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
