Top > Releases ・ Announcements > Fukushima Daiichi NPS Prompt Report > 2013 > Recent topics:Remote Controlled Boat Identifies Source Of Leak At Fukushima Daiichi

Fukushima Daiichi NPS Prompt Report 2013

Fukushima Daiichi NPS Prompt Report (Nov 14, 2013)Recent topics:Remote Controlled Boat Identifies Source Of Leak At Fukushima Daiichi

Discovery on outer container of the Unit 1 reactor marks major step forward in reducing contaminated water at the site

FUKUSHIMA, Japan, Nov.15, 2013-TEPCO announced today that an investigation using a remote controlled boat on November 13 has discovered what is believed to be the primary source of contaminated water leaks from the Unit 1 reactor at Fukushima Daichi NPS. It was the first time that leakage locations were identified at the reactor container at the site.

Two leaks were discovered around the upper half of the suppression chamber of the primary containment vessel, which is the donut-shaped part of the outer reactor container. Following the accident of March 2011, tons of water have been injected into the reactors of Units 1, 2 and 3 to cool the fuel and have been presumed to be leaking from the reactors into the basements of the reactor and turbine buildings.

The water is currently pumped, processed and reused to cool the reactors. The water has been pumped from the basements to keep levels below groundwater level, in an attempt to prevent the contaminated water from leaking out of the buildings.
TEPCO has investigated the south half of the container on November 14, and will continue to evaluate the conditions of the reactor.

For the video and photo of the investigation and the result overview (for November 13), please go to

The results of the investigation held on November 14 will be posted on the above page too, as soon as they have been prepared.

TEPCO, Inc. is a provider of electricity to the Kanto region, which includes Tokyo and Yokohama. The company is headquartered in Tokyo. For more information, please go to

to TOP