Tokyo Electric Power (Tepco) said the battle to stabilize the crippled Fukushima Daiichi reactors will last at least until June, leaving the plant vulnerable to further earthquakes and radiation leaks.
Bloomberg reports Tepco engineers have so far rejected a proposal to flood reactors at its damaged plant, which could lower the temperature in days rather than months, according to its source speaking under anonymity. Instead, the utility is pumping in water and venting off steam, a method called “feed and bleed.”
Tepco has been reluctant to flood the reactors because it could increase the amount of contaminated water that eventually flows into the ocean, according to the unnamed source. The utility is also concerned that pushing in more water could raise the risk of more explosions because it would compress hydrogen inside the containment.
Decommissioning of the four crippled reactors at Fukushima cannot start until the reactors have been stabilized by lowering their temperature and pressure. The clean-up from the disaster, which has caused the evacuation of hundreds of thousands of people living within 20km of the plant, could take decades and cost more than $12bn.
While Tepco hasn’t announced a timeline for resolving the crisis, the source said the utility drafted an internal document two weeks ago called the “Tepco Short/Medium/Long Range Recovery Plan” that aims to have the reactors stabilized by the end of June.
Tepco President Masataka Shimizu, speaking publically this week for only the second time since the disaster started, said a schedule for dealing with the crisis “will be presented soon.”
The primary danger at the plant is reactor No. 1, where temperatures and pressure are still high, the source said. Flooding the space between the pressure vessel and a surrounding containment with water would bring temperatures down in days rather than months.
A make-shift combination of fire hoses and pumps being used to cool the reactor is not providing enough water, according to the person. Temperatures of 204.5 degrees inside the vessel yesterday, or twice boiling point, cause the water to turn into steam, creating a sauna-like cooling system that is less effective, the person said.
Water levels inside the core of reactor No. 1 dropped yesterday, according to data released by Tepco, leaving 1.65 metres of fuel rods exposed to air, where they can heat up and melt, releasing radiation into the pressure vessel. While Tepco's plan for ending the crisis says getting exposed fuel rods covered with water again is one measure of stabilization, according to the person briefed on the document, the utility’s data shows pumping efforts have failed to raise the water level more than 20 centimetres in the 35 days since the disaster started.
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