*Updates are underlined 

All 6 units of Fukushima Daiichi Nuclear Power Station have been shut down. 

Unit 1 (Shut down) 
-Explosive sound and white smoke were confirmed after the big quake
 occurred at 3:36 pm on March 12th. It was assumed to be hydrogen
 explosion.
-At approximately 2:30 am on March 23rd, seawater injection to the
 nuclear reactor through the feed water system was initiated.
-From 3:37 pm on March 25th, we started injecting freshwater.
-As it is suspected that hydrogen gas is accumulated inside reactor
 containment vessel, we commenced the valve opening operation concerning
 injection of nitrogen gas into the reactor container vessel at 10:30 pm
 April 6th and commenced injection at 1:31am April 7th. 

Unit 2(Shut down) 
-At approximately 6:00 am on March 15th, an abnormal noise began
 emanating from nearby Pressure Suppression Chamber and the pressure
 within the chamber decreased. 
-From 10:10 am on March 26th, we started injecting freshwater to the
 reactor and are now injecting fresh water by a motor driven pump
 powered by the off-site transmission line. 

Unit 3(Shut down) 
-Explosive sound and white smoke were confirmed at approximately 11:01am
 March 14th. It was assumed to be hydrogen explosion.
-From 6:02 pm on March 25th, we started injecting fresh water to the
 reactor and are now injecting fresh water by a motor driven pump
 powered by the off-site transmission line. 

Unit 4 (outage due to regular inspection) 
-At approximately 6:00 am on March 15th, we confirmed the explosive
 sound and the sustained damage around the 5th floor rooftop area of the
 Nuclear Reactor Building.
-At this moment, we do not consider any reactor coolant leakage inside
 the reactor happened. 

Unit 5 (outage due to regular inspection) 
-Sufficient level of reactor coolant to ensure safety is maintained.
-At 5:00 am, March 19th, we started the Residual Heat Removal System
 Pump (C) in order to cool the spent fuel pool.
-At 2:30 pm, March 20th, the reactor achieved reactor cold shutdown. At
 around 5:24 pm on March 23rd, when we switched the temporary Residual
 Heat Removal System Seawater Pump, it has stopped automatically. At
 around 4:14 pm, March 24th we replaced the pump, and restarted cooling
 of reactor at around 4:35 pm.
-At this moment, we do not consider any reactor coolant leakage inside
 the reactor happened. 

Unit 6 (outage due to regular inspection) 
-Sufficient level of reactor coolant to ensure safety is maintained.
-At 10:14 pm, March 19th, we started the Residual Heat Removal System
 Pump (B) of Unit 6 in order to cool the spent fuel pool.
-At 7:27 pm, March 20th, the reactor achieved reactor cold shutdown.
-In relation to the two seawater side pumps of the Residual Heat Removal
 System, we switched the power source from temporary to permanent at
 3:38 pm and 3:42 pm, Mar 25 respectively.
-At this moment, we do not consider any reactor coolant leakage inside
 the reactor happened. 

Operation for cooling the spent fuel pools 
-From 5:15 pm to 7:15 pm on April 10th, we conducted the spraying water to 
 Unit 3 by the concrete pumping vehicle. 
-We will conduct further water spray depending on the conditions of spent
 fuel pools, if needed. 

