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 the earthquake
(Units 4 to 6: outage due to regular inspections)
*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 has been connected to Unit 1 to 6 by March 22, 2011.
*Unit 1
-The explosive sound and white smoke was confirmed near Unit 1 when the
big quake occurred at 3:36 pm, 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 8:32 am, Mar 29th, transfer from the fire
fighting pump to a temporary motor driven pump was made. From 10:42am to
11:52am on April 3rd we temporarily switched the pump to the fire
fighting pump to inject fresh water to use power through off-site
transmission line. We're now injecting fresh water to the reactor by a
motor driven pump powered by off-site transmission line.
-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.
-At approximately 5:00 pm, March 24th, draining water from underground
floor of turbine buildings into a condenser was started and it was
paused at approximately 7:30 am, March 29th because we confirmed that
the water level reached almost full capacity of a condenser. In order to
move the water in the condenser into a condensate storage tank, water
transfer from the condensate storage tank to suppression pool's water
surge-tanks was conducted from around 0:00 pm, March 31st to 3:26 pm,
April 2nd.
-From 1:03 pm, March 31st, the water spray by the concrete pumping
vehicle was started, and finished at 4:04 pm.
-In order to confirm the position of water spray to the spent fuel pool
by the concrete pumping vehicle, the water spray was conducted from 5:16
pm to 5:19 pm.
-Some of turbine building lights were turned on April 2nd.
-The water transfer from the condenser to the condensate storage tank has
been implemented since 1:55 pm, April 3rd.
-As it is suspected that hydrogen gas may be accumulated inside reactor
containment vessel, at 10:30 pm, April 6th, we started the operation of
the valve for the injection of nitrogen to the reactor in order to
prevent the increase of oxygen density. Following this, the injection of
nitrogen to the reactor was started at 1:31AM, April 7th.
*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 was 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 approximately 3:05 pm to approximately 5:20 pm on March 20th, about
40 tons of seawater was injected into Unit 2 by TEPCO employees.
-At approximately 6:20 pm 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 4:00 pm to 5:00 pm on March 22nd, approximately 18 tons of
sea water was injected into the spent fuel pool by TEPCO employees.
-From 10:10 am on March 26th, freshwater (with boric acid) injection was
initiated. (switched from the seawater injection) At 6:31pm, March 27th,
transfer from the fire fighting pump to a temporary motor driven pump
was made. From 10:22am to 0:06pm on April 3rd, we temporarily switched
the pump to the fire fighting pump to inject fresh water to use power
through off-site transmission line. We're now injecting fresh water to
the reactor by a motor driven pump powered by off-site transmission line.
-From 10:30 am on March 25th, seawater injection through Fuel Pool
Cooling and Filtering System was initiated. The work was finished at
12:19 pm, March 25th. From 4:30 pm, March 29th, freshwater injection
through Fuel Pool Cooling and Filtering System was initiated. (We
switched from seawater to freshwater). The work was finished at 6:25 pm
on March 29th. At 9:25 am, March 30th, we started fresh water injection
by a temporary motor driven pump, but we switched the pump to the fire
fighting pump due to the pump trouble. At 1:10 pm, March 30th,
freshwater injection was suspended, because we found the crack on a part
of the hose. At 7:05 pm, March 30th, freshwater injection was resumed
and finished at 11:50 pm, March 31.
-At approximately 4:46 pm, March 26th, lights in the main control room
were restored.
-At approximately 4:45 pm, March 29th, the water in a condensate storage
tank was being transferred to suppression pool water surge-tanks to
prepare for water transfer from a condenser to a condensate storage tank
in order to drain water on the underground floor of the turbine building
into a condenser. At 11:50 am, April 1st, transfer was completed.
-At 2:56 pm, April 1st, water injection into spent fuel pool in Unit 2 by
temporary motor driven pump was initiated. At 5:05 pm on April 1st, the
water injection was finished.
-The water transfer from the condenser to the condensate storage tank has
been implemented since 5:10 pm, April 2nd.It was finished at 1:10 pm,
April 9th. -Some of turbine building lights were turned on April 2nd.
-At 11:05 am, April 4th, water injection into spent fuel pool in Unit 2
by a temporary motor driven pump was initiated. At 1:37 pm, April 4th,
the water injection was finished.
-At 1:29 pm, April 7th, water injection into spent fuel pool in Unit 2 by
a temporary motor driven pump was initiated. At 2:34 pm, April 7th, the
water injection was finished.
