Press Releases 2016

Tokyo Electric Power Company (TEPCO) would like to once again express our deep sorrow for the stress and anxiety that the accidents at our Fukushima Daiichi and Fukushima Daini Nuclear Power Stations have caused everyone in the surrounding communities and society at large.

TEPCO received questions from the Niigata Prefecture Technical Committee about the communication of information and data at the time of the Fukushima accident. As we verify and summarize what transpired during the Fukushima accident, we have done our own investigations that are not limited to a technical analysis of the causes, but also examines the content of the notifications and reports transmitted to the national and local governments at the time of the accident.

In the course of our investigations, it was discovered that TEPCO's internal manual at the time clearly stated that a core meltdown was to be determined if the percentage of core damage exceeded 5%.

During our explanation to the Niigata Prefecture Technical Committee about what happened during the accident, we failed to check adequately the above manual and mistakenly explained that there was no basis for determining a core meltdown and we sincerely apologize for this.

Furthermore, we again confirmed that the following notification and report about the state of the reactor core were made at the time of the accident.
Specifically, in the early morning of March 14, 2011, instruments were restored for monitoring the radiation level inside the Unit 3 primary containment vessel (PCV), making it possible to check the radiation level inside the PCV and the percentage of core damage. Following statutory and regulatory operations at the time, TEPCO recorded these figures and issued a report.

Moreover, from the results of our investigation into the content of other notifications and reports, we have confirmed that there were events where it may have been possible to issue notifications and reports more promptly immediately after the tsunami hit on March 11, 2011.

With the cooperation of third parties, we will be conducting a detailed investigation into, among other things, the circumstances and causes behind our failure to determine and announce the core meltdowns in accordance with TEPCO's internal manual at the time of the accident as well as the content of our notifications and reports.

Presently, statutes, regulations and TEPCO's internal rules governing notifications and reports when an accident occurs have been revised. As TEPCO conducts training in line with these new rules, we are informing everyone involved of the appropriate operations. Furthermore, we will be taking into account the investigation results as we endeavor to further improve safety.