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, 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, 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.
* Updates since the previous press release 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)
* Since December 22, the atmospheric temperatures at point C of Unit 1
Primary Containment Vessel (PCV) monitored by the Containment Atmospheric
Monitoring System had risen (the atmospheric temperature of the PCV on
December 22 was approx. 38°C, at 7 pm on December 27 was approx. 49°C).
The other temperatures had not risen, so we conducted a survey checking
the reliability of the meters from 9 am to 10 am on December 28, and we
confirmed that there are no problems. From 11:00am to 12:15pm on the
same day, we adjusted the volume of Nitrogen injection, from approx. 8
Nm3/h to approx.18 Nm3/h, and emission of the gas management system, from
approx. 23 Nm3/h to approx.30 Nm3/h, in order to identify the cause by
monitoring the system with the same injection and emission volume as
before December 22. The temperature went up to approx. 54.6°C at 6 pm on
December 28 and fell to approx. 48.4°C at 11 am on December 30.
Temperatures at other two points also indicated slight increases but are
currently in the stable status.
Point D: (Maximum) approx. 35.8°C at 5:00 pm on December 29 →
approx. 34.5°C at 11:00 am on December 30.
Point E: (Maximum) approx. 40.0°C at 5:00 pm on December 29 →
approx. 38.4°C at 11:00 am on December 30.
We will continuously conduct the survey for the cause of temperature
increase and surveillance of the plant.
* At 10:27 am on December 30, since inlet pressure of the primary
circulation pump was decreasing in the alternative cooling system of the
spent fuel pool of Unit 3, cooling of the spent fuel pool was temporary
stopped by shutting down the pump, in order to flush the inlet strainer
of the primary circulation pump. (Temperature of the spent fuel pool was
approx. 13.0°C at the time of shutdown.) Flushing was conducted
subsequently, and since inlet pressure of the pump was recovered, cooling
of the spent fuel pool resumed by restarting the pump, at 1:42 pm of the
same day. (Temperature of the spent fuel pool was approx. 13.1°C at the
time of restart.)
* At 2:37 pm on December 30, we started the transfer of the accumulated
water from the basement of turbine building of Unit 3 to the Centralized
Radiation Waste Treatment Facility (the Miscellaneous Solid Waste Volume
Reduction Treatment Building [High Temperature Incinerator Building] and
the Process Main Building).
· Fukushima Daini Nuclear Power Station:
Units 1 to 4: shutdown due to the earthquake
· Kashiwazaki Kariwa Nuclear Power Station: Units 5, 6: under normal
operation
(Units 1 to 4 and 7: outage due to regular inspections)
[Thermal Power Station]
· Power supply has returned to normal and facilities damaged by the
earthquake are now being handled in a timely manner.
[Hydro Power Station]
· Power supply has returned to normal and facilities damaged by the
earthquake are now being handled in a timely manner.
[Impacts on Transmission Facilities]
· Power supply has returned to normal and facilities damaged by the
earthquake are now being handled in a timely manner.
[Impacts on Power Supply and Demand Balance]
This winter, there will be some minus factors such as the regular
inspection of Unit 5 at Kashiwazaki-Kariwa Nuclear Power Station. On the
other hand, there will be several plus factors such as the recovery of the
common thermal power stations which suffered the earthquake. As a result,
we expect to secure 54.9 GW (at the end of December), 54.6 GW (at the end
of January), 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 - 3.4 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 3:00 pm, December 30, 2011) (PDF 256KB)
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB)
* Revised past progress