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Nuclear Accidents/Incidents
Nuclear Accidents/Incidents
Nuclear Emergencies
There are well developed and tested arrangements for responding to any nuclear emergency already in place for all UK civil nuclear sites as part of the licensing requirements imposed by the Health & Safety Executive's Nuclear Installations Inspectorate. See the Emergency Planning page of the website for more information.
International Notification Requirements
BERR is responsible for notifying the international community in the event of a UK nuclear accident under the International Atomic Energy Agency Convention on Early Notification of a Nuclear Accident, and the European Council Decision of 14 December 1987 on Community arrangements for the early exchange of information in the event of a radiological emergency. Bilateral arrangements also exist for early notification of a UK nuclear accident between the UK and Denmark, France, Netherlands, Norway, the former Soviet Union (Russian Federation) and Ireland.
The intention is to make other States aware of possible transboundary consequences of any release so that consideration can be given to any emergency measures that may be required for the protection of the general public and the environment.
International Nuclear Event Scale (INES)
To aid public understanding of the safety significance of events at nuclear installations and their consequences, the IAEA and the Nuclear Energy Agency of the OECD have developed the International Nuclear Event Scale ('INES').
The levels and criteria summarised below can be applied to any event associated with radioactive material and/or radiation to any event occurring during the transport of radioactive material:
| Level 0 | Below scale. No safety significance |
|---|---|
| Level 1 | Anomaly. Variation from permitted procedures |
| Level 2 | Incident with potential safety consequences on site but with sufficient safety defences remaining. Insignificant release of radioactivity off site |
| Level 3 | Serious Incident. Very small release of radioactivity. Radiation exposure off site a fraction of the prescribed limits. Local protective measures unlikely except for some food monitoring and control. Possible acute health effects to a worker |
| Level 4 | Accident with minor release of radioactivity. Radiation exposure off site of the order of prescribed limits. Local protective measures unlikely except for some food monitoring and control. Significant plant damage. Fatal exposure of a worker |
| Level 5 | Accident with off site risks. Release of radioactivity. Severe plant damage. Partial implementation of local counter measures |
| Level 6 | Serious accident. Significant release of radioactivity. Full implementation of local counter measures |
| Level 7 | Major accident. Major release of radioactivity. Acute health and long term environment effects |
As shown in the table, only events at level 4 and above are accidents with a significant release of radioactivity off-site. The accident at an RBMK reactor at the Chernobyl nuclear power plant, in the former Soviet Union in 1986, had widespread environmental and human health effects and was rated as level 7. The accident at the Three Mile Island nuclear power plant in the United States in 1979 resulted in a severely damaged reactor core. The event was rated at level 5 on the basis of the on-site impact. In 1957, in the early stages of development of the UK nuclear programme, an accident occurred at the United Kingdom Atomic Energy Authority's (UKAEA) site at the Windscale (now Sellafield) facility in Cumbria which involved an external release of radioactive fission products. On the basis of the off-site impact, it was rated at level 5, the highest rated accident which has occurred in the United Kingdom.
Further information on the International Nuclear Event Scale can be found on the Internation Atomic Energy Agency website.
Ministerial Reporting Arrangements
Voluntary arrangements for reporting nuclear incidents at civil nuclear installations in England, Scotland and Wales to Ministers were first announced in April 1987 by Alastair Goodlad, Parliamentary Under Secretary for Energy. These arrangements are generally referred to as the 'Goodlad' arrangements and set out the approach agreed with the nuclear operators for reporting nuclear incidents occurring on their sites which, although not requiring the emergency plans to be invoked, have possible implications for the safety of the site.