Method for preventing mistaken dilution of boron concentration in primary loop

Abstract

The invention relates to the technical field of nuclear power plant boron concentration control, and discloses a method for preventing primary loop boron concentration from being mistakenly diluted. According to the working condition information, whether the real-time working condition accords with a preset box changing working condition or not is determined; when the real-time working condition accords with the preset box changing working condition, outputting a switching signal for switching the connection between the suction end of the charging pump and the volume control box to the connection between the suction end of the charging pump and a refueling water tank; wherein the boron concentration of the solution stored in the refueling water tank is greater than that of the solution stored in the volume control box. The method can prevent the boron concentration of the primary loop from being mistakenly diluted, and can improve the safety of a nuclear power plant unit.

Description

Technical Field

[0001] The invention relates to the technical field of boron concentration control in nuclear power plants, and in particular to a method for preventing erroneous dilution of boron concentration in a primary circuit. Background Art

[0002] In a nuclear power plant, an accident may cause accidental boron dilution in the primary circuit, resulting in a potential risk of core drying and melting. For example, when the residual heat removal system is not connected to the reactor coolant system and the plant transformer suddenly loses power, the reactor coolant pump will stop operating and the forced circulation of the primary circuit will be lost. However, since the chemical and volume control systems and the reactor boron and water supply systems powered by the emergency plant equipment busbar can continue to operate, if the dilution is not stopped or the dilution operation is in progress, clean water will accumulate at the entrance of the upper charging pipeline into the primary circuit and in the pump casing of the main pump due to insufficient natural circulation capacity. When the power is restored and the reactor coolant system is restarted, the clean water will be pushed into the core, diluting the boron concentration, resulting in the rapid introduction of positive reactivity, which may cause a supercritical reaction in the reactor. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for preventing the boron concentration in a primary circuit from being accidentally diluted.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing a method for preventing the boron concentration in a circuit from being accidentally diluted, which comprises:

[0005] Obtain working condition information;

[0006] Determining whether the real-time working condition meets the preset box-changing working condition according to the working condition information;

[0007] When the real-time operating condition meets the preset tank-changing operating condition, a switching signal is output to switch the suction end of the charging pump from being connected to the capacity control tank to being connected to the material-changing water tank; wherein the boron concentration of the solution stored in the material-changing water tank is greater than the boron concentration of the solution stored in the capacity control tank.

[0008] Preferably, the operating condition information includes primary circuit related system operating condition information and residual heat removal system operating condition information;

[0009] The step of determining whether the real-time working condition meets the preset box-changing working condition according to the working condition information includes:

[0010] Determining whether the forced circulation functions of the three loops of the primary circuit are lost according to the primary circuit-related system operating condition information;

[0011] determining whether the waste heat removal system is in a connected state with the primary circuit according to the waste heat removal system operating condition information;

[0012] Determining whether the primary circuit is in a low natural circulation flow condition according to the system operating condition information related to the primary circuit;

[0013] When the forced circulation functions of the three loops are lost, the waste heat removal system is not connected to the first loop, and the first loop is in the natural circulation low flow condition, it is determined that the real-time condition meets the preset box-changing condition.

[0014] Preferably, the primary loop related system operating condition information includes the water flow of the three loops and the operating status of the main pumps of the three loops, and the main pump operating status includes the main pump shutdown status and the main pump operation status; the step of determining whether the forced circulation function of the three loops of the primary loop is lost according to the primary loop related system operating condition information includes:

[0015] When the water flow rates of the three loops are all less than the set flow rates or the operating states of the main pumps of the three loops are all in the main pump shutdown state, it is determined that the forced circulation functions of the three loops are lost.

[0016] Preferably, the residual heat removal system operating condition information includes a path state between the suction end of the residual heat removal system and the primary circuit; the step of determining whether the residual heat removal system and the primary circuit are in a connected state according to the residual heat removal system operating condition information includes:

[0017] When the passage state between the suction end of the residual heat removal system and the primary circuit is in a closed state, it is determined that the residual heat removal system and the primary circuit are in a disconnected state.