Others 
-We measured radioactive materials (iodine etc.) inside of the nuclear
 power station area (outdoor) by monitoring car and confirmed that
 radioactive materials level is getting higher than ordinary level. As
 listed below, we have determined that specific incidents stipulated in
 article 15, clause 1 of Act on Special Measures Concerning Nuclear
 Emergency Preparedness (Abnormal increase in radiation dose measured at
 site boundary) have occurred.
· Determined at 4:17 pm Mar 12th (Around Monitoring Post 4 )
· Determined at 8:56 am Mar 13th (Around Monitoring Post 4 )
· Determined at 2:15 pm Mar 13th (Around Monitoring Post 4 )
· Determined at 3:50 am Mar 14th (Around Monitoring Post 6 )
· Determined at 4:15 am Mar 14th (Around Monitoring Post 2 ) 
· Determined at 9:27 am Mar 14th (Around Monitoring Post 3 ) 
· Determined at 9:37 pm Mar 14th (Around main entrance ) 
· Determined at 6:51 am Mar 15th (Around main entrance ) 
· Determined at 8:11 am Mar 15th (Around main entrance ) 
· Determined at 4:17 pm Mar 15th (Around main entrance ) 
· Determined at 11:05 pm Mar 15th (Around main entrance )
· Determined at 8:58 am Mar 19th (Around MP5)
Hereafter, if the measured figure fluctuates and goes above and below
 500 micro Sv/h, we deem that as the continuous same event and will not
 regard that as a new specific incidents stipulated in article 15,
 clause 1 of the Act on Special Measures Concerning Nuclear Emergency
 Preparedness (Abnormal increase in radiation dose measured at site
 boundary) has occurred. In the interim, if we measure a manifestly
 abnormal figure and it is evident that the event is not the continuous
 same event, we will determine and notify.
-The national government has instructed evacuation for those local
 residents within 20km radius of the periphery and evacuation to inside
 for those residents from 20km to 30km radius of the periphery, because
 it is possible that radioactive materials are discharged.
-In total 12 fire engines are lent for the water spraying to the spent
 fuel pools and water injection to the nuclear reactors by various
 regional fire departments* as well as Tokyo Fire Department. Also,
 instruction regarding the setting and operation of large scale
 decontamination system was provided by Niigata City Fire Headquarter and
 Hamamatsu City Fire Headquarter.
*: Koriyama Fire Department, Iwaki Fire Brigade Headquarters, Fire
 Headquarters of Sukagawa District Wide Area Fire-fighting Association,
 Yonezawa City Fire Headquarters, Utsunomiya City Fire Headquarters,
 Fire Headquarters of Aizu-Wakamatsu wide area municipal association,
 Saitama City Fire Bureau, and Niigata City Fire Bureau.
-At around 11:35 am April 1st, a worker fell into the sea when he got
 into a barge of the U.S. Forces to repair a hose of the ship. The
 worker was rescued immediately, and was not injured and not
 contaminated. The worker will be checked using the whole-body counter
 to ensure his health.
-From April 2nd, we began to transfer the radioactive water we collected
 from the Central Environmental Facility to the Unit 4 turbine building.
 On April 4th, water level of the pit in the trench of Unit 3 increased by
 15cm from previous day. Pathway of water flow is unknown. We can not deny
 the possibility that water in the turbine building of Unit 4 flows into
 the trench of Unit 3. So, we stopped transferring water to the Unit 4
 turbine building to make assurance. Present water level of the pit in the
 trench of Unit 3 is not changed from the time we stopped transferring,
 and is being stable.
-As a countermeasure against outflow of radioactive water into the sea
 near the cooling water intake at Unit 2 of Fukushima Daiichi Nuclear
 Power Station, we have injected coagulant into the pit from April 5th and
 we have observed stoppage of spilling of water from the crack on the
 concrete lateral of the pit at 5:38 am, April 6th. We have put 6,000
 litters of coagulant into the breakage and surrounding ground after
 investigation of the leakage route by putting tracer into the 9 holes
 drilled around electrical conduit and the pit. On April 6th, we installed
 rubber boards and jigs as a countermeasure against the outflow from the
 intake. We will further investigate if there is any other leakage.
-From 7:03 pm, April 4, we started to discharge to the sea approximately
 ten thousand tons of the accumulated low level radioactive water in the
 Central Radioactive Waste Disposal Facility. We are confirming the amount 
 of discharged water. From 9:00 pm on April 4, we conducted discharging a
 total of 1,500 tons of the low level radioactive subsurface water stored
 in the sub drain pits of Unit 5 and 6. The amount of discharged water was
 approximately 1,323 tons.
-From 3:00 pm to 4:30 pm, April 5th, in order to prevent diffusion of
 radioactive contaminated water out from the site port facility to
 breakwater area which is south to the power station, we began repair of
 breakwater by founding the large sandbag around it to replace damaged
 steel water bar. We will continue the operation to prevent diffusion.
 From 8:45 am to 10:45 am, April 11, in order to prevent water containing 
 radioactive material from spilling from a plant’s port to the sea, we 
 conducted works to install 120m wide double silt fences around a 
 breakwater on the south of the station. 
-We will continue to take all measures to ensure the safety and to
 continue monitoring the surrounding environment around the Power Station.
-From 3:59 pm to 4:28 pm on April 10th, an unmanned helicopter was sent 
 over Unit 1 to 4 to grasp the situation of reactor building.