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)
- 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).
During our observing the plant parameter after the decreasing the flow
rate of feed water system on February 22, we found that one thermometer
in the lower part of the RPV indicated the different movement from
others. From 0:21 pm to 2:48 pm on February 23, we investigated the
concerned device. As the result of the measurement of DC resistance,
we found no breaking wire and availability of the thermometer. But we
confirmed that the DC resistance of it became higher than the previous
measurement test data. We will evaluate the soundness of the concerned
device and examine correspondence in future. We make sure no re-
criticality state because there were no significant changes at the
monitoring post and as the result of the sampling for the Gas Control
System of the Unit 2, we confirmed that the concentration of Xe-135
was below the detectible limit.
· At 5:00 am on March 1, the temperature of the lower part of the RPV
(top of the lower head 135°) : approx. 44.3 °C
· At 5:00 am on March 1, the temperature of the lower part of the RPV
(top of the lower head 270°) : approx. 41.0 °C (reference)
- At 8:17 am on February 29, we started transferring the water
accumulated in the outlet pit of the circular water pump in the Unit 3
pump room to the basement of Unit 2 Turbine Building, since it was
found by the surveys on trenches on Jan 19 that the high level
radioactive waste water was accumulated in the pit. At 3:40 pm on the
same day, we stopped transferring. At 8:26 am on March 1, we resumed
transferring.
- At 10:00 am on February 29, we started transferring the water
accumulated in the basement of Unit 6 Turbine Building to temporary
tanks. At 4:00 pm on the same day, we stopped transferring. At 10:00
am on March 1, we resumed transferring.
- In order to conduct the work to improve the reliability of water
treatment facilities, we are planning to stop water treatment
facilities one after another. At 8:45 am on March 1, we stopped the
cesium adsorption apparatus. It will be out of service until March 15.
We calculated the estimated water level increase at each building due
to the stop o the facilities, and confirmed that the water levels in
each building will be maintained within the limits. We also have
sufficient volume of treated water, therefore there will be no impact
on the water injection to the reactors.
· 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 on March 1, 2012) (PDF 531KB)
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB)
* Revised past progress
