A rapid water replenishment device and method for a spent fuel pool in a nuclear power plant

Abstract

The present invention relates to the field of submersible pumps, and in particular to a device and method for rapidly replenishing water in a spent fuel pool of a nuclear power plant. The rapid water replenishment device comprises: a submersible pump having a float switch fixed on its body; the submersible pump is connected to a fire hose via a pipeline; a stop valve, a swing check valve, a filter, and a fire quick connector are sequentially arranged on the pipeline; a lifting motor drives a cable turntable to rotate, and the cable of the cable turntable is connected to the submersible pump; an upper limit switch and a lower limit switch are respectively fixed on the induction connecting rod; a control box receives switch signals from the upper limit switch, the lower limit switch, and the float switch to control the forward and reverse rotation and start and stop of the lifting motor; and also controls the start and stop of the submersible pump. The present invention is suitable for rapidly replenishing water in a spent fuel pool of a nuclear power plant when the liquid level in the spent fuel pool drops abnormally, thereby ensuring that the spent fuel can be adequately cooled.

Description

Technical Field

[0001] The present invention relates to the field of submersible pumps, and in particular to a device and method for quickly replenishing water in a spent fuel pool of a nuclear power plant. Background Art

[0002] Currently, spent fuel pools in nuclear power plants are used to store spent fuel. Since spent fuel will continue to release decay heat, it must be continuously cooled. Spent fuel is stored in spent fuel pools, so the spent fuel pools must maintain the necessary water volume. Insufficient water volume will result in the inability to discharge the spent fuel decay heat.

[0003] There are currently two methods for replenishing spent fuel pools:

[0004] One method is for mechanical personnel to connect a hose from the desalted water pipeline and then replenish desalted water into the spent fuel pool. This method requires the cooperation of mechanical personnel, and they must wait for the mechanical personnel to arrive before connecting the hose, which takes about 20 minutes. In addition, this method of replenishing desalted water into the spent fuel pool will cause the boron concentration in the spent fuel pool to decrease, affecting the reactivity of the spent fuel.

[0005] Another method is to use the spent fuel cooling water pump to draw water from the refueling water tank and replenish the spent fuel tank. This method requires the relevant valves to be online and takes more than 10 minutes. This method will also interrupt the cooling of the spent fuel pool for more than 30 minutes, and the spent fuel decay heat cannot be discharged during this time. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a device and method for quickly replenishing water in a spent fuel pool of a nuclear power plant, which is suitable for realizing rapid water replenishment of the spent fuel pool when the liquid level of the spent fuel pool of a nuclear power plant drops abnormally, thereby ensuring that the spent fuel can be adequately cooled.

[0007] The present invention provides a rapid water replenishment device for a spent fuel pool in a nuclear power plant, comprising:

[0008] A submersible pump with a float switch fixed on its body;

[0009] The submersible pump is connected to a fire hose through a pipeline; a stop valve, a swing check valve, a filter, and a fire quick connector are sequentially arranged on the pipeline;

[0010] The lifting motor drives the cable turntable to rotate, and the cable of the cable turntable is connected to the submersible pump;

[0011] The upper limit switch and the lower limit switch are fixed on the sensing link respectively.

[0012] The control box receives the switch signals from the upper limit switch, lower limit switch and float switch to control the forward and reverse rotation and start and stop of the lifting motor; it also controls the start and stop of the submersible pump.

[0013] In a specific embodiment of the present invention, the cable is further connected to a hanging basket, and a submersible pump is placed in the hanging basket.

[0014] In a specific embodiment of the present invention, the cable passes through a first pulley and a second pulley in sequence to connect to the hanging basket.

[0015] In a specific embodiment of the present invention, the fire-fighting quick connector is connected to a fire-fighting hose.

[0016] The present invention also provides a method for rapidly replenishing water in a spent fuel pool of a nuclear power plant using the rapid water replenishment device of the above technical solution, comprising the following steps:

[0017] The nuclear power plant spent fuel pool rapid water replenishment device described in the above technical solution is placed in the loading well and connected to the fire hose via a fire quick connector;

[0018] The submersible pump is started only when the liquid level in the loading well is above the float switch. When the liquid level in the loading well drops below the float switch, the control box issues a stop command for the submersible pump.

