Nuclear Safety in the UK

Given the number of TV series and documentaries recently broadcast about Chernobyl and the interest they have generated prompted us to think about the UK’s nuclear safety record. This article gives a high level overview of Health and Safety in the UK nuclear industry.

The UK built its first nuclear reactor in 1947. In the seven decades since the UK’s nuclear safety record has been good, though not without some blemishes.

The UK’s Nuclear Safety Record

In 1957 a fire at one of the Windscale (now Sellafield) reactors caused the release of radioactive Iodine-131. Although judged not severe enough to evacuate the local populace, milk from nearby farmland was diluted and destroyed for the next month. Prime Minister Harold Macmillan suppressed the report into the incident as it showed the extent of the disaster, technical shortcomings and organisational problems. The report was not made public for 30 years.

Transparency has been a problem on other occasions. In 2000 British Nuclear Fuels chief executive, John Taylor resigned over a scandal relating to faked safety records at the Sellafield plant, and in 2009 Magnox Electric Ltd, operators of the Bradwell-on-Sea nuclear plant was found guilty of allowing a radioactive leak to continue at the site for 14 years between 1990 and 2004.

In 2009 a report by the government’s chief nuclear inspector showed that between 2001-02 and 2007-08, there had been 1,767 safety incidents reported at Britain’s nuclear plants, including leaks, breakdowns or other “events”. About half of these were subsequently judged by inspectors to have been serious enough “to have had the potential to challenge a nuclear safety system”.

The most significant response to a nuclear incident came weeks after the 1986 explosion of the Chernobyl reactor in Ukraine, then inside the Soviet Union. The sale of sheep was banned from thousands of farms in North Wales and parts of Cumbria, Scotland and Northern Ireland as it was deemed likely they had ingested radioactive material from fallout absorbed by plants.

In total, almost 9,000 British farms were affected by restrictions on the movement and sale of sheep meat. Livestock had to be approved by government officials before they were allowed to enter the food chain.

Sheep from some farms in Wales were still failing radioactive tests ten years after the accident. The last remaining restrictions on the movement and sale of sheep were lifted in 2012, 26 years after the accident.

Although some studies have linked increased incidences of infant leukaemia in Britain to the Chernobyl disaster, the results are inconclusive.

Today most of the background radiation in the UK comes from natural radon gas. Treating the highest levels are addressed in the UK National Radon Action Plan [PDF].

Safety Regulation and Legislation

Since 2011 the UK safety regulator for the nuclear industry has been the Office for Nuclear Regulation (ONR). It regulates the safety of nuclear installations (including conventional safety) and the transport of radioactive materials in Great Britain. It also regulates nuclear security and safeguards.

Operators of nuclear facilities must comply with a long list of safety-related legislation and regulations. These include the relevant statutory provisions of the Health and Safety at Work Act 1974 and the Nuclear Installations Act 1965. Radiation protection is regulated according to the Ionising Radiations Regulations 2017, and emergency preparedness and associated radiation protection are governed by the Radiation (Emergency Preparedness and Public Information) Regulations 2001. Risk assessments have to comply with the Management of Health and Safety at Work Regulations 1999 and the Dangerous Substances and Explosive Atmospheres Regulations 2002. Other regulations to be met include the Personal Protective Equipment at Work Regulations 1992, the Control of Major Accident Hazards Regulations 1999 and the Pressure Systems Safety Regulations 2000

Fundamental Safety Principles

The ONR follow a set of fundamental principles considered to be the foundation for safety and radioactive waste management principles. These Safety Assessment Principles (SAP) lay out the standards to be followed when assessing safety. They are consistent with HSE’s Decision-Making Process’ Reducing Risks, Protecting People’ (abbreviated to R2P2), which provides an overall framework for decision making to help establish coherence and consistency for all risks falling within the scope of the Health and Safety at Work Act.

These fundamental principles are as follows:

  • Responsibility for safety – The prime responsibility for safety must rest with the person or organisation responsible for the facilities and activities that give rise to radiation risks.
  • Leadership and management for safety – Effective leadership and management for safety must be established and sustained in organisations concerned with, and facilities and activities that give rise to, radiation risks.
  • Optimisation of protection – Protection must be optimised to provide the highest level of safety that is reasonably practicable.
  • Safety assessment – Dutyholders must demonstrate effective understanding and control of the hazards posed by a site or facility through a comprehensive and systematic process of safety assessment.
  • Limitation of risks to individuals – Measures for controlling radiation risks must ensure that no individual bears an unacceptable risk of harm.
  • Prevention of accidents – All reasonably practicable steps must be taken to prevent and mitigate nuclear or radiation accidents.
  • Emergency preparedness and response – Arrangements must be made for emergency preparedness and response in case of nuclear or radiation incidents.
  • Protection of present and future generations – People, present and future, must be adequately protected against radiation risks.

Popular Presentation of Safety Issues

Producing nuclear power is an expensive and sometimes emotive business, and stakeholders sometimes view the associated issues differently. Some commentators believe that the Office for Nuclear Regulation has a staffing shortfall of inspectors and therefore is too stretched to perform its function adequately. The ONR disagrees.

The press may also sometimes be drawn into a sensationalist approach and play on safety fears. In 2018 the Hunterston B nuclear power plant in Ayrshire was shut down after the discovery of about 370 hairline cracks in the reactor – exceeding the operational limit.

The plant’s owners, EDF, want to return the 43-year-old reactor to service by the end of July, though they insist this will only happen if it is safe to do so. They also want the ONR to increase the operational limit of cracks allowed from 350 to 700.

Many news publications presented this situation as an unexpected flaw with experts warning of a restart possibly leading to radioactive contamination of large areas of central Scotland, including Glasgow and Edinburgh. However, the Nuclear Industry Association has stated that “as part of the usual ageing of nuclear reactors, cracks are expected in the graphite bricks which make up the reactor core, and EDF Energy regularly inspects its fleet for signs of cracks. While these cracks are expected, the inspection of unit 3 at Hunterston B found additional cracks that were forming at a faster rate than expected. Hunterston B has been kept offline while EDF Energy and the regulator understand exactly why this has happened.”