Two weeks before engineers can declare plant safe
Published 25/03/2011 | 05:00
JAPANESE engineers are battling to deal with radioactive water and a potentially dangerous salt build-up inside the Fukushima nuclear power station, meaning it will be up to two weeks before they can declare the site safe.
The restoration of power to the stricken plant, 140 miles north of Tokyo, had led to hopes that the threat of a meltdown and major radiation leak was over.
Two workers were exposed to radioactive elements on the skin of their feet while laying cables at Unit 3 of the Fukushima facility, and were yesterday taken to hospital for treatment.
Scientists say the danger is far from over, and they still face some of the most difficult and dangerous tasks. These include manually draining hundreds of gallons of radioactive water from the plant and "bleeding" radioactive gas from the pumps and piping of the emergency cooling systems.
Technicians are also increasingly concerned about salt build-up caused by evaporated seawater.
Crusts around fuel rods could block cooling water from getting to the radioactive fuel and cause them to heat up again. Hundreds of thousands of pounds of salt crystals are thought to have been deposited in the plant.
Making the plant safe also requires a technician to reach a dozen valves -- with a great risk of radiation exposure.
Four of the plant's reactors are still considered volatile.
"It's still a bit early to make an exact prognosis, but my guess is in a couple of weeks the reactors will be cool enough to say the crisis is over," said Peter Hosemann, a nuclear expert at the University of California. (© Daily Telegraph, London)