Citation:
TEPCO makes effort to grasp precise water levels
Tokyo Electric Power Company will fix gauges in two of the reactors at the Fukushima Daiichi nuclear plant to determine precise water levels.
It appears there was a problem with the gauge in the No.1 reactor that showed the level of cooling water at about half the level of the fuel rods. The gauge was fixed on Thursday and then revealed that the rods were completely exposed and melted down.
TEPCO says the gauges at the No.2 and 3 reactors might not be showing the actual water levels, and that the worst case is that the rods have melted down.
The company says the temperatures of the two reactors are stable, so it can proceed with cooling them even if finds that meltdown took place.
TEPCO says workers will go into the reactor buildings and fix the gauges, getting the precise data on water levels needed to continue cooling the reactors.
But conditions inside the buildings are not known and the operation will be difficult.
Monday, May 16, 2011 05:31 +0900 (JST)
Citation:
Rapid meltdown occurs in No.1 reactor
Tokyo Electric Power Company says most of the fuel rods in the No.1 reactor at the Fukushima Daiichi nuclear plant had dropped to the bottom of the pressure vessel within 16 hours of the earthquake on March 11th.
The plant operator revealed its findings on Sunday.
TEPCO said it analyzed the data and calculated a timeline for developments in the No. 1 reactor on the assumption that it lost its cooling system as soon as the tsunami hit.
The firm said that about four and half hours after the quake the level of water in the pressure vessel fell below the top of fuel rods and that parts of them began melting.
The temperature of the rods is believed to have reached 2,800 degrees Celsius at this stage, and the meltdown advanced rapidly.
Almost all the rods melted and dropped to the bottom of the pressure vessel by 6:50 am on March 12th.
TEPCO said the temperature dropped after water was poured into the reactor starting at 5:50 AM the same day.
The firm says the melted rods created small holes in the bottom of the vessel. It believes the amount of radioactive substances that could spread from the reactor will be limited.
NHK's correspondent says TEPCO should analyze the situations at the No. 2 and No. 3 reactors as soon as possible.
Monday, May 16, 2011 05:31 +0900 (JST)
Citation:
15 May 2011 Last updated at 12:46 GMT
Japan nuclear: Tepco halts Fukushima cooling plan
Japanese engineers have abandoned their latest attempt to stabilise a stricken reactor at the Fukushima nuclear plant.
The plant's operator, Tepco, had intended to cool reactor 1 by filling the containment chamber with water.
But Tepco said melting fuel rods had created a hole in the chamber, allowing 3,000 tonnes of contaminated water to leak into the basement of the reactor building.
The power plant was badly damaged by the earthquake and tsunami on 11 March.
Cooling systems to the reactors were knocked out, fuel rods overheated, and attempts to release pressure in the chambers led to explosions in the buildings housing the reactors.
The government and Tepco (Tokyo Electric Power Company) said it would take until next January to achieve a cold shut-down at the plant.
Government spokesman Goshi Hosono said the latest setback would not affect the deadline.
"We want to preserve the timetable, but at the same time we're going to have to change our approach," he said.
Tepco says it will come up with a new plan to stabilise the reactor by Tuesday.
Japanese broadcaster NHK said Tepco was now studying a plan to circulate water from the basement through a decontamination filter and back into the reactor.
The earthquake and tsunami killed thousands of people and left many more homeless.
The tsunami flattened buildings in fishing villages and port towns, and swept debris miles in land.
Last week the government agreed a huge compensation package for those affected by the disaster.
Analysts say the final bill for compensation could top $100bn (£61bn).
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