Small amounts of plutonium believed to have escaped from Japan’s tsunami-crippled nuclear plant have been detected in soil more than 40km away, say government researchers, a finding that will fuel already widespread fears about radiation risk.
The discovery came as authorities lifted evacuation advisories on other towns near the crippled Fukushima Daiichi power station in the north-east prefecture of Fukushima, saying radiation readings showed they were safe for residents.
Government officials played down the health implications of the discovery of the first traces of plutonium from Fukushima Daiichi to be found outside the plant’s immediate environs, saying clean-up efforts should still concentrate on the far greater amounts of radioactive caesium contaminating the area.
The plutonium was found at six sites — including one in Iitate around 40km from the plant — all of which are subject to evacuation orders. However, plutonium’s long half-life and the potential for even small amounts to pose a health hazard if ingested is likely to make it a focus of popular concern.
Japanese authorities, who significantly underestimated radiation releases from the plant in the early days of the crisis, have since struggled to convince the public that they are able effectively to guard against radiation health threats.
Fierce debate among experts on the point at which radiation becomes dangerous enough to warrant evacuation is adding to the government’s difficulty in coming up with a coherent policy.
The failure of Fukushima Daiichi’s cooling systems, which prompted the world’s worst nuclear crisis in 25 years, has thrown Japan’s atomic energy sector into doubt.
Yoshihiko Noda, Japan’s new prime minister, on Friday reiterated that it would be “difficult” to build any new reactors in the country. Mr Noda has said he aims to restart nuclear plants currently closed for maintenance or repair once their safety can be assured, but their future remains uncertain.
Kyodo news agency quoted the science ministry as saying on Friday that it had decided to postpone a trial run of a troubled fast-breeder reactor in Fukui Prefecture because of public fears.
The Monju prototype reactor, which burns plutonium refined from the spent fuel of conventional reactors, was shut down in 1995 following a coolant leak and efforts to put it into full operation have been repeatedly delayed.
Seiji Maehara, an influential member of the ruling Democratic party who is now its policy chief, told the Financial Times in July that the 280-megawatt plant should be scrapped.
The government’s failure to ensure that the Fukushima Daiichi plant was protected against a tsunami has undermined claims that reactors elsewhere are safe, a problem exacerbated by revelations that even regulators used underhand methods to drown out anti-nuclear critics.
An independent panel set up to investigate the backstage manipulation of public seminars and community gatherings found that the Nuclear and Industrial Safety Agency had repeatedly asked power companies to organize participants to express pro-nuclear views.
“The close relationships between the agencies and power companies were behind this improper behavior,” Jiji news agency quoted the panel as saying.