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Monitoring by sampling

Results of Radioactive Analysis around Fukushima Daiichi Nuclear Power Station

Results of radioactive nuclide analysis are published by sampling below items on the premises and the surrounding area of Fukushima Daiichi NPS.

Results of Analysis (February, 2018)

Air

* Radioactive nuclide analysis for the air sampled on the west gate of the nuclear plant, 3 points near the site boundary (MP-1,3,8), 3 points around Unit 1-4 (Unit 1 north side slope, Unit 1-2 west side slope, Unit 3-4 west side slope) and the sea side area near Unit 1-4 are discontinued after August 30, 2017. Monitoring with the continuous dust monitors already installed at the site has been implemented.
<Reference: Radioactive Concentration measured at Dust Monitors near the Site Boundary of Fukushima Daiichi Nuclear Power Station>
http://www.tepco.co.jp/en/nu/fukushima-np/f1/dustmonitor/index-e.html
February 15, 2018 Analysis of Strontium and Plutonium in the air by the monitoring car at the west gate of the nuclear power station

Seawater

Seawater near Power Station

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Result of radioactive nuclide analysis for the seawater sampled onshore and offshore of the power station.

Seawater near Intake Canals by Unit 1-4 side

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Result of radioactive nuclide analysis for the seawater sampled near the intake canals by the side of Unit 1-4 turbine buildings.

Leaked Water near South Discharge Cannel on Unit 1-4 side

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  • *The sampling location has been changed on November 26, 2012. (Sampling is performed at approx. 1km south of the previous location.)

Result of radioactive nuclide analysis for the water sampled near the South Discharge Channel (approximately 280m south of the South Discharge Channel on Unit 1-4 side) in response to the leaked water from the pipeline connecting from Desalination System (Reverse Osmosis Membrane) to Concentrated Water Storage Tank (occurred on March 26 and April 5, 2012).

Seawater at Port Entrance
(measurement by radiation monitor)


Real-time data which are updated every 10 minutes started to be published from October 1, 2016.

Subdrain Water

Subdrain Water near the Turbine Buildings

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Result of radioactive nuclide analysis for the water sampled from the subdrain system near Unit 1-6 turbine buildings.

Subdrain Water around Centralized Radiation Waste Treatment Facility

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Result of radioactive nuclide analysis for the water sampled from the subdrain around the centralized waste treatment facility.

Sampling from Subdrain and Groundwater Drain

The subdrain and groundwater drain systems started operations from September 2015. The subdrain system (a measure to prevent the increase of contaminated water) pumps up groundwater from around the reactor buildings before it flows into them. The groundwater drain system (a measure to prevent the leakage of contaminated water) pumps up groundwater held back by the installed seaside impermeable wall before it flows into the port area. The water pumped by either system is purified, tested, and then discharged into the port area.
It is then stored in temporary storage tanks and the radioactive concentration is measured to confirm that the water quality does not surpass the upper limits set by TEPCO.
Third-party organizations also analyze the radioactive concentration to ensure the objectivity of the analysis results.

 
Cesium 134
Cesium 137
Gross β
Strontium
Tritium
TEPCO's upper limit of radioactive concentration for temporary storage tanks
1Bq/l
1Bq/l
3Bq/l
-
1500Bq/l
Regulatory Notification Limit (for reference)
60Bq/l
90Bq/l
-
30Bq/l
60000Bq/l
WHO Guideline for Drinking Water
10Bq/l
10Bq/l
-
10Bq/l
10000Bq/l

Related materials about the activities and current operational status of Subdrain and Groundwater drain can be found HERE.

Analysis Results of Relay Tanks

The newest data is on June 14, 2016.

Analysis Results of Temporary Storage Tanks and Water Collecting Tanks

Analysis Results of Weighted Average Sampling

*The analysis of the water sampled before being discharged, which is mixed at the rate of each amount out of the whole amount of discharged water in a month.