*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 the
Article 15, the Clause 1 of Act on Special Measures Concerning Nuclear
Emergency Preparedness occurred (abnormal increase of the pressure of
reactor containment vessel). Afterwards, the pressure gradually
decreased (as of 9:05 am, 490 kPa).
-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 was 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.
-Before 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 12:30 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 was 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 control room
were restored.
-At approximately 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 8:30 pm on March
28th, the injection of fresh water was switched to temporary electricity
pumps from the fire engine pumps. From 10:03am to 0:16pm on April 3rd,
we temporarily switched the pump to the fire fighting pump to inject
fresh water to use power through off-site transmission line. We're now
injecting fresh water to the reactor by a motor driven pump powered by
off-site transmission line.
-At approximately 12:34pm March 27th, the injection of water by the
concrete pump truck was started. At approximately 2:36 pm, March 27th,
the operation was finished.
-At approximately 2:17pm March 29th, the injection of fresh water by the
concrete pump truck was started. (Sea water had been injected so far and
transfer from seawater to freshwater was made). The water injection was
finished at 6:18 PM, March 29th.
-At approximately 5:40 pm, March 28th, the water in a condensate storage
tank was being transferred to suppression pool water surge-tanks to
prepare for water transfer from a condenser to a condensate storage tank
in order to drain water on the underground floor of the turbine building
into a condenser. We finished the transfer work at approximately 8:40 am,
March 31st.
-From 4:30 pm, March 31st, the water spray by the concrete pumping
vehicle was started, and finished at 7:33 pm.
-From 9:52 am, April 2nd, the water spray by the concrete pumping vehicle
was started, and finished at 0:54 pm.
-Some of turbine building lights were turned on April 2nd.
-From 5:03 am, April 4th, the water spray by the concrete pumping vehicle
was started, and finished at 07:19 pm.
-From 6:53 am, April 7th, water spray by the concrete pumping vehicle was
started, and finished at 8:53 am.
*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 were 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.
-From 4:55 pm on March 27th, water spray by the concrete pumping vehicle
was started and finished at 7:25 pm on March 27th.
-At approximately 11:50 am on March 29th, lights in the main control room
were restored.
-From 2:04 pm on March 30th, water spray by the concrete pumping vehicle
was started and finished at 6:33 pm on March 30th.
-Some of turbine building lights were turned on March 31st.
-From 8:28 am, April 1st, the water spray by the concrete pumping vehicle
was started. At 2:14 pm, the water spray finished.
-From 5:14 pm, April 3rd, the water spray by the concrete pumping vehicle
was started. At 10:16 pm, the water spray finished.
-From 5:35 pm, April 5th, the water spray by the concrete pumping vehicle
was started. At 6:22 pm, the water spray finished.
-From 6:23 pm, April 7th, the water spray by the concrete pumping vehicle
was started. At 7:40 pm, the water spray finished.
*Unit 5 and 6
-At 5:00 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 was 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 was 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.
*On March 21st, 23rd to April 6th we detected technetium, cobalt, iodine,
cesium, tellurium, barium, lanthanum and molybdenum from the seawater
around the discharge canal of the station. (We are reevaluating)
*On March 20th, 21st, 23rd to April 6th, we detected iodine, cesium,
tellurium and ruthenium in the air collected at the site of Fukushima
Daiichi Nuclear Power Station. (We are reevaluating)
*Plutonium has been detected from the sample of soil at the site of
Fukushima Daiichi Nuclear Power Station collected on 21st, 22nd, 25th
and 28th of March, Concentration level of Plutonium detected was same as
that of under usual environment and it was thought not to be harmful to
human health. We will strengthen environmental monitoring of power
station and surrounding environment.
Additionally Iodine, Cesium, Tellurium, Barium, Niobium, Ruthenium,
Molybdenum, Technetium, Lanthanum, Beryllium, Silver have been detected
from the sample of soil collected at Fukushima Daiichi Nuclear Power
Station on 21st, 22nd, 25th and 28th of March.
*We detected radioactive materials contained in the puddles found in the
turbine building of Unit 1 to 4. We are planning to conduct water
analysis in preparation for treating the water. The analysis will be
carried out in Fukushima Daini Nuclear Power Station with support from
other nuclear companies (Japan Atomic Energy Agency, Japan Nuclear Fuel
Limited).
*At approximately 3:30 pm, March 27th, we found water pooling in the
vertical shaft of the trench outside of the turbine buildings for Units
1 to 3. The radiation dose at the surface of the water amounted 0.4 mSv/h
in Unit 1 and over 1,000 mSv/h in Unit 2. We could not confirm the amount
of the radiation dose in Unit 3. We will keep observing the condition of
the water in the vertical shaft.
