People should stay in their homes after a nuclear accident

MASS relocation of residents following a major nuclear accident is largely unnecessary, according to new research in the UK.

Philip Thomas, professor of risk management at the University of Bristol, led a team from the Universities of Manchester and Warwick, The Open University and City, University of London. The researchers studied both the Fukushima and Chernobyl accidents to look at issues such as risk and life expectancy to determine how to cope with a nuclear accident. The research papers resulting from this study were published in a special issue of the IChemE journal Process Safety and Environmental Protection.

Following the Fukushima Daaichi accident, 111,000 people were relocated by the Japanese government. 85,000 of these have still not returned four and a half years later. After the Chernobyl disaster in 1986 in what was then the Ukrainian Soviet Socialist Republic of the Soviet Union, 116,000 people were relocated just after the accident with a further wave of 220,000 relocations in 1990.The multi-university team found that was difficult to justify.

The team studied the judgement, or J-value, developed by Thomas to balance the cost of a safety measure against the increase in life expectancy achieved. It helps to assess how much money to spend to protect human life and the environment.

The researchers determined that the 900 people most at risk of the second wave of the Chernobyl relocations would have lost on average just three months of life expectancy by staying in their homes. For comparison, the average Londoner loses four and half months due to air pollution. Based on the J-values, the researchers say only 10–20% of the 335,000 people relocated after the Chernobyl disaster actually needed to leave their homes on the grounds of radiological contamination.

Mathematicians at Manchester modelled hundreds of possible large nuclear reactor accidents around the world and found that relocation was not an appropriate policy in any expected case scenarios and only rarely an appropriate policy in very sensitive case scenarios. Energy experts at the Open University used Public Health England software to model a severe accident at a fictional reactor in the south of England and again found only a very small number of people would need to be relocated.

“Mass relocation is expensive and disruptive. But it is in danger of becoming established as the prime policy choice after a big nuclear accident. It should not be. Remediation should be the watchword for the decision maker, not relocation,” said Thomas.

Process Safety and Environmental Protection doi.org/cgzf