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Corporate Information

 
Press Release (Mar 28,2011)
Status of TEPCO's Facilities and its services after Tohoku-Taiheiyou-Oki Earthquake (as of 4:00PM)
Due to the Tohoku-Taiheiyou-Oki Earthquake which occurred on March 11th
2011, TEPCO's facilities including our nuclear power stations have been
severely damaged. We deeply apologize for the anxiety and inconvenience
caused.  

Below is the status of TEPCO's major facilities.
*new items are underlined
[Nuclear Power Station] 
Fukushima Daiichi Nuclear Power Station: 
   Units 1 to 3: shutdown due to earthquake 
   (Units 4 to 6: outage due to regular inspection) 

*The national government has instructed the public to evacuate for those
local residents within 20km radius of the site periphery and to evacuate
voluntarily for those local residents between 20km and 30km radius of the
site periphery.

*Off-site power was connected to Unit 1 to 6. 

*Unit 1
- The explosive sound and white smoke was confirmed near Unit 1 when the
  big quake occurred at 3:36pm, March 12th.
- We started injection of sea water at 8:20 pm, March 12th, and then boric
  acid which absorbs neutron into the reactor afterwards.
- At approximately 2:30 am, March 23rd, we started the injection of sea
  water into the reactor from feed water system. After that, the injection
  of freshwater was started from 3:37 pm on March 25th (switched from the
  seawater injection).
- At approximately 10:50 am on March 24th, white smoke was confirmed
  arising from the top of the reactor building.
- At approximately 11:30 am, March 24th, lights in the main control room
  were restored.

*Unit 2
- At 1:25 pm, March 14th, since the Reactor Core Isolation Cooling System
  has failed, it was determined that a specific incident stipulated in
  Clause 1, Article 15 of Act on Special Measures Concerning Nuclear
  Emergency Preparedness occurred (failure of reactor cooling function).
  At 5:17 pm, March 14th, while the water level in the reactor reached the
  top of the fuel rod, we have restarted the water injection with the
  valve operation.
- At approximately 6:14 am, March 15th, the abnormal sound was confirmed
  near the suppression chamber and the pressure inside the chamber
  decreased afterwards. It was determined that there is a possibility that
  something happened in the suppression chamber. While sea water injection
  to the reactor continued, TEPCO employees and workers from other
  companies not in charge of injection work started tentative evacuation
  to a safe location. 
  Sea water injection to the reactor continued.
- On March 18th, power was delivered up to substation for backup power
  through offsite transmission line. We completed laying cable further to
  unit receiving facility in the building, and at 3:46 pm, March 20th the
  load-side power panel of the receiving facility started to be energized.
- From 3:05 pm to 5:20 pm on March 20th, 40 tons of seawater was injected
  into Unit 2 by TEPCO employees.
- At 6:20 on March 21st, white smoke was confirmed arising from the top of
  the reactor building. As of 7:11 am on March 22nd, smoke decreased to the
  level where we could hardly confirm.
- From around 4 pm to 5 pm on March 22nd, approximately 18 tons of sea
  water was injected into the spent fuel pool by TEPCO employees. 
- From 10:30 am on March 25th, seawater injection through Fuel Pool
  Cooling and Filtering System was initiated. The work finished at 0:19 pm
  on March 25th.
- From 10:10 am on March 26th, freshwater (with boric acid) injection was
  initiated. (switched from the seawater injection) At 06:31PM, Mar 27th,
  transfer from the fire fighting pump to a temporary motor driven pump
  was made.
- At approximately 4:46 pm, March 26th, lights in the main control room
  were restored.

