Some scientists say authorities in favour of nuclear energy tend to deny the negative results of researchers.
In the aftermath of the earthquake and tsunami that hit Japan on 11 March 2011, the Daiichi nuclear plant in Fukushima was badly wrecked in a series of meltdowns and explosions that severely damaged three reactors and one spent-fuel pool.
The accident released enormous quantities of radionuclides (radioactive material) into the atmosphere and the sea. This led to the government setting up exclusion zones in regions around the plant and the evacuation of over 155,000 residents.
Three years on, calculating the injurious effects of this radiation on plant, animal and human health has become a matter of controversy, as different groups of researchers reach different conclusions.
Negative data ignored?