[0018] Preferably, the primary loop related system operating condition information includes reactor nuclear power, and the step of determining whether the primary loop is in a low natural circulation flow condition according to the primary loop related system operating condition information includes:

[0019] When the nuclear power of the reactor drops from greater than the set power to less than the set power, the time after the first set delay time is set as the start time of the low natural circulation flow rate condition;

[0020] When the nuclear power of the reactor increases from a state less than the set power to a state greater than the set power, the moment after the delay of the second set time is determined as the end moment of the low natural circulation flow rate condition;

[0021] When the reactor nuclear power is within the duration between the start time and the end time, it is determined that the primary circuit is in the natural circulation low flow condition.

[0022] Preferably, the operating condition information also includes nuclear instrument operating condition information;

[0023] The step of determining whether the real-time working condition meets the preset box-changing working condition according to the working condition information further includes:

[0024] Determining whether the reactor is in a shutdown state according to the primary loop related system operating condition information;

[0025] determining whether the neutron flux in the source range is greater than a set flux according to the nuclear instrument operating condition information;

[0026] When the reactor is in a shutdown state and the source range neutron flux is greater than the set flux, it is determined that the real-time operating condition meets the preset tank-changing operating condition.

[0027] Preferably, the method for preventing the primary-loop boron concentration from being accidentally diluted further comprises:

[0028] A third set time is delayed starting at the moment of outputting the switching signal, and after the delay is over, an indication signal is output to prompt the operator to allow manual switching back;

[0029] Determine whether a manual switch-back signal is received;

[0030] When the manual switch-back signal is received, the suction end of the charging pump is switched back from being connected to the material replacement water tank to being connected to the capacity control box.

[0031] Preferably, the method for preventing the primary-loop boron concentration from being accidentally diluted further comprises:

[0032] Determine whether the primary circuit is in a boron dilution condition or a boron water replenishment condition according to the operating condition information;

[0033] When the primary circuit is in the boron dilution condition or when the primary circuit is in the boron water replenishment condition, determining whether the real-time condition meets the requirement of the prohibited dilution condition according to the condition information;

[0034] When the real-time operating condition meets the requirement of the dilution-prohibited operating condition, a dilution-prohibited signal for prohibiting dilution of the boron concentration is output.

[0035] Preferably, when the primary circuit is in a boron dilution condition, the step of determining whether the real-time condition meets the dilution-prohibited condition according to the condition information includes:

[0036] Determining whether the forced circulation functions of the three loops are lost according to the system operating condition information related to the primary loop;

[0037] determining whether the waste heat removal system is in a connected state with the primary circuit according to the operating condition information of the waste heat removal system;

[0038] When the forced circulation functions of the three loops are all lost or the waste heat removal system is in a connected state with the first loop, it is determined that the real-time operating condition meets the dilution-prohibited operating condition.

[0039] Preferably, the primary circuit related system operating condition information also includes the primary circuit measured boron concentration, boric acid tank boron concentration, boric acid flow rate and makeup water flow rate; when the primary circuit is in the boron water makeup operating condition, the step of determining whether the real-time operating condition meets the prohibited dilution operating condition according to the operating condition information comprises:

[0040] Calculate the boron concentration of the make-up water according to the boron concentration of the boric acid box, the boric acid flow rate and the make-up water flow rate, and determine whether the boron concentration of the make-up water is less than the boron concentration actually measured in the primary circuit;

[0041] Calculating the deviation between the measured boron concentration of the primary loop and the boron concentration of the feed water, and determining whether the deviation of the boron concentration of the feed water is greater than a set concentration deviation;

[0042] determining whether the waste heat removal system is in a connected state with the primary circuit according to the operating condition information of the waste heat removal system;

[0043] When the boron concentration of the makeup water is lower than the measured boron concentration of the first loop, the deviation value of the boron concentration of the makeup water is higher than the set concentration deviation value, and the waste heat removal system is connected to the first loop, it is determined that the real-time operating condition meets the prohibited dilution condition.