*Unit 3
- At 6:50 am, March 14th, while water injection to the reactor was under  
  operation (injection of boric acid was done on Mar 13th), the pressure in  
  the reactor containment vessel increased to 530 kPa. As a result, at 7:44  
  am, it was determined that a specific incident stipulated in article 15,  
  clause 1 occurred (abnormal increase of the pressure of reactor  
  containment vessel). Afterwards, the pressure gradually decreased (as of  
  9:05 am, 490 kPa).  
- We continue injecting water into a reactor (Boric acid was added on March 13)
 * We announced in our past reports that "On March 14, the pressure in the 
   primary containment vessel increased and it was determined that a 
   specific incident stipulated in the Article 15, the Clause 1 of Act on 
   Special Measures Concerning Nuclear Emergency Preparedness occurred". 
   However, we made a mistake in the calculation of the pressure value and 
   the status of Unit 3 did not fall under the above-mentioned specific 
   incidents. We will delete the related description from our latest report.
- At approximately 11:01 am, March 14th, an explosion followed by white
  smoke occurred near Unit 3. 4 TEPCO employees and 3 workers from other
  companies (all of them were conscious) sustained injuries and were taken
  to the hospital by ambulances.
- As the temperature of water in the spent fuel pool rose, spraying water
  by helicopters with the support of the Self Defense Force was considered.
  However the operation on March 16th was cancelled.
- At 6:15 am, March 17th, the pressure of the Suppression Chamber
  temporarily increased, but currently it is stable within a certain range.
  On March 20th, we were preparing to implement measures to reduce the
  pressure of the reactor containment vessel (partial discharge of air
  containing radioactive material to outside) in order to fully secure
  safety. However, at present, it is not a situation to immediately
  implement measures and discharge air containing radioactive material to
  outside. We will continue to monitor the status of the pressure of the
  reactor containment vessel.
- In order to cool spent fuel pool, water was sprayed by helicopters on
  March 17th with the cooperation of Self-Defense Forces.
- At approximately past 7:00 pm, March 17th, Self-Defense Forces and the
  police started spraying water by water cannon trucks upon our request
  for the cooperation. At 8:09 pm, March 17th, they finished the operation.
- At 2:00 pm, March 18th, spraying water by fire engines was started with
  the cooperation of Self-Defense Forces and the United States Armed
  Forces. At 2:45 pm, March 18th, the operation was finished.
- At approximately 0:30 am, March 19th, spraying water was started with
  the cooperation of Fire Rescue Task Forces of Tokyo Fire Department.
  At approximately 1:10 am, March 19th, the operation was finished. They
  resumed spraying water at 2:10 pm and finished at approximately 3:40 am,
  March 20th.
- At approximately 9:30 pm, March 20th, spraying water was started with
  the cooperation of Fire Rescue Task Forces of Tokyo Fire Department.
  At approximately 3:58 am, March 21st, the operation was finished.
- At approximately 3:55 pm, March 21st, light gray smoke was confirmed
  arising from the southeast side of the 5th floor roof of the Unit 3
  building. The situation was reported to the fire department at
  approximately 4:21 pm. The parameters of reactor pressure vessel,
  reactor containment vessel, and monitored environmental data remained
  stable without significant change. However, employees working around
  Unit 3 evacuated to a safe location. On March 22nd, the color of smoke
  changed to somewhat white and it is slowly dissipating.
- At approximately 3:10 pm on March 22nd, spraying water to Unit 3 by
  Tokyo Fire Department's Hyper Rescue and Osaka City Fire Department was
  conducted, and completed at approximately 4:00 PM on the same day.
- At approximately 10:45 pm on March 22nd, lights in the main operation
  room were restored.
- At 11:00 am on March 23rd, the injection of sea water to spent fuel
  pool was conducted, and finished approximately at 1:20 pm on the same day.
- At 4:20 pm on March 23rd, light gray smoke was observed belching from
  Unit 3 building. The situation was reported to the fire department at
  4:25 pm on March 23rd. The parameters of the reactor, the reactor
  containment vessel of Unit 3, and monitored figures around the site's
  immediate surroundings remained stable without significant change. To
  be safe, workers in the main control room of Unit 3 and around Unit 3
  evacuated to a safe location. At approximately 11:30 pm on March 23rd
  and 4:50 am on March 24th, TEPCO employees confirmed the smoke has
  disappeared. Accordingly, workers evacuation was lifted.
- From approximately 5:35 am on March 24th, sea water injection through
  Fuel Pool Cooling and Filtering System was initiated, and finished at
  approximately 4:05 pm on the same day.
- From 1:28 pm on March 25th, Hyper Rescue team started water spray. The
  work finished at 4:00 pm on March 25th.
- From 6:02 pm on March 25th, the injection of freshwater to the reactor
  was started (switched from the seawater injection).
- At approximately 0:34pm March 27th , Injection of water by concrete pump
  truck was started. At approximately 2:36 pm, March 27th, the operation
  was finished.

