Kabushiki Kaisha Toshiba

Ryoichi Hamazaki

Takashi Sato

Hirohide Oikawa

Kunihiko Wada

Tsuneji Kameda

Yutaka Ishiwata

Yuka Suzuki

Mikihide Nakamaru

Yoshihiro Kojima

Mika Tahara

Makoto Akinaga

Tomohisa Kurita

Noriyuki Katagiri

Seiichi Yokobori

Fumiyo Kuno

Hiromasa Yanagisawa

Akira Murase

There is provided a holding device which can hold a molten corium for a predetermined period even when the molten corium is exposed to heat or undergoes any chemical reaction and which is applicable to practical use. There is provided a holding device provided below a nuclear reactor pressure vessel for holding a molten corium, wherein the holding device includes a base material in contact with a cooling medium, and a multilayer stack structure on the base material. The multilayer stack structure has a first layer having heat-resistant property, a second layer formed on the first layer and having heat-resistant property with lower heat conductivity than that of the first layer, and a third layer formed on the second layer and having corrosion-resistant property and impact-absorbing property.

Holding device

A drain sump of a reactor containment vessel having a containment vessel floor down below a reactor pressure vessel, and includes a heat-proof sump cover and two or more drain flow paths. The drain sump is arranged inside the containment vessel floor. The heat-proof sump cover has a thickness, and covers an upper part of the drain sump. The thickness allows a top surface of the sump cover to lie in the same surface as a top surface of the containment vessel floor. The drain flow paths pass through the sump cover in a thickness direction to flow water therethrough and solidify a molten corium therein. The molten corium is produced in the unlikely event of a severe accident.

Drain sump of nuclear reactor containment vessel

Core debris generated during a molten reactor core in a reactor containment vessel penetrating the reactor containment vessel is configured to be caught by a core catcher located beneath the reactor containment vessel which has a main body having first stage cooling water channels and second stage surrounded by cooling fins extending radially. The number of the second stage cooling channels is larger than that of the first stage cooling channels. Cooling water is supplied from a cooling water injection opening and distributed to the first cooling water channels at a distributor. An intermediate header is formed between the first and the second cooling water channels, and the cooling water is distributed to the second cooling water channels uniformly.

Core catcher, manufacturing method thereof, reactor containment vessel and manufacturing method thereof

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Yokohama, Japan

Ryoichi Hamazaki