous liquid waste as quickly as possible, the regulator has allowed reprocessing to continue – not just of overseas spent fuel, which the NDA has claimed it is legally bound to reprocess, but mainly of AGR waste spent fuel – perhaps to free up space so that EdF Energy can extend the life of its ageing AGR reactors, and avoid the cost of new spent fuel storage facilities.

References

Pete Roche is an energy consultant based in Edinburgh, policy adviser to the Nuclear Free Local Authorities and editor of the no2nuclearpower.org.uk website. Until 2004 he was a nuclear campaigner for Greenpeace UK for 13 years and before that co-founder of the Scottish Campaign to Resist the Atomic Menace (SCRAM) in 1976.