Status of the Fukushima Daiichi Nuclear Power Plant Updated information (27-03-2011 at 1800hrs) (Prepared by Emergency Response Systems and Methods Section, RSSD, HS&E Group) AC Power—Units 1 to 4 The restoration work of off-site power is still in progress. Off-site power is connected to Units 1–4. Power distribution panels (Power Center) in Units 2 and 4 have been connected to the off-site electricity supply. Individual components are still being checked prior to being energised. The lighting in units 1 and 3 control rooms has been restored. Some instrumentation was recovered for units 1, 2 and 4. Due to the extent of damage inflicted by the earthquake and tsunami, it is not possible to estimate when equipment may be returned to service. AC Power—Units 5 and 6 Power has been restored to a transformer and is being provided to Unit 5 and Unit 6 houseloads. Unit 1 Fresh water continues to be injected into the reactor pressure vessel via a feedwater injection line at an indicated rate of about 7.2 m3/h. The indicated temperature at the feed water nozzle of the Reactor Pressure Vessel (RPV) slightly increased at about to 209oC and at the bottom of RPV to 144oC. The dose rate in the containment vessel (D/W) and suppression chamber (S/C) continued to decrease to 35.3 Sv/h and 23.8 Sv/h, respectively. NISA informed that the radiation dose in control room for Units 1 and 2 is 0.3-0.4 mSv/h. Unit 2 Seawater injection to the RPV continues with a flow rate of 20.4 m3/h. The RPV temperature at the feed water nozzle and at the bottom head of RPV are stable at 109oC and 100 oC, respectively. The dose rates in the containment vessel (D/W) and the suppression chamber (S/C) continued to decrease at 43.8 Sv/h and 1.5 Sv/h, respectively. The spent fuel pool temperature is 52oC. Unit 3 Fresh water is being injected into the RPV with the flowrate of 14.4 m3/h. The RPV temperature measurement at the feed water nozzle is still unreliable although the temperature at the bottom of RPV indication dropped down to 102.5oC. Seawater injection to the Spent Fuel Pool via the Cooling and Purification Line continues. The dose rate in the containment vessel (D/W) and suppression chamber (S/C) continued to decrease to 38.8 Sv/h and 1.3 Sv/h, respectively. The radiation dose in control room for Units 3 and 4 is 0.06 mSv/h.

Unit 4 From March 22 to Match 25, 130 to 150 ton of water was poured into the Spent Fuel Pool each day using a concrete pump. Sea water was also poured in through Spent Fuel Cooling System from 1100 JST on March 25 to 2120 on March 25. White smoke is still emitting as of 0800 JST March 26. Unit 5 The reactor remains in cold shutdown. Power was switched from the diesel generator to off-site power.The reactor water temperature decreased to 30.3oC as the RHR pump recovered power. Unit 6 The reactor remains in cold shutdown. Power was switched from the diesel generator to off-site power.The RPV water temperature is stable at 22.1oC. The Spent Fuel Pool water temperature has slightly increased to 27.0oC Some of the monitoring results are as follows: