Japan's nuclear agency has upgraded the severity level of a radioactive water leak at the Fukushima plant from one to three on an international scale.

Highly radioactive water was found to be leaking from a storage tank into the ground at the plant on Monday.

It was first classified as a level one incident on the International Nuclear and Radiological Event Scale (Ines).

But Japan's Nuclear Regulation Authority proposes elevating it to level three on the seven-point scale.

Japanese reports say it is a provisional move that had to be confirmed with the IAEA, the UN's nuclear agency.

This week is the first time that Japan has declared an event on the Ines scale since the 2011 earthquake and tsunami.

The move was announced in a document on the agency's website and was subsequently approved at a weekly meeting of the regulatory body.

Shares of plant operator Tokyo Electric Power Company (Tepco) fell as much as 13% to 537 yen as investors worried about the impact of the development.

The March 2011 tsunami knocked out cooling systems to the reactors at the plant, three of which melted down.Water is now being pumped in to cool the reactors but this means that a large amount of contaminated water has to be stored on site.
There have been leaks of water in the past but this one is being seen as the most serious to date, because of the volume - 300 tonnes of radioactive water, according to Tepco - and high levels of radioactivity in the water.A puddle of the contaminated water was emitting 100 millisieverts an hour of radiation, Kyodo news agency said earlier this week.Masayuki Ono, general manager of Tepco, told Reuters news agency: "One hundred millisieverts per hour is equivalent to the limit for accumulated exposure over five years for nuclear workers; so it can be said that we found a radiation level strong enough to give someone a five-year dose of radiation within one hour."Teams of workers at the plant have surrounded the leaking tank with sandbags and have been attempting to suck up large puddles of radioactive water.But, reports the BBC's Rupert Wingfield-Hayes in Tokyo, it is a difficult and dangerous job. The water is so radioactive that teams must be constantly rotated and it is clear that most of the toxic water has already disappeared into the ground.Under the Ines, events have seven categories starting with Level 0 ("without safety significance") and Levels 1-3 denoting "incidents" while Levels 4-7 denote "accidents".The triple meltdown at Fukushima two years ago was classed as a level 7 incident.


http://www.reuters.com/article/2013/08/21/us-japan-fukushima-severity-idUSBRE97K02B20130821

Japan's nuclear crisis deepens, China expresses 'shock'

The U.N.'s International Atomic Energy Agency (IAEA) said on Wednesday it viewed the situation at Fukushima "seriously" and was ready to help if called upon, while nearby China said it was "shocked" to hear contaminated water was still leaking from the plant, and urged Japan to provide information "in a timely, thorough and accurate way".

"We hope the Japanese side can earnestly take effective steps to put an end to the negative impact of the after-effects of the Fukushima nuclear accident," China's Foreign Ministry said in a statement faxed to Reuters in Beijing.

Japan's Chief Cabinet Secretary Yoshihide Suga called the situation "deplorable", and the Nuclear Regulation Authority (NRA) said it feared the disaster - the worst nuclear accident since Chernobyl a quarter of a century earlier - was "in some respects" beyond the plant operator's ability to cope.

The plant's operator, Tokyo Electric Power Co, or Tepco, has been criticized for its failure to prepare for the disaster and has since been accused of covering up the extent of the problems at the plant. After months of denial, Tepco recently admitted the plant was leaking contaminated water into the Pacific Ocean from trenches between the reactor buildings and the shoreline.

It said on Tuesday that contaminated water with dangerously high levels of radiation was leaking from a storage tank - the most serious problem in a series of recent mishaps, including power outages, contaminated workers and other leaks.

The NRA said it was worried about leakage from other similar tanks that were built hastily to store water washed over melted reactors at the station to keep them cool. Water in the latest leak is so contaminated that a person standing close to it for an hour would receive five times the annual recommended limit for nuclear workers.

A spokesman for the NRA said the agency plans to upgrade the severity of the crisis from a Level 1 "anomaly" to a Level 3 "serious incident" on an international scale for radiological releases. An upgrade would be the first time Japan has issued a warning on the International Nuclear Event Scale (INES) since the three reactor meltdowns at Fukushima in March 2011. Explosions then led to a loss of power and cooling, triggering a maximum INES Level 7 at the plant.

"HAUNTED HOUSE"

NRA Chairman Shunichi Tanaka likened the stricken nuclear plant to a house of horrors at an amusement park. "I don't know if describing it this way is appropriate, but it's like a haunted house and, as I've said, mishaps keep happening one after the other," he told reporters. "We have to look into how we can reduce the risks and how to prevent it from becoming a fatal or serious incident."

He said the NRA would consult with the IAEA about whether it was appropriate to assign a rating to the leakage at the plant.

"Japanese authorities continue to provide the Agency with information on the situation at the plant, and Agency experts are following the issue closely," Gill Tudor, spokesperson at the Vienna-based IAEA, said in an e-mailed statement.

"The IAEA views this matter seriously and remains ready to provide assistance on request."

Each one-step INES increase represents a 10-fold increase in severity, according to a factsheet on the IAEA website. (www.iaea.org/) A Level 3 rating is assigned when there is exposure of more than 10 times the limit for workers, according to the factsheet.

In an emailed comment, Andrew Sherry, director of the Dalton Nuclear Institute at the University of Manchester, said: "Though serious, this leak is a long way from the Level 7 incident we were facing in 2011. The approach taken by Tepco to drain the tank, pump leaked water to temporary storage, and protect the drainage of contaminated water to ground water, is entirely sensible."

"This incident highlights the need for an inspection program for these many hundreds of storage tanks, and the need to consider replacing bolted or sealed storage tanks, which were relatively quick to build, with a more robust welded design."

South Korea's Asiana Airlines Inc said it would cancel charter flights between Seoul and Fukushima city in October due to public concerns over the radioactive water leaks.

The city, around 60 kms (37 miles) from the nuclear facility and with a population of some 284,000, is a popular destination for golfers and tourists visiting nearby local hot springs and lakes.

(With additional reporting by Kentaro Hamada, Olivier Fabre and Chris Meyers in TOKYO, Ben Blanchard in BEIJING, Kim Miyoung in SEOUL, Fredrik Dahl in VIENNA and Kate Kelland in LONDON; Writing by Aaron Sheldrick; Editing by Edmund Klamann, Paul Tait and Ian Geoghegan)