The Vulnerability of the UK’s Nuclear Facilities to Terrorism


In addition to the threat of weapons of mass destruction — chemical, biological and nuclear — the risk that a Nuclear Power Plant (NPP) might be used as a radiological weapon has received much attention post-11 September 2001. While there is no danger of a nuclear-yield explosion if a NPP were attacked, a successful terrorist attack or sabotage attempt at a NPP containing a range of hazardous materials and facilities could cause the release of radioactive particles into the atmosphere. This would disperse radioactive contamination over a wide area. The contaminated area would thus become uninhabitable, with grave consequences for the environment, the economy and future generations. An attack on a NPP would at best cause the disruption to domestic and commercial energy supplies, at worst radioactive fallout, public hysteria and mass fatalities.

Attack on a nuclear power plant or spent fuel facility
In 2002, the United Kingdom (UK) had in operation 31 nuclear reactors in 13 NPPs.1 Of these reactors, 30 are gas-cooled and graphite-modified types: 16 of these are the Magnox reactors operated by British Nuclear Fuels Limited (BNFL); while 14 are Advanced Gas-cooled Reactors (AGRs) owned by the private nuclear power generator British Energy. The last reactor to enter service was a Pressure Water Reactor (PWR) completed in 1995, owned by British Energy.

NPPs in most countries are protected by containment vessels several feet thick and are equipped with redundant safety systems. Armed guards and other security systems also protect them.2 In order to cause a core meltdown and disperse a substantial amount of the NPP’s radioactive material into the atmosphere, attackers would have to defeat the plant’s security systems and destroy or disable its multiple safety systems simultaneously. Yet NPPs are capable of withstanding a commando-style raid by only a small group of lightly armed insurgents. A heavily armed group might therefore be able to overwhelm a NPP’s security systems, especially with insider knowledge of the security.

Besides a commando-style raid, other methods of attack exist. These might involve hijacked airplanes, a maritime vessel with crew-served weapons on-board (surface-to-surface missiles, for example), or a truck packed with explosives. In fact, a large truck bomb detonated outside the protected area of a NPP could cause sufficient damage to critical safety systems and lead to a core meltdown.3 By far the most potentially devastating radiological release would come from sabotage to a NPP or spent fuel facility: both of these facilities contain huge concentrations of highly radioactive material and would generate the nuclear or chemical energy needed for wide dispersal of the radioactive material.

International security standards differ, however. The Three Mile Island NPP facility in the USA was designed to withstand the impact of a Boeing 707, although it might be vulnerable to a full speed, direct hit from larger commercial airliners, such as a 767. But the UK’s NPPs were never constructed with such an attack in mind. The fact that 30 out of 31 of the UK’s reactors are graphite-moderated types is also a cause for concern because when graphite is used as a moderator it burns easily. In 1986, the fire in the graphite-type Chernobyl reactor lasted for over a week and released radioactivity over 1,000 metres into the atmosphere, spreading it over a large area. If an airliner crashed into a UK graphite reactor, a similar long lasting fire with long-distance fallout is possible.

Bellona recommends improved security at the UK’s NPPs, including better containment for reactors to withstand the crash impact from an airliner or from a high-yield conventional explosive detonated offsite. Security improvements at the Magnox reactors could prove uneconomical, as they are due to close by 2010.

NPPs burn uranium fuel in their cores, which produce highly radioactive and physically hot spent fuel rods: rods are removed from the reactor and those from the Magnox and AGR stations are plunged into onsite cooling ponds for a short period of time before being transferred to containers (flasks) and sent to Sellafield for reprocessing – a method of handling spent nuclear fuel. Rods from the PWR station are initially stored in onsite water-filled storage pools. BNFL operates two reprocessing plants at Sellafield, Magnox B205 and Thermal Oxide Reprocessing Plant (THORP). B205 operates according to the Plutonium Uranium Extraction method and reprocesses fuel from British Magnox reactors. THORP was designed to separate plutonium for use in ‘breeder’ reactors, but now reprocesses spent nuclear fuel (SNF) from British AGRs as well as imported SNF.4 Other than Sellafield, there are only two other major reprocessing plants in operation worldwide: Cap de la Hague in France and Mayak in Russia.