[0044] The implementation of the present invention has the following beneficial effects: providing a method for preventing the boron concentration in a primary circuit from being accidentally diluted, by obtaining operating condition information, then determining whether the real-time operating condition meets the preset tank-changing operating condition according to the operating condition information, and finally, when the real-time operating condition meets the preset tank-changing operating condition, outputting a switching signal for switching the suction end of the upper charging pump from being connected to the control box to being connected to the refueling water tank, so that the suction end of the upper charging pump can obtain a solution with a higher boron concentration from the refueling water tank than the boron concentration of the water stored in the control box, thereby preventing the boron concentration in the primary circuit from being accidentally diluted, and improving the safety of the nuclear power plant unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0046] Figure 1 is a flowchart of a method for preventing the boron concentration in a primary circuit from being accidentally diluted in some embodiments of the present invention;

[0047] Figure 2 is a flowchart of a procedure for determining whether a real-time operating condition meets a preset box-changing operating condition in some embodiments of the present invention;

[0048] Figure 3is an example diagram of the duration of a low natural circulation flow rate condition in some embodiments of the present invention;

[0049] Figure 4 is a flowchart of a procedure for avoiding excessive dilution of boron concentration in a primary circuit in some embodiments of the present invention;

[0050] Figure 5 is a flowchart of step S212 in some embodiments of the present invention;

[0051] Figure 6 is a logic control diagram for avoiding excessive dilution of boron concentration in a primary circuit in some embodiments of the present invention;

[0052] Figure 7 is a flowchart of a procedure for determining whether the real-time working condition meets the preset box-changing working condition in other embodiments of the present invention;

[0053] Figure 8 It is a schematic diagram of the structure of the refueling water tank, the volume control box and each charging pump in some embodiments of the present invention;

[0054] Fig. 9 is a flowchart of a method for preventing the boron concentration in a primary circuit from being accidentally diluted in other embodiments of the present invention;

[0055] Fig.10 is a circuit structure block diagram of a terminal device in some embodiments of the present invention;

[0056] Fig.11 It is a schematic diagram of the structure of a system for preventing the boron concentration in a circuit from being accidentally diluted in some embodiments of the present invention. DETAILED DESCRIPTION

[0057] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0058] It should be noted that the flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor do they have to be executed in the order described. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0059] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0060] Figure 1The flowchart of the method for preventing the primary loop boron concentration from being accidentally diluted in some embodiments of the present invention is shown in FIG. 1 , which can prevent the primary loop boron concentration from being accidentally diluted, improve the safety of nuclear power plant units, and reduce the probability of core drying and melting. Figure 1 As shown, the method includes step S10, step S20 and step S30.

[0061] Step S10 includes: obtaining operating condition information.

[0062] In this step, the operating condition information may include the operating condition information of the primary circuit related system, the operating condition information of the waste heat removal system and the operating condition information of the nuclear instrument.

[0063] The operating information of the primary loop related system includes some detection information collected during the operation of the primary loop related system to monitor the operating status of the reactor, including but not limited to the reactor status information, the measured boron concentration of the primary loop, the boron concentration of the boric acid box, the boric acid flow rate, the feed water flow rate, the water flow rate of the three loops of the primary loop, and the operating status of the main pumps of the three loops. Among them, the measured boron concentration of the primary loop indicates the measured value of the boric acid concentration of the primary loop (monitored in real time by online instruments), the boric acid concentration of the boric acid box indicates the boric acid concentration in the boric acid box (the boric acid box is used to store boric acid with a higher concentration than the feed water tank), the boric acid flow rate indicates the flow rate of boric acid output by the boric acid box when replenishing water to the primary loop, and the feed water flow rate indicates the clean water flow rate required for the boric acid box to blend the target boric concentration of the primary loop when replenishing water to the primary loop.

[0064] The residual heat removal system operating condition information includes part of the operating information of the residual heat removal system (ie, the RRA system) during operation, and specifically may include the state of the passage between the suction end and the primary circuit of the residual heat removal system.

[0065] The nuclear instrument operating condition information includes the measurement values ​​of some instruments in the nuclear power plant, which may include the source range neutron flux and reactor nuclear power.

