Method for preventing abnormity of mechanical seal leakage rate of nuclear reactor coolant pump

Abstract

The invention relates to a method for preventing abnormity of mechanical seal leakage rate of a nuclear reactor coolant pump. An injection water loop of a No. 1 shaft seal of a coolant pump is provided with two parallel columns of filters; one row of the filters are operating on the line, and the other column of filters are for standby. The preventive method comprises the following steps: S1. detecting a boron concentration of a loop; S2. comparing the boron concentration of the loop with that of the row of filters for standby; and S3. when a difference between the boron concentration of the standby row and that of the loop exceeds a preset value, switching the standby column of filters to on-line operation, and switching the on-line operating row of filters into a standby state. In the preventive method of the invention, when the difference between the boron concentration of the standby column and that of the loop exceeds the preset value, filter switching is carried out; and a sealing surface of the No. 1 shaft seal can be flushed timely by shaft seal injection water with a relative high boron concentration in the standby column of filters, so as to improve a seal status of the sealing surface of the No. 1 shaft seal timely and effectively.

Description

technical field [0001] The invention relates to a safety maintenance method of a nuclear power plant, and more specifically relates to a method for preventing an abnormal leakage flow rate of a nuclear reactor coolant pump mechanical seal. Background technique [0002] The reactor coolant system (hereinafter referred to as RCP system) is the main circuit of the primary circuit of the nuclear power plant. Its main function is to circulate the coolant, transfer the heat generated by nuclear fission in the core to the secondary circuit through the evaporator, and cool the core at the same time to prevent Fuel elements burned or destroyed. The reactor coolant pump is referred to as the main pump for short, and each main loop of the primary loop has a main pump, which is used to drive the coolant to circulate in the RCP system. The shaft seal assembly (also known as the shaft seal system) is a key component of the main pump of the primary circuit of the nuclear reactor, and its ...

AI Technical Summary

Problems solved by technology

When the pressure difference across the filter exceeds the rated value, it means that a large amount of impurities have accumulated in the filter, which may have caused damage to the No. 1 shaft seal, which is not conducive to the prevention of leakage of the No. 1 shaft seal.

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