Mars 2011: Kärnkraftverket i Fukushima - utbruten och sammanfogad tråd

Long-term climate change, or the natural changes in climate patterns over millions of years, can modify the motion of plates in a feedback mechanism.

Shareholders to sue TEPCO executives

Tokyo Electric Power Company shareholders will be suing the utility's current and former executives over the Fukushima Daiichi nuclear power plant accident.

Last November, 42 shareholders demanded the company's auditors file a lawsuit against 60 people who held executive posts.

They requested over 5.5 trillion yen, or about 71 billion dollars, in compensation.

But on Monday, TEPCO notified the shareholders in writing that it will not take legal action against them. The utility stated that the size of the March 11th tsunami was unforeseeable. It said because of this, the executives cannot be held responsible for the nuclear disaster.

In response, the shareholders say they want to file a suit with the Tokyo District Court by the end of January.

Hiroyuki Kawai, a lawyer representing the shareholders, criticized TEPCO auditors for claiming the tsunami was unforeseeable and expressing no remorse.
Monday, January 16, 2012 18:36 +0900 (JST)

Preparations going on for reactor endoscopy

Preparations are under way to use an endoscope to examine the inside of a containment vessel of the damaged No. 2 reactor at the Fukushima Daiichi nuclear power plant.

At the No.1, 2, and 3 reactors of the plant, the nuclear fuel has melted down, but the exact state of the fuel and details of the inside of the containment vessels are yet to be confirmed. This is causing a big problem for the operator, Tokyo Electric Power Company, in its continued efforts to stabilize the cooling of the reactors and its plans to decommission them. The reactors were damaged by the March 11th earthquake and tsunami.

On Tuesday, 10 groups of 4 workers each entered the first floor of the No.2 reactor building from the northwestern side. The workers drilled a hole in the containment vessel to insert an endoscope. An industrial endoscope that can withstand high levels of radiation will be used.

The utility says the workers were exposed to up to 3 millisieverts of radiation. The company says the workers had rehearsed the job at the No. 5 reactor, the same type as the No.2, in order to minimize their exposure.

TEPCO says Tuesday's operation went smoothly and it will insert the endoscope on Thursday as scheduled. It hopes to gain the first internal view of one of the damaged reactors since the accident.
Tuesday, January 17, 2012 20:26 +0900 (JST)

Govt ramping up probe into irradiated gravel

Japan's central government and Fukushima Prefecture plan to expand their investigation into the distribution of gravel possibly contaminated with radioactive substances after the March nuclear accident.

The investigation is now underway after higher-than-usual levels of radioactive cesium were detected in concrete used in a newly built apartment in Nihonmatsu City. The city escaped a major impact from the accident at the Fukushima Daiichi nuclear power plant.

The concrete was made from crushed stones from a quarry in Namie Town, designated an evacuation zone following the accident.

The Economy, Trade and Industry Ministry and the prefecture decided to expand the number of quarries to be investigated from 10 to 17.

The ministry also decided to investigate whether gravel obtained from local rivers after the accident is contaminated.

It has so far been learned that gravel from the quarry in Namie was sold to more than 200 construction companies and used in the construction of buildings and roads at about 1,000 locations.
Wednesday, January 18, 2012 14:21 +0900 (JST)

Evaluation of "stress tests" to be disclosed

Japan's nuclear safety agency will announce on Wednesday that the safety tests for two nuclear reactors were appropriate.

This will be the first step in the resumption of the country's halted nuclear plants, although getting approval from local municipalities will be another issue.

Ninety percent of Japan's 54 nuclear reactors are halted due to concerns they could be vulnerable to major earthquakes and tsunami.

The government ordered the computer-simulated stress tests to be carried out before the idle reactors could be restarted. The nuclear safety body has received the results for 14 reactors so far.

The agency's experts will meet on Wednesday to give their assessment of the tests for 2 reactors at the Ohi nuclear plant in Fukui Prefecture, central Japan.

The operator, Kansai Electric, had submitted a report that 2 reactors could withstand an earthquake 1.8 times the intensity and a tsunami 4 times the height of the estimated maximums for the area.

The experts are expected to conclude that an appropriate method was used for the tests. They will report their evaluations to the government after seeking advice from the International Atomic Energy Agency.

The government of Fukui Prefecture has criticized the stress tests, saying they do not take account of the lessons of the Fukushima Daiichi accident.
Wednesday, January 18, 2012 07:06 +0900 (JST)

TEPCO fails to clearly see inside damaged reactor

The operator of the crippled Fukushima Daiichi nuclear power plant has failed in an attempt to get clear images from inside damaged reactors using fiber-optic lines.

Tokyo Electric Power Company is trying to determine the state of nuclear fuel inside the plant's Number 1, 2 and 3 reactors. The fuel melted through the wall of each reactor's core units and fell to the bottom of their containment vessels after the March 11th 2011 earthquake and tsunami.

On Thursday, TEPCO inserted an optical fiber scope known as an endoscope through a hole into the containment vessel of the Number 2 reactor.

Photos taken by a camera attached to the endoscope show parts of walls and pipes inside the containment vessel. But the images were blurred, probably due to radiation and vapor from contaminated water, leaving details, including the surface of the contaminated water, unclear.

TEPCO says that the photos showed no serious damage or deformation to walls and pipes.

The utility also measured the temperature of the inside of the vessel for the first time since the disaster at 44.7 degrees Celsius. The figure almost matches the 42.6 degrees already shown by thermometers around the vessel.

It's the first time that TEPCO has examined the inside of the damaged reactors since the disaster. The company says it must understand the state of the reactors before it can complete its shutdown of the plant.
Thursday, January 19, 2012 20:01 +0900 (JST)