Dounreay was the UK’s centre of fast reactor research and development between 1955 and 1994 and is now described as Scotland’s largest nuclear clean-up and demolition project. In April 2005 the Nuclear Decommissioning Authority (NDA) took over the ownership of the Dounreay nuclear facility in Caithness on the north coast of Scotland from the United Kingdom Atomic Energy Authority (UKAEA).
At the start of Britain’s nuclear programme uranium resources were thought to be scarce. Fast reactors were thought to be the way forward. These reactors, generally fuelled by plutonium, can, at the same time as generating electricity, convert the useless portion of uranium into more plutonium. Officially the reason given for the end to Britain’s fast reactor programme was that these reactors proved to be more expensive than expected and by the 1980s uranium was no longer in scarce supply. So in 1988, Britain decided it would not need fast reactors for the foreseeable future and the programme was cancelled signalling the end for Dounreay.
But Fast Reactors have been a disaster world-wide – economic realities, problems associated with reprocessing (separating plutonium from spent nuclear fuel), concerns over nuclear proliferation, serious technical problems and the risk of catastrophic accident have all come together to stop the development and construction of commercial scale fast breeder reactors. One major difficulty with fast reactors is that they use liquid metal as a coolant – usually liquid sodium, which explodes on contact with air. Currently, only one Fast Reactor of commercial scale in the world is operating–the Beloyarsk BN-600 FBR in Russia. India is only intermittently operating its Fast Breeder Test Reactor (FBTR) at Kalpakkam. The French closed down their Superphénix Fast Reactor in 1996 after it had achieved an average capacity factor of less than 7% over eleven years’ of operation.2 It had repeated shutdowns, the longest of which lasted four years. Japan’s fast reactor at Monju has been mostly shut since a leak of liquid sodium coolant in 1995. It was reopened in May 2010 but three months later, it was closed again after another accident. In the two decades since the reactor started tests in 1991, it has managed to generate electricity for only one full hour.3
The Dounreay Fast Reactor (DFR) first achieved criticality in 1958, and operated until 1977. The Prototype Fast Reactor (PFR) opened in 1974 and closed in 1994. The site also housed a fast reactor reprocessing plant, as well as a research reactor reprocessing plant. Overseas research reactor spent fuel was imported for reprocessing up until 1974 when it stopped because foreign customers were unwilling to take their waste back. Then in 1992 Dounreay re-entered the research reactor spent fuel reprocessing business with spent research reactor fuel imported, mainly from Germany until it was announced in 1998 that Dounreay would not take on any new contracts. Dounreay was also site of a materials test reactor which operated between 1958 and 1969. The Vulcan submarine reactor test facility is also at Dounreay.
In 1958 the Scottish Office authorised use of an underground shaft – built to remove spoil during construction of a sub-sea effluent discharge tunnel – as a disposal facility for intermediate level radioactive waste. More than 11,000 disposals took place between 1959 until 1977, when a chemical explosion occurred and the practice ceased. Decommissioning the 65-metre deep shaft is a major challenge. A second facility, the intermediate-level waste silo, also needs to be emptied and its contents made safe. A concrete-lined box built just beneath the surface, it was used to dispose of waste between 1971 and 1998. Contractors started to prepare the ground for a major new plant which will retrieve radioactive waste from the underground shaft and silo in March 2009.4
Radioactive particles on beaches
Another major problem is the appearance of radioactive particles in the environment. These small fragments of irradiated nuclear fuel have been found on the seabed off Dounreay, on the Dounreay foreshore and on Sandside Beach west of Dounreay, which is open to the public. One particle was found in 2005 on Dunnet beach east of Dounreay.5 It will be around 200 years, before the activities of the larger particles, have decayed sufficiently that they can no longer be considered a potential hazard. Radioactive particles will keep polluting public beaches for decades to come, and the environment will never be completely cleaned up. It may not even be possible to aim to return the environment to a pristine condition. Despite assurances that the risk is low of a member of the public coming into contact with a particle which is a serious hazard to health, we cannot be certain that this will continue to be the case.
