Press Release (Apr 09,2011)Plant Status of Fukushima Daiichi Nuclear Power Station (as of 1:30 pm, A

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    Posted April 9th, 2011 by TEPCO
    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 and are now injecting fresh water by a motor driven pump powered by the off-site transmission line.-As it is suspected that hydrogen gas is accumulated inside primary 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 primary containment vessel 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 primary containment vessel 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 5:06 pm to 8:00 pm on April 8th, spraying water to Unit 3 by

    concrete pump vehicle was conducted.-We will conduct further water spray depending on the conditions of spent fuel pools, if needed.Draining water from underground floor of turbine buildings-At 1:55 pm April 3rd, in Unit 1, water transfer from the condenser to the condensate storage tank was commenced. -From 5:10 pm, April 2ndto 1:10 pm, April 9th, in Unit 2, water in the condenser was transferred to the condensate storage tank.-On April 7th, we knocked holes in the external walls (including louvers)

    of turbine buildings at Units 2 to 4 in order to get the draining hoses

    through to the Central Environmental Facility.



    The injured

    -At 9:19 am, April 9th, one contractor with a full-face mask who were

    working on cables in the water treatment building felt sick and got

    injured by stepping into the manhole whose cover was dislocated. This

    person was transported to the hospital.

    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) From now on, 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. From 9:00 pm, April 4, we started to discharge a total of 1,500 tons of the low level radioactive subsurface water stored in the sub drain pits of Unit 5 and 6. -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.-We will continue to take all measures to ensure the safety and to continue monitoring the surrounding environment around the Power Station.
    Press Release (Apr 09,2011)Plant Status of Fukushima Daiichi Nuclear Power Station (as of 1:30 pm, April 9) | PressReleasePoint
     

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