The Sellafield plant houses 21 steel tanks in above ground concrete cells that contain high level radioactive waste in the form of self heating, acidic liquid. This radioactive waste has to be constantly cooled and stirred to prevent a chain reaction, which is achieved by continuously being cooled and agitated to prevent the stored waste from boiling and causing a radiological release. The tanks contain 2,400kg of caesium-137, a radioactive material responsible for offsite radiation exposure from Chernobyl, although the amount released from Chernobyl was approximately 27kg. It is estimated that if an airliner crashed into one of the key structures at Sellafield, it would release into the atmosphere 44 times the radioactivity of the 1986 Chernobyl accident.5

If the cooling system were sabotaged, or if terrorist attack on the facility were successful, it would release liquid waste into the Irish Sea, along with strontium-90, caesium-137 and technetium-99, which has a half-life of 213, 000 years. Such radioactive substances would contaminate fisheries and travel north from Cumbria, heavily contaminating fisheries in western Scotland. Anywhere downwind of Sellafield during the release would be rendered uninhabitable for generations, and people caught in the fallout would have a higher chance of contracting cancer. Depending on the wind direction, cities such as Dublin, Edinburgh, Leeds and Newcastle would be well within fallout range.

Indeed, in a report to the House of Commons Defence Committee on 9 January 2002, Dr Gordon Thompson, executive director of the Institute for Research and Security Studies in Cambridge, Massachusetts, suggested that an attack on the B205 facility could release 100 times the radioactivity produced by the Chernobyl accident, which would make the north of England uninhabitable for generations.6

Moreover, a report by the Nuclear Installations Inspectorate on 2 July 2002 reported that two sets of tanks housing medium-level radioactive waste at Sellafield were so old and in such a dangerous condition that they pose an unacceptable risk. BNFL has been warned that neither the structural integrity of the tanks, nor the building containing them, could be guaranteed beyond ten years. While BNFL has already surrounded the tanks with a steel building and commissioned specialist machinery to empty the tanks, the condition of the tanks require the building of new tanks or another solution for processing the waste.

Bellona advocates the need for crash-proof tanks to contain the medium and high-level radioactive waste stored at Sellafield. The liquid waste should be immobilised as soon as possible and disposed of geologically.

Attack on reprocessing or storage transports
In 1996, BNFL opened the Sellafield MOX Plant (SMP) for the production of mixed oxide (MOX) fuel, receiving its licence for production in October 2001. The only use for the plutonium that THORP and B205 have produced is to mix it with uranium oxide and fabricate MOX fuel for use in light water reactors. While the UK has the facilities to produce MOX fuel, it does not use MOX fuel. And given the cost of conversion, British NPP operators have no plans to convert their plants to burn MOX fuel. BNFL, having already built a MOX fuel manufacturing plant, has been forced to look overseas for customers in countries including Germany, Switzerland and Japan.

The transportation of nuclear materials, such as fresh MOX fuel and SNF for reprocessing, means that there will be an ever increasing traffic in nuclear materials by air, land and sea. Shipments of SNF and fresh MOX fuel might be vulnerable to terrorist attack and could be used to create a radiological explosion or to gain the material to fabricate a radiological dispersal device such as a "dirty bomb".

No nuclear freight is allowed to travel through the Channel Tunnel. Previously, SNF for reprocessing sent to Sellafield was shipped into Dover Docks by train-ferry before travelling on by rail. The ferry has now been withdrawn from service and all flasks go by sea to Barrow-in-Furness, and then by train to Sellafield. Flasks are made of steel and are lead-lined in order to contain the intense heat and radioactivity of the spent fuel rods and are carried on special low-loading freight wagons.7 While the flasks are designed to meet International Atomic Energy Agency safety standards, a successful terrorist attack might cause either a high-speed derailment or collision, which could release the radioactive contents.

BNFL operates seven vessels for the transport of MOX fuel. Two of these vessels are armed with 30mm cannons. Armed officers from the UK Atomic Energy Authority (UKAEA) Constabulary, which provide security for civil nuclear sites and for the transport of nuclear material within the UK, are on guard against boarders. Should the Constabulary be overpowered, would-be attackers would than have to crack open the vessels’ reinforced hatch covers and unload the rods without the aid of deck cranes.8 Yet BNFL’s vessels only have a top speed of 13 knots and are not as maneuverable or well-defended as a military or coastguard escort vessel.9 Jane’s maritime specialists suggest that the vessels are capable of repelling a light attack and should be protected by at least one well-armed frigate.10 And while MOX fuel flasks can resist temperatures of 800C for up to 30 minutes, fires on ships can burn for 24 hours at a temperature of 1,000C.

