Reprocessing & Plutonium

What is reprocessing?

Uranium-fuelled nuclear reactors produce plutonium during normal operation. Reprocessing has been carried out in a few countries since the 1950s to retrieve plutonium (and unused uranium) from spent nuclear waste fuel, originally for use in nuclear weapons. The largest centres of commercial reprocessing today are at Sellafield and La Hague in France.1

Reprocessing is only one of several spent nuclear waste fuel management options. In 2000 only about a sixth of the world’s spent fuel was reprocessed, the rest was stored. Reprocessing involves dissolving spent fuel in boiling nitric acid to separate out plutonium and uranium. This leaves behind highly radioactive liquid waste, which is so radioactive that it generates its own heat and has to be constantly cooled.

Discharges of radioactivity into the environment from reprocessing activities are high. Most discharges in France and the UK come from reprocessing.

Why reprocess?

Apart from the need to separate plutonium for nuclear weapons, the industry was hoping to develop a new reactor-type known as the Fast Breeder Reactor (FBR). The basic idea was that FBRs would be fuelled by plutonium, but as well as plutonium fuel, the reactors would also contain a ‘blanket’ of the otherwise useless uranium-238. During reactor operation this uranium-238 would transmute into more plutonium. It was the scientists dream – like the perpetual motion machine – because FBRs could, in theory, create more fuel than they consumed. This would greatly extend the life of uranium reserves. Unfortunately for the industry, things did not quite work out as planned. (See Dounreay).

Sellafield – horrible history

Sellafield in Cumbria is the location of two reprocessing plants – the Magnox reprocessing plant (also known as B205), and the Thermal Oxide Reprocessing Plant (THORP), as well as the Sellafield MoX Plant, which is supposed to fabricate mixed plutonium and uranium oxide fuel, and several waste processing plants. Sellafield was also the site of Britain’s worst nuclear accident in 1957. Since 2003, when the Calder Hall Magnox reactors were closed down, Sellafield has not had any operating nuclear reactors

In 1947, the UK Government ordered construction to begin on two plutonium producing reactors – known as the Windscale Piles – along with a separation plant to extract weapons-grade plutonium for the UK’s nuclear weapons programme.

From 1946 to 1954 Britain’s nuclear activities were in the hands of the Ministry of Supply. Then in 1954 the UK Atomic Energy Authority (UKAEA) was established to design, test and produce nuclear weapons, as well as to draw up plans for Britain’s first nuclear power stations. Britain’s first nuclear reactor was built at Calder Hall, next to Sellafield, and opened by the Queen on 17th October 1956. In 1957 the UKAEA got the go-ahead to build a pilot advanced gas-cooled reactor (AGR) at Sellafield – the Windscale AGR (WAGR) .This classic dome-shaped reactor operated between 1963 and 1981.

On 1st April 1971 the UKAEA was split up. A new quasi-‘commercial’ company, called British Nuclear Fuels Ltd (BNFL), took over all the UKAEA’s fuel-service activities, including the fuel manufacturing plant at Springfields near Preston, the uranium enrichment plant at Capenhurst in Cheshire, and the spent-fuel complex at Sellafield (which at the time was called Windscale), and the dual-purpose Calder Hall and Chapelcross plutonium-plus-electricity reactors. BNFL was supposed to be a commercial operation but 100% of its shares were held by the Government.

The Magnox reprocessing plant opened in 1964, followed by the THORP plant in 1994. Construction of the Sellafield MoX Plant was completed in 1997.

In 2005 ownership of the Sellafield site transferred to the Nuclear Decommissioning Authority (NDA) who oversee both the commercial operations and decommissioning work. But the work is carried out by Sellafield Ltd. Sellafield Ltd is called a Site Licence Company.2 After a bidding process the contract to run the Sellafield Parent Body Organisation (PBO) which will own all the shares in the Site Licence Company – Sellafield Ltd – for the duration of the contract was awarded to a consortium known as Nuclear Management Partners (NMP) on 24th November 2008.3 NMP includes URS Washington Division (previously known as Washington Group International), Amec and Areva.

