On March 11 2011, turbines and reactors of Fukushima Daini Nuclear Power 
Station Units 1 to 4 (Boiling Water Reactors, rated output 1,100 
Megawatts) that we had been constantly operating at rated thermal output 
were automatically shut down at 2:48 pm due to the 
Tohoku-Chihou-Taiheiyou-Oki Earthquake (previously announced on March 11).

At 7:15 am on March 15, the reactor of Unit 4 achieved cold shutdown. As a 
result, all reactors of Units 1 to 4 at Fukushima Daini Nuclear Power 
Station achieved cold shutdown (previously announced on March 15).

As of 3:00 pm on August 29, the reactors of Unit 1 to 4 are in cold 
shutdown (please refer to the appendix). We will continue to make our 
endeavors to further stabilize each plant of cold shutdown.

 <Underlined are new matters> 
 ○ Stoppage of a motor for HPCS auxiliaries cooling system seawater pump, 
 Unit 2 
 Today, in order to adjust the water quality in HPCS auxiliaries cooling 
 system, Unit 2, we were operating HPCS auxiliaries cooling system and HPCS 
 auxiliaries cooling seawater system. At 12:59 pm, a motor for HPCS 
 auxiliaries cooling system seawater pump stopped. 
 We tested the insulation resistance at the work site and found 
 deterioration. As such, at 2:10 p,. we determined that this was a 
 malfunction of important facilities for plant safety. 
 We will investigate the root cause. 
 There is no external radioactivity impact from this incident. 
 As Unit 2 is under cold shutdown and the necessary water injection 
 function is secured, Unit 2 is satisfying the safety administration 
 requirement set out in the safety regulation without this motor.

 Appendix: Outline drawing of High Pressure Core Spray System

 *1 HPCS auxiliaries cooling system 
 This is one of the emergency reactor cooling systems. This cools the 
 facility that injects water to the Reactor if the Reactor water level goes 
 down abnormally,

 *2 HPCS auxiliaries cooling seawater system 
 This cools HPCS auxiliaries cooling system by seawater heat exchanger.

 ○ Status of restoration of RHRS (A), Unit 3 
 We have been restoring RHRS (A), Unit 3 that stopped due to the impact by 
 the tsunami. At 11:46 am on August 30, we finished the test-run and put it 
 in stand-by mode

 ○Poor physical condition of a site worker of co-operating company
 On August 29, in the heater building* of unit 4, condition of a site 
 worker of a co-operating company who was in charge of rerouting the 
 temporary cable got worse. At around 10:50 am, as heat stroke was 
 suspected, we treated the patient with drip infusion and at 11:26 am, we 
 transferred to J-Village by our ambulance. At 11:58 am, the patient was 
 transferred to Iwaki Kyoritsu Hospital by ambulance. No radioactive 
 material attached to the body was found.
                                                 (announced on August 29) 

 At 4:00 pm on the same date, the patient was diagnosed as having heat 
 stroke (limited to indoor work on light duty for a day or two). 
 We keep on improving the work environment. We also encourage prevention 
 measures for heat stroke including co-operating companies.

 * Heat exchanger building
 The building in which the heat exchanger is installed. The heat exchanger 
 is the facility for carrying out heat exchange of the cooling water of the 
 facility used in reactor containment vessel, turbine building and 
 centralized waste treatment facility. (Non-Controlled Area) 

Appendix: Outline drawing of High Pressure Core Spray System (PDF 14.3KB) 
Appendix: TEPCO Plant Status of Fukushima Daini Nuclear Power Station 
                                                         (PDF 15.4KB)