2011年5月10日 6:42
「中部電力」が浜岡原子力発電所(静岡・御前崎市)の全面停止を決めたことを受け、イギリスでは再処理工場の存続に不安の声が上がっている。
9日付の「インディペンデント」紙は、1面で「セラフィールド核燃料再処理工場の将来に暗い影を落とした」と報じている。イギリス北西部にあるセラフィールド工場は、去年、中部電力と交わした混合酸化物燃料(MOX燃料)の製造契約が唯一の契約であるため、「浜岡原発の停止によって工場が存続の危機に立たされるのでは」と指摘されている。
記事では「セラフィールド工場は日本からの受注を想定し、約650億円をかけて建設された」としている。
Closure of Japanese plant casts doubt on viability of Sellafield's Mox operation
Future in doubt for plant at nuclear complex in wake of Fukushima disaster / Japanese operation that is key customer set to close amid earthquake fears
By Steve Connor, Science Editor
Monday, 9 May 2011
The future of a nuclear fuel plant at Sellafield in Cumbria hangs in the balance after the Japanese Prime Minister called for the closure of a nuclear power station near Tokyo, which was to be the UK plant's most important customer.
The setback is the latest blow to Britain's faltering strategy for dealing with its growing mountain of reprocessed nuclear waste, and further evidence of the extent to which the devastating Japanese earthquake of 11 March has changed the nuclear picture – in particular the international trade in reprocessed nuclear fuel.
If the power plant at Hamaoka, 200km from Tokyo, closes, shipments of nuclear fuel to Japan from the Sellafield Mox Plant would stop before they had even started. It is the latest in a long series of problems for the nuclear fuel plant at the Sellafield complex which had already cost taxpayers £1.34bn even before the impact of the earthquake and tsunami was felt.
Nuclear officials in Britain have demanded urgent talks with their counterparts in Japan after the proposal by Naoto Kan. The Prime Minister wants the Hamaoka complex closed on the grounds that, following the earthquake-triggered disaster at the Fukushima plant, it too is at risk of a major earthquake. The consequences of such an event could be serious enough to cause the evacuation of Tokyo, 200km north-east of Hamaoka.
Japanese nuclear authorities are still struggling to control the stricken reactors at the Fukushima power plant which were inundated by an 18-metre wall of seawater. Residents living within 20km of the plant have been evacuated and there are no plans as yet to allow them to return to their abandoned homes.
Hamaoka, which has been described as the world's most dangerous nuclear power facility because it sits on two geological faults, was to be the first site in Japan for the delivery of mixed oxide (Mox) nuclear fuel made at the troubled Sellafield Mox Plant.
If the Japanese premier gets his way, however, Hamaoka will be shut long before Sellafield is ready to fulfil its only definite order for Mox fuel. This would torpedo the entire rationale for building and opening the £498m Sellafield Mox Plant, which was to fabricate hundreds of tonnes of Mox fuel for Japanese reactors.
Mr Kan's proposal last Friday stunned Japan's power industry. "This is a decision made for the safety of the Japanese people when I consider the special conditions of the Hamaoka plant," Mr Kan said. He added that studies by earthquake experts at Japan's Ministry of Education predicted an 87 per cent chance of a magnitude 8 earthquake in the Tokai region of Hamaoka within 30 years and the risk of a major tsunami similar to the one that devastated Fukushima.
Japan is crucial to Britain's attempts to generate a market in Mox fuel, which is made by mixing plutonium dioxide retrieved from spent fuel rods with uranium oxide. The promise of lucrative Japanese contracts for Mox fuel was the primary reason the Mox plant was finally licensed in 2001 after years of legal wrangling. However, since it was given its operating licence by the previous government, the Sellafield Mox Plant has been beset by problems. Instead of producing 120 tonnes of fuel a year, it has managed just over 13 tonnes in eight years, at a total cost to the taxpayer of £1.34bn – and a further £800m in future running costs expected this decade.
British Nuclear Fuels, which ran Sellafield before the site was taken over by the Nuclear Decommissioning Authority, boasted 10 years ago that it had enough interest from Japanese power companies for Mox fuel to make the plant break even, if not make a profit. However, the Nuclear Decommissioning Authority said that it has only one guaranteed order, from Chubu Electric, to supply Mox fuel to the nuclear reactors at Hamaoka.
