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. After that, the injection
of freshwater was started from 3:37 PM on March 25th (switched from the
seawater injection).
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. The work finished at 0:19 pm on March
25th.
* 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.
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).
* 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.
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 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. After that, all 3 workers arrived at 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
