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:
Dec. 14, 1993
Filed:
Mar. 14, 1991
Masataka Hidaka, Katsuta, JP;
Michio Murase, Mito, JP;
Toshitsugu Nakao, Hitachi, JP;
Akihiko Minato, Ibaraki, JP;
Shigeto Murata, Katsuta, JP;
Yoshiyuki Kataoka, Ibaraki, JP;
Shoichiro Kinoshita, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a boiling water nuclear reactor, a reactor primary cooling water line is filled with water at the start-up time, and the inside of a pressure vessel is pressurized by a pressurized tank and at the same time control rods are withdrawn to thereby heat cooling water in a state of single-phase flow to high temperature. Succeedingly, the pressurization is released and the pressure of the pressure vessel is gradually approximated to the saturation pressure corresponding to the cooling water temperature to thereby make the cooling water transit into a state of two-phase flow, and thereafter the cooling water is heated by nuclear reaction in the state of two-phase flow to thereby obtain predetermined reactor running temperature and pressure. This prevents the flow fluctuation and the reduction of stability of core due to occurrence of unstable phenomena of low temperature two-phase flow at the start-up time of the reactor to thereby make it possible to perform stable starting-up of the reactor and to shorten the start-up time of the reactor to thereby realize improvement in economy as well as reliability.