[0019] When the spent fuel pool needs to be replenished with water, the control box controls the lifting motor to start forward rotation, driving the cable turntable to start forward rotation, the cable starts to be released from the cable turntable, and the submersible pump descends. When it descends to the lower limit switch in the loading well, the lower limit switch sends a signal to the control box, the lifting motor stops, the submersible pump stops descending, and remains in this position;

[0020] The control box starts the submersible pump, and the boric acid solution in the loading well passes through the stop valve, swing check valve, filter, fire quick connector, and is then transferred to the spent fuel pool through the fire hose. After the water replenishment is completed, the control box stops the submersible pump.

[0021] When the water replenishment is completed, the control box controls the lifting motor to reverse and start, driving the cable turntable to reverse, the cable begins to wrap around the cable turntable, and the submersible pump rises. When it rises to the upper limit switch in the loading well, the upper limit switch sends a signal to the control box, the lifting motor stops, the submersible pump stops rising, and remains in this position.

[0022] In a specific embodiment of the present invention, when the submersible pump is placed in the hanging basket,

[0023] When the spent fuel pool needs to be replenished with water, the control box controls the lifting motor to start forward rotation, driving the cable turntable to start forward rotation, the cable starts to be released from the cable turntable, and the basket and submersible pump descend. When they descend to the lower limit switch in the loading well, the lower limit switch sends a signal to the control box, the lifting motor stops, the basket stops descending, and remains in this position;

[0024] When the water replenishment is completed, the control box controls the lifting motor to start in reverse, driving the cable turntable to reverse, the cable begins to wrap around the cable turntable, the basket and the submersible pump rise, and when they rise to the upper limit switch in the loading well, the upper limit switch sends a signal to the control box, the lifting motor stops, the basket stops rising, and remains in this position.

[0025] In a specific embodiment of the present invention, the control box controls the submersible pump to stop in two ways:

[0026] The first one is that when the liquid level in the loading well drops to the level of the float switch, the control box receives a signal from the float switch and issues a stop command to the submersible pump, and the submersible pump stops.

[0027] The second method is that when the liquid level in the spent fuel pool reaches the required level, the personnel press the stop button on the control box to issue a stop command for the submersible pump, and the submersible pump stops.

[0028] Compared to existing technologies, the present invention's rapid water replenishment device and method for a nuclear power plant spent fuel pool boasts a simple structure and can be operated by one person. The submersible pump can be placed in the loading well and water replenishment can begin within one minute, enabling rapid water replenishment. This device is suitable for rapidly replenishing spent fuel pools in nuclear power plants when the liquid level drops abnormally, ensuring adequate cooling of the spent fuel. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram showing the structure of a rapid water replenishment device for a spent fuel pool in a nuclear power plant;

[0030] In the figure,

[0031] 1-lifting motor, 2-control box, 3-sensing connecting rod, 4-upper limit switch, 5-lower limit switch, 6-cable turntable, 7-first pulley, 8-second pulley, 9-hanging basket, 10-submersible pump, 11-float switch, 12-pipeline, 13-stop valve, 14-swing check valve, 15-filter, 16-fire quick connector. DETAILED DESCRIPTION

[0032] In order to further understand the present invention, embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than for limiting the present invention.

[0033] The embodiment of the present invention discloses a rapid water replenishment device for a spent fuel pool in a nuclear power plant, such as Figure 1 Shown, including:

[0034] A submersible pump 10, on the body of which a float switch 11 is fixed;

[0035] When the liquid level in the loading well is above the float switch 11, the submersible pump 10 can be started. When the liquid level in the loading well drops below the float switch 11, the control box 2 will issue a shutdown command for the submersible pump 10 to protect it.

