Kabushiki Kaisha Toshiba

Tokyo Shibaura Electric Co., Ltd.

Katsuhiko Mawatari

Akira Nakamura

Kiyoshi Hattori

Tadashi Narabayashi

Nobuhiko Tanaka

Hiroshi Miyano

Katsumi Yamada

Yasuhiko Aida

Osamu Ozaki

Takao Fujii

Shigeaki Tsunoyama

Hideo Komita

Takashi Ishitori

Kunio Shimano

Yoshifumi Satoh

Iwao Oshima

Mititaka Terasawa

Osamu Morimiya

A control rod driving apparatus adapted to drive a control rod assembly for a nuclear reactor is disposed in a housing mounted to a reactor pressure vessel of the nuclear reactor and includes a guide tube disposed in the housing, a connection pipe disposed inside the guide tube coaxially therewith and having one end to which a control rod assembly is connected, a ball spindle disposed inside the connection pipe and supported thereby so as to be rotatable by a ball nut assembly engaged with the ball spindle so as to be axially movable along the ball spindle, the ball nut assembly supporting another end of the connection pipe, a hydraulic drive operatively connected to the ball spindle to rotate the ball spindle, and a transmission mechanism operatively connected to the drive for transmitting a power of the drive to the ball spindle. When the hydraulic drive is driven, the ball spindle is rotated, the ball nut assembly engaged with the ball spindle is axially rotated, and the connection pipe supported by the ball nut assembly is then driven vertically to thereby drive the control rod assembly for inserting or withdrawing the control rod assembly into or from a reactor core. The reactor is a boiling water reactor.

Control rod driving apparatus

A boiling water reactor comprises a reactor pressure vessel accommodated in a vertical fashion, a core disposed at a low portion in the reactor pressure vessel, a plurality of control rods to be inserted from an upper side of the core into the spaces between adjacent fuel assemblies and withdrawn therefrom upwardly, a shroud surrounding the fuel assemblies so as to define the core and having an upper end opening, a shroud head which closes the upper end opening of the shroud and through which the control rods are inserted or withdrawn, a separator standing upward from the shroud head to carry out gas-water separation of steam generated from the core, a fixing pedestal disposed above the separator, a control rod driving mechanism mounted on the fixing pedestal and adapted to drive the control rods, a drier unit including a plurality of drier elements annularly arranged along an upper inner wall surface of the reactor pressure vessel and adapted to dry the steam passing through the steam flow hole of the fixing pedestal, and a jet pump unit disposed in a space between an outer surface of the shroud and an inner wall surface of the reactor pressure vessel.

Boiling water reactor

A method and apparatus for implanting radioactive gas in a base material which comprises the steps of conducting radioactive gas received in a reservoir to an ion source for ionization; accelerating said ionized radioactive gas into a high energy form; and implanting said high energy radioactive ion beam in a foil made of, for example, stainless steel, aluminium or copper and received in an ion implantation unit.

Method and apparatus for implanting radioactive gas in a base material

Growing community of inventors

Tokyo, Japan

Katsuhiko Mawatari