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 then we updated the progress status of roadmap considering the
current situation, on July 19. Accomplishment of the Step1 target
"Radiation dose is in steady decline" has been confirmed. On November 17,
we updated the further progress.
By bringing the reactors and spent fuel pools to a stable cooling condition
and mitigating the release of radioactive materials, we will make every
effort to enable evacuees to return to their homes and for all citizens to
be able to secure a sound life.
Below is the status of TEPCO's major facilities.
* Underlined are updates from the previous press release.
[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)
* At 11:33 am on December 4, workers found that there was puddle water
inside the barrier around the evaporative condensation apparatus
(estimated volume of water was approx. 45 m3). At 11:52 am, we stopped
the apparatus, and at 12:14 pm, workers made visual inspection of the
apparatus and the leakage seemed to have stopped. After that, we
conducted investigation at 2:30 pm, and found a crack in the concrete
barrier, and water leaking from this crack to the gutter (surface dose
rate of leaked water: beta ray 110 mSv/h, gamma ray 1.8 mSv/h). We also
found water leaking from between the barrier and the base concrete. We
are considering measures to stop this leakage to outside of the barrier.
The water desalination apparatus (reverse osmosis membrane type) is
continuing operation. As we have sufficient volume of desalinated water,
there is no impact on the Reactor water injection. At 3:30 pm we
confirmed that the leakage had stopped by piling up sandbags between the
barrier and base concrete, and in the gutter. From 6:20 pm to 10:20 pm
we sent the leaked water remaining in the barrier to the waste water RO
supply tank with a water pump. Since the gutter led to the generally used
channel of the power plant, we have taken sea water from the channel
around the water desalinations (evaporative concentration apparatus) and
the south drain (drain for the generally used channel) and have conducted
a nuclide analysis. We concluded that the figures of the results of the
analysis were as the same or slightly higher than the usual results we
are announcing daily. On 5 December we again sampled the water of the
channel near the water desalination (evaporative concentration apparatus)
and the south drain (exit of the channel) and conducted a nuclide
analysis, and the results of the south drain showed the same level as the
results we are announcing daily.
* At 10:00 am on 5 December, we started transferring accumulated water in
the basement of unit 6 turbine building to the temporary tank.
* On 5 December we started increasing nitrogen injection to reactors of
Unit 1 and 3, from which we started on 30 November, due to stabilized
parameters of the facilities of the power plants such as the Reactor
Pressure Vessel and the Primary Containment Vessel.
· Unit 1:10:44 am, increased nitrogen injection from approx. 5m3/h to
10m3/h.
· Unit 3: 10:25 am, increased nitrogen injection from approx. 5m3/h to
10m3/h.
* At 10:31 am of 5 December, we stopped the transfer of accumulated water
from the basement of the turbine building of unit 3 to the Centralized
Radiation Waste Treatment Facility (Process Main Building).
* At 10:35 am of 5 December, we started dust sampling above the reactor
building of unit 3 with a large crane. At 12:05 pm we finished this.
· 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.
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Appendix: Past Progress (As of 3:00 pm, December 5, 2011) (PDF 374KB)
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB)
* Revised past progress