[0036] The submersible pump 10 is connected to the fire hose through a pipe 12; the pipe 12 is provided with a stop valve 13, a swing check valve 14, a filter 15, and a fire quick connector 16 in sequence;

[0037] The lifting motor 1 drives the cable turntable 6 to rotate, and the cable of the cable turntable 6 is connected to the submersible pump 10;

[0038] The cable is also connected to a hanging basket 9, in which a submersible pump 10 is placed;

[0039] Specifically,

[0040] The cable passes through the first pulley 7 and the second pulley 8 in sequence to connect the hanging basket 9 and the submersible pump 10;

[0041] The upper limit switch 4 and the lower limit switch 5 are fixed on the sensing link 3.

[0042] The upper limit switch 4 and the lower limit switch 5 are used to send position signals of the hanging basket 9 and the submersible pump 10.

[0043] The control box 2 receives the switch signals from the upper limit switch 4, the lower limit switch 5 and the float switch 11 to control the forward and reverse rotation and start and stop of the lifting motor 1; it also controls the start and stop of the submersible pump 10.

[0044] An embodiment of the present invention further discloses a method for rapidly replenishing water in a spent fuel pool of a nuclear power plant using the rapid water replenishment device of the above technical solution, comprising the following steps:

[0045] The nuclear power plant spent fuel pool rapid water replenishment device described in the above technical solution is placed in the loading well and connected to the fire hose via the fire quick connector 16;

[0046] When the liquid level in the loading well is above the float switch 11, the submersible pump 10 is started. When the liquid level in the loading well drops below the float switch 11, the control box 2 issues a stop command for the submersible pump 10.

[0047] When the spent fuel pool needs to be replenished with water, the control box 2 controls the lifting motor 1 to start forward rotation, driving the cable turntable 6 to start forward rotation, the cable starts to be released from the cable turntable 6, and the submersible pump 10 descends. When it descends to the lower limit switch 5 in the loading well, the lower limit switch 5 sends a signal to the control box 2, the lifting motor 1 stops, the submersible pump 10 stops descending, and remains in this position;

[0048] The control box 2 controls the submersible pump 10 to start, and the boric acid solution in the loading well passes through the stop valve 13, the swing check valve 14, the filter 15, the fire quick connector 16, and is then transferred to the spent fuel pool through the fire hose. After the water replenishment is completed, the control box 2 controls the submersible pump 10 to stop.

[0049] When the water replenishment is completed, the control box 2 controls the lifting motor 1 to start, driving the cable turntable 6 to start reversing, the cable starts to wrap around the cable turntable 6, and the submersible pump 10 rises. When it rises to the upper limit switch 4 in the loading well, the upper limit switch 4 sends a signal to the control box 2, the lifting motor 1 stops, the submersible pump 10 stops rising, and remains in this position.

[0050] When the submersible pump 10 is placed in the hanging basket 9,

[0051] When the spent fuel pool needs to be replenished with water, the control box 2 is used to control the descent of the hanging basket 9 and the submersible pump 10. When the descent button is pressed, the lifting motor 1 starts to rotate forward, driving the cable turntable 6 to start rotating forward, and the cable begins to be released from the cable turntable 6. The hanging basket 9 and the submersible pump 10 begin to descend under the action of gravity. When the hanging basket 9 descends to the lower limit switch 5 in the loading well, the lower limit switch 5 sends a signal to the control box, the lifting motor 1 stops, and the hanging basket 9 and the submersible pump 10 stop descending and remain in this position.

[0052] The control box 2 controls the submersible pump 10 to start. When the hanging basket 9 descends to the lower limit switch 5, the start button on the control box is pressed to start the submersible pump. The boric acid solution in the loading well passes through the stop valve 13, the swing check valve 14, the filter 15, the fire quick connector 16, and is then transferred to the spent fuel pool through the fire hose.

[0053] When the water replenishment is completed, the control box 2 controls the submersible pump 10 to stop. There are two stop commands for the submersible pump 10: one is when the liquid level in the loading well drops to the level of the float switch 11. When the control box 2 receives the signal from the float switch 11, it issues a stop command for the submersible pump 10 and the submersible pump stops; the other is when the liquid level in the spent fuel pool reaches the required level. The operator presses the stop button on the control box 2 to issue a stop command for the submersible pump 10 and the submersible pump stops.

