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Press Release (Mar 13,2011)
Plant Status of Fukushima Daini Nuclear Power Station (as of 2:00am March 13th)
There is no update from the release issued at 1:00 am

Unit 1 (shut down at 2:48pm on March 11th)
- Reactor is shut down and reactor water level is stable.
- Offsite power is available.
- At 8:19am, there was an alarm indicating that one of the control rods was 
  not properly inserted, however, at 10:43am the alarm was spontaneously 
  called off. Other control rods has been confirmed that they are fully 
  inserted (reactor is in subcritical status)
- Status of main steam isolation valve: closed
- Injection of water into the reactor is done by Make-up Water Condensate 
  System.
- At 6:08pm, we announced the increase in reactor containment vessel 
  pressure, assumed to be due to leakage of reactor coolant.  However, we 
  do not believe there is leakage of reactor coolant in the containment 
  vessel at this moment.
- At 5:22am, the temperature of the suppression chamber exceeded 100 
  degrees. As the reactor pressure suppression function was lost, at 5:22am, 
  it was determined that a specific incident stipulated in article 15, 
  clause 1 has occurred.
- We decided to prepare implementing measures to reduce the pressure of the 
  reactor containment vessel (partial discharge of air containing 
  radioactive materials) in order to fully secure safety. This preparation 
  work started at around 9:43am and finished at 6:00pm.
- Restoration work in reactor cooling function is in progress to achieve 
  reactor cold shutdown.

Unit 2 (shut down at 2:48pm on March 11th)
- Reactor is shut down and reactor water level is stable.
- Offsite power is available.
- Control rods are fully inserted (reactor is in subcritical status)
- Status of main steam isolation valve: closed
- Injection of water into the reactor is done by Make-up Water Condensate 
  System.
- We do not believe there is leakage of reactor coolant in the containment 
  vessel.
- At 5:32am, the temperature of the suppression chamber exceeded 100 
  degrees. As the reactor pressure suppression function was lost, at 5:32am, 
  it was determined that a specific incident stipulated in article 15, 
  clause 1 has occurred.
- We decided to prepare implementing measures to reduce the pressure of the 
  reactor containment vessel (partial discharge of air containing 
  radioactive materials) in order to fully secure safety. This preparation 
  work started at around 10:33am and finished at 10:58pm.
- Restoration work in reactor cooling function is in progress to achieve 
  reactor cold shutdown.


Unit 3 (shut down at 2:48pm on March 11th)
- Reactor is shut down and reactor water level is stable.
- Offsite power is available.
- Control rods are fully inserted (reactor is in subcritical status)
- Status of main steam isolation valve: closed
- We do not believe there is leakage of reactor coolant in the containment 
  vessel.
- We decided to prepare implementing measures to reduce the pressure of the 
  reactor containment vessel (partial discharge of air containing 
  radioactive materials) in order to fully secure safety. The preparation 
  woke started at around 12:08pm and finished at 12:13pm.
- Reactor cold shutdown at 12:15pm

Unit 4 (shut down at 2:48pm on March 11th)
- Reactor is shut down and reactor water level is stable.
- Offsite power is available.
- Control rods are fully inserted (reactor is in subcritical status)
- Status of main steam isolation valve: closed
- Injection of water into the reactor is done by Make-up Water Condensate 
  System.
- We do not believe there is leakage of reactor coolant in the containment 
  vessel.
- In order to cool down the reactor, injection of water into the reactor 
  had been done by the Reactor Core Isolation Cooling System, however, At 
  6:07am, the temperature of the suppression chamber exceeded 100 degrees. 
  As the reactor pressure suppression function was lost, at 6:07am, it was 
  determined that a specific incident stipulated in article 15, clause 1 
  has occurred.
- We decided to prepare implementing measures to reduce the pressure of the 
  reactor containment vessel (partial discharge of air containing 
  radioactive materials) in order to fully secure safety. The preparation 
  woke started at around 11:44am and finished at around 11:52am.
- Restoration work in reactor cooling function is in progress to achieve 
  reactor cold shutdown.

Indication from monitoring posts installed at the site boundary did not 
show any difference from ordinary level.
No radiation impact to the external environment has been confirmed. We will 
continue to monitor in detail the possibility of radioactive material being 
discharged from exhaust stack or discharge canal. 
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