*Unit 4
- At approximately 6:00 am, March 15th, an explosive sound was heard and
  the damage in the 5th floor roof of Unit 4 reactor building was confirmed.  
  At 9:38 am, the fire near the north-west part of 4th floor of Unit 4
  reactor building was confirmed. At approximately 11:00 am, TEPCO
  employees confirmed that the fire was out. 
- At approximately 5:45 am on March 16th, a TEPCO employee discovered
  a fire at the northwest corner of the Nuclear Reactor Building. TEPCO
  immediately reported this incident to the fire department and the local
  government and proceeded with the extinction of fire. At approximately
  6:15 am, TEPCO staff confirmed at the site that there are no signs of fire.
- At approximately 8:21 am on March 20th, spraying water by fire engines
  was started with the cooperation of Self-Defense Forces and they
  finished the operation at approximately 9:40 am. At approximately
  6:45 pm spraying water was started by Self-Defenses' water cannon trucks
  and finished at approximately 7:45 pm.
- At approximately 6:30 am, March 21st, spraying water by fire engines
  was started with the cooperation of Self-Defense Forces and the United
  States Armed Forces. At approximately 8:40 am, March 21, they had
  finished the operation.
- On March 21st, cabling has been completed from temporary substation
  to the main power center.
- From approximately 5:20 pm on March 22nd, spraying water from the
  concrete pumping vehicle was conducted and ended at approximately 8:30 pm
  on the same day.
- From approximately 10:00 am on March 23rd, spraying water from the
  concrete pumping vehicle was conducted and ended at approximately 1:00 pm
  on the same day.
- From approximately 2:35 pm on March 24th, spraying water by the concrete
  pumping vehicle was conducted and ended at approximately 5:30 pm on the
  same day.
- From 6:05 am on March 25th, seawater injection through Fuel Pool Cooling
  and Filtering System was initiated and finished at approximately 10:20 am
  on the same day.
- From 7:05 pm on March 25th, water spray by the concrete pumping vehicle
  was started and finished at 10:07 pm on March 25th.
- From 4:55 pm on March 27th, water spray by the concrete pumping vehicle
  was started and finished at 7:25 pm on March 27th.

*Unit 5 and 6
- At 5 am on March 19th, we started the Residual Heat Removal System Pump
  (C) of Unit 5 in order to cool the spent fuel pool. At 10:14 pm, we
  started the Residual Heat Removal System Pump (B) of Unit 6 in order to
  cool the spent fuel pool.
- Unit 5 has been in reactor cold shutdown since 2:30 pm on March 20th.
  Unit 6 has been in reactor cold shutdown since 7:27 pm on March 20th.
- 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.
- At approximately 5:24 pm on March 23rd, the temporary Residual Heat
  Removal System Seawater Pump automatically stopped when its power source
  was switched. We restarted the pump at around 4:14 pm, March 24th, and
  resumed cooling of reactor at around 4:35 pm.

*On March 18th, regarding the spent fuel in the common spent fuel pool,
we have confirmed that the water level of the pool is secured. At around
10:37 am March 21st, water spraying to common spent fuel pool and finished
at 3:30 pm. At around 6:05 pm, fuel pool cooling pump was started to cool
the pool.
  *common spent fuel pool: a spent fuel pool for common use set in a
   separate building in a plant site in order to preserve spent fuel which
   are transferred from the spent fuel pool in each Unit building.

*On March 17th, we patrolled buildings for dry casks and found no signs of
abnormal situation for the casks by visual observation. A detailed
inspection is under preparation.
  *dry cask: a measure to store spent fuel in a dry storage casks in
   storages. Fukushima Daiichi Nuclear Power Station started to utilize
   the measure from August 1995.

*In total 13 fire engines are lent for spraying water 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.

*On March 24, 2011, 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 170mSv. 2 of them were confirmed that their leg skins
were contaminated. Although they were decontaminated by laundering, they
were transferred to Fukushima Medical University hospital because there
is possibility that they get a burn injury by beta ray. On March 25th,
remaining worker was also transferred to Fukushima Medical University
hospital. After that, all 3 workers arrived at National Institute of
Radiological Sciences in Chiba Prefecture. The 3 workers were discharged
 from the institute on March 23rd. We will assess radiation dose of 2
worker's skin on their legs by beta ray. We thoroughly instruct our
employees and workers of cooperative companies to recognize APD alarm and
evacuate when the alarm rings. We will explain this event, together with
appropriate measures to be taken, to the government and to people concerned
in order to fully secure the safety in relation to radiation dose
management and operations associated with radiation exposure.

*On March 21st, 23rd to 26th, we detected technetium, cobalt, iodine,
cesium, tellurium, barium, lanthanum and molybdenum from the seawater
around discharge canal of Unit 1, 2, 3 and 4.

