Top > Releases ･ Announcements > Fukushima Daiichi NPS Prompt Report > 2013 > Tritium Density Result of Water Quality Survey inside the Port of Fukushima Daiichi NPS (Follow-up Information 25)
This is follow-up information on the latest situation concerning the detection of high densities of Tritium and Strontium in the observation hole at the east side of the Unit 1-4 Turbine Buildings of Fukushima Daiichi NPS.
Today (on August 1), we would like to make an announcement on measurement results as follows on samples taken on July 31 from the Unit 2 seawater pipe trench vertical shaft C and the Unit 3 seawater pipe trench vertical shaft B where sampling has been newly started for the survey conducted for such purposes as identification of the contamination source of high-density contaminated water inside the sea-side trench, as we obtained the results.
With regards to the analysis results on the Unit 2 seawater pipe trench vertical shaft C, the 1-meter and 7-meter water depth locations showed almost the same values, and the 13-meter water depth location showed higher values than the 1-meter and 7-meter water depth locations. With respect to the analysis results on the Unit 3 seawater pipe trench vertical shaft B, no water-depth related difference was found.
<Unit 2 seawater pipe trench vertical shaft C>
- Sampling on July 31:
[1-m water depth]
Chlorine 700ppm
Cesium-134 110,000,000Bq/L (110,000Bq/cm3)
Cesium-137 230,000,000Bq/L (230,000Bq/cm3)
All-β 330,000,000Bq/L (330,000Bq/cm3)
[7-m water depth]
Chlorine 700ppm
Cesium-134 110,000,000Bq/L (110,000Bq/cm3)
Cesium-137 240,000,000Bq/L (240,000Bq/cm3)
All-β 330,000,000Bq/L (330,000Bq/cm3)
[13-m water depth]
Chlorine 7,500ppm
Cesium-134 300,000,000Bq/L (300,000Bq/cm3)
Cesium-137 650,000,000Bq/L (650,000Bq/cm3)
All-β 520,000,000Bq/L (520,000Bq/cm3)
<Unit 3 seawater pipe trench vertical shaft B>
- Sampling on July 31:
[1-m water depth]
Chlorine 16,000ppm
Cesium-134 13,000,000Bq/L (13,000Bq/cm3)
Cesium-137 26,000,000Bq/L (26,000Bq/cm3)
All-β 32,000,000Bq/L (32,000Bq/cm3)
[7-m water depth]
Chlorine 17,000ppm
Cesium-134 10,000,000Bq/L (10,000Bq/cm3)
Cesium-137 22,000,000Bq/L (22,000Bq/cm3)
All-β 34,000,000Bq/L (34,000Bq/cm3)
[13-m water depth]
Chlorine 17,000ppm
Cesium-134 12,000,000Bq/L (12,000Bq/cm3)
Cesium-137 24,000,000Bq/L (24,000Bq/cm3)
All-β 34,000,000Bq/L (34,000Bq/cm3)
<Quality of water leaked into the Unit 2 water intake screen room in April 2011>
Cesium-134 1,800,000,000Bq/L (1,800,000Bq/cm3)
Cesium-137 1,800,000,000Bq/L (1,800,000Bq/cm3)
In addition, we would like to announce the measurement results of water levels in the sea-side trenches (seawater pipe trench and water intake power cable trench) as follows.
The water level in the Unit 2 water intake power cable trench was 3,180mm, showing an increase of approx. 30mm from the previous value (3,150mm). We will keep track on the trend while reflecting results that will be available in the subsequent measurement. The water level in the seawater pipe trench (A of Unit 2) measured at the same point in time was 3,045mm.
We are continuing to tackle this problem in such manners as to intensely bring forward implementation of contamination prevention measures such as foundation improvement work to the bank protection, and comprehensively intensify the monitoring by using the results of additional boring to drill additional locations, and the analyses results on seawater at such locations as the port interior and the water outlets.
For the past sampling results, please refer to the following page on our website:
http://www.tepco.co.jp/en/nu/fukushima-np/handouts/index-e.html
© Tokyo Electric Power Company Holdings, Inc.
