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Corporate Information

 
Press Release (Apr 03,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 0:30 PM, April 3)
Updates are underlined
All 6 units of Fukushima Daiichi Nuclear Power Station have been shut down.
Unit 1(Shut down) 
-Explosive sound and white smoke were confirmed after the big quake 
 occurred at 3:36 pm on March 12th. It was assumed to be hydrogen 
 explosion.
-At approximately 2:30 am on March 23rd, seawater injection to the
 nuclear reactor through the feed water system was initiated.
-At approximately 10:50 am on March 24th, white fog-like steam arising 
 from the roof part of the reactor building was observed.
-We had been injecting seawater into the reactor, but from 3:37 pm on 
 March 25th, we started injecting freshwater.
-We had been injecting fresh water to the reactor using fire engines;
 however we switched over utilizing temporary electrical pump at 8:32 am
 on March 29th.
-Some of turbine building lights were turned on April 2nd. 
-We injected fresh water to the reactor by a temporary motor driven pump, 
 but, from 10:42am to 11:52am on April 3rd we temporarily switched 
 the pump to the fire fighting pump to inject fresh water to use power 
 through off-site transmission line. We're now injecting fresh water to 
 the reactor by a motor driven pump powered by off-site transmission  
 line.
 Unit 2(Shut down) 
-At approximately 6:00 am on March 15th, an abnormal noise began
 emanating from nearby Pressure Suppression Chamber and the pressure
 within the chamber decreased. 
-We have been injecting seawater into the reactor, but from 10:10 am on
 March 26th, we started injecting freshwater (with boric acid).
-We had been injecting fresh water in to the reactor utilizing fire pump,
 however, we switched over to utilizing temporary electrical pump from 
 6:31 pm on March 27th. 
-Some of turbine building lights were turned on April 2nd. 
-We injected fresh water to the reactor by a temporary motor driven pump, 
 but, from 10:22am to 0:06pm on April 3rd, we temporarily switched the 
 pump to the fire fighting pump to inject fresh water to use power 
 through off-site transmission line. We're now injecting fresh water to 
 the reactor by a motor driven pump powered by off-site transmission  
 line.
Unit 3(Shut down) 
-Explosive sound and white smoke were confirmed at 11:01am March 14th.
 It was assumed to be hydrogen explosion.
-We had been injecting seawater into the reactor pressure vessel, but
 from 6:02 pm on March 25th, we started injecting freshwater.
-We had been injecting fresh water in to the reactor utilizing fire pump,
 however, we switched over to utilizing temporary electrical pump from 
 8:30 pm on March 28th.
-Some of turbine building lights were turned on April 2nd. 
-We injected fresh water to the reactor by a temporary motor driven pump, 
 but, from 10:03am to 0:16pm on April 3rd, we temporarily switched the 
 pump to the fire fighting pump to inject fresh water to use power 
 through off-site transmission line. We're now injecting fresh water 
 to the reactor by a motor driven pump powered by off-site transmission 
 line.
Unit 4(outage due to regular inspection) 
-At approximately 6 am on March 15th, we confirmed the explosive sound
 and the sustained damage around the 5th floor rooftop area of the 
 Nuclear Reactor Building.
-Some of turbine building lights were turned on April 2nd. 
-At this moment, we do not consider any reactor coolant leakage inside
 the reactor happened.
Unit 5(outage due to regular inspection) 
-Sufficient level of reactor coolant to ensure safety is maintained.
-At 5 am, March 19th, we started the Residual Heat Removal System Pump
 (C) in order to cool the spent fuel pool.
-At 2:30 pm, March 20th, the reactor achieved reactor cold shutdown. At
 around 5:24 pm on March 23rd, when we switched the temporary Residual
 Heat Removal System Seawater Pump, it has stopped automatically. At
 around 4:14 pm, March 24th we replaced the pump, and restarted cooling
 of reactor at around 4:35 pm.
-At this moment, we do not consider any reactor coolant leakage inside
 the reactor happened.
Unit 6(outage due to regular inspection) 
-Sufficient level of reactor coolant to ensure safety is maintained.
-At 10:14 pm, March 19th, we started the Residual Heat Removal System
 Pump (B) of Unit 6 in order to cool the spent fuel pool.
-At 7:27 pm, March 20th, the reactor achieved reactor cold shutdown.
-In relation to the two seawater side pumps of the Residual Heat Removal
 System, we switched the power source from temporary to permanent at 3:38
 PM and 3:42PM, Mar 25 respectively.
-At this moment, we do not consider any reactor coolant leakage inside
 the reactor happened.
Today's work for cooling the spent fuel pools 
-Water spray by the concrete pump truck to Unit 3 started at 9:53 am and
 continued until 0:54 pm.
-Water spray by the concrete pump truck to Unit 1 started at 5:16 pm and
 continued until 5:19 pm.
-We are considering further spraying subject to the conditions of spent
 fuel pools.
Draining water from underground floor of turbine buildings 
-In regard with transferring water from a condensate storage tank to a
 suppression pool water surge-tank in unit 1, work began at 0:00 pm March
 31st and continued until around 3:30 pm on April 2nd.
-Water transfer from a condenser to a condensate storage tank in unit 2,
 began at approximately 5:10 pm, April 2nd.
Casualties 
-Presence of 2 TEPCO employees at the site is not confirmed on March
 11th.
