Fukushima Daiichi NPS Prompt Report 2014

FUKUSHIMA, May 29, 2014-One of the three units of the system designed to remove most remaining radioactive contaminants from water at the Fukushima Daiichi Nuclear Power Station has been successfully restarted, and the other two are expected to be restarted soon, Tokyo Electric Power Co. (TEPCO) announced on May 23.

 

The unit (B) is one of three (A, B, C) in the multi-nuclide removal facility ("ALPS"), the advanced water treatment facility. The facility is designed as a "secondary" system, to remove most remaining radioactivity after the primary treatment system removes Cesium. The ALPS system has experienced some problems with filters and gaskets deteriorating from radiation exposure, and had been taken offline while those parts were being upgraded.

The successfully restarted Unit B had been shut down on March 18 after monitoring detected radiation in output water that exceeded limits. The water was safely stored on-site and did not flow to the sea.

Inspection revealed that a part of the gasket inside the filter was deteriorating due to exposure to radiation. The original Teflon gasket has been replaced with one made from a synthetic rubber that is expected to withstand radiation more effectively. Unit B restarted operation on May 23 and so far no problem has occurred, the company said.

The equivalent filters have also been replaced in the other two units, A and C, and they are due to restart operation within June.

The ALPS system is a sophisticated water processing facility that could remove most remaining radioactive contaminants from water at the Fukushima Daiichi site. Since its installation in October 2012, it has been under test operation, processing total of approximately 85,000 tons of water. Full operation of the facility will represent important progress in water management at the site, where approximately 400 tons of contaminated water is collected from the basements of the reactor facilities every day.

Detailed explanation of the investigation may be seen athttp://www.tepco.co.jp/en/nu/fukushima-np/handouts/2014/images/handouts_140523_08-e.pdf

< What is multi-nuclide removal facility? >
Basic system overview of the facility is explained at http://www.tepco.co.jp/en/nu/fukushima-np/roadmap/images/m120227_03-e.pdf

About TEPCO

Tokyo Electric Power Company, Inc. (TEPCO) is Japan's largest power company, supplying energy to the greater Kanto area, including Japan's two most populous cities, Tokyo and Yokohama. Its 35,000 employees are committed to providing safe, reliable power to its 28.8 million customers, diversifying energy resources to ensure sustainability, and contributing to economic growth while fully meeting its responsibilities after the Fukushima Daiichi accident.