Analysis Results Regarding Discharge

Sampling regarding Groundwater Bypass

As a measure to prevent contaminated water from accumulating, the groundwater bypass has begun its operation since May 2014, which pumps up groundwater on the mountain side before flowing into the buildings and drains the water into the ocean after checking its purity. The pumped up groundwater is once stored in temporary storage tanks, and then its radioactive material concentration is mesured to confirm that its quality meets the operation target.
The third-party organization also analyzes the radioactive material concentration to ensure the objectivity of the analysis result.

 
Cesium 134
Cesium 137
Gross β
Strontium
Tritium
Operation Target
1Bq/l
1Bq/l
5Bq/l
-
1500Bq/l
Notification Level Limit (Reference)
60Bq/l
90Bq/l
-
30Bq/l
60000Bq/l
WHO Drinking Water Guideline
10Bq/l
10Bq/l
-
10Bq/l
10000Bq/l

Documents about summary, operational status, and related information of groundwater bypass are HERE.

Analysis Results of Pump Well

Analysis Results of Temporary Storage Tanks

Analysis Results of Weighted Average Sampling

*The analysis of the water sampled before being discharged, which is mixed at the rate of each amount out of the whole amount of discharged water in a month.

Analysis Results Regarding Discharge

The newest data is on December 16, 2017.

Monitoring regarding Water Leakage Tanks

The sampling near the South Water Outlet, at the Drainage Channel, and around tanks in the H4 area has been continued in order to monitor the impact of several leakage accidents such as the leakage from the bottom flange of the No.5 tank in the H4 area I group happened in August, 2013, the dripping from the top plate of the B-A5 tank in the B south area happened in October, 2013, and the leakage from the top plate flange of the C1 tank in the H6 area happened in February, 2014.

South Water Outlet, Drainage Channel

Observation Hole around H4 Area

Observation Hole around H6 Area

Analysis Results of Rainwater sprinkling Obtained Inside the Dike in the Tank Area After Treated by the Rainwater Treatment System

The rainwater accumulated inside the dike in the tank area has been sprinkled on the premises of Fukushima Daiichi NPS since May, 2014 after being purified by the desalination system (reverse osmosis membrane) etc.

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The newest data is on June 14, 2016.

Monitoring at the East Side of Unit 1-4 Turbine Buildings

Results of radioactive nuclide analysis for groundwater at the east side of Unit 1-4 Turbine Buildings and seawater at the port in order to monitor the source, the extent, and the effect of the radioactive materials in the groundwater toward the ocean.

  Highest Dose   English form

Detailed Analysis Results of Groundwater around Unit 1-4 Buildings

Radioactive materials were detected from the accumulated water inside the pits as a result of purification test at wells (subdrain pits), which is adjacent to Unit 1-4 Buildings at Fukushima Daiichi NPS. Since there is a possibility of being affected by fallout, we installed new observation well around Unit 1-4 Buildings in order to assess the impact of fallout.

The newest data is on October 1, 2014.

Sampling Results of Drainage Water at Fukushima Daiichi Nuclear Power Station

Water in each drainage channel is continuously sampled in order to check the impact of radioactive materials on the ocean, since rainwater flows into drainage channels through the ground surface, which was contaminated by the fallout at the time of the accident.

  Highest Dose   English form

Analysis Results of Underground Reservoirs

open

The groundwater sampled from the leakage detection holes by the undergounrd reservoirs and the surrounding observation holes has been analyzed, and its impact on the surrounding environment has been monitored after the water leakage accident from the underground reservoirs happened in April, 2013.
The leak volume from the underground reservoirs was evaluated as approximatly 20~30 litters after the accident.

Analysis Results at Water Treatment Facility

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February 9, 2018 Nuclide analysis results of water at water treatment facility

Daily Analysis Results on Radioactive Material at Fukushima Daiichi Nuclear Power Station(Japanese site)


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