TEPCO will reuse flange-type tanks to store treated water

July 7, 2016

TEPCO to reuse tanks holding radioactively contaminated water at Fukushima plant

http://mainichi.jp/english/articles/20160707/p2a/00m/0na/003000c

Tokyo Electric Power Co. (TEPCO) will reuse highly contaminated tanks at the crippled Fukushima No. 1 Nuclear Power Plant to store radioactively contaminated water after treatment, company sources said.

The company will return contaminated water to flange-type tanks that had held such water after removing radioactive materials from the water using the Advanced Liquid Processing System (ALPS). This is because TEPCO has failed to prevent contaminated water from being generated on the premises of the plant or to secure enough storage tanks to hold treated water.

TEPCO had submitted the reuse plan to the Nuclear Regulation Authority, which approved it on July 6 or earlier. TEPCO is set to begin reusing contaminated tanks as early as this month.

Flange-type tanks are assembled by tightening multiple steel plates with bolts. Since such tanks have higher risks of leaking contaminated water, TEPCO is gradually replacing them with tanks assembled by welding steel plates together.

TEPCO is trying to freeze underground soil to surround reactor buildings at the Fukushima power plant to prevent underground water from flowing beneath them and becoming contaminated with radioactive materials.

However, as the efforts have proven ineffective, the utility has decided to reuse flange-type tanks, which it had initially planned to dismantle.

Massive amounts of water are flowing onto the premises of reactor buildings at the atomic power station, generating some 400 tons of radioactively contaminated water a day. TEPCO uses ALPS to purify contaminated water, but the system cannot remove radioactive tritium.

The power company has stored the treated water mainly in welded-type tanks. There are already 1,000 water tanks on the premises of the power station.