Meanwhile, the severe production problems at the Sellafield Mox Plant have meant that the first fuel shipments will not be delivered until at least the end of the decade, more than 10 years behind schedule.
A spokesman for the authority said that the contract to manufacture Mox fuel rods at Sellafield for Chubu was signed last year and that the preparations for manufacturing fuel rods are "ongoing". These preparations involve an extensive refurbishment of the troubled plant. "We will be discussing with Chubu at the earliest opportunity what impacts, if any, will result from this latest announcement," he said.
The developments come at a difficult time for Sellafield and the Government, which said that it wants to build a second Mox plant on the Cumbrian site in order to tackle the enormous waste stockpile of British-owned civilian plutonium, the biggest in the world.
The Government's public consultation over what to do with the civil plutonium stockpile ends this week but it has already indicated that its preferred option is to build a second Mox plant at Sellafield to use up the waste plutonium as nuclear fuel.
However, nuclear officials are deeply embarrassed over the existing Mox plant, which has been described as one of the biggest disasters in Britain's industrial history. They had been hoping to gloss over its problems in order to secure the estimated £6bn it would cost to build a second Mox plant at Sellafield.
Now, the near-meltdown of the nuclear reactors at Fukushima has cast further doubts over the international trade in Mox fuel. One shipment to Japan from France on ships operated by Sellafield has already been abandoned and some commentators believe future shipments may end altogether because of growing hostility in Japan towards nuclear power. Another unsolved difficulty is that Mox fuel is about 30 per cent more expensive than ordinary uranium fuel made from ore dug out of the ground, which is why nuclear operators prefer not to use Mox if they can avoid it. If the Government builds a second Mox plant to deal with the UK's plutonium waste stockpile, it will have to subsidise power companies to burn it in their reactors – yet it has insisted there will be no subsidies for nuclear operators.
The Sellafield saga
September 1996
The Sellafield Mox Plant is built on the coast of Cumbria at a cost that will eventually reach £498m. Its purpose is to convert nuclear waste into Mox, a fuel used in reactors. However, the plant does not yet have a licence to operate.
September 1999
The first consignment of Mox fuel bound for Japan, made in a smaller Mox Demonstration Facility, is ordered to be shipped back to Sellafield after The Independent reveals that quality control data had been falsified. Quality checks had been bypassed using data sheets from previous samples, meaning some batches of rods were passed as safe when they had not been checked.
October 2001
After five public consultations, the Sellafield Mox Plant receives an operating licence. The economic case is made in a heavily redacted report by independent consultants, which states that the plant would provide the UK with a profit of £150m over its lifetime. The plant goes on to cost a further £840m.
August 2002
The plant's operating company, British Nuclear Fuels Limited (BNFL), is forced to hire its main rival, the French firm Areva, to cover an order of MOX from a Swiss facility because of delays in getting the plant into production. The next month, fuel from the first 1999 consignment to Japan arrives back in the UK unused.
August 2003
BNFL admits it has again subcontracted an order of Mox to Areva. Environmental groups estimate the cost could have been as much as £20m.
October 2004
Areva is called in to fix the plant – still yet to produce a single finished product – leading two former environment ministers from opposing political parties to demand a parliamentary inquiry.
September 2006
A report cites more than 6,000 minor failures of equipment in two months, equating to 37,000 failures a year, each stopping the production line for between 15 minutes and an hour, along with 100 significant failures a year, with an average recovery time of several days.
May 2010
Sellafield signs first and only contract with a Japanese utility, Chubu Electric, to supply Mox fuel from the plant to the company's Hamaoka reactors.
March 2011
Former chief scientist Sir David King recommends British taxpayers should spend between £3bn to £6bn on a new facility for making Mox fuel at Sellafield, despite the existing MOX plant being well-documented as one of the biggest industrial failures in British history. Former environment minister Michael Meacher calls for an official inquiry into the evidence used to justify the operating licence.
May 2011
Five people are arrested for taking photographs of Sellafield, underlining the potential security risk posed by the site. They are later released without charge. Meanwhile, Sellafield admits that no Mox fuel is likely to be shipped to Japan until the end of the decade, 10 years after the plant was supposed to have completed all its orders.