The value of the contract was £1.3bn in its first year and over the full lifetime of the contract approximately £22bn.4 Half of the NDA’s total budget is being spent on this one contract – the largest nuclear contract in the world after Savannah River, South Carolina, in the US.5

Waste Management

Reprocessing at Sellafield has generated large inventories of radioactive waste in various physical and chemical forms, but the largest hazard is posed by the storage of the liquid high-level radioactive waste (HLW).6 Concentrated liquid HLW is stored in steel tanks at Sellafield (known as B215) before being solidified into glass blocks – a process known as vitrification. This highly radioactive waste generates its own heat, so has to be constantly cooled. Should the cooling system fail, the waste in the tanks would boil, releasing radioactivity into the atmosphere.

Many commentators believe this highly dangerous nitric acid solution is making us extremely vulnerable to a terrorist attack. The fact that the radioactivity is in a liquid form makes it much more susceptible to dispersal were there to be a deliberate or accidental impact. The Parliamentary Office of Science and Technology reported in July 2004 that if there were such an attack it is possible that the area between Glasgow and Liverpool would need to be evacuated.7 This kind of release could result in around 2 million fatalities.8

In 2010 the Norwegian Radiation Protection Authority (NRPA) carried out an impact assessment of a “worst-case” hypothetical accident at Sellafield’s B215 facility.9 The report concludes that if only 1% of the caesium is released to air, the radioactive fallout in Western Norway could be five times higher than in the areas of Norway that were worst affected by the Chernobyl accident.10

Sellafield Controversy

Sellafield has been the most controversial nuclear facility in the UK, if not Europe, for most of the last twenty to thirty years. The site discharges up to 8 million litres of radioactive liquids into the Irish Sea every day.11 Radioactivity is measured in Becquerels (Bq) – the standard international unit of radioactivity. One becquerel is one radioactive disintegration per second. Radioactive discharges tend to be reported in Terabecquerels (TBq) (1,000,000,000,000 or 1012 becquerels).

In 2000 the Radioactive Waste Management Advisory Committee, which no longer exists, gave indicative discharges from Sellafield with both reprocessing plants operating at high throughput rates.12 Total discharges, excluding tritium, are given as:

  • Magnox: 132 Terabecquerels (TBq)
  • THORP: 9 TBq
  • Other Plant: 33TBq

This compares to discharges of around 0.1–2 TBq for an operating nuclear station. Radioactivity from Sellafield can be found as far away as the Arctic. It concentrates in fish, shellfish, seaweed and other marine animals and plants. Plutonium discharged from Sellafield was expected to remain locked in the sediments at the bottom of the Irish Sea, but there is now evidence that these sediments are being re-mobilised. Radioactivity can also be detected in seaspray and it can move inland up rivers by a process known as tidal inundation.13

Sellafield also discharges radioactivity into the atmosphere. These discharges are dominated by the inert gas, Krypton-85. 60,000 TBq of Krypton-85 were discharged from Sellafield in 2011.14 Because Krypton does not react chemically it travels right around the globe raising radioactivity levels in the atmosphere everywhere.

The Future of Sellafield

The Nuclear Decommissioning Authority (NDA) took over ownership of Sellafield in April 2005. The original White Paper about establishing the NDA – “Managing the Nuclear Legacy” – was published in July 2002. Unfortunately, since it was originally proposed, the role of the NDA has radically changed. The Authority has been heavily dependent on waste-producing activities for its income. Half of the NDA’s estimated £2bn funding for 2005-2006 was meant to be generated by commercial operations. Consequently the NDA continues to oversee the operation of commercial nuclear facilities which create nuclear waste – thus adding to our waste problems.15

Magnox Reprocessing

There are two reprocessing plants at Sellafield, the older Magnox reprocessing plant which opened in 1964, and the newer Thermal Oxide Reprocessing Plant (THORP) which opened in 1994. The Magnox Reprocessing Plant (also known as B205) was built to reprocess spent nuclear waste fuel from Britain’s Magnox stations and two Magnox stations sold to Japan and Italy. In May 2000 BNFL announced B205 would close around the end of 2012.16 The plant (B205) is responsible for a majority of the site’s radioactive discharges into the Irish Sea, so closure by that date was a key part of the UK Government’s strategy for achieving its commitments under the international treaty – the Convention for the Protection of the Marine Environment of the North-East Atlantic, or the OSPAR Convention. Under this Treaty the UK agreed in 1998 to ensuring that by 2020:

