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:
Jul. 28, 1998
Filed:
May. 19, 1997
Mitsunari Nakamura, Hitachi, JP;
Katsumasa Haikawa, Jyuou, JP;
Akihiro Yamanaka, Hitachi, JP;
Akiko Kanda, Hitachi, JP;
Takaaki Mochida, Hitachi, JP;
Junichi Yamashita, Hitachi, JP;
Shigetada Tanabe, Hitachi, JP;
Shinichi Kirihara, Mito, JP;
Hitachi, Ltd., , JP;
Abstract
In a fuel loading method of the present invention, a nuclear reactor is operated up to the second cycle without exchanging the fuel. Low-enrichment fuel is discharged from a core at the end of the second cycle and at the end of the third cycle. Moreover, high-enrichment fuel with an average enrichment higher than that of replacement fuel is discharged from the core at the end of the third cycle and reloaded into the core at the end of the fifth cycle. According to the present invention, because the high-enrichment fuel discharged from the core at the end of the third cycle normally has a high enrichment, a short combustion period, and a low burnup compared to the replacement fuel burned for 4 to 5 cycles, a lot of fissionable material are left in the high-enrichment fuel. By reloading the high-enrichment fuel to the core after one cycle or more passes, it is possible to greatly increase the discharge exposure of initially loaded fuel. Thereby, it is possible to greatly decrease the number of pieces of the replacement fuel.