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Press Release (Apr 03,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 6:00 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 March 31st .
-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 4 started at 5:14 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, the work began at 1:55 pm 
 April 3rd. 
-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.  
-Today at around 9:30 am, we detected water containing radiation dose overc 
 1,000 mSv/h in the pit* where supply cables are stored near the intake 
 channel of Unit 2. Furthermore, there was a crack about 20 cm on the 
 concrete lateral of the pit, from where the water in the pit was out 
 flowing.(We already informed.) During the same day, we injected fresh 
 concrete to the pit, but we could not observe a reduction in the amount 
 of water spilling from the pit to the sea. 
 Therefore, we considered that a new method of stopping the water and 
 determined to use the polymer. Necessary equipment and experts of water 
 shutoff will be dispatched to the site and after checking the condition, 
 we're doing continuous work to stop water by injecting polymer(April 3rd). 
-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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