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 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.
*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. 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.
*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
