TOKYO — Workers at a crippled Japanese nuclear plant are investigating why highly radioactive water leaked from a new storage tank, amid concerns that the problem could further hamper cleanup efforts.<\/p>\n
The Fukushima Dai-ichi plant suffered multiple meltdowns after a massive earthquake and tsunami in March 2011 knocked out power. It is currently using a fragile makeshift cooling system that creates large amounts of highly radioactive water.<\/p>\n
Plant operator Tokyo Electric Power Co. said Thursday that the leak stopped after some of the water in the faulty tank was moved to two adjacent containers, but that its cause is still unknown.<\/p>\n
The leak occurred in one of nearly 40 steel tanks TEPCO hastily assembled last month to hold radioactive water from several underground storage pools that were defective and also leaked. They are a portion of about 300 similar tanks of different sizes spread across the plant to contain the growing amounts of contaminated water.<\/p>\n
A worker on Wednesday spotted water dripping from a seam on the 500-ton tank. The total leakage was about 1 liter (a quarter gallon), according to TEPCO spokesman Masayuki Ono.<\/p>\n
Three other tanks of the same design had similar leaks last year.<\/p>\n
TEPCO says the tanks are not intended for long-term use. Ono said additional tanks are being built with welded seams that are more watertight.<\/p>\n