Prime minister Shinzo Abe makes pledge amid growing concern at scale and complexity of operation
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The prospect of greater state involvement in decommissioning Fukushima Daiichi – the scene of a triple meltdown after it was hit by a tsunami in March 2011 – comes amid growing concern that Tepco is ill-equipped to cope with the scale and complexity of the cleanup.
Those doubts were fuelled by evidence that the plant is seeping up to 300 tonnes of contaminated water into the Pacific Ocean every day. In a separate incident, a water storage tank was found to have leaked about 300 tonnes of highly toxic water, some of which could have found its way into the sea.
At the weekend, radiation near another tank was measured at 1,800 millisieverts an hour – a level that could kill an unprotected person in just four hours – and 18 times higher than previously thought.
Tepco had initially recorded radiation near the tank at about 100 millisieverts an hour, but admitted that this was because the equipment used could only read measurements up to that level. The latest reading came from a more advanced device capable of reading up to 10,000 millisieverts.
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At present, water is used to cool melted nuclear fuel in three reactor basements, where it becomes contaminated and then mixes with groundwater seeping down from the hills behind the plant. The site’s tanks, basements and pits contain an estimated 338,000 tonnes of tainted water.
The chairman of the country’s nuclear regulation authority, Shunichi Tanaka, said on Monday that discharging the water remained an option, but only after it had been treated to bring radiation levels to below regulatory limits.
“If we decide to discharge water into the ocean, we will use various methods to ensure that radiation is below accepted levels,” Tanaka told reporters in Tokyo. “We will have to dispose of it eventually, but we are committed to reducing or removing radioactive materials.
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But the utility took issue with media reports suggesting workers at the site were at risk of being irradiated.
Most of the radiation in the most recent incident – measured at 1,800 millisieverts an hour – was emitted in the form of beta rays, it said. Beta radiation travels only a short distance and can be blocked by a thin sheet of metal, such as aluminium, it added.
“We believe that we can control radiation exposure by the using proper equipment and clothing,” the firm said in an emailed statement. “We will investigate the cause of this issue, taking any appropriate countermeasures immediately, and continue to make every effort to secure the safety of workers.”
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Of Japan’s 50 working nuclear reactors, only two are in operation. One of those was to be shut down on Monday evening to undergo routine checks, the other will go offline on 15 September, leaving Japan without atomic energy for only the second time in almost 50 years.
Concern is growing that the stream of bad news from Fukushima could threaten Tokyo’s bid to host the 2020 Olympics. The International Olympic Committee will announce the host city – the two other candidates are Madrid and Istanbul – in Buenos Aires on Saturday.
Read more at Fukushima: Japan promises swift action on nuclear cleanup