[0066] Step S20 includes: determining whether the real-time operating condition meets the preset box-changing operating condition according to the operating condition information.

[0067] In this step, the preset box-changing condition includes a first set condition and a second set condition. Among them, the first set condition is a condition in which a circuit loses both forced circulation capacity and natural circulation capacity; the second set condition is a condition in which the reactor is shut down and the neutron flux in the source range is high. It should be noted that when a circuit is in a low natural circulation flow condition, it is determined that the circuit loses its natural circulation capacity. When the neutron flux in the source range is greater than the set flux, it is determined that the circuit is in a high source range neutron flux condition.

[0068] Further, in some embodiments, the following can be performed: Figure 2Steps S201, S202, S203 and S204 are shown to determine whether the real-time operating condition meets the first set operating condition.

[0069] Step S201 includes: determining whether the forced circulation functions of the three loops of the primary circuit are lost according to the primary circuit related system operating condition information.

[0070] In some embodiments, the system operating condition information related to a loop may include the water flow of the three loops and the operating status of the main pumps of the three loops, and the operating status of the main pumps includes the main pump shutdown status and the main pump operation status. Accordingly, when the water flow is less than the set flow or the operating status of the main pumps of the three loops is the main pump shutdown status, it is determined that the forced circulation function of the three loops is lost.

[0071] In some embodiments, whether the water flow rate of each loop is less than the set flow rate can be determined in the following manner: obtain the measured flow rates output by three flow meters used to collect data for a certain loop (the system operating condition information related to a loop includes the measured flow rates of all flow meters), and determine whether at least two of the three measured flow rates are less than the set flow rate. If so, it is determined that the water flow rate of the loop is less than the set flow rate.

[0072] Optionally, the setting range of the set flow rate may be 83% to 93%, with a preferred value being 88.8% of the rated flow rate.

[0073] Step S202 includes: determining whether the waste heat removal system is in a connected state with a primary circuit according to the waste heat removal system operating condition information.

[0074] In some embodiments, the residual heat removal system operating condition information may include a passage state between the suction end of the residual heat removal system and the primary circuit. Accordingly, when the passage state between the suction end of the residual heat removal system and the primary circuit is closed, it is determined that the residual heat removal system and the primary circuit are in a disconnected state.

[0075] In a nuclear power plant, the suction end of the waste heat removal system and the primary circuit are connected through the pipeline of column A or column B. Therefore, the state of the passage between the suction end of the waste heat removal system and the primary circuit can be determined by the following method: the state information of all valves on the pipeline of column A and the pipeline of column B between the suction end of the waste heat removal system and the primary circuit is obtained (the operating information of the waste heat removal system includes the state information of these valves); when the pipeline of column A is closed due to the closure of at least one valve on the pipeline, and the pipeline of column B is closed due to the closure of at least one valve on the pipeline, the state of the passage between the suction end of the waste heat removal system and the primary circuit is determined to be a closed state.

[0076] It should be noted that since multiple valves are set on the A column pipeline and the B column pipeline, and the connection mode of these valves can include series connection, parallel connection and parallel-series composite form. If each valve is set on a certain column pipeline in a series connection form, then as long as at least one valve in the column pipeline is closed, the column pipeline will be in a closed state; if each valve is set on a certain column pipeline in a parallel connection form, then when all valves in the column pipeline are closed, the column pipeline is in a closed state; if each valve is set on a certain column pipeline in a parallel connection composite form, at least one valve connected in series connection will be closed to make the column pipeline in a closed state, or all valves connected in series connection will be closed to make the column pipeline in a closed state.

[0077] Step S203 includes: determining whether the primary circuit is in a low natural circulation flow condition according to the primary circuit related system condition information.

[0078] In some embodiments, the nuclear instrument operating condition information may include the reactor nuclear power. Accordingly, it may be determined whether the primary circuit is in a low natural circulation flow condition by executing the following steps S2031, S2032 and S2033.

[0079] Step S2031 includes: when the nuclear power of the reactor drops from a state greater than the set power to a state less than the set power, the moment after the first set delay time is set as the start moment of the low natural circulation flow condition.