[0054] When the spent fuel pool does not need to be replenished with water, the control box 2 controls the basket 9 and the submersible pump 10 to rise: when the up button is pressed, the lifting motor 1 starts, driving the cable turntable 6 to start reversing, the cable starts to wind around the cable turntable 6, and the basket 9 and the submersible pump 10 start to rise under the traction of the cable. When the basket 9 rises to the upper limit switch 4, the upper limit switch 4 sends a signal to the control box, the lifting motor 1 stops, the basket 9 and the submersible pump 10 stop rising, and remain in this position.

[0055] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0056] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A rapid water replenishment device for a spent fuel pool in a nuclear power plant, characterized in that: include: A submersible pump with a float switch fixed on its body; One end of the submersible pump is connected to the fire hose through a pipe; the other end of the pipe is equipped with a stop valve, a swing check valve, a filter, and a fire quick connector in sequence; The lifting motor drives the cable turntable to rotate, and the cable of the cable turntable is connected to the submersible pump; The upper limit switch and the lower limit switch are fixed on the sensing link respectively. The control box receives the switch signals from the upper limit switch, lower limit switch and float switch to control the forward and reverse rotation and start and stop of the lifting motor; it also controls the start and stop of the submersible pump; The cable is also connected to a hanging basket, in which a submersible pump is placed; The cable passes through the first pulley and the second pulley in sequence to connect to the hanging basket; The fire-fighting quick connector is connected to the fire-fighting hose.

2. A rapid water replenishment method using the rapid water replenishment device for a spent fuel pool in a nuclear power plant according to claim 1, characterized in that: The following steps are involved: The nuclear power plant spent fuel pool rapid water replenishment device according to claim 1 is placed in the loading well and connected to the fire hose via a fire quick connector; The submersible pump is started only when the liquid level in the loading well is above the float switch. When the liquid level in the loading well drops below the float switch, the control box issues a stop command for the submersible pump. When the spent fuel pool needs to be replenished with water, the control box controls the lifting motor to start forward rotation, driving the cable turntable to start forward rotation, the cable starts to be released from the cable turntable, and the submersible pump descends. When it descends to the lower limit switch in the loading well, the lower limit switch sends a signal to the control box, the lifting motor stops, the submersible pump stops descending, and remains in this position; The control box starts the submersible pump, and the boric acid solution in the loading well passes through the stop valve, swing check valve, filter, fire quick connector, and is then transferred to the spent fuel pool through the fire hose. After the water replenishment is completed, the control box stops the submersible pump. When the water replenishment is completed, the control box controls the lifting motor to reverse and start, driving the cable turntable to reverse, the cable begins to wrap around the cable turntable, and the submersible pump rises. When it rises to the upper limit switch in the loading well, the upper limit switch sends a signal to the control box, the lifting motor stops, the submersible pump stops rising, and remains in this position.

3. The method for rapidly replenishing water in a spent fuel pool of a nuclear power plant according to claim 2, characterized in that: When the submersible pump is placed in the hanging basket, When the spent fuel pool needs to be replenished with water, the control box controls the lifting motor to start forward rotation, driving the cable turntable to start forward rotation, the cable starts to be released from the cable turntable, and the basket and submersible pump descend. When they descend to the lower limit switch in the loading well, the lower limit switch sends a signal to the control box, the lifting motor stops, the basket stops descending, and remains in this position; When the water replenishment is completed, the control box controls the lifting motor to start in reverse, driving the cable turntable to reverse, the cable begins to wrap around the cable turntable, the basket and the submersible pump rise, and when they rise to the upper limit switch in the loading well, the upper limit switch sends a signal to the control box, the lifting motor stops, the basket stops rising, and remains in this position.

4. The method for rapidly replenishing water in a spent fuel pool of a nuclear power plant according to claim 2, characterized in that: There are two ways for the control box to stop the submersible pump: The first one is that when the liquid level in the loading well drops to the level of the float switch, the control box receives a signal from the float switch and issues a stop command to the submersible pump, and the submersible pump stops. The second method is that when the liquid level in the spent fuel pool reaches the required level, the personnel press the stop button on the control box to issue a stop command for the submersible pump, and the submersible pump stops.

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