High radiation levels on two tanks

August 22, 2013

High-level radiation detected along seams of two Fukushima water tanks

JIJI

http://www.japantimes.co.jp/news/2013/08/22/national/high-level-radiation-detected-along-seams-of-two-fukushima-water-tanks/#.UhZvdn9Sab0

Tokyo Electric Power Co. said Thursday it has detected high levels of radiation along the seams of two temporary storage tanks containing contaminated water at its crippled Fukushima No. 1 nuclear power station.

The seams on the bottom of the 1,000-ton tanks were dry, and no water was found near them, Tepco said.

Radiation levels of up to 100 millisieverts per hour were measured at each of the two tanks in question, according to the utility.

The cause of the high-level radiation along the seams of the two tanks remains unclear and the possibility of leaks cannot be ruled out, Tepco said.

The two tanks are the same type as the one that has leaked an estimated 300 tons of contaminated water at the plant, which suffered three reactor core meltdowns after the March 2011 mega-quake and tsunami. The leaking tank was discovered Sunday.

There are some 350 such tanks at the plant and about 300 are being used to temporarily store highly radioactive water. On Thursday, Tepco checked all 300 tanks. They are made of steel plates bolted together, with sealed seams. Tepco is also using more durable welded steel tanks.

High radioactivity found on 2 tanks

http://www3.nhk.or.jp/nhkworld/english/news/20130822_33.html

The operator of the Fukushima Daiichi nuclear power plant has detected high levels of radiation on the surface of 2 tanks storing radioactive wastewater.

Tokyo Electric Power Company made the discovery on Thursday while checking about 300 tanks for leaks. TEPCO revealed on Monday that one tank leaked more than 300 tons of highly radioactive water.

The tanks are of the same type, made from steel plates bolted together rather than welded.These tanks are considered more vulnerable to leaks.

Radioactivity of 100 and 70 millisieverts per hour was measured on the joints of 2 tanks.

TEPCO says the surface of the tanks is dry and there are no signs of recent leaks and no changes in water levels inside. It says the leaks may be old. The company is checking radiation levels around the tanks.

TEPCO is concerned that water from the first tank may already have reached the sea via a drainage system.

Engineers on Wednesday night finished transferring the remaining 700 tons of water in the damaged tank. They will examine the joints and the bottom of the empty tank to identify the source of the leak.