[0080] Specifically, see Figure 3 , when the nuclear power of the reactor drops from a state greater than the set power P1 to a state less than the set power P1, the first set time △T1 is delayed, and the end time of the first set time △T1 is the start time of the low natural circulation flow condition. Figure 3 In the illustrated embodiment, both point A and point B are the start time of the natural circulation low flow condition.

[0081] Optionally, the setting range of the set power may be 38% to 42%, with a preferred value being 40% of the rated power.

[0082] Step S2032 includes: when the nuclear power of the reactor increases from a state of less than the set power to a state of greater than the set power, the moment after the delay of the second set time is determined as the end moment of the low natural circulation flow condition.

[0083] Specifically, see Figure 3 , when the nuclear power of the reactor rises from less than the set power P1 to greater than the set power P1, the second set time △T2 is delayed, and the end time of the second set time △T2 is the end time of the low natural circulation flow condition. Figure 3 In the illustrated embodiment, both point C and point D are the end moments of the natural circulation low flow condition.

[0084] Step S2033 includes: when the nuclear power of the reactor is within the duration between the start time and the end time, determining that the primary circuit is in the low natural circulation flow condition. It can be understood that the primary circuit will enter the low natural circulation flow condition at the start time of the low natural circulation flow condition, and exit the low natural circulation flow condition at the end time of the low natural circulation flow condition.

[0085] Step S204 includes: when the forced circulation functions of the three loops are lost, the waste heat removal system is not connected to one loop and one loop is in a natural circulation low flow condition, determining that the real-time condition meets the preset box change condition (i.e. meets the first set condition).

[0086] In order to avoid excessive dilution of the boron concentration in the primary loop, in some embodiments, Figure 4 As shown, the method for preventing the boron concentration in a loop from being accidentally diluted also includes step S211, step S212 and step S213.

[0087] Step S211 includes: determining whether a circuit is in a boron dilution condition or a boron water replenishment condition according to the operating condition information.

[0088] In this step, the operating condition information includes a boron dilution operating condition signal indicating that a circuit is diluting the boric acid concentration of the circuit (only clean water is injected into the circuit), and a boron water replenishment operating condition signal indicating that the circuit is replenishing boron water (high-concentration boric water and clean water are injected into the circuit in proportion). When a boron dilution operating condition signal is received, it indicates that the circuit is in a boron dilution operating condition, and when a boron water replenishment operating condition signal is received, it indicates that the circuit is in a boron water replenishment operating condition.

[0089] It should be noted that both the boron dilution operating condition signal and the boron water replenishment operating condition signal can be issued by the existing relevant systems of the nuclear power plant, which will not be described in detail here.

[0090] Step S212 includes: when a circuit is in a boron dilution condition or a boron water replenishment condition, determining whether the real-time condition meets the prohibited dilution condition according to the condition information.

[0091] The operating condition information includes the operating condition information of the primary circuit related system and the operating condition information of the waste heat removal system. In some embodiments, please refer to Figure 5 and Figure 6 When the primary circuit is in the boron dilution condition, the specific steps of determining whether the real-time condition meets the dilution-prohibited condition according to the condition information may include step S2121, step S2122 and step S2123:

[0092] Step S2121 includes: determining whether the forced circulation functions of the three loops are lost according to the system operating condition information related to the primary loop. It should be noted that the specific steps for determining whether the forced circulation functions of the three loops are lost can be referred to above and will not be repeated here.

[0093] Step S2122 includes: determining whether the waste heat removal system is connected to the primary circuit according to the waste heat removal system operating condition information. It should be noted that the specific steps for determining whether the waste heat removal system is connected to the primary circuit can be referred to above and will not be repeated here.

[0094] Step S2123: When the forced circulation functions of the three loops are lost or the waste heat removal system is connected to one loop, it is determined that the real-time operating condition meets the prohibited dilution condition.

[0095] See also Figure 6 In this embodiment, if the forced circulation function of the three loops in the first circuit is lost or the dilution operation is performed when the waste heat removal system is connected to the first circuit, it may cause the boron concentration in the first circuit to be excessively diluted. Therefore, it is necessary to stop and prohibit the dilution of the boron concentration in the first circuit, which meets the prohibited dilution working condition.

