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 apologies 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.
* The level of radioactive materials ( iodine etc.) inside the nuclear power
station area (outdoor) measured by the monitoring car exceeded the normal
level. We have determined that specific incidents stipulated in article 15,
clause 1 of the Act on Special Measures Concerning Nuclear Emergency
Preparedness (Abnormal increase in radiation dose measured at site boundary)
have occurred.
-Determined at 8:58am, Mar 19th (Around Monitoring Post 5)
From now on, if the measured figure fluctuates and goes above and below 500
micro Sv/h, we deem that as the continuous same event and will not regard
that as a new specific incidents stipulated in article 15, clause 1 of the
Act on Special Measures Concerning Nuclear Emergency Preparedness (Abnormal
increase in radiation dose measured at site boundary) has occurred. In the
interim, if we measure a manifestly abnormal figure and it is evident that
the event is not the continuous same event, we will determine and notify.
* 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 and then boric acid into the reactor afterwards.
* 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 article 15,
clause 1 of Act on Special Measures Concerning Nuclear Emergency
Preparedness occurred (failure of reactor cooling function).
At 5:17 pm, 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 is still under operation.
As of March 18th , power from offsite transmission line has received until
temporary substation for backup power. Now, cabling to unit receiving
facility is underway.
* 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, 490 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
dispatched 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 works on March 16th was cancelled.
At 6:15 am, March 17th, the pressure of the Suppression Chamber temporally
increased, but currently it is stable in a certain range. Monitoring will
be continued.
In order to cool spent fuel pool, water discharge by helicopters has been
conducted on March 17th with the cooperation of Self-Defense Force.
At approximately past 7:00 pm, March 17th , Self-Defense Forces and the
police had started water discharge by water cannon trucks upon our request
for the cooperation. At 8:09 pm, March 17th, they had finished water
discharge.
At 2:00 pm, March 18th , water discharge by fire engine has started with
the cooperation of Self-Defense Forces and Military of United States of
America. At 2:45 pm, March 18th , they had finished water discharge.
At 0:45 am, March 19th, water discharge by the hyper rescue troop has
started with the cooperation of Tokyo Fire Department. At 1:10 am, March
19th, they finished water discharge. Again, the hyper rescue troop began
the water discharge at 2:10 pm. At approximately 3:40 am, March 20th, they
had finished water discharge.
* Unit 4
At approximately 6:00 am, March 15th, an explosive sound occurred 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 employee confirmed
that the fire was off.
At approximately 5:45 am, 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, March
20th, water discharge by fire engine has started with the cooperation of
Self-Defense Forces.
* 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. A detailed
inspection is under preparation.
* 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.
* The restoration work of electricity supply from external source for Unit
3, 4, 5 and 6 are being implemented. And the repair of emergency diesel
generator A of Unit 6 is completed.
* At 5 am, Mar 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.
* 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
* 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
Higashi-Ohgishima Thermal Power Station Unit 1: shutdown due to earthquake
[Hydro Power Station]
* All the stations have been restored.
[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
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 drier and to shut down the breaker of distribution
board when you leave your house.
For the customer who has in-house power generation, please secure fuel for
generator.
* Revised past progress
