Important Report from TEPCO

The Tokyo Electric Power Company, Incorporated, would like to make comments on subjects that are reported by the newspapers, TV or websites.

We affirm that the Reactor Building and Spent Fuel Pool of Unit 4 will not collapse in the event of an earthquake

April 26, 2012

The upper part of the Reactor Building of Unit 4 was damaged due to a hydrogen explosion. We confirmed the items below and affirm that the building, including its spent fuel pool will not collapse should another earthquake occur.

1) We measured the distance between the water surface of the spent fuel pool and the floor surface of the building, and confirmed that the building has not tilted.

2) Our analyses show that the building, including the spent fuel pool, will not collapse even if an earthquake equivalent (seismic intensity 6) to the Tohoku-Chihou-Taiheiyou-Oki Earthquake occurs in the area.

3) In addition, we have improved the seismic safety margin by 20% by reinforcing the bottom of the spent fuel pool.

4) We will regularly check the reactor building and the spent fuel pool four times per year to confirm their soundness.

* Please refer to the attachment for the details of 1) to 4).

(Attachment): We affirm that the reactor building and the spent fuel pool of Unit 4 will not collapse in the event of an earthquake. (PDF 162KB)

Related material and data

• Water level measurement in order to confirm the soundness of the Unit 4 Reactor Building at Fukushima Daiichi Nuclear Power Station (PDF 18.0KB)
• Submission of Reports concerning the study of the current seismic safety and reinforcement of reactor buildings at Fukushima Daiichi Nuclear Power Station (1)
• Completion of the installation of the supporting structure at the bottom of the spent fuel pool at the Unit 4 Reactor Building of Fukushima Daiichi Nuclear Power Station (PDF 73.6KB)

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