Tag Archive: Junichi Matsumoto


Radioactive water leaks from Japan’s damaged plant

An aerial view shows Fukushima Daiichi nuclear power plant in FukushimaAn undated composite montage image of laser scan data and construction data shows the damaged No. 1 reactor of the Fukushima Daiichi nuclear power planthttp://beta.news.yahoo.com/radioactive-water-leaks-tepco-plant-070542086.html

TOKYO (Reuters) – Tons of radioactive water were discovered on Tuesday to have leaked into the ground from Japan’s Fukushima nuclear plant, the latest in a series of leaks at the plant damaged in a March earthquake and tsunami, the country’s nuclear watchdog said.

More than three months after the disaster, authorities are struggling to bring under control damaged reactors at the power plant, 240 km (150 miles) north of Tokyo.

About 15 tonnes of water with a low level of radiation leaked from a storage tank at the plant on the Pacific coast, the Nuclear and Industrial Safety Agency said.

Plant operator Tokyo Electric Power Co (Tepco) said it was investigating the cause of the leak which was later repaired.

Vast amounts of water contaminated with varying levels of radiation have accumulated in storage tanks at the plant after being used to cool reactors damaged when their original cooling systems were knocked out by the March 11 disaster.

Dealing with that radioactive water has been a major problem for Tepco, which is trying to use a decontamination system that cleans water so it can be recycled to cool the reactors.

But the system has encountered technical glitches and officials have said the water could spill into the Pacific Ocean unless the system was operating properly.

The system was halted an hour and a half after it started on Monday because of a water leakage.

Tepco fixed the problem and restarted the system on Tuesday afternoon, said Junichi Matsumoto, an official at the utility.

(Reporting by Shinichi Saoshiro and Yoko Kubota; Editing by Michael Watson and Robert Birsel)

 

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Workers enter Japan nuclear reactor building

http://news.yahoo.com/s/ap/20110505/ap_on_re_as/as_japan_earthquake

By TOMOKO A. HOSAKA, Associated Press Tomoko A. Hosaka, Associated Press 2 hrs 10 mins ago

TOKYO – Workers entered one of the damaged reactor buildings at Japan’s stricken nuclear power plant Thursday for the first time since it was rocked by an explosion in the days after a devastating earthquake, the plant’s operator said.

Tokyo Electric Power Co. said workers connected ventilation and air filtration equipment in Unit 1 in an attempt to reduce radiation levels in the air inside the building.

The utility must lower radiation levels before it can proceed with the key step of replacing the cooling system that was knocked out by the March 11 quake and subsequent tsunami that left more than 25,000 people dead or missing along Japan’s northeastern coast.

Workers have not been able to enter the reactor buildings at the Fukushima Dai-ichi nuclear power plant, about 140 miles (230 kilometers) northeast of Tokyo, since the first days after the tsunami. Hydrogen explosions at four of the buildings at the six-reactor complex in the first few days destroyed some of their roofs and walls and scattered radioactive debris.

TEPCO spokesman Junichi Matsumoto called Thursday’s development “a first step toward a cool and stable shutdown,” which the utility hopes to achieve in six to nine months.

In mid-April, a robot recorded radioactivity of about 50 millisieverts per hour inside Unit 1’s reactor building — a level too high for workers to realistically enter. Readings taken later in April in another part of the building were as high as 1,200 millisieverts.

The decision to send the workers in was made after robots last Friday collected fresh data that showed radiation levels in some areas inside the building were safe enough for workers to enter, said Taisuke Tomikawa, another TEPCO spokesman.

Two utility workers, wearing a mask and air tank similar to those used by scuba divers, entered the reactor building for about 25 minutes to check radiation levels. They were exposed to 2 millisieverts during that time, Tomikawa said. Outside the building, the utility erected a temporary tent designed to prevent radioactive air from escaping.

Later, 11 other workers — two from TEPCO and nine from its subcontractors — wearing similar gear went into the reactor building to install ducts for the air filtering equipment. Twenty other workers provided help from outside.

The utility hopes to start allowing workers into the building to set up a cooling system around mid-May. In addition to reducing radioactivity with the new air filtering system, it hopes to reduce it further by removing or covering up contaminated debris inside the building, Matsumoto said.

TEPCO is proceeding with a plan to fill the Unit 1 containment vessel with water to soak the core and cool it, and also plans to install big fans as an external cooling system, he said. TEPCO hopes to take similar steps at Units 2 and 3 but is struggling with tougher obstacles such as contaminated water leaks and debris.

Radiation leaking from the Fukushima plant has forced 80,000 people living within a 12-mile (20-kilometer) radius to leave their homes. Many are staying in gymnasiums and community centers.

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Associated Press writer Mari Yamaguchi contributed to this report.

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