search



Corporate Information

 
Press Release (Mar 25,2011)
Status of TEPCO's Facilities and its services after Tohoku-Taiheiyou-Oki Earthquake (as of 3:00PM)
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 to evacuate for those local 
residents within 20km radius of the site periphery and to remain indoors 
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 have 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 have started the injection of 
sea water into the reactor from feed water system. 

At approximately 10:50 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 can 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, sea water injection through Fuel Pool 
Cooling and Filtering System was initiated. 

*Unit 3 
 At 6:50 am, March 14th, while water injection to the reactor was under 
 operation, 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 
 has gradually decreased (as of 9:05 am, 450 kPa). 

We continue injecting water into a reactor.
* 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 are conscious) have sustained injuries and they 
were already 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 in a certain range. 
On March 20th, we were preparing to implement a measurement 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 take a measure 
immediately to discharge air containing radioactive material to outside. 
We will continue to monitor the status of the pressure of the reactor 
containment vessel. Monitoring will be continued.

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 had started spraying water by water cannon trucks upon our 
request for the cooperation. At 8:09 pm, March 17th, they had 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, they had finished the operation.

At approximately 0:30 am, March 19th, spraying water was started with 
the cooperation of Fire Rescue Task Forces of Tokyo Fire Department 
started spraying water. At approximately 1:10 am, March 19th, they 
finished the operation. They resumed spraying water at 2:10 pm. At 
approximately 3:40 am, March 20th, they finished the operation.

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, they finished the operation.

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, and 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 
at the same level. However, employees working around Unit 3 evacuated 
to a safe location. It is observed the smoke has been decreasing. On 
March 22nd, the color of smoke changed to somewhat white and it is 
slowly dissipating.

At approximately 3:10 pm on March 22nd, water discharge into 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.
*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 off. 

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.
*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 plan to repair the pump while maintaining the 
appropriate the water level and the temperature in the reactor. At 
around 4:14 pm, March 24th, we started replaced pump and at around 
4:35 pm, cooling of reactor has restarted.

*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. All 3 workers are now being transferred to National Institute 
of Radiological Sciences in Chiba Prefecture. We will assess radiation 
dose of 2 worker's leg skin 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 and 24th, we detected cobalt, iodine, cesium and 
tellurium from the seawater around discharge canal of Unit 1, 2, 3 and 4.

* On March 21st, 23rd and 24th, we detected iodine, cesium and tellurium
in the air collected at the site of Fukushima Daiichi Nuclear Power 
Station.

*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 
released 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 properly under 
 consideration)
[Transmission System, etc.] 
All substation failed due to the earthquake have been restored.
[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] 
Backup supply from Shinshinano Conversion Station: 600MW
Backup supply from Sakuma Conversion Station: 300MW
Backup supply from Higashi Shimizu Conversion Station: 100MW
Backup supply from Hokkaido-Honshu Interconnection Facilities: 600MW

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
back to page top


to TOP