Skip to content (Press enter)


Sizewell B

Radiation is a form of energy. Visible light is a form of natural, medium-frequency radiation. Large doses of high-frequency radiation, also known as ionising radiation, can damage living tissue. Radiation can be useful when handled with care. In medicine, x-rays are used to diagnose ailments and radiotherapy can be used to treat cancer. Radiation can also be used in food preservation and in household smoke detectors.

Nuclear power stations generate electricity by harnessing the energy released from splitting uranium atoms. Potentially harmful ionising radiation is emitted during this process, so nuclear power stations are designed to protect those outside from the harmful effects of this radiation.

Radiation dosage

People are constantly exposed to natural sources of radiation. According to data collected between 2001 and 2003, an average person in the UK receives an annual radiation dosage of 2.7 millisieverts (mSv, the units in which radiation dosage is measured), 2.23mSv of which is from natural sources and 0.42mSv of which is from man-made sources, such as medical x-rays.

Nuclear power stations are specifically designed to contain harmful ionising radiation. The average dose received by the public from nuclear power is 0.0002mSv per year. Radiation levels at nuclear power stations are monitored by the operators and independently verified by the Environment Agency and the Scottish Environment Protection Agency.

In 2009, 95.3% of people who worked in EDF Energy's nuclear plants received less than 0.5mSv effective dose; 96.8% received less than 1mSv effective dose; and the remaining 3.2% (488 people) received an average dose of 2.588mSv. The maximum annual dose allowed to workers by legislation regulated by the Health and Safety Executive is 20mSv per year.

Information sources

What is radiation

Doctor studying an X-ray

Radiation is a continuous energy spectrum that exists all over the natural world from sunlight to the Earth's rocks. Radiation from nuclear materials is just one aspect of radiation.