(19)
(11)EP 2 565 878 A3

(12)EUROPEAN PATENT APPLICATION

(88)Date of publication A3:
12.11.2014 Bulletin 2014/46

(43)Date of publication A2:
06.03.2013 Bulletin 2013/10

(21)Application number: 12182386.8

(22)Date of filing:  30.08.2012
(51)Int. Cl.: 
G21C 5/02  (2006.01)
G21C 7/32  (2006.01)
G21C 5/10  (2006.01)
G21C 5/18  (2006.01)
G21C 1/08  (2006.01)
(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME

(30)Priority: 31.08.2011 JP 2011188882

(71)Applicant: Hitachi-GE Nuclear Energy, Ltd.
Hitachi-shi Ibaraki 317-0073 (JP)

(72)Inventors:
  • Mitsuyasu, Takeshi
    Tokyo, 100-8220 (JP)
  • Aoyama, Motoo
    Tokyo, 100-8220 (JP)
  • Nakadozono, Naoyuki
    Tokyo, 100-8220 (JP)
  • Ishii, Kazuya
    Tokyo, 100-8220 (JP)

(74)Representative: Beetz & Partner 
Patentanwälte Steinsdorfstraße 10
80538 München
80538 München (DE)

  


(54)Initial core of nuclear reactor and method of loading fuel assemblies of nuclear reactor


(57) In an initial core (3) of a nuclear reactor (1), a plurality of water regions (6) having a square cross section for occupying a cross sectional area capable of disposing four fuel assemblies (4) are formed. No fuel assemblies are loaded in these water regions (6). In the initial core (3), each fuel assembly (4) is supported by fuel supports (9). A pressure loss of a first orifice installed in a cooling water supply passage (32) formed in first fuel supports (9a) disposed in a central portion (3a) of the initial core (3) is larger than that of a second orifice installed in a cooling water supply passage formed in second fuel supports (9b) disposed in a peripheral portion (3b) surrounding the central portion (3a). Each water region (6) is formed right above a part of the first fuel supports (9a) disposed in the central portion (3a). The control rod operation in the nuclear reactor (1) can be simplified by action of cooling water in the water regions (6).