Soundness Investigation of the Unused (Unirradiated) Fuel Removed from Unit 4 Spent Fuel Pool at Fukushima Daiichi Nuclear Power Station

*11 A system (a part of Emergency Core Cooling System (ECCS)) to cool coolant (to remove heat decay) by pumps or heat exchangers or inject water to maintain reactor water in case

• The self-propelled investigation device ran on the deposits of the CRD rail and reached the area toward the pedestal (the vicinity of hanging balance), further than the area

Reactor automatically trip (scram) Electrical power supplied by transmission lines Power provided by generator operating with diesel fuel (emergency diesel generator) Cooling by

 By measuring muon particles which passed through the reactor building, main structures in the reactor building including the concrete wall surrounding PCV, the spent fuel pool

・ As preparatory work to remove fuel from the Unit 1 spent fuel pool, rubble removal on the operating floor north side started from January 22.. ・ Rubble is being removed

・ To help spent fuel removal from the pool of the Unit 2 Reactor Building, preparatory work to form an opening, which would allow access to the operating floor, was completed in

operation to remove spent fuel beginning from around the middle of FY 2018, always making safety our

・ To help spent fuel removal from the pool of the Unit 2 Reactor Building, preparatory work to form an opening, which would allow access to the operating floor, was completed in