Top > Releases ･ Announcements > Fukushima Daiichi NPS Prompt Report > 2013 > Water Dropping from the Top Plate of the B Area (south) Tank at Fukushima Daiichi NPS (From the First Issue to the Follow-up Information 2)
On October 2, we have done rainwater transfer from inside the dike to tanks in the B area (south), for the purpose of preventing overflow of rainwater inside the dike in B area (south), due to the rainfall by the approaching Typhoon No.22.
At around 8:00*1 PM on October 2, a TEPCO employee found water dropping (approx. the size of a pencil) from around the top plate of B area (south) tank (No.5 tank at Group A in B area).
At 8:05*2 PM, we found that the leaked water was not only dropping inside of the dike but also dropping to the outside of the dike via the scaffold installed around the tank for inspections work.
We analyzed the leaked water (sampled at 3:00 PM on October 2), and the measurement results are as follows.
- All-β: 200,000Bq/L (by a simplified measurement method)
- Cesium-134: 18Bq/L
- Cesium-137: 54Bq/L
At 9:55 PM yesterday (on October 2), we determined that this incident corresponds to "a case when nuclear fuel material (not in the form of gas) or the like has leaked within an area controlled by the company due to an unpredictable event such as a failure of a nuclear reactor facility for power generation" as per Article 18, item 12 of the regulations concerning the operational safety and the protection of specified nuclear fuel material at the TEPCO's Fukushima Daiichi NPS nuclear reactor facilities.
It cannot be denied that the water leaked from the top plate of the tank flowed into the drainage (the drainage channel C) via the side ditch nearby, and leaked into the sea. Therefore, we performed water-stop measures by putting sandbags in the side ditchwhich connects to drainage channel C.
We will sample and analyze water in the side ditch, the drainage channel C, and the seawater etc.
Please refer below for the latest situation.
URL:http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_131003_01-e.pdf
*1The time issued first turned out to incorrect. We would like to announce the correct time, "8:00 PM".
*2 The time issued first turned out to incorrect. We would like to announce the correct time, "8:05 PM".
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