TEPCO Digest Fukushima-Daiichi Today
12th May 2011
Tokyo Electric Power Company
<Number of People Working at Fukushima sites>
[At 6:30 12th May]
-Fukushima-Daiichi (plants + office)
Total : 207 people
TEPCO : 175 people
Contractors : 32 people
-Fukushima-Daini (plants + office + Back Office for Daiichi)
Total : 701 people (Incl. Back Office :184 people)
TEPCO : 648 people (Incl. Back Office :184 people)
Contractors : 53 people (Incl. Back Office : 0 )
[At noon 11th May]
-Fukushima-Daiichi (plants + office+ Back Office)
Total : 1472 people
TEPCO : 391 people
Contractors : 1081 people
-Fukushima-Daini (plants + office)
Total : 1567 people
TEPCO : 444 people
Contractors : 1123 people
<Workers Exposed Dose(as of 0:25 12th May )>
Over 100mSv :Total : 30 people
TEPCO : 27 people
Contractors : 3 people
Over 250mSv :Total : 0 people
TEPCO : 0 people
Contractors : 0 people
<Plant Parameters>
Please see the attached file (1)
<Water Injection to Reactor Vessels(as of 17:00 12th May)>
[Unit 1] Fresh water is being injected.(7.9m3/h)
[Unit 2] Fresh water is being injected.(7.0m3/h)
[Unit 3] Fresh water is being injected.(8.9m3/h)
<Nitrogen Gas Injection to Containment Vessel at Unit 1>
- The total volume of injected nitrogen is 23,200m3 as of 17:00 May 12th.
(Containment Vessel Pressure : 121.6kPa(abs))
<Watering to Spent Fuel Pools>
- No watering work today.
<Puddle Water in Turbine Building and Trench>
[Unit 2]
- We started pumping the Unit 2 Trench water to the Central Waste Treatment Facility at 10:08 19th April.
- Approx. 4,690 of the Unit 2 Trench water has been pumped out as of 17:00 12th May.
- The capacity of the Central Waste Treatment Facility is about 10,000tons and we will transfer 10,000tons of the water.
- We conducted Nuclide Analysis of water in the sub-drain near the Central Waste Treatment Facility in order to see the facility's soundness. And no substantial change was detected so far. (Please see the attached file (2))
<Draining Water at Underground Floor of Turbine Building(T/B)>
[Unit 6]
- Approx. 120tons of draining water was transformed from the T/B underground floor to temporary storage tanks today.(Total 1194tons as of today)
(Reference)
- TEPCO plans to construct a temporary drainage water tanks in order to mitigate the seawater contamination.
- The water from the drainage canals is temporarily stored in the tanks.
- The stored water is treated at a water-treatment facility and water samplings/analysis are conducted before release the water.
- The construction schedule is as shown below,
29 April : 1000m3 (Construction completed)
1 May : +1200m3 (Construction completed)
Mid May : +6400m3
End of May : +3600m3
<Works in Unit 1 Reactor Building>
- We plan to install and calibrate a reactor water level gauge etc. and install an alternative reactor cooling system to achieve cold shutdown.
- We implemented the gauge calibrations etc. on 11th May.
[Results]
(1)Gauge Calibrations etc.
PCV Pressure Gauges : Calibration was completed
Reactor Water Level Gauges : Condition surveillances were implemented
(2)Reactor Water Level
It was found that the reactor water level was lower than 500cm below the TAF(Top of Active Fuel),which means water level was lower than the original bottom level of fuels.
It is estimated that the damaged fuels with control rods moved down to the lower plenum in the reactor and they are being cooled there stably, because the reactor vessel temperature has been approx. 100 - 120 C.
<Change of Unit 3 Reactor Cooling Water Injection Line>
- We completed connecting the new line of reactor cooling water.
- We started the switching work to the new line from 16:53 today.
- It will take about one or a few days to complete the switching.
<Atmosphere Surveillance in Unit 3 Reactor Building>
- We implemented atmosphere surveillances in the Unit 3 Reactor Building using the remote control robots on 10th May.
[Results] Please see the attached file (3)
Time : 12:20 - 13:35 10th May 2011
Workers : 10 people (TEPCO 4, Contractor 6)
Exposed Dose : 1.74mSv(max) TEPCO
<Construction of Support Structure for Unit 4 SFP>
- We started rubble removal works around unit 4 carry-in entrance area with manned heavy machines from 9th May.
- The removal works will take about 10 - 14 days.
(Reference)
- TEPCO decided to construct some support structures under the spent fuel pool of Unit 4, because the reactor building's outer wall was heavily damaged.
<Anti-Scattering Agents>
- We started the full-scale use of the anti-scattering agents in the Fukushima-Daiichi site from 26th April. We plan to continue the work until end of the May.
- Total sprayed area : 152,830m2 (as of 12th May)
Trial use : 26,590m2 (1st - 25th April)
Full-scale use : 126,240m2 (26th April - 12th May)
<Rubbles Removal>
- We removed 4 containers of rubbles around unit 3 and other areas by remote-control device on 12th May.
(Total 138 containers as of 12th May. / Container size: 3.2m x 1.6m x 1.1m )
<Environmental Investigation>
[Seawater Sampling]
- Please see the attached file (4).
[Air Sampling]
- Please see the attached file (5).
[Soil Sampling]
- Please see the attached file (6).
[Radiation Level]
- Around the Daiichi Site : Please check the following URL.
http://www.tepco.co.jp/en/nu/fukushima- ... dex-e.html
- In the Daiichi Site : Please check the following URL.
http://www.tepco.co.jp/en/nu/fukushima- ... ex3-e.html
<Coverage in Japan>
(Nikkei)
- Japan Govt Fails To Agree On Tepco Aid Plan
http://e.nikkei.com/e/fr/tnks/Nni20110512D12JF485.htm
- Unlimited Tepco Liability A Mistake: U.S. Think Tank Chief
http://e.nikkei.com/e/fr/tnks/Nni20110511D11JFA01.htm
- Nuclear Fuel At Fukushima No. 1 Unit Melted After Full Exposure
http://e.nikkei.com/e/fr/tnks/Nni20110512D12JF428.htm
- U.S. Ready To Support Fukushima Effort 'For Years': Roos
http://e.nikkei.com/e/fr/tnks/Nni20110512D12JFA03.htm
<Links>
- TEPCO English website
http://www.tepco.co.jp/en/nu/fukushima-np/index-e.html
- METI(Ministry of Economy Trade and Industry)
http://www.meti.go.jp/english/index.html
- NISA(Nuclear and Industrial Safety Agency)
http://www.nisa.meti.go.jp/english/
- JAIF(Japan Atomic Industrial Forum Inc.)
http://www.jaif.or.jp/english/
- FEPC(The Federation of Electric Power Companies of Japan)
http://www.fepc.or.jp/english/index.html