Fukushima reactors below boiling point

2011-09-28 17:10

Tokyo - All three damaged reactors at Japan's crippled Fukushima Daiichi nuclear power plant are below the boiling point, paving the way to bring them to a state of cold shutdown by the end of the year, the operator of the complex said on Wednesday.

After a devastating earthquake and tsunami in March knocked out cooling systems and caused meltdowns of nuclear fuel rods at three of the plant's six reactors, Tokyo Electric Power (Tepco) has been trying to cool them and bring temperatures below the boiling point.

Temperatures at two of the three reactors had already dropped below 100°C in July and early September, leaving just one reactor above boiling point.

But temperatures at the last of the three reactors fell to 99.4°C on Wednesday, according to Tepco spokesperson Takeo Iwamoto.

"The temperature has been moving up and down but it is on a steady decline," Iwamoto told Reuters. "We have cleared the temperature issue and taken a step forward towards achieving cold shutdown by the end of this year."

Technically, a cold shutdown occurs when water used to cool nuclear fuel rods remains steadily below 100°C, preventing the fuel from reheating.

But Tepco has said it won't declare a cold shutdown until other criteria are met, like further reducing the amount of radiation being emitted from the plant.

Last week the Japanese government and Tepco said at a monthly review of the Daiichi plant's cleanup timetable that they are now aiming to bring the plants to a cold shutdown within this year, instead of by January as initially planned, with their cleanup work proceeding steadily.

Achieving a cold shutdown is a precondition for the return of residents who were forced to evacuate areas near the plant.

  • Stuart - 2011-09-29 14:28

    Of course the three reactors are below boiling point... because the molten fuel has long since melted through the pressure and primary containment vessels and fallen thirty feet to the concrete drywell floors. Hard to believe all the pathetic excuses for media keep reporting TEPCO's absurd line about being ahead of schedule for a cold shutdown. They love to use that term because it is the one used for the NORMAL process for taking a reactor offline, or turning it off. They want to pretend that they are getting things back under control, returning to normal. However, a cold shutdown requires intact fuel rods that will allow the control rods to be inserted between them to absorb the neutrons and stop the fission reaction. It requires intact pressure vessels to contain the cooling water around the fuel rods, and a functioning cooling system to circulate the water through an intact heat exchanger to cool it with an uncontaminated water source (water from the Pacific Ocean in this case). Obviously, none of these conditions necessary for a cold shutdown exist at the Fukushima reactors. So why is it that the media keeps reporting these ridiculous lies as if they were to be taken at face value? These reactors are nowhere near to being "under control". They continue to release massive amounts of radiation into the Ocean and the atmosphere every hour of every day, and will continue to do so for decades, if not centuries.

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