[0096] In addition, the specific methods for determining whether the three loops have lost their forced circulation function and whether the waste heat removal system is in a connected state with a loop can be referred to the above embodiments and will not be described in detail here.

[0097] In some embodiments, the primary loop related system includes the primary loop measured boron concentration, boric acid tank boron concentration, boric acid flow rate and feed water flow rate; accordingly, please refer to Figure 6 When the primary circuit is in a boron water replenishment condition, the specific steps of determining whether the real-time condition meets the prohibited dilution condition according to the condition information may include: calculating the boron concentration of the replenishment water according to the boron concentration of the boric acid box, the boric acid flow rate and the replenishment water flow rate, and determining whether the boron concentration of the replenishment water is less than the actual boron concentration of the primary circuit; calculating the deviation between the actual boron concentration of the primary circuit and the boron concentration of the replenishment water, and determining whether the deviation of the boron concentration of the replenishment water is greater than the set concentration deviation; determining whether the residual heat removal system is in a connected state with the primary circuit according to the condition information of the residual heat removal system; when the boron concentration of the replenishment water is less than the actual boron concentration of the primary circuit, the deviation is greater than the set concentration deviation, and the residual heat removal system is in a connected state with the primary circuit, it is determined that the real-time condition meets the prohibited dilution condition.

[0098] In this embodiment, when the boron concentration of the make-up water is lower than the actually measured boron concentration of the first circuit and the deviation value is greater than the set concentration deviation value, it means that during the boron water replenishment process of the first circuit, the water flow rate is too large and / or the boric acid flow rate is too small, resulting in the blended make-up water boron concentration being lower than the actually measured boron concentration of the first circuit. If the waste heat discharge system is connected to the first circuit at this time, continuing to replenish water will cause the boron concentration to continue to decrease. Therefore, it is necessary to stop and prohibit the dilution of the boron concentration of the first circuit, which meets the prohibited dilution condition.

[0099] In some embodiments, please refer to Figure 6 , the calculation step of the boron concentration of the replenishing water of a circuit can be realized by the replenishing water boron concentration calculation unit. After the replenishing water boron concentration is calculated by the replenishing water boron concentration calculation unit, it will be input to the second comparison unit. The comparison step of comparing the deviation value of the boron concentration of the replenishing water with the set concentration deviation value is realized by the first comparison unit. The first comparison unit will output a setting signal that can represent the comparison result (such as a high level indicating that the deviation value of the boron concentration of the replenishing water is greater than the set concentration deviation value) to the AND gate connected thereto according to the comparison result. The comparison step of the boron concentration of the replenishing water and the measured boron concentration of a circuit is also realized by the second comparison unit. The second comparison unit will output a setting signal that can represent the comparison result (such as a high level indicating that the boron concentration of the replenishing water is less than the measured boron concentration of a circuit) to the AND gate connected thereto according to the comparison result. Finally, the comparison results output by the first comparison unit and the second comparison unit are subjected to an AND logic operation, and the AND operation result signal is output.

[0100] Since the measured boron concentration in a circuit, the boron concentration in the boric acid box, the boric acid flow rate and the make-up water flow rate are volatile in actual measurements, in order to avoid frequent misidentification that the real-time operating condition meets the prohibited dilution condition, in some embodiments, the occurrence of this situation can also be reduced by executing the following steps: the comparison results output by the first comparison unit and the second comparison unit are subjected to post-delay processing after the AND logic operation, so that the AND operation result is flipped only after the delay set time, so as to avoid frequent misidentification that the real-time operating condition meets the prohibited dilution condition.

[0101] Furthermore, in some embodiments, Figure 6 As shown, the method for preventing the boron concentration in a circuit from being accidentally diluted also includes the following steps: when the first circuit is in a boron water replenishment condition, when the boron concentration of the replenishment water is less than the actually measured boron concentration in the first circuit and the deviation value is greater than the set concentration deviation value, a low replenishment water boron concentration alarm signal (signal REA509AA) is output to remind the staff that the boron concentration of the replenishment water is low and the boric acid flow rate and / or the replenishment water flow rate need to be adjusted in time.

