Nuclear reactor shutdown device with high reliability

Abstract

The invention belongs to the technical field of reactivity control of a nuclear reactor, and particularly relates to a nuclear reactor shutdown device with high reliability. The device is installed above a nuclear reactor control rod guide tube support plate, and the whole device takes a fuel tank as a main structure; a head cover is installed at the upper end of the fuel tank, the fuel tank is filled with combustible poison balls, a guide grid partition plate and a solenoid switch are installed on the fuel tank, and a valve and a combustible poison guide tube are installed at the lower end of the fuel tank. When the nuclear reactor needs to be subjected to shutdown, the solenoid switch is turned off, a valve is switched on, and the combustible poison balls in the fuel tank can fall under the action of gravity, flow into a control rod guide tube along the combustible poison ball guide tube and enter a reactor core; boron in the combustible poison balls can absorb neutrons in the nuclear reactor, reactivity of the nuclear reactor is reduced, and shutdown is achieved. The nuclear reactor shutdown device is simple in structure manufacturing and small in occupied area, tapping on the head cover of a pressure vessel is not needed, falling is accurate, reaction is rapid, the rod seizure accident cannot occur, and high reliability is achieved.

Description

technical field [0001] The invention belongs to the technical field of nuclear power plant emergency safety, and in particular relates to a nuclear reactor shutdown device with high reliability. Background technique [0002] The reactivity control system is used to control the reactivity of the nuclear reactor, which includes a melting control system and a rod control system. When an accident occurs in a nuclear power plant and the reactor needs to be shut down, the boric acid solution will be injected into the nuclear reactor, and at the same time the control rods will fall into the core of the nuclear reactor to absorb the neutrons in the core, reduce the reactivity, and eventually shut down the reactor. [0003] A reactor in normal operation is a critical reactor. In order to control its reactivity, it is necessary to add boron-containing control rods to the fuel rods and add boric acid solution to the coolant. Boron has a high neutron capture cross-section and can absor...

AI Technical Summary

Problems solved by technology

[0007] (2) The control rod is too long, and may be deformed due to thermal expansion in a high-temperature reactor, so the rod will be stuck during the falling process;

[0008] (3) The driving mechanism of the control rod is relatively complicated, and there may be accidents of sticking the rod or dropping it by mistake;

[0009] (4) The length of the control rod is longer and takes up a lot of space;

[0010] (5) The length of the control rod is long, and it is necessary to open holes on the top cover of the reactor pressure vessel, which reduces the safety of the pressure vessel;

[0011] (5) The original position of combustible poison is left unused, resulting in a waste of space

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