Safety of Plants

Safety of Nuclear Power Reactors

From the outset, there has been a strong awareness of the potential hazard of both nuclear criticality and release of radioactive materials. Both engineering and operation are designed accordingly. There have been three major reactor accidents in the history of civil nuclear power: Three Mile Island, Chernobyl and Fukushima. These are the only major accidents to have occurred in over 17,000 cumulative reactor-years of commercial operation in over 30 countries.

Chernobyl Accident

The Chernobyl accident in 1986 was the result of a flawed reactor design that was operated with inadequately trained personnel. Two Chernobyl plant workers died on the night of the accident, and a further 28 people died within a few weeks as a result of acute radiation poisoning.

Fukushima Daiichi Accident

This information paper describes in detail the causes of the nuclear accident at Fukushima Daiichi in March 2011 and the actions taken since.

Liability for Nuclear Damage

Operators of nuclear power plants are liable for any damage caused by them, regardless of fault. They therefore normally take out insurance for third-party liability, and in most countries they are required to do so. Liability is limited by both international conventions and by national legislation, so that beyond the limit (normally covered by insurance) the state can accept responsibility as insurer of last resort, as in all other aspects of industrial society.

Nuclear Power Plants and Earthquakes

Nuclear power plants are designed to withstand earthquakes, and in the event of major earth movement, to shut down safely. In areas where the frequency and magnitude of earthquakes is significant, such as in Japan, particular attention is paid to seismic issues in the siting, design and construction of nuclear power plants.

Three Mile Island accident

In 1979 a cooling malfunction caused part of the core to melt at Three Mile Island 2. The reactor was destroyed. Some radioactive gas was released a couple of days after the accident, but not enough to cause any dose above background levels.

Tokaimura Criticality Accident

On 30 September 1999 three workers received high doses of radiation in a Japanese plant preparing fuel for an experimental reactor. Two of the doses proved fatal. The accident was caused by bringing together too much uranium enriched to a relatively high level, causing a 'criticality'.