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)
- From February 2, tendency of temperature rise at the bottom of PCV was
observed. Thus, from 0:19 am to 3:20 am on February 7 we injected boric
acid into the reactor as a safety countermeasures against the
re-criticality, and changed the amount of the core spray system
injection water from 3.7m3/h to 6.7m3/h at 4:24 am (the amount of the
continuing feed water system injection is 6.8m3/h). Currently, the
temperature is approx.66.7°C (as of 5 am on February 8). We will
monitor the progress continuously.
- At around 5:00 am on February 8, the alarm of "abnormally low suction
pressure of the high pressure RO pump" in the desalination apparatus
for the Unit 2 spent fuel pool went off, and the its operation was
automatically stopped. The interlock arrangement closed all the
isolation valves in the system, and the alternative cooling system for
the spent fuel pool continues its operation. Therefore, there is no
impact on the cooling. We also confirmed by the site investigation
that there was no leakage from the apparatus.
- At 10:00 am on February 8, we started to transfer the water accumulated
in the basement of Unit 6 Turbine Building to temporary tanks.
- As finding of accumulated water containing radioactive materials at
the trench between the Process Main Building and the Miscellaneous
Solid Waste Volume Reduction Treatment Building [High Temperature
Incinerator Building] (December 18, 2011), we started the inspection
of other trenches at the site on January 11.
As a result of the inspection made on February 7, the preliminary
results of the nuclide analysis and executed place are as follows:
· Inside the duct for power cables for the Unit 5 water intake
I-131: below the detectible limit, Cs-134: 1.4x10-1 Bq/ cm3,
Cs-137: 2.0x10-1 Bq/ cm3
· Inside the duct for Unit 5 seawater pipes
I-131: below the detectible limit, Cs-134: 8.2x10-2 Bq/ cm3,
Cs-137: 1.1x10-1 Bq/ cm3
· Inside duct for Unit 5 main transformer cables
I-131: below the detectible limit, Cs-134: 7.3x10-2 Bq/ cm3,
Cs-137: 1.3x10-1 Bq/ cm3
· Inside duct for Unit 5 start-up transformer cables
I-131: below the detectible limit, Cs-134: 2.0x10-1 Bq/ cm3,
Cs-137: 2.9x10-1 Bq/ cm3
· 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 10:00 am, February 8, 2012) (PDF 407KB)
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB)
* Revised past progress