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.
* 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 around 3:43pm on February 20, we observed that an error message was
displayed in the screen of the noble gas monitoring system B of the
gas management system of the primary containment vessel of Unit 2.
Accordingly, the density of the noble gas in the system B was no longer
observable at the Central Monitoring Station in the Main Anti-Earthquake
Building. Observation was continued using the system A, one of the two
systems A and B, which did not display any error message. However, at
around 5:20pm on February 21, the same error message was displayed in
the screen of system A. As a result, the density of the noble gas was
no longer observable at Central Monitoring Station in the Main Anti-
Earthquake Building. After investigating the situation at the site, we
detected a failure of the transmission system which connects the site
and the Central Monitoring Station in the Main Anti-Earthquake Building.
However, there is no difficulty in confirming the subcriticality, as
both the system A and B can be observed from the monitor at the site
and, at the moment, the monitor screen can be remotely watched from
the Central Monitoring Station in the Main Anti-Earthquake Building.
The cause of the failure is now being investigated for restoration.
The gas management system of the primary containment vessel of Unit 2
itself is in normal operation.
- At 10:00 am on February 21, we started transfer of the accumulated
water at the Unit 6 Turbine Building basement to the temporary tank.
At 4:00 pm on the same day, we stopped the transfer.
- According to the investigation on trenches on January 19, 2012, high
density contaminated water inside was found inside circulating water
pump discharge valve pit of Unit 2 water pump room. Therefore, on
February 20, we started transfer of the accumulated water from the pit
to the basement of Unit 2 Turbine Building. At 9:50 am on February 21,
we started the transfer. At 3:34 pm on the same day, we stopped the
transfer. At 9:43 am on February 22, we restarted the transfer.
- At 9:40 am on February 21, at the centralized radiation waste treatment
facility, we started transfer of accumulated water from site banker to
process main building. We stopped the transfer at 3:45 pm on the same
day.
- With regard to the water injection volume for Unit 2 reactor, which
was increased with temperature figure raising, we have gradually
adjusted it to the original volume before temperature increasing (Feed
water system: approx. 3.0m3/h, core spray system: approx. 6.0m3/h). As
no abnormality has been observed in the variation of the plant
parameter after the change in the flow rate on February 20, at 7:44 pm
on February 21, we changed the water injection volume from feed water
system from approx.5.5m3/h to approx. 4.0m3/h (The water injection
level from core spray system is continuing at approx. 6.0m3/h).
- At 9:30 am on February 20, regarding the accumulated water at the
basement of Unit 3 Turbine Building, transfer to Centralized Waste
Treatment Facility (Miscellaneous Solid Waste Volume Reduction
Treatment Building [High Temperature Incinerator Building]) started.
At 9:52 am on February 22, we stopped the transfer.
· 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.
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Appendix: Past Progress (As of 10:00 am on February 22, 2012) (PDF 443KB)
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB)
* Revised past progress