[0102] Step S213 includes: when the real-time operating condition meets the dilution prohibiting condition, outputting a dilution prohibiting signal for prohibiting dilution of the boron concentration.

[0103] In this step, by inputting a dilution prohibition signal into a related system for controlling boron dilution, the dilution of the first loop can be suspended and prohibited, thereby preventing the boron concentration of the first loop from being excessively diluted.

[0104] In some embodiments, the primary loop related system operating information may also include reactor status information, including shutdown status and startup status; the nuclear instrument operating information includes source range neutron flux. Accordingly, the following may be performed: Figure 7 Steps SS201, SS202 and SS203 are shown to determine whether the real-time operating condition meets the second set operating condition.

[0105] Step SS201 includes: determining whether the reactor is in a shutdown state according to the primary loop related system operating condition information.

[0106] In this step, the primary loop related system monitors whether the reactor is in a shutdown state and outputs a predetermined function. Therefore, the reactor status information can be obtained by interacting with the existing primary loop related system to determine whether the reactor is in a shutdown state.

[0107] Step SS202 includes: determining whether the source range neutron flux is greater than the set flux according to the nuclear instrument operating condition information. In this step, when the source range neutron flux is greater than the set flux, it is determined that the primary circuit is in a source range neutron flux high operating condition. In addition, the source range neutron flux is used to characterize the reactor neutron flux level during the reactor subcritical period. It is one of the important parameters for monitoring the reactor power and status in a nuclear power plant, and is measured by the existing source range neutron measurement channel in the nuclear power plant.

[0108] In some embodiments, the range of the set flux can be 6.98×10 -10 Ampere to 7.02×10 -10 Ampere, the preferred value is 7×10 -10 ampere.

[0109] Step SS203 includes: when the reactor is in a shutdown state and the source range neutron flux is greater than the set flux, determining that the real-time operating condition meets the preset tank change operating condition (ie, meets the second set operating condition).

[0110] Step S30 includes: when the real-time working condition meets the preset tank-changing working condition, outputting a switching signal for switching the suction end of the charging pump from being connected to the capacity control box to being connected to the material-changing water tank.

[0111] Specifically, see Figure 8The first route of the suction end of each charging pump is connected to the capacity control box through valve RCV375VP and valve RCV376VP, the second route is connected to the capacity control box through valve RCV034VP and valve RCV033VP, the third route is connected to the refueling water tank through valve RIS012VP, and the fourth route is connected to the refueling water tank through valve RI S013VP.

[0112] Accordingly, the switching signal may include multiple first valve control signals, and the multiple first valve control signals are used to control at least one of valve RCV375VP and valve RCV376VP to be closed, control at least one of valve RCV034VP and valve RCV033VP to be closed, and control at least one of valve RIS012VP and valve RIS013VP to be opened when the real-time operating conditions meet the preset box-changing conditions. It can be understood that when at least one of the valves RCV375VP and RCV376VP is closed and at least one of the valves RCV034VP and RCV033VP is closed, it is equivalent to disconnecting the connection between the volume control box and each charging pump, and at least one of the control valves RI S012VP and RI S013VP is opened, which is equivalent to connecting the connection between the refueling water tank and each charging pump, so that the suction end of the charging pump can take water from the refueling water tank. Since the boron concentration of the solution stored in the refueling water tank is greater than the boron concentration of the solution stored in the volume control box, the solution with a higher boron concentration is injected into the charging pump, thereby preventing the dilution of the boron concentration in the first circuit. It should be noted that the boron concentration of the solution in the refueling water tank is less than the boron concentration of the solution stored in the boric acid tank.

[0113] To avoid excessive boronization of a loop, in some embodiments, as Fig. 9 As shown, after step S30, step S40, step S50 and step S60 may also be included.

[0114] Step S40 includes: starting a delay of a third set time at the moment of outputting the switching signal, and outputting an indication signal for prompting the operator to manually switch back after the delay ends. The operation indication signal may be information from a transmitting end display terminal or a mobile terminal.

