| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nuclear reactor core for reducing increase of output of fuel assemblies in increase of coolant flow in the fuel assemblies to improve thermal margin. <P>SOLUTION: In a reactor core 5A, a plurality of fuel assemblies 10 and 11 are arranged on the inside of an outermost layer area 9. The fuel assemblies 10 are formed in a fuel support metal fitting, and connected to a first cooling water passage provided with a first orifice at its entrance. The fuel assemblies 11 are formed in the fuel support metal fitting, and connected to a second cooling water passage provided with a second orifice at its entrance. Pressure loss of the first orifice is smaller than that of the second orifice. The number of the fuel assemblies 10 adjacent to four sides of the plurality of fuel assemblies 10 is one or less, and the fuel assemblies 11 are adjacently arranged to the remaining sides. In the fuel assemblies 10, coolant water flow increases, however, since three or more of the fuel assemblies 11 with low output are adjacent to them, rise ratio of the output is suppressed. <P>COPYRIGHT: (C)2013,JPO&INPIT |
