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Press Release (Feb 12,2012)
Status of TEPCO's Facilities and its services after the Tohoku-Chihou-Taiheiyou-Oki Earthquake (as of 3:30 pm, February 12)
Due to the Tohoku-Chihou-Taiheiyou-Oki Earthquake which ocurred 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)
  - From February 2, tendency of temperature rise at the bottom of PCV has 
    been observed. While we increased the water injection to the reactor 
    and have been monitoring the trend of the temperature, it is still high 
    around 70°C. On February 6, we sampled the gas by the gas control 
    system of Unit 2 Primary Containment Vessel. The density of Xenon 135 
    at the entrance of the system was below the detection limit. Since it 
    is below 1Bq/cm3, which is the threshold for judging re-criticality, 
    we confirmed the reactor didn't go re-critical, however, in order to 
    avoid the possibility of going re-critical being increased as a result 
    of the water density in the reactor being increased by rapid injection 
    of cold water is increased, we injected the boric acid into the reactor 
    as a safety countermeasure from 0:19 am to 3:20 am on February 7, which 
    was before we increased the volume of the water injection. At 4:24 am 
    on the same day, we changed the amount of the core spray system 
    injection water from 3.7m3/h to 6.7m3/h (the amount of the continuing 
    feed water system injection is 6.8m3/h). After that, we continued to 
    monitor the temperature tendency, finding that the temperature slowly 
    increased. At 10:45 pm on February 11, we changed the water injection 
    amount through the reactor feed water system from approx. 6.8m3/h to 
    7.8m3/h (the water injection amount through the core spray system is 
    kept at approx. 6.8m3/h). On February 12, we conducted a sampling of 
    gas in the gas management system in the Primary Containment Vessel of 
    Unit 2 and the result is that around the entry of the system, Xe-135 
    was below the detection limit (9.5 x 10-2 Bq/cm3). As it is below 1 
    Bq/cm3, the criterion to judge re-criticality, we have confirmed that 
    it has not reached re-criticality. After that, we continued monitoring 
    the tendency of the temperature fluctuation, and then found that the 
    temperature at the bottom of PCV tended to be still high. Therefore, 
    in order to avoid a chance of the re-criticality due to the increase 
    of water density in the PCV by sudden cold water injection, from 11:38 
    am to 1:50 pm on February 12, before starting water flow rate change, 
    we injected boric acid into the reactor for the safety measures. Then, 
    from 2:10 pm on the same day, although we increased the water injection 
    rate, the indicated temperature of the bottom of PCV was confirmed to 
    be 82°C beyond 80 °C so that, At 2:20 pm, we judged that it was not 
    satisfied "the temperature is below 80 °C at the bottom of PCV *1", 
    which is stipulated in "the Reactor Facility safety Regulation *2" as 
    one of the "Conditions of operation". Thereafter, we continued the 
    increased water injection, and changed the water flow rate from approx. 
    7.2m3/h to 7.5m3/h through the reactor feed water system, and from 
    approx. 6.9m3/h to 9.9m3/h through the core spray system. Currently, 
    the temperature is approx. 79.2 °C as of 3pm on February 12 for 
    reference. We continue to monitor the tendency of the temperature.
    *1) Reactor Facility Safety Regulation provides necessary conditions 
        such as the numbers of the permitted machines etc. or criteria of 
        temperatures and pressures for securing multiple safety function 
        for operating reactors and for keeping nuclear power stations 
        stable and these are treated as conditions for operation. When 
        there happen some malfunctions of equipment provided in the 
        regulation and a nuclear power station can not clear the conditions 
        temporarily, operators have to take required countermeasures.
    *2) Based on the management of facilities stipulated at the Article 12 
        "Mid-term safety securing" of Act of the Regulation of Nuclear 
        Source Material, Nuclear Fuel Material and Reactors, it provides 
        "Operational Limit" and "measures required in the case that does 
        not satisfy the Operational Limit", it is required to respond based 
        on the measures required in the case that does not satisfy the 
        Operational Limit. In our case, in order to implement the 
        preservation work, it was shifted to outside of operational limit 
        condition as planned (from 1:55 pm on February 12), we change the 
        water injection amount into the reactor of Unit 2. At 2:20 pm, we 
        judged that it was not satisfied "the temperature is below 80 °C 
        at the bottom of PCV ", which is stipulated in "the Reactor 
        Facility safety Regulation" as one of the "Conditions of operation". 
        as the indicated temperature was 82 °C beyond 80 °C. We continue 
        to change the water injection amount accordingly.
· 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 3:30 pm on February 12, 2012) (PDF 425KB) 
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB) 

* Revised past progress 
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