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AssigneeHitachi, Ltd.
InventorsKunio Enomoto, Masahiro Otaka, Kunio Hasegawa, Makoto Hayashi, Shinji Sakata, Hideyo Saito, Koichi Kurosawa, Takashi Saito, Yoshinori Karatsu, Motoya Ito
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A method of maintaining the housing of a reactor pressure vessel having: a reactor pressure vessel into which cooling water is introduced; a cylindrical housing which penetrates an end bracket of the reactor pressure vessel; and a circumferential weld for securing the intermediate portion of the housing to the reactor pressure vessel by welding, the method of maintaining a housing of a reactor pressure vessel comprising the steps of: remaining the cooling water in the reactor pressure vessel; preventing leakage of the cooling water in the reactor pressure vessel through the housing by sealing the housing; making the inside portion of the housing lower than the seal to be a hollow space of a gas atmosphere; heating a heat affected zone due to welding by using a heating device inserted into the hollow space from a lower portion so as to compressive-yield the inner surface of the housing in the heat affected portion upper than the circumferential weld and tensile-yield the outer surface; and cooling heated portion inside of the housing, which has been yielded, so as to tensile-yield the inner surface of the housing by using a cooling device inserted into the housing from a lower portion, whereby compressive stress is allowed to remain in the tensile-yielded portion.
A method of treating a hollow housing member penetrating an end bracket of a reactor pressure vessel and being secured to said end bracket by a circumferential weld at an intermediate portion of said hollow housing member, said method comprising the steps of:
A method of treating a hollow housing member penetrating an end bracket of a reactor pressure vessel and being secured to said end bracket by a circumferential weld at an intermediate portion of said hollow housing member, said method comprising the steps of:
A heat treatment equipment for heat-treating a hollow housing member of a reactor pressure vessel, wherein said hollow housing member penetrating an end bracket of said reactor pressure vessel and being secured to said end bracket by a circumferential weld at an intermediate portion of said hollow housing member, said heat treatment equipment comprising:
A heat treatment equipment for heat-treating a hollow housing member of a reactor pressure vessel, wherein said hollow housing member penetrating an end bracket of said reactor pressure vessel and being secured to said end bracket by a circumferential weld at an intermediate portion of said hollow housing member, said heat treatment equipment comprising:
A heat treatment equipment for heat-treating a hollow housing member penetrating an end bracket of said reactor pressure vessel and being secured to said end bracket by a circumferential weld at an intermediate portion of said hollow housing member, said heat treatment equipment comprising:
A heat treatment equipment for heat-treating a hollow housing member of a reactor pressure vessel, wherein said hollow housing member penetrating an end bracket of said reactor pressure vessel and being secured to said end bracket by a circumferential weld at an intermediate portion of said hollow housing member, said heat treatment equipment comprising:
A heat treatment equipment for heat-treating a hollow housing member of a reactor pressure vessel, wherein said hollow housing member penetrating an end bracket of said reactor pressure vessel and being secured to said end bracket by a circumferential weld at an intermediate portion of said hollow housing member, said heat treatment equipment comprising:
A heat treatment equipment for heat-treating a hollow housing member of a reactor pressure vessel, wherein said hollow housing member penetrating an end bracket of said reactor pressure vessel and being secured to said end bracket by a circumferential weld at an intermediate portion of said hollow housing member, said heat treatment equipment comprising:
Dependencies are inferred from the claim text.