“…discharges emissions and losses of radioactive substances are reduced to levels where the additional concentrations in the marine environment above historic levels, resulting from such discharges emissions and losses, are close to zero.” 17

In its latest Magnox Operating Programme (MOP9) the NDA strategy continues to be that it will reprocess all Magnox spent nuclear waste fuel, but because the performance of the reprocessing plant has been so poor this could mean extending the life of the magnox reprocessing plant to anywhere between 2017 to 2028.18 While the NDA blames poor throughput for not being able to close B205 by 2012, but at the same time it is extend the life of the Wylfa Magnox nuclear station on Anglesey, from March 2010 to September 201419 as well as reprocess breeder fuel from Dounreay, further adding to the spent fuel to be reprocessed before B205 closes. Continued high levels of radioactive discharges will infuriate many of the North-East Atlantic Governments.20


The NDA’s original plan for Sellafield was that THORP operations would finish in March 2011. THORP should have reprocessed 7000 tonnes of spent fuel in its first decade of operation to 2004 – the so-called ‘baseload contracts’ – but, by the time an accident in April 2005 closed the facility for almost three years it had only reprocessed 5729 tonnes. The plan now is to close THORP in 2018 having completed all overseas contracts, and reprocessed the AGR spent fuel the NDA is contracted to reprocess. Sellafield’s spent fuel ponds will have enough capacity to store the remaining AGR spent fuel, even if the lives of the 7 AGRs are extended by an average of 7 years. (See Sellafield’s Dangerous Balancing Act, NuClear News No.44, October 2012)

For more information see: Towards a Safer Cumbria: How government, regulators and the Nuclear Decommissioning Authority have neglected nuclear waste in Cumbria By Pete Roche, Friends of the Earth, March 2013.


1.Possible Toxic Effects from the Nuclear Reprocessing Plants at Sellafield (UK) and Cap de la Hague (France), European Parliament Scientific and Tecchnological Options Assessment, November 2001.
2. For more information about the break-up of BNFL see here.
3. NDA Press Release 6th October 2008
4. NDA Press Release 24th November 2008
5.  Sunday Telegraph 9th March 2008.
6. See The Storage of Liquid High Level Waste at BNFL Sellafield, Nuclear Installations Inspectorate, February 2000, and Addendum to Feb 2000 report.
7. Assessing the risk of terrorist attacks on nuclear facilities,Parliament Office of Science and Technology Report 222, July 2004.
8. Possible Toxic Effects from the Nuclear Reprocessing Plants at Sellafield (UK) and Cap de la Hague (France), European Parliament Scientific and Tecchnological Options Assessment, November 2001, p38.
9. Consequences in Norway of a Hypothetical Accident in Sellafield, Norwegian Radiation Protection Authority, 2010.
10. Norwegian Ministry of the Environment Press Release 26th March 2009.
11. This figure is from BNFL’s quarterly reports to the Environment Agency.
12. RWMAC (November 2000) Advice to Ministers on the Radioactive Waste Implications of Reprocessing. Annex 7.
13. SNIFFER (August 2003) “Studies on the solid speciation and remobilisation of plutonium in northern Irish Sea waters” AIR(99)01  Guardian 23rd April 1999. and New Scientist 24th April 1999.
14. Radioactivity in Food and the Environment, 2011 (RIFE-17), EA, FSA, NIEA, SEPA, 2012.
15. See Briefing on the Nuclear Decommissioning Authority, GreenpeaceUK, September 2005.
16. BNFL Press Release 23rd May 2000.
17. UK Strategy for Radioactive Discharges DECC, July 2009.
18. Magnox Operating Programme 9 (MOP9), NDA, July 2012.
19. Magnox Sites website, accessed 22nd November 2012.
20.  CORE Press Release 7th Nov 2007


Published: 22 November 2012
Last updated: 25 June 2013