PROBLEM TO BE SOLVED: To provide a method which enables quick retrieval of fuel debris from a boiling water reactor.SOLUTION: The present invention for solving the above problem is a method of retrieving fuel debris from a boiling water nuclear plant which involves setting up a first house and a third house, each having airtight capability, on a reactor building, setting up a second house, similarly having airtight capability, in a DSP as well, and controlling atmosphere in a reactor well, a reactor pressure vessel, and the first through third houses to retrieve molten fuel debris while the reactor pressure vessel is filled with air.
