Due to the Tohoku-Chihou-Taiheiyou-Oki Earthquake which occurred on March
11, 2011, TEPCO's facilities including our nuclear power stations have
been severely damaged. We deeply apologize for the anxiety and
inconvenience caused.
With regard to the accident at Fukushima Daiichi Nuclear Power Station, on
April 17, 2011, we have compiled the roadmap towards restoration from the
accident and on July 19 we accomplished the Step1 target "Radiation dose
is in steady decline". Then on December 16 we confirmed the accomplishment
of the Step 2 target "Release of radioactive materials is under control
and radiation doses are being significantly held down".
In addition, on December 21, 2011, we have compiled the "Mid-to-long-Term
Roadmap toward the Decommissioning of Fukushima Daiichi Nuclear Power
Units 1-4, TEPCO".
In addition to the maintenance of the plant's stable condition, we will
implement Mid-to-Long Term countermeasures towards the decommissioning of
Fukushima Daiichi Nuclear Power Units 1-4 to enable evacuees to return to
their homes as soon as possible and reduce the anxiety of the people in
Fukushima and the whole nation as soon as possible.
Below is the status of TEPCO's major facilities.
*The updates are underlined
[Nuclear Power Station]
· Fukushima Daiichi Nuclear Power Station: Unit 1 to 3: shut down due to
the earthquake:
(Units 4 to 6: outage due to regular inspections before the earthquake)
- At 10:00 am on February 18, regarding the accumulated water at the
basement of Unit 6 Turbine Building, transfer to the temporary tank
started. At 4:00 pm on the same day, the transfer came to a stop.
- At 7:05 am on February 18, within the Unit 2 SFP alternative cooling
system, an alarm sounded showing that the water flow difference was
large at the gateway of primary system pump and the system automatically
shutdown. After that, we confirmed there was no abnormalities such as
leakage at the location where the primary system shutdown. However, as
temperature decreased in the outer temperature, the secondary system
cooing water temperature also decreased and it may freeze, with a view
toward facility protection, we resumed it so as to prevent the primary
and secondary system from freezing. Upon resumption, we made sure there
was no leakage or parameter abnormalities, and by releasing the alarm at
11:54 pm on February 18, we activated the system. Since we do not see
any abnormalities, operation of the system is still continuing.
- At around 5:00 am on February 8, the alarm which indicates the
abnormally low suction pressure of the high pressure RO pump in the
desalination apparatus of Unit 2 spent fuel pool went off and the device
was automatically shut down. The interlock closed all the isolation
valves in the system and the alternative cooling system for the spent
fuel pool was activated so there was no interruption to the cooling
process. We also confirmed that there was no leakage from the apparatus.
Due to the investigation afterwards we assumed that an instantaneous
fall in the pressure had caused this shut down. After we confirmed that
certain measures have been taken to prevent this we restarted the
operation at 3:20 pm of February 18, but at 7:05 pm on the same day
another alarm which indicates that the difference of the water flow
between the entrance and the exit of the primary line pump of the
substitutive cooling system of the spent fuel pool of unit 2 went off
and the system shut had down automatically. Due to this the desalting
facility has also shut down, but later we reactivated the system and at
10:44 on February 19 we restarted the operation of the desalting facility.
- At 9:57 am on February 19, with regard to the water injection volume for
Unit 3 reactor, as there was latitude of the current water injection
volume against the equivalent decay heat, for the purpose of reducing
the transfer and treatment works of the increased accumulated water due
to the increase in water injection to Unit 2, we changed the water
injection volume by feed water system from approx. 3.0 m3/h to 2.0 m3/h.
(The water injection level from reactor core system is continuing at 5.0
m3/h.)
- At 10:00 am on February 19, as for the accumulated water at the Unit 6
Turbine Building basement, transfer to the temporary tank commenced.
· Fukushima Daini Nuclear Power Station:
(Units 1 to 4: shutdown due to the earthquake)
· Kashiwazaki Kariwa Nuclear Power Station: Units 6: under normal
operation
(Units 1 to 5 and 7: outage due to regular inspections)
[Thermal Power Station]
· Power supply has returned to normal and the facilities damaged by the
earthquake are now being handled in a timely manner.
[Hydro Power Station]
· Power supply has returned to normal and the facilities damaged by the
earthquake are now being handled in a timely manner.
[Impacts on Transmission Facilities]
· Power supply has returned to normal and the facilities damaged by the
earthquake are now being handled in a timely manner.
[Impacts on Power Supply and Demand Balance]
This winter, there are some minus factors such as the regular inspection
of Unit 5 at Kashiwazaki-Kariwa Nuclear Power Station. On the other hand,
there are several plus factors such as the recovery of the common thermal
power stations which suffered the earthquake. As a result, we expect to
secure 53.7 GW (at the end of February) supply power.
Compared to the maximum demand in the last winter, which is 51.5 GW, we
will have 2.2 GW generation reserve margin.
We expect to maintain stable power supply this winter. However, as there
remains possibilities of unplanned shutdowns at our power stations and
growth in the demand according to the rapid change in the temperature, we
would like to ask your reasonable effort to save electricity.
We will continue to make our efforts to maintain stable operation and
maintenance of the power facilities in order to "prevent in principle" the
planned blackouts and secure power supply.
Appendix: Past Progress (As of 11:00 am on February 19, 2012) (PDF 721KB)
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB)
* Revised past progress
