Radiation release from overseas nuclear site

Impact 5
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upper likelihood error bar risk indicator
lower likelihood error bar
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Impact & Likelihood
Impact key
5 Catastrophic
4 Significant
3 Moderate
2 Limited
1 Minor
Likelihood key
5 >25%
4 5-25%
3 1-5%
2 0.2-1%
1 <0.2%


Another risk that the government is planning for is an accident at an overseas nuclear site that results in the release of radiation. Impacts on the UK homeland would most likely be felt if the accident occurred at a site in a country close to the UK as opposed to a geographically distant location. For example, the 2011 Fukushima disaster in Japan resulted in very low levels of radioactive iodine being detected. Countries near the UK have well-established civil nuclear sectors, with robust safety procedures in place.


In line with good practice the UK plans for a range of scenarios, including less likely, more severe scenarios that are beyond reasonable worst-case. This scenario is extremely unlikely. It is based on an accident occurring at an overseas nuclear site, close to the UK. This could affect the UK and its interests overseas, with overall impacts being highly dependent on weather patterns and distance from the UK.

There would likely be no acute radiation-linked immediate health effects for people in the UK although, depending on the weather patterns, there could be an increased risk of cancer over the longer term if the release occurred from an overseas site close to the UK. British nationals in the accident country would likely require consular assistance.

The resulting contamination could affect the environment and food production, and there could be disruption to domestic and international transport into Europe (including Channel shipping lanes). This could impact the import of food from the accident country and surrounding countries. The overall impacts of a release are dependent on weather patterns.

Key assumptions

Scientific modelling has been used to determine the scenario and the countermeasures required.


Smaller-scale scenarios could occur, which would decrease the area affected and the risk to people, the environment and the economy.

Response capability requirements

There would be a large-scale, multi-agency response. A communications campaign would be needed to provide key messages to the public. Immediate capabilities would be radiation monitoring and decontamination services, alongside remediation services to restrict the spread of radioactive material.


Around affected parts of the UK, there could be prolonged long-term health, environmental and economic impacts requiring sustained recovery.