-On March 24th, it was confirmed that 3 workers from cooperative
 companies who were in charge of cable laying work in the 1st floor and
 the underground floor of turbine building were exposed to the radiation
 dose of more than 170 mSv. 2 of them were confirmed that their skins on
 legs were contaminated. After they were decontaminated, since there was
 a possibility of beta ray burn injury, they were transferred to
 Fukushima Medical University Hospital. The third worker was also
 transferred to Fukushima Medical University Hospital on March 25th.
 Later, the 3 workers were transferred to National Institute of
 Radiological Sciences in Chiba Prefecture. They all left the hospital on
 March 28th.
 Regarding this event, TEPCO has reported to the related government
 ministries and agencies on measures to be taken to assure appropriate
 radiation dose control and radiation exposure related operations.
 We will inform the related parties of countermeasures and continue to
 take all possible measures to future management.
Others 
-We measured radioactive materials (iodine etc.) inside of the nuclear
 power station area (outdoor) by monitoring car and confirmed that
 radioactive materials level is getting higher than ordinary level. As
 listed below, we have determined that specific incidents stipulated in
 article 15, clause 1 of Act on Special Measures Concerning Nuclear
 Emergency Preparedness (Abnormal increase in radiation dose measured at
 site boundary) have occurred.
 · Determined at 4:17 pm Mar 12th (Around Monitoring Post 4 )
 · Determined at 8:56 am Mar 13th (Around Monitoring Post 4 )
 · Determined at 2:15 pm Mar 13th (Around Monitoring Post 4 )
 · Determined at 3:50 am Mar 14th (Around Monitoring Post 6 )
 · Determined at 4:15 am Mar 14th (Around Monitoring Post 2 )
 · Determined at 9:27 am Mar 14th (Around Monitoring Post 3 )
 · Determined at 9:37 pm Mar 14th (Around main entrance )
 · Determined at 6:51 am Mar 15th (Around main entrance )
 · Determined at 8:11 am Mar 15th (Around main entrance )
 · Determined at 4:17 pm Mar 15th (Around main entrance )
 · Determined at 11:05 pm Mar 15th (Around main entrance )
 · Determined at 8:58 am Mar 19th (Around MP5)
 From now on, if the measured figure fluctuates and goes above and below
 500 micro Sv/h, we deem that as the continuous same event and will not
 regard that as a new specific incidents stipulated in article 15, clause
 1 of the Act on Special Measures Concerning Nuclear Emergency
 Preparedness (Abnormal increase in radiation dose measured at site
 boundary) has occurred. In the interim, if we measure a manifestly
 abnormal figure and it is evident that the event is not the continuous
 same event, we will determine and notify.

-The national government has instructed evacuation for those local
 residents within 20km radius of the periphery and evacuation to inside
 for those residents from 20km to 30km radius of the periphery, because
 it is possible that radioactive materials are discharged.
-At around 10:37 am March 21st, water spraying to common spent fuel pool
 and finished at 3:30 pm (conducted by TEPCO).
-At around 3:37 pm, March 24th, electricity supply to common spent fuel
 pool has started from external power source. At around 6:05 pm, fuel
 pool cooling pump was started to cool the pool.
-We found no signs of abnormal situation for the casks by visual
 observation during the patrol activity. A detailed inspection is under
 preparation.
-At Units 5 and 6, in order to prevent hydrogen gas from accumulating
 within the buildings, we have made three holes on the roof of the
 reactor building for each unit.
-In total 12 fire engines are lent for the water spraying to the spent
 fuel pools and water injection to the nuclear reactors by various
 regional fire departments* as well as Tokyo Fire Department. Also,
 instruction regarding the setting and operation of large scale
 decontamination system was provided by Niigata City Fire Headquarter and
 Hamamatsu City Fire Headquarter.
 *:Koriyama Fire Department, Iwaki Fire Brigade Headquarters, Fire
   Headquarters of Sukagawa District Wide Area Fire-fighting Association,
   Yonezawa City Fire Headquarters, Utsunomiya City Fire Headquarters,
   Fire Headquarters of Aizu-Wakamatsu wide area municipal association,
   Saitama City Fire Bureau, and Niigata City Fire Bureau.
-By March 22nd, Units 1 through 6 were started to be energized from the 
 external power source.
-At around 11:35 am April 1st, a worker fell into the sea when he got
 into a barge of the U.S. Forces to repair a hose of the ship. The worker
 was rescued immediately, and was not injured and not contaminated.
 The worker will be checked using the whole-body counter to ensure his
 health.
-The second barge of the U.S. Forces with freshwater to be used to cool
 down the reactors etc. was towed by a ship of Maritime Self-Defense
 Force and came alongside the pier at 9:10 am on April 2nd. We began to 
 replenish the filtrate tanks with water of a barge (the first barge) at
 around 10:20 am on April 2nd and continued until 4:40 pm.
-We began to transfer fresh water from the second barge to the first 
 barge on April 3rd at 9:52 am and continued until 11:15 am on April 3rd. 
-We also began to transfer the radioactive water we collected from the 
 building of Radioactive Waste Treatment Facilities to the Unit 4 turbine 
 building. 
-Monitoring posts of No. 1  No.8 set up near the boundary of power
 station area have been restored. We will periodically monitor the data
 and announce the results of monitoring.
-We will continue to take all measures to ensure the safety and to
 continue monitoring the surrounding environment around the Power
 Station. 
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