Method for saving fuel in heavy water reactor

Abstract

The present invention relates to a method for saving fuel in a heavy water reactor and, particularly, to a method for saving nuclear fuel capable of producing cobalt-60 while suppressing unnecessary power cutback by changing the material of an adjuster rod, comprising: a first step of installing seven groups of adjuster rods composed of first to seventh groups of adjuster rods so as to be respectively inserted into and drawn out of different portions of a nuclear fuel assembly, wherein the seventh group of adjuster rods is manufactured such that a reactivity value of the adjuster rods constituting the seventh group of adjuster rods is smaller than a reactivity value of the adjuster rods constituting the remaining groups of adjuster rods; and a second step of drawing out the seventh group of adjuster rods last when the first to seventh group of adjuster rods are all drawn out of the nuclear fuel assembly. As such, it is possible to prevent the seventh group of adjuster rods from being automatically re-inserted due to a water level of a liquid zone control (LZC) system being automatically raised above an adjuster rod insertion condition water level, thereby reducing the phenomenon ofunnecessarily suppressing the degree of combustion due to the re-insertion of the seventh groups of adjuster rods, such that the degree of combustion is increased to greatly save the amount of fuel to be consumed.

Description

technical field [0001] The present invention relates to a method for saving nuclear fuel, in particular, to a method for saving nuclear fuel capable of producing cobalt-60 by suppressing unnecessary power reduction by changing the material of an adjustment rod. Background technique [0002] The nuclear power plants that have been constructed and put into use in Korea are roughly classified into light water reactors and heavy water reactors. This classification is based on whether light water or heavy water is used as a deceleration material that decelerates neutrons and enables stable nuclear power generation. [0003] In addition, light water reactors need to increase the enrichment of nuclear fuel to reach a critical state where nuclear fission can occur stably, but heavy water reactors can reach criticality even if they use unenriched natural uranium or low-enriched nuclear fuel, resulting in waste. The amount is small, and the nuclear fuel can be replaced in the operati...

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Problems solved by technology

[0020] In view of this, the purpose of the present invention is to provide a method for saving nuclear fuel in heavy water reactors, which can solve the problem of excessive consumption of nuclear fuel caused by the inability to automatically draw out adjustment rods in existing heavy water reactors, while maintaining existing At the same time, the nuclear fuel is greatly reduced, so that not only can the operating efficiency of the nuclear reactor be improved, but also the improvement of the operating efficiency of the nuclear reactor can be organically combined with the production of cobalt-60

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