Protective Structure and Protective Method for Protecting Core Instrument Line

Abstract

The invention discloses a protection structure for protecting the instrumentation line of the core and a protection method thereof. The protection structure for protecting the instrumentation line of the core includes an upper support column belonging to the upper internal components of the reactor, and also includes a sleeve for protecting the instrumentation line of the core. During the working period of the nuclear reactor, the casing part is located in the upper support column, and the core instrument line is located in the casing part; it is characterized in that, during the maintenance of the nuclear reactor, the core instrument line is stationary relative to the upper support column and integrated with the internal components of the reactor and the upper support column Lifting, the casing member can pass through the lower end of the upper support column and move freely under the upper support column and cover the end of the core instrumentation line.

Description

technical field [0001] The invention relates to a structural part for providing protection and shielding for core instruments, belonging to nuclear reactor internal components, in particular to a protection structure for protecting core instrument lines and a protection method thereof. Background technique [0002] Nuclear reactors are generally equipped with dozens of core instruments for measuring the neutron flux rate of the core. During the operation of the reactor, these core instruments pass through the pressure vessel and the upper reactor internals, insert the fuel assembly, and stop the reactor. Before the pressure vessel is opened for refueling, it is necessary to extract these core instruments from the fuel assembly, and provide shielding and protection for a section of high-irradiation dose core instruments inserted into the fuel assembly. There are two commonly used solutions: one is Lift the core instruments one by one from the fuel assembly into the upper inte...

AI Technical Summary

Problems solved by technology

[0002] Nuclear reactors are generally equipped with dozens of core instruments used to measure the neutron flux rate of the core. During the operation of the reactor, these core instruments pass through the pressure vessel and the upper reactor internals, insert the fuel assembly, and stop the reactor. Before the pressure vessel is opened for refueling, it is necessary to extract these core instruments from the fuel assembly, and provide shielding and protection for a section of high-irradiation dose core instruments inserted into the fuel assembly. There are two commonly used solutions: one is Lift the core instruments one by one from the fuel assembly into the upper internals. This method is easy to get stuck in the upper internals due to the embrittlement of the core instruments after being irradiated. The radiation dose of personnel is relatively large, and the operation time is relatively long; the second is to set up a complex guide structure above the upper support column. In the instrument tube of the guide structure, this method needs to set up a complicated guide structure in the upper stack internals, which will affect the installation and maintenance of the control rod guide assembly, and the hoisting tools required by this method should be able to lift the guide structure and move it with the upper stack. The components are stored together, resulting in complicated lifting tools and operation steps

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