The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 02, 2005
Filed:
Oct. 17, 2001
Mikihide Nakamaru, Fujisawa, JP;
Hideaki Heki, Yokohama, JP;
Takehiko Saito, Tokyo, JP;
Kouji Hiraiwa, Chigasaki, JP;
Tadashi Narabayashi, Yokohama, JP;
Satoru Oomizu, Yokohama, JP;
Tsuyoshi Shimoda, Yokohama, JP;
Kenji Arai, Kawasaki, JP;
Shinichi Morooka, Tokyo, JP;
Seijiro Suzuki, Yokohama, JP;
Mikihide Nakamaru, Fujisawa, JP;
Hideaki Heki, Yokohama, JP;
Takehiko Saito, Tokyo, JP;
Kouji Hiraiwa, Chigasaki, JP;
Tadashi Narabayashi, Yokohama, JP;
Satoru Oomizu, Yokohama, JP;
Tsuyoshi Shimoda, Yokohama, JP;
Kenji Arai, Kawasaki, JP;
Shinichi Morooka, Tokyo, JP;
Seijiro Suzuki, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
The present invention is to provide a reactor core that allows a nuclear plant to continuously operate for a long term period, for example 15 years or longer, without requiring any fuel exchange, reduces the duration and number of maintenance steps involved in regular plant inspections, markedly improves plant availability and economic efficiency, and is effective in terms of nuclear nonproliferation. A plurality of fuel assemblies, themselves obtained by arranging fuel rodsand water rodsin square lattices, are arranged in a square lattice at a certain pitch. The bladesof a cross-shaped (cruciform) control rodin a cross section are inserted into four adjacent spaces formed by four fuel assembliesfacing each other. A value of 0.06 cmor greater is selected for the ratio (B/S) of the width (B) of each blade on the cruciform control rodand the surface (S) of the fuel lattice defined by the surface area of a square whose side is equal to the pitch between the fuel assemblies