Refueling method for fuel assemblies of reactor core of PWR (pressurized water reactor) nuclear power plant

Abstract

The invention is applicable to the field of fuel management on reactor cores of pressurized water reactors, and provides a refueling method for fuel assemblies of a reactor core of a PWR (pressurized water reactor) nuclear power plant. The method comprises: classifying the fuel assemblies of the reactor core into three enrichment areas according to different enrichment degrees; in an initial cycle, respectively adding 8, 12 and 16 burnable poison rods into the fuel assemblies, and according to a cycle length of 18 months, placing the fuel assemblies with high enrichment degree outside the reactor core, and placing the fuel assemblies with low enrichment degree in the reactor core, wherein the enrichment degrees of the fuel assemblies of an initial reactor core are respectively 3.9%, 3.1% and 2.0%; and in subsequent cycles, starting from a second cycle, and rapidly transitioning the subsequent cycles to an equilibrium cycle according to an enrichment degree of 4.45%, wherein a mode of 18-month refueling is adopted, and the fuel assemblies of 1 / 2-1 / 3 of the reactor core are replaced every time; meanwhile, placing the new fuel assemblies in the reactor core, and placing the fuel assemblies which are burned outside the reactor core. By using the refueling method provided by the invention, the cycle period is extended, the fuel consumption is improved, and the purpose of completely low neutron leak loading is achieved in the subsequent cycles.

Description

[0001] This application is a divisional application of the patent application for invention with application number 200710077351.2 submitted by the applicant on September 26, 2007, and its entire contents are incorporated into this application by reference. technical field [0002] The invention belongs to the field of pressurized water reactor core fuel management, and in particular relates to a method for refueling a reactor core fuel assembly in a one-million-kilowatt unit of a Chinese pressurized water reactor nuclear power plant for 18 months. Background technique [0003] In the layout of the reactor core fuel assembly in the pressurized water reactor nuclear power plant, the traditional loading mode in the reactor core is the high leakage (OUT-IN) mode, that is, the core fuel assembly is divided into three enrichment areas according to the different enrichment degrees. , in which the fuel assembly with the highest enrichment degree is placed in the outer area of ​​the ...

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Problems solved by technology

[0005] The purpose of the embodiment of the present invention is to provide an 18-month refueling method for the reactor core fuel assembly in a 1 million-kilowatt unit of a pressurized water reactor nuclear power plant, aiming at solving the problem of the traditional OUT-IN mode arrangement and annual refueling of the core fuel assembly The method of updating 1 / 3 of the fuel assembly each time leads to the problem of short fuel assembly cycle and low fuel consumption

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