WRAPUP 12-Japan weighs need to bury nuclear plant; tries to restore power
* Japan nuclear agency says aware of "Chernobyl solution", to bury reactor
* Engineers still trying to restore power to reactors
* G7 agrees rare concerted intervention to restrain yen rise
* Japan's Nikkei index ends up 2.72 percent, down 10.2 pct on week (Adds details)
By Shinichi Saoshiro and Yoko Nishikawa
TOKYO, March 18 (Reuters) - Japanese engineers conceded on Friday that burying a crippled nuclear plant in sand and concrete may be a last resort to prevent a catastrophic radiation release, the method used to seal huge leakages from Chernobyl in 1986.
But they still hoped to solve the crisis by fixing a power cable to two reactors by Saturday to restart water pumps needed to cool overheating nuclear fuel rods. Workers also sprayed water on the No.3 reactor, the most critical of the plant's six.
It was the first time the facility operator had acknowledged burying the sprawling 40-year-old complex was possible, a sign that piecemeal actions such as dumping water from military helicopters or scrambling to restart cooling pumps may not work.
"It is not impossible to encase the reactors in concrete. But our priority right now is to try and cool them down first," an official from the plant operator, Tokyo Electric Power Co, told a news conference.
As Japan entered its second week after a 9.0-magnitude earthquake and 10-metre (33-foot) tsunami flattened coastal cities and killed thousands, the world's worst nuclear crisis since Chernobyl and Japan's worst humanitarian crisis since World War Two looked far from over.
Around 6,500 people have been confirmed dead from the earthquake and tsunami while 10,300 are missing, many feared dead.
Some 390,000 people including many elderly are homeless and battling near-freezing temperatures in makeshift shelters in northeast coastal areas. Food, water, medicine and heating fuel is in short supply.
The government signalled it could have moved faster in dealing with the multiple disasters.
"An unprecedented huge earthquake and huge tsunami hit Japan. As a result, things that had not been anticipated in terms of the general disaster response took place," Chief Cabinet Secretary Yukio Edano told a news conference.
Japan also raised the severity rating of the nuclear crisis from Level 4 to Level 5 on the seven-level INES international scale, putting it on a par with America's Three Mile Island accident in 1979, although some experts say it is more serious.
Chernobyl was a 7 on the INES scale.
www.reuters.com/article/2011/03/18/japan-idUSL3E7EI17N20110318
March 18, 2011