Fukushima Daiichi NPS Prompt Report 2014

FUKUSHIMA, July 8, 2014- The cooling of the spent fuel pool of Unit 5 at Fukushima Daiichi Nuclear Power Station which was stopped due to seawater leak found at a pipe resumed cooling by another system at 15:40 today, and all the fuel inside is safely cooled, Tokyo Electric Power Company (TEPCO) announced.

Unit 5 is a reactor which achieved safe shutdown and all fuels inside remained undamaged after the earthquake and tsunami that hit the station in March 2011.

A system that cools the spent fuel pool at Unit 5 has been stopped on July 6 2014, after seawater was found leaking from a pipe of the indirect cooling system called the "Auxiliary Sea Water (SW) System". After investigation on July 6, the company found seawater leaking from a hole approximately 3mm in diameter, on a valve that is used to control amount of water flow. The leak was stopped after the suspension of the system, and the hole was immediately repaired inserting a hardener. The company said it is planning to restart the SW cooling system after further repair is done.

Meanwhile, the cooling of 994 fuel assemblies inside the spent fuel pool will be continued through another system which is normally used to cool the reactor, called the "Residual Heat Removal (RHR) System", the company explained.

There was no effect to the environment, and there was no radiation exposure to the workers by the stop of cooling of the spent fuel pool, the company explained.

Detailed explanatory materials may be found at TEPCO Official Webpage:
http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2014/images/handouts_140707_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.