Advanced first circulation 18-month refuelling and loading method

Abstract

The invention belongs to a design technology of reactors, and in particular relates to a first circulation 18-month refuelling and loading method n a reactor core of a pressurized water reactor nuclear power station. According to the method, aiming at the reactor core consisting of 177 group of fuel assemblies, in the first circulation, gadolinium-containing fuel assemblies are used as part of fuel assemblies, Gd2O3 is a combustible toxic material, Gd2O3 and UO2 in gadolinium-containing fuel rods of the gadolinium-containing fuel assemblies are mixed and uniformly dispersed in fuel core blocks, and 2%-10% of Gd2O3 is contained in the gadolinium-containing fuel core blocks by weight percent. According to the method, under the premise of meeting various safety criterions, the condition that the natural circulation length is 482 equivalent full power days is met; and compared with the conventional method of using solid combustible toxic materials of borosilicate glass in the first circulation, the method has the advantage that the circulation length is prolonged by 147 equivalent full power days and is equivalent to the balance circulation length of 18-month refueling, and is quietly high in economy and operation flexibility.

Description

technical field [0001] The invention belongs to reactor design technology, in particular to a method for refueling and loading the reactor core of a pressurized water reactor nuclear power plant during the first 18-month cycle. Background technique [0002] In the first-cycle fuel assembly arrangement of the PWR nuclear power plant reactor core composed of 177 sets of fuel assemblies, the traditional arrangement method is: the core fuel assemblies are divided into three areas according to the enrichment degree, and the richness of the three areas The enrichment degrees are 1.8%, 2.4%, and 3.1%, respectively. The fuel assembly with the enrichment degree of 1.8% does not contain solid burnable poisons, and the fuel assemblies with the enrichment degrees of 2.4% and 3.1% may contain solid burnable poisons. The solid burnable poison used in the cycle is borosilicate glass. Under the premise of meeting various safety criteria, the natural circulation length of the traditionally ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a first-cycle loading method for a reactor core composed of 177 sets of fuel assemblies, aiming to solve the problem of using traditional borosilicate glass solid burnable poisons in the first cycle to cause a lot of radioactive waste, which is not conducive to environmental protection and control The rod design is inflexible, and the cycle length is quite different from the balance cycle length of 18-month refueling

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