Nuclear repairs halted
JAPAN’S government is on ‘ ‘ maximum alert’ ’after highly radioactive water halted repair work at the crippled Fukushima power plant and plutonium was found in soil.
The earthquake and tsunami that ravaged Japan’s north-east coast and left more than 28,000 dead or missing also knocked out reactor cooling systems at the Fukushima plant, which has leaked radiation into the air and sea.
Prime Minister Naoto Kan conceded the situation at the coastal atomic power station remained ‘‘ unpredictable’’ and pledged his government would ‘‘ tackle the problem while in a state of maximum alert’’.
Emergency crews braving the radiation threat have used fire engines and pumps to pour thousands of tons of water onto reactors where fuel rods are assumed to have partially melted, and also topped up pools for spent fuel rods.
But the run-off from the stop-gap operation is now making it too dangerous for workers to go near several of the reactor buildings – already charred by explosions – to repair the cooling systems needed to stabilise the plant.
For now, however, they have no choice but to keep pumping water i nto t he stricken reactors, said top government spokesman Yukio Edano.
If the rods were fully exposed to the air, they would rapidly heat up, melt down and spew out far greater plumes of radiation at the site, located about 250km northeast of Tokyo, nuclear experts fear.
‘‘ We need to stop the fuel rods from heating up and drying up,’’ said Edano in a televised press conference.
‘‘ Continuing the cooling is unavoidable . . . we need to prioritise injecting water.’’
Run-off has accumulated during the operation in the basements of the turbine rooms connected to three reactors, and filled up their adjacent tunnel systems that stop roughly 60m short of the Pacific Ocean shore.
The water out of reactor t wo has measured 1 0 0 0 millisieverts per hour – four t i mes t he r ecently-hiked total exposure limit for emergency staff, and a level that can cause radiation sickness with nausea and vomiting within an hour of exposure.
The immediate challenge is to safely dispose of the massive amounts of contaminated water – the tunnel near reactor two alone holds 6000 cubic metres, more than two Olympic swimming pools.