Nuclear power plant reactor control rod driving mechanism

Abstract

The invention discloses a driving mechanism for a reactor control rod of a nuclear power plant. The driving mechanism for the reactor control rod of the nuclear power plant comprises a pressure-resistant shell assembly, a falcula assembly, a driving rod assembly, a coil assembly and a rod position detector assembly, wherein the pressure-resistant shell assembly is an integrated shell, the top of the pressure-resistant shell assembly is of a blind pipe structure, and the bottom of the pressure-resistant shell assembly is connected by virtue of a screw thread and is detachably arranged on a CRDMpipe socket of a pressure vessel head in a sealing manner. Compared with the prior art, the driving mechanism for the reactor control rod of the nuclear power plant adopts the integrated pressure-resistant shell assembly, no weld joint is formed on the pressure-resistant shell assembly, and the pressure-resistant shell assembly and the CRDM pipe socket are connected by adopting the screw thread and are sealed by virtue of a pair of sealing rings, so that the risk of reactor coolant leakage can be effectively reduced. Besides, the falcula assembly adopts a double-tooth falcula structure, the wear resistance of a falcula can be greatly improved, the service life of a control rod driving mechanism is prolonged, the falcula assembly is assembled and disassembled from the bottom of the pressure-resistant shell assembly, and irradiation injury risk produced to operating personnel can be reduced.

Description

technical field [0001] The invention belongs to the field of pressurized water reactor nuclear power plants, and more specifically, the invention relates to a driving mechanism for control rods of nuclear power plant reactors. Background technique [0002] The Control Rod Drive Mechanism (CRDM for short) is a vertical step-by-step magnetic lifting device installed on the top cover of the reactor pressure vessel. As an important device for implementing reactivity control, CRDM can drive the control rod assembly to move up and down within the core range according to the command, and keep it at the command height, or the control rod can be inserted into the core under the action of gravity to control the start-up of the reactor. , power regulation and shutdown functions. In addition, the CRDM pressure vessel, as the primary circuit pressure boundary in contact with the coolant, is a safety barrier for radioactive containment. [0003] At present, the commonly used CRDM mainly...

AI Technical Summary

Problems solved by technology

[0011] 1) There are three Ω sealing welds in total. The Ω sealing welds are thin-walled welds with a thickness of 1.9-2.3mm. Damage and leakage accidents are prone to occur in the Ω weld area, and the risk of damage and leakage is relatively high

[0012] 2) The single-precision rod position detector has low measurement accuracy and low reliability, and does not meet the single failure criterion

[0013] 3) The current of the coil is large, and the temperature resistance of the coil material is poor, so ventilation and cooling are required

[0017] 1) The Ω seal weld is located between the rod travel sleeve and the claw shell. When disassembling the claw assembly, lift the claw assembly out of the claw shell. The claw assembly contaminated by the reactor coolant is radioactive. Exposure to the environment after lifting out will cause radiation injury risk to the operator

[0018] 2) The current of the coil is large, and the temperature resistance of the coil material is poor, and ventilation and cooling are also required

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