MOX fuel is plutonium and uranium blended and held in ceramic form, so it is possible to undertake the chemical separation of plutonium from fresh MOX fuel. While it is debatable whether or not this could be used to fabricate a crude nuclear device, the material could be used to make a dirty bomb capable of scattering plutonium dust in the wind: just one speck of plutonium breathed into the lungs is enough to cause cancer, so the population near any blast involving radioactive material would have to be evacuated immediately.

Given the security threats of transporting fresh and spent MOX fuel, including the risk of accidents at land and sea and nuclear material proliferation, as well as the additional costs of increasing security, Bellona calls for a ban to be placed on the international transport of MOX fuel.

Reducing the vulnerability of nuclear facilities
Since 11 September 2001, attention has been drawn to the physical protection of NPPs. By deploying point air-defence systems around Cap de la Hague, French defence officials have tightened security around Europe’s largest nuclear processing plant. In the UK, the House of Commons defence committee stressed that attention should be focused on the vulnerability of nuclear installations. The UK Home Office, too, has underscored the need to protect the UK’s key nuclear facilities through the government’s Civil Contingencies Committee. The Royal Air Force Tornado F3 fighters based at Coningsby, Lincolnshire, are responsible for intercepting hijacked commercial aircraft deemed a threat to UK nuclear sites.

In July 2002, the British government published a White Paper entitled "Managing the Nuclear Legacy: A Strategy for Action" which proposed to transform the UKAEA Constabulary into a stand-alone force, the Civil Nuclear Constabulary (CNC).11 The new, armed force will be able to make arrests at non-nuclear locations such as sea ports, airports and railway stations. It will also be able to patrol and stop and search individuals and vehicles up to three miles from nuclear sites.

Bellona believes that these responses do not tackle the underlying vulnerability of NPPs, however. What is needed is a comprehensive upgrade of security systems including improved reactor containment. In fact, in the short term, security standards should be improved, and it would be prudent to enhance security systems. In the long term, however, Bellona advocates an end to commercial reprocessing and the vitrification and disposal of high-level radioactive waste preferably in a dry-storage geological repository. Nuclear energy provides 23% of Britain’s total energy requirements, so reducing the need for nuclear power is feasible, especially on financial grounds.

In 2001, BNFL developed a £1.7bn “net asset deficit” in its accounts. To avoid prosecution under the 1985 Companies Act, BNFL managers called an extraordinary general meeting on 28 November 2001. Since then, the British government has set up a Liabilities Management Authority to take responsibility for and control the UK’s nuclear waste including everything owned and run by the UK Atomic Energy Agency and BNFL. It appears that BNFL failed to set aside sufficient money to pay for cleaning up old nuclear power stations and has developed a £44bn deficit. The bill for dealing with nuclear waste alone exceeds £38bn, and the British taxpayer will now have to pay £1.5bn a year in liabilities.12

1. For more information, see Erik Martiniussen, Bellona Working Paper, ‘Sellafield: Reprocessing Plant in Great Britain’, No.05: 2001, (29 October 2001), Bellona
2. Matthew Bunn and George Bunn ‘Reducing the Threat of Nuclear Sabotage’, Intersec, (Vol.12, Issue 4, April 2002).
3. Power Technology, ‘Nuclear Terrorism’, Power Technology
4. Campaign for Nuclear Disarmament, Briefing Paper, ‘Nuclear Power and Nuclear Weapons’, CND
5. ‘Sellafield Time Bomb Warning’, 23 October 2001, BBC News
6. Paul Brown and Richard Norton-Taylor, ‘Terror attack on Sellafield would wipe out the north’, 10 January 2002, the Guardian
7. CND, Rail Transport: fact sheet, ‘UK Nuclear Power Stations and Nuclear Fuel Transport’, CND
8. ‘MOX: The Voyage Home’, 11 July 2000, BBC News
9. Greenpeace, Background Briefing, ‘The Sellafield MOX Plant’, November 2001, Greenpeace
10. Geoffrey Lean, ‘Pirates could snatch plutonium’, the Independent, (4 July 1999).
12. Paul Brown, ‘Nuclear fallout’, 14 December 2001, the Guardian