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)
- To improve reliability of water injection to a reactor, line connecting
to injection piping in water injection line of reactor injection pump on
the hill of Unit 1 had replaced with polyethylene piping. So at 10:35 am,
we changed injection route from injection pump in turbine building to
reactor injection pump on the hill.
- Due to replacement to polyethylene piping was done, the amount of water
injected has been changed gradually. At 10:55 am in February 2, we
adjusted water injection volume to the reactor of Unit 2 through the
feed water system from approx. 3.9 m3/h to approx. 3.0 m3/h, and the
volume from the reactor core spray system from approx. 5.1 m3/h to
approx. 6.0m3/h. At 11:10 am we adjusted water injection volume to the
reactor of Unit 3 through the feed water system from approx. 3.8 m3/h to
approx. 3.0 m3/h, and the volume from the reactor core spray system from
approx. 5.2 m3/h to approx. 6.0m3/h.
- At 8:36 am on February 2, second Cesium adsorption apparatus was stopped
to backwash the filter because there was a gradual downward tendency. At
11:12 am of the same day, we restarted the apparatus and at 11:15 am,
reached to steady volume of water flow (36m3/h)
- At approx. 10:30 pm on January 31, we found that the water was leaking
from the indicator test line in the rack instruments for jet pumps were
stored. At 10:43 pm, the leakage was stopped after the main valve
leading to the rack was closed. Debris were scattered around on the
floor, and the volume of leaked water was approx. 6 litters as far as we
could confirmed. Please note that it didn't run off outside of the
reactor building. We sampled the water in the test line and measured the
radioactivity concentration. From the results, we estimated the water
leaked from the reactor well (analysis result: 35.5 Bq/cm3). We
estimated the amount of water leaked is 8,500 litters by measuring
decrease in water level of skimmer surge tank
- We confirmed the decrease in volume of injecting water to reactors, so
at 3:15 pm on February 2, we adjusted volume of water injection in each
reactor as follows:
· Unit 1:Feed water system from approx. 4.2 m3/h to approx. 4.5 m3/h,
Reactor core spray system from approx. 1.5 m3/h to approx. 2.0m3/h.
· Unit 2:Feed water system from approx. 2.5 m3/h to approx. 3.0 m3/h,
Reactor core spray system from approx. 5.2 m3/h to approx. 5.5m3/h.
· Unit 3:Feed water system from approx. 2.5 m3/h to approx. 3.0 m3/h,
Reactor core spray system from approx. 5.2 m3/h to approx. 5.5m3/h.
- At 3:20 pm on February 2, a Tepco worker on patrolling at reactor
building of Unit 4 found the very small flow(just as much as lead in
pencil) of water in north west corner in first floor of the reactor
building. This leakage seemed to be occurred at make up water system in
reactor well because the valve at reactor well is closed totally and so
the leakage seemed not be from reactor well. We are investigating
further. No water leakage to out side of reactor building.
- Newly found water leakage caused by congelation after the latest report
(at 10:00 am February 1) are as follows:
· two valves in discharged water piping at water treatment building where
filtrate water purified(Found at 3:30 pm on February 2 )
· (Filtrate water(water taken from dam): approx. 0.5 litters)
- At 10:00 am on February 2, we started transferring the water accumulated
in the basemen of Turbine Building at Unit 6 to temporary tanks. At 4:00
pm of the same day, we stopped transferring.
· Fukushima Daini Nuclear Power Station:
(Units 1 to 4: shutdown due to the earthquake)
- To switch from the temporary power board to the regular power board with
finishing installation of the circuit breaker supplying power for Unit 3,
the Fuel Pool Cooling and Filtering System was suspended from 1:36 pm to
2:14 pm on February 2, and the Clean Up Water System was suspended from
1:40 pm to 2:10 pm(Temperature of the spent fuel pool when
stopped:25.4°C, Temperature of the spent fuel pool when restarted:25.4°C)
· 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 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 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.
* Correction of Description in [Impacts on Power Supply and Demand Balance]
We described,"there will be some minus factors such as the regular
inspection of Unit 5 at Kashiwazaki-Kariwa Nuclear Power Station" in the
previous press release. However, because Unit 5 of Kashiwazaki-Kariwa
Nuclear Power Station has already conducted a regular inspection since
January 25, we revise the previous sentence to "there are some minus
factors such as the regular inspection of Unit 5 at Kashiwazaki-Kariwa
Nuclear Power Station". We would like to apologize for the correction
(February 8, 2012).
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Appendix: Past Progress (As of 4:00 pm, February 2, 2012) (PDF 472KB)
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB)
* Revised past progress