On March 29th, we detected niobium, tellurium, ruthenium, silver,
tellurium, iodine, cesium, and ruthenium in the water collected at the
trench of unit 1.
On March 30th, we took samples from the water in the trench of Unit 2
and 3, and conducted nuclide analysis on them. We are now confirming the
results of the analysis.
*At approximately 9:30 am, April 2nd, we found that there was water in
the shaft for storing power cable (concrete product) near the intake of
water for Unit 2, the radioactive air dose was over 1,000mSv/h and the
water spilled into the sea from the crack (approximately 20 cm) on the
side of the shaft. We injected fresh concrete to the shaft twice,
however, we could not observe a change in the amount of water flowing
into the sea. Therefore, we considered that a new method of stopping the
water and determined to use the polymer. Necessary equipment and experts
of water shutoff will be dispatched to the site and after checking the
condition, we began to stop water shutoff and were injecting polymer on
April 3rd. On April 4th, we injected the tracer from the vertical shaft
of the trench to start to examine the water current. We did not observe
reduction of flow or change of color or water leaking. We checked the
diagram and confirmed the route. At the same time, we checked the
situation of the pit in detail and considered the possibility that the
water was not from the pit, rather, from the joint between the piping
upstream of the pit and the duct, then the water seeped through a layer
of gravel below the piping. In order to stop that seepage from the layer
of gravel, we decided to conduct the water sealing to the bedrock around
the piping. We arranged for the specialist and gathered equipments. On
April 5th, liquid glass was injected to the bedrock. Tracer was put
through the two new holes drilled near the pit to investigate the water
flow. At 2:15 pm, April 5th, it was observed the water with tracer came
out from the crack on the concrete wall of the pit. At 3:7 pm, April 5th,
injection of coagulant from the holes was initiated and we have confirmed
the outflow from the crack on the concrete wall of the pit has stopped
at 5:38 am, April 6th. We confirmed water level has not been rising in
the turbine building of unit 2. On April 6th, a countermeasure by using
rubber plate and fixer was implemented to prevent discharge of
radioactive materials, and we are continuously monitoring for any
existence of leakage. From 3:00pm April 5th, a construction of
installing large sandbags around the pier to prevent the outflow of the
contaminated water from station's port on the south side to the ocean
was started. Also we are preparing spillage prevention fences as
countermeasures for lowering the outflow to the ocean.
Iodine and Cesium were detected from the water sampled in the pit and in
the sea near the water discharge. Additional nuclide analysis will be
implemented.
In addition, from April 2nd, we will implement sampling at 15km offshore
Fukushima Daiichi and Fukushima Daini Nuclear Power Stations(3 points
have been added since April 5th) and will evaluate these samples
comprehensively.
*Since approximately 9:20 am, March 31st, the water transfer from the
vertical shaft of Unit 1 to the reservoir of the centralized
environmental facility was conducted. We finished the task around 11:25
am of the same day.
*We found a puddle of water at the main building of the centralized
environmental facility process. We analyzed and detected approximately
1.2 x 101Bq/cm3 of radioactivity in full dose in the Controlled Area and
2.2 x 101Bq/cm3 in full dose in the Non-Controlled Area on March 29.
From April 3rd, the water level in the trench of Unit 3 increased by 15
cm. The route is not yet known, but there is a possibility that water in
the turbine building of Unit 4 may be running to the trench of Unit 3.
To be safe, at 09:22am, April 4th, we stopped transferring water to the
turbine building of Unit 4. At this moment, the water level in the
trench of Unit 3 became stable after stopping the water transfer.
*There is plenty of radioactive wastewater in the turbine buildings.
Especially, Unit 2's wastewater is very highly radioactive. To store
this stably, it was decided that this needed to be transferred to the
Central Radioactive Waste Disposal Facility. However, within that
facility, we are storing ten thousand tons of low level radioactive
wastewater. In order to transfer more wastewater, we need to discharge
the low level radioactive wastewater. In addition, as low radioactive
subsurface water is piling up in sub-drain pits of Units 5 and 6 and a
part of subsurface water is running into buildings. We are concerned
that important equipment to secure the safety of reactors may be
submerged.
Based on the Section 1 of the Article 64 of the Nuclear Reactor
Regulation Law, we have decided to discharge to the sea approximately
ten thousand tons of the accumulated low level radioactive water and a
total of fifteen hundred tons of the low level radioactive subsurface
water stored in the sub drain pits of Unit 5 and 6 as soon as we get
ready.
From 7:03 pm, April 4th, we are discharging the low level radioactive
wastewater stored in the Central Radioactive Waste Disposal Facility to
the south of the water discharge canal. By 7:10 pm, we started ten pumps.
Also, from 9:00 pm, April 4th, we are discharging the low level
radioactive wastewater stored in the sub drain pits of Unit 5 and 6 by
using one pump via the water discharge canal of Units 5 and 6.
We evaluate the impact on the discharge of the low radioactive
wastewater to the sea as approximately 0.6 mSv per year per an adult if
an adult eats adjacent fish and seaweeds everyday. The amount (0.6 mSv
of effective radioactive doses per year) is one-forth of annual
radioactive dose (2.4 mSv) to which the general public is exposed from
nature.
*On April 7th, we knocked holes in the external walls of turbine
buildings at Units 2 to 4 for the preparation of draining the puddles to
the centralized waste treatment facility. We are checking the heath in
the building of centralized waste treatment facility.
*The first barge of the U.S. Forces with fresh water to be used to cool
down reactors etc. was towed by a ship of Maritime Self-Defense Force
and docked at 3:42 pm on March 31st 2011. At approximately 3:58 pm,
April 1st, we started to replenish filtrate tanks with the fresh water,
and finished at 4:25 pm. At approximately 10:20 am, April 2nd, we
resumed replenishing filtrate tanks with the fresh water, and finished
at 4:40 pm.
The second barge of the U.S. Forces with the fresh water towed by the
ship of Maritime Self-Defense Force came alongside the pier at
approximately 9:10 am, April 2nd. It was in preparation for replenishing
filtrate tanks with the fresh water. We began to transfer fresh water
from the second barge to the first barge on April 3rd at 9:52 am and
continued until 11:15 am on April 3rd.
*At 11:35 am, April 1st, a worker fell into the sea while stepping into
the ship from the pier during the hose laying work of the barge. Other
crew immediately rescued the worker. While no injury or contamination
was confirmed, whole body counter has been implemented to check the
contamination inside the body just in case.
*At 9:19 am, April 9th, one contractor with a full-face mask who was
working on cables in the water treatment building felt sick and got
injured by stepping into the manhole whose cover was dislocated. This
person was transported to the hospital.
*From 3:00 pm, April 1st, we started spraying inhibitor in order to
prevent diffusion of radioactive materials. This attempt was conducted
on a trial basis at the mountain side area of the common spent fuel
pool in the range of 500m2. The spraying finished at 4:05 pm. On April
5th and 6th , we also sprayed the inhibitor in order to prevent the
spread of radioactive materials on a trial basis at the mountain side
area of the common spent fuel pool in the range of 600m2. On April 8th,
we conducted trial spraying of the inhibitor at the mountain side area
of the common spent fuel pool in the range of 680m2.
*Monitoring posts (no.1 to no.8) which were installed around the site
boundary have been restored. We will continue monitoring the measured
value and make announcements on those values accordingly.
*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 the 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.
*At 2:30 pm on March 30th, the power source of the residual heat removal
system (B) to cool the reactor of Unit 1 was secured from an emergency
power source in addition to an offsite power. This means that all the
units secure backup power sources (emergency power sources) for the
residual heat removal system (B).
*Unit 1
As it was 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 was 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 the
earthquake
-Hitachinaka Thermal Power Station Unit 1: shutdown due to the
earthquake
-Kashima Thermal Power Station Unit 6: shutdown due to the earthquake
[Hydro Power Station]
-Power supply has returned to normal, but facilities damaged by the
earthquake are now being handled in a timely manner.
[Impacts on Transmission Facilities]
-Power supply has returned to normal, but facilities damaged by the
earthquake are now being handled in a timely manner.
[Avoidance of further Implementation on Planned Rolling Blackouts and
Request for Conserving Electricity Consumption]
Currently, we are giving our utmost efforts to restore power supply
after our nuclear and thermal power facilities are severely damaged by
Tohoku-Taiheiyou-Oki Earthquake. The widespread understanding and
cooperation to the conservation of electricity among each customer have
contributed to the improvement in the tight power supply-demand balance.
Amidst this backdrop, in principle, we have decided not to implement
further rolling blackouts.
However, we must sincerely ask for your continued cooperation in
conserving electricity consumption due to the possible increase in
demand caused by abrupt climate change or unexpected trouble in power
stations that are currently being restored. In case the electricity
supply-demand balance becomes tighter than expected, on the condition of
prior announcement, we may reluctantly implement the rolling blackouts.
We kindly ask for your cooperation.
Also, we will give our utmost efforts to maintain this policy of
avoiding further implementation on rolling blackouts in summer.
* Revised past progress