*On March 20th, 21st, 23rd to 26th, we detected iodine, cesium, tellurium
and ruthenium in the air collected at the site of Fukushima Daiichi Nuclear
Power Station.
*On March 28th, we detected radioactive materials contained in the puddles
found in the turbine building of Unit 1 to 4.
*At approximately 3:30 pm, March 27th, we found water pooling in the
vertical shaft of the trench outside of the turbine buildings for Units 1
to 3. The radiation dose at the surface of the water amounted 0.4 mSv/h in
Unit 1 and over 1,000 mSv/h in Unit 2. We could not confirm the amount of
the radiation dose in Unit 3. We will keep observing the condition of the
water in the vertical shaft. 

*We will continuously endeavor to securing safety, and monitoring of the
surrounding environment.
Fukushima Daini Nuclear Power Station:
  Units 1 to 4: shutdown due to earthquake 
*The national government has instructed evacuation for those local
residents within 10km radius of the periphery.

*In order to achieve cold shutdown, reactor cooling function was restored
and cooling of reactors was conducted. As a result, all reactors achieved
cold shutdown: Unit 1 at 5:00 pm, March 14th, Unit 2 at 6:00 pm, March 14th,
Unit 3 at 0:15 pm, March 12th, Unit 4 at 7:15 am, March 16th. 

*Since March 12th, we had been preparing measures for reducing the
pressure of reactor containment vessels (partial discharge of air
containing radioactive materials to outside), but on March 17th, we
stopped such preparation in all Units.

*(Unit 1)
As it is confirmed that the temperature of the Emergency Equipment Cooling
Water System *1 has increased, at 3:20 pm, March 15th, we stopped
the Residual Heat Removal System (B) for the inspection. Subsequently,
failure was detected in the power supply facility associated with the
pumps of the Emergency Equipment Cooling Water System. At 4:25 pm,
March 15th, after replacing the power facility, the pumps and the Residual
Heat Removal System (B) have been reactivated.

*(Unit 4)
As it is confirmed that the pressure at the outlet of the pumps of the
Emergency Equipment Cooling Water System*1 has been decreased, at 8:05 pm,
March 15th, we stopped the Residual Heat Removal System (B) for the
inspection. Subsequently, failure was detected in the power supply facility
associated with the pumps of the Emergency Equipment Cooling Water System.
At 9:25 pm, March 15th, after replacing the relevant facility, the pumps
and the Residual Heat Removal System (B) have been reactivated.

*1:emergency water system in which cooling water (pure water) circulates
which exchanged the heat with sea water in order to cool down bearing pumps
and/or heat exchangers etc.
Kashiwazaki Kariwa Nuclear Power Station: 
  Units 1, 5, 6, 7: normal operation 
  (Units 2 to 4: outage due to regular inspection)
[Thermal Power Station] 
- Hirono Thermal Power Station Units 2 and 4: shutdown due to earthquake
- Hitachinaka Thermal Power Station Unit 1: shutdown due to earthquake
- Kashima Thermal Power Station Units 2, 3, 5, 6: shutdown due to earthquake
[Hydro Power Station] 
- All the stations have been restored.
  (Facilities damaged by the earthquake are now being repaired in a timely
  manner.)
[Transmission System, etc.] 
- All substation failed due to the earthquake have been restored.
  (Facilities damaged by the earthquake are now being repaired in a timely
   manner.)
[Blackout in TEPCO's Service Area] 
- All the blackouts are resolved.
[Supply and Demand Status within TEPCO's Service Area to Secure Stable
Power Supply] 
- Considering the critical balance of our power supply capacity and
  expected power demand forward, in order to avoid unexpected blackout,
  TEPCO has been implementing rolling blackout (planned blackout alternates
  from one area to another) since Mar 14th. We will make our utmost to
  secure the stable power supply as early as possible. For customers who
  will be subject to rolling blackout, please be prepared for the announced
  blackout periods. Also for customers who are not subject to blackouts,
  TEPCO appreciates your continuous cooperation in reducing electricity
  usage by avoiding using unnecessary lighting and electrical equipment.
[Others] 
- Please do NOT touch cut-off electric wires.
- In order to prevent fire, please make sure to switch off the electric
  appliances such as hair driers when you leave your house.
- For the customer who has in-house power generation, please secure fuel
  for generator.

* Revised past progress
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