Since 1983 almost 500 radioactive particles have been found on three local beaches near the Dounreay nuclear facility in Caithness and the Dounreay foreshore. More than 200 of these have been found on the publicly accessible Sandside beach. A particle found on Sandside beach in February 2012 was reported to be possibly the most radioactive yet.6
Radioactive particles on the seabed
Radioactive particles were also discovered on the seabed in 1997. As a result a fishing ban was implemented to prevent the removal of fish, crustaceans and molluscs in an area of 2km (1.2 mile) radius centred on the disused Dounreay discharge point near where the highest density of particles has been detected. The particles lie in a “plume” on the seabed spread over an area equivalent in size to that of 600 Olympic swimming pools. The fragments are thought to be the source of nuclear material found on nearby beaches. Originating from the reprocessing of nuclear fuel, they were pumped into the sea up to 50 years ago.
Underwater clean-up started in August 2008, targeting a 60-hectare area of seabed where the most hazardous particles are found. By the end of 2012, more than 2200 particles had been removed from the seabed. Of these, 409 were deemed “significant” in terms of their potential health effects. By the end of 2012 all 60 hectares had been covered by the underwater detection and retrieval system. In 12th June 2013 the Caithness Courier reported that there would be no underwater particle retrievals during 2013.
Worryingly the Scottish Environment Protection Agency (SEPA) has decided to give up on its aim of returning the seabed to a “pristine condition”. The Agency has admitted that the contamination will never be completely cleaned up. To do so, it said, could cause “more harm than good”. SEPA opted instead to encourage remediation “as far as is practically achievable” but to abandon any hope of removing all the radioactive pollution from the seabed.8
Waste Transports to Cumbria
NB. Spent fuel from nuclear reactors, whether at Dounreay, Torness or Hunterston, is not officially defined as “waste” – because it supposedly contains “useful” plutonium and unused uranium.
The first of 90 rail shipments of nuclear material from Dounreay in Caithness to Sellafield in Cumbria was made overnight on 16th/17th December 2012. The BBC reported that the journey was understood to have been made under armed escort.
The material to be transported falls into two categories.
The first category is around forty-four tonnes of “breeder material”, which will be moved in about 40 trainloads over a four or five year period. This material formed the uranium-238 blanket in the Prototype Fast Reactor at Dounreay, so it is not thought to be terribly radioactive, but there is concern the plutonium formed by the neutron bombardment of the uranium could be a prime target for theft. The NDA estimates that although these transports will cost around £60m, it is a cheaper option than trying to deal with it at Dounreay. This “breeder material” is expected to be reprocessed in the old Magnox reprocessing plant at Sellafield to separate out the plutonium.
The second category is a mixed bag of material called “exotics”. This includes fuel containing unirradiated highly-enriched uranium; unirradiated plutonium and irradiated fuels.. This will be transported from Dounreay to Sellafield at a later date and will probably take another 50 or 60 journeys over six years starting sometime in 2014 or 2015.
Nuclear engineer John Large condemned these proposed transports. He said: “We’re talking about bomb-grade material that would be a target for terrorists. It is also fuel from an experimental reactor which will have got broken up and will have been in storage in an uncertain condition. It will be very difficult to inspect it before it is transported and the only safeguard is based on their assumption that they would not encounter an accident with a big enough impact to break open the flask.”9
During the period 2014 to 2018 while both types of materials are being moved to Sellafield there could be as many as 15 transports per year. A campaign group has been set up in the Highlands in a bid to stop these trains. A meeting was held at Dingwall in March 2013 to gather public views about the journeys. The shipments pass through several towns and the Highland capital Inverness. The group wants the shipments stopped until there is a full public consultation.10
1. A Guide to Dounreay, NDA and Dounreay Site Restoration Ltd, April 2008
2. Fast Neutron Reactors, World Nuclear Association Briefing May 2012
3. New York Times 17th June 2011
4. Dounreay Site Restoration Ltd. 24th March 2009.
5. Particle Clean-up. Dounreay Site Restoration Ltd (DSRL) website accessed 14th November 2012
6. DSRL Press Release 20th Feb 2012
7. Particle Clean Up, DSRL website accessed 14th November 2012
8. Guardian 21st September 2011
9. John O Groat Journal 23rd November 2011
10. North Star 6th March 2013
For Further Information see NDA page on Exotic Fuels.