Due to the Tsunami generated by Tohoku-Chihou-Taiheiyou-Oki Earthquake
which occurred on March 11th 2011, TEPCO's facilities including our
nuclear power stations have been severely damaged, released radioactive
materials. We deeply apologize for the anxiety and inconvenience caused to
local residents near the site, residents of Fukushima prefecture and
throughout the entire society.
Based on the instruction document on emergency countermeasures for safety
at Fukushima Daini Nuclear Power Station received from the Minister of
Economy, Trade and Industry on 21st April, we have summarized
implementation status of emergency countermeasures for safety at Fukushima
Daini Nuclear Power Station to prevent damages of reactor core and spent
fuel, suppress discharge of radioactive materials and restore cooling
function of reactor facility, even if three functions such as function of
all facilities that supplies AC power, function of all facilities that
cools reactor facility and function of all facilities that cools spent
fuel pool by seawater are lost by tsunami and to maintain reactor cold
shutdown, and reported to the Minister of Economy, Trade and Industry
today.
[1. Implementation of the emergency countermeasures for safety]
I. Based on the accident of Fukushima Daiichi Nuclear Power Station, we
have drawn up the response procedure in case that the above mentioned
three functions were lost.
(1)Securing of power source in case of lost of all AC power supply
(2)Enhancement of water injection and cooling functions of the reactor
(3)Securing of source of fresh water
(4)Securing of decompression function of Primary Containment Vessel
(5)Enhancement of water injection and cooling functions of spent fuel pool
(6)Enhancement of heat removal function of reactor and spent fuel pool
II. We have implemented following emergency countermeasures for safety to
prevent damages of reactor core and spent fuel, suppress discharge of
radioactive materials and restore cooling function of reactor facility
even if three functions are lost by tsunami, by 19th May 2011.
(1)Implementation of emergency inspection
-Implementation of visual observation and function check of necessary
equipments and facilities in emergencies
(2)Implementation of review and training of emergency response plan
-Preparation of response plan (manual) in emergencies
-Implementation of response training to be prepared for emergencies
(3)Securing of power source in emergencies
-Drawing up of procedure to supply power to motor driven pump for water
injection to the reactor in case of lost of all AC power supply, and
deployment of necessary power-supply car and/or equipments
(4)Securing of definitive heat removal function in emergencies
-Drawing up of procedure of alternative water injection to maintain
water injection to the reactor, and deployment of necessary equipments
-Drawing up of procedure of securing of water source to prevent
exhaustion of water source for alternative water injection (Condensate
Storage Tank) and procedure of securing of water source by
fire-extinguishing vehicle, etc.
-Drawing up of procedure to secure decompression function of Primary
Containment Vessel in case of lost of all AC power supply
(5)Securing of cooling of spent fuel pool in emergencies
-Drawing up of procedure of alternative water injection to maintain
water injection to spent fuel pool, and deployment of necessary
equipments
(6)Implementation of immediate countermeasures taken in consideration of
configuration of power station
-Implementation of measures to prevent building in which facilities
important to safety are installed from flood such as banking and sandbag
-Deployment of heavy machineries to secure accessibility of roads in
power station (debris removal)
[2. Measures to be taken in the future]
We will implement following measures to maintain reactor cold shutdown
with certainty.
I. Making building in which facilities important to safety are installed
watertight
We will close equipment hatch and/or doorway and/or make them
watertight in order to prevent facilities important to safety from
being submerged.
II. Deployment of large power-supply facility
We will deploy large power-supply facility considering reliability of
power supply to facility necessary for securing of cooling function of
reactor and spent fuel pool.
III. Others
We will strengthen environmental monitoring facility and communication
facility to make assurance doubly sure on information gathering and
communication in emergencies.
In addition to above mentioned measures, from a viewpoint of further risk
mitigation, we will consider necessity of implementation on expansion of
banking, additional installation of fresh water source, installation of
alternative cooling source and supplement of emergency power panel for
large power-supply facility.
And hereafter, , we will take necessary measures immediately if any issue
to be reflected to Fukushima Daini Nuclear Power Station is verified
through analysis and/or evaluation of the accident cause.
At Fukushima Daini Nuclear Power Station, all the reactors have been in
cold shutdown since 15th May 2011, we continue to make our endeavors to
improve reliability of cold shutdown of plants.
Attachment: Outline of emergency countermeasures for safety at Fukushima
Daini Nuclear Power Station
Reference: Implementation status report on emergency countermeasures for
safety at Fukushima Daini Nuclear Power Station
Appendix: Emergency Countermeasures for Safety at Fukushima Daini Nuclear
Power Station (Summary) (PDF 94.0KB)
Reference: Emergency Countermeasures for Safety at Fukushima Daini Nuclear
Power Station (report of the implementation status)
No.1, No.2, No.3, No.4, No.5
* The attachment is available only in Japanese version.
* Instruction Document
"Order to conduct enforcement of emergency countermeasures for safety at
Fukushima Daini Nuclear Power Station (Order)"
20th Release of April 20th, 2011
Nuclear and Industrial Safety Agency
Regarding the emergency countermeasures for safety, Nuclear and Industrial
Safety Agency (NISA) have ordered enforcement of emergency countermeasures
for safety to the Nuclear Power Station other than Fukushima Daiich
Nuclear Power Station and Fukushima Daini Nuclear Power Station. The Order
is based on the "order to conduct enforcement of emergency countermeasures
for safety at Fukushima Daiich Nuclear Power Station and Fukushima Daini
Nuclear Power Station" (dated March 28th, 2011; 7th Release of March 28th,
2011 NISA).
Based on the situation of cold shutdown at Fukushima Daini Nuclear Power
Station, we will give an order to the site to conduct enforcement of
emergency countermeasures for safety.
Enforcement of emergency countermeasures for safety is intended to resume
cooling feature at reactor in the situation of power outage due to Tsunami,
with limiting released radioactive materials.
The proceeding of this enforcement go through the following steps, TEPCO
conduct enforcement of emergency countermeasures and NISA confirm by
inspection to prevent core damage caused by loss of power due to Tsunami.
This will lead to prevent nuclear disaster.
Therefore, we demand TEPCO to conduct enforcement of emergency
countermeasures below immediately, following the regulations dated March
30, 2011 laying down safety regulation for maintenance regarding
installation and operation of commercial power reactor to maintain Reactor
Facility in cases where Tsunami occurs.
In the meantime, NISA ask TEPCO to report implementation status to keep
reactor cold shutdown by May 20th, 2011.
Note:
TEPCO should take following emergency countermeasures for safety to
prevent damages of reactor core and spent fuel, suppress discharge of
radioactive materials and restore cooling function of reactor facility,
even if three functions such as function of all facilities that supplies
AC power, function of all facilities that cools reactor facility and
function of all facilities that cools spent fuel pool by seawater are lost
by tsunami.
1.Implementation of emergency inspection
Implementation of emergency inspection of equipments and facilities for
emergency response caused by tsunami
2.Implementation of review and training on emergency response plan
Implementation of review and training on emergency response plan that
assumes losses of function of all facilities that supplies AC power,
function of all facilities that cools reactor facility and function of
all facilities that cools spent fuel pool by seawater
3.Securing of power source in emergencies
Securing of backup power source which can supply necessary power agilely
in case any power sources in Fukushima Daini Nuclear Power Station are
lost and any emergency power sources cannot be secured
4.Securing of definitive heat removal function in emergencies
Preparation of restoration countermeasures of agile heat removal
function that assumes loss of seawater system facility or its function
5.Securing of cooling of spent fuel pool in emergencies
Implementation of countermeasures to supply cooling water agilely in
case of stoppage of cooling of spent fuel pool and normal water supply
to spent fuel pool in Fukushima Daini Nuclear Power Station
6.Implementation of immediate countermeasures taken in consideration of
the configuration of Fukushima Daini Nuclear Power Station