[0115] Step S50 includes: determining whether a manual switch-back signal is received.

[0116] In this step, a manual switch-back signal can be obtained through a human-computer interaction unit (such as a mouse, keyboard, voice control module, touch screen, etc.). Specifically, the staff can input the manual switch-back signal by operating the human-computer interaction unit.

[0117] Step S60 includes: when a manual switch-back signal is received, switching the suction end of the charging pump from being connected to the material exchange water tank back to being connected to the capacity control box.

[0118] Specifically, see Figure 8 When a switch-back signal is received, multiple second valve control signals can be output. The multiple second valve control signals are used to control the opening of valves RCV375VP, RCV376VP, RCV034VP and RCV033VP, and to control the closing of valves RI S012VP and RI S013VP. In this way, the suction end of the charging pump can be turned to draw water from the control tank, so that each charging pump can be restored to the state of drawing water from the control tank.

[0119] like Fig.10 As shown, the present invention also provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for preventing the incorrect dilution of the boron concentration in a single circuit provided in an embodiment of the invention are implemented.

[0120] like Fig.11 As shown, the present invention also provides a first-loop boron concentration mis-dilution system, including the terminal device provided in the embodiment of the present invention, and a control box control unit and a refueling water tank control unit connected to the processor in the terminal device for communication. The control box control unit may include Figure 8 The valve RCV375VP, valve RCV376VP, valve RCV034VP and valve RCV033VP shown, the refueling tank control unit may include Figure 8 The valve RI S012VP and valve RI S013VP shown. When the processor executes the computer program and determines that the real-time working condition meets the preset tank change working condition, multiple first valve control signals will be input to the control box control unit and the refueling water tank control unit to control at least one of the valves RCV375VP and RCV376VP to be closed, control at least one of the valves RCV034VP and RCV033VP to be closed, and control at least one of the valves RIS012VP and RI S013VP to be opened, so as to switch the suction end of the upper charging pump from being connected to the control box to being connected to the refueling water tank, so that the suction end of the upper charging pump obtains a solution with a higher boron concentration from the refueling water tank than the boron concentration of the water stored in the control box, thereby preventing the boron concentration in the primary circuit from being accidentally diluted.

[0121] In some embodiments, Fig.11As shown, the first-loop boron concentration mis-dilution system may also include a human-computer interaction unit (such as a mouse, keyboard, voice control module, touch screen, etc.). The human-computer interaction unit is communicatively connected to the processor in the terminal device, and the staff can input a manual switch-back signal by operating the human-computer interaction unit. When the processor receives the manual switch-back signal, it will output multiple second valve control signals to the control box control unit and the refueling water tank control unit. The second valve control signal can control the valve RCV375VP, valve RCV376VP, valve RCV034VP and valve RCV033VP in the control box control unit to open, so as to connect the connection between the control box and each upper charging pump. The second valve control signal can also control the valve RI S012VP and valve RI S013VP in the refueling water tank control unit to close, so as to disconnect the connection between the refueling water tank and each upper charging pump. The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0122] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0123] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0124] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A method for preventing the boron concentration in a primary circuit from being accidentally diluted, characterized in that: The method for preventing the primary loop boron concentration from being accidentally diluted comprises: Obtain working condition information; Determining whether the real-time working condition meets the preset box-changing working condition according to the working condition information; When the real-time operating condition meets the preset tank-changing operating condition, a switching signal is output to switch the suction end of the charging pump from being connected to the capacity control tank to being connected to the material-changing water tank; wherein the boron concentration of the solution stored in the material-changing water tank is greater than the boron concentration of the solution stored in the capacity control tank.

2. The method for preventing the primary loop boron concentration from being accidentally diluted according to claim 1, characterized in that: The operating condition information includes operating condition information of a primary circuit-related system and operating condition information of a waste heat removal system; the step of determining whether the real-time operating condition meets the preset box-changing operating condition according to the operating condition information includes: Determining whether the forced circulation functions of the three loops of the primary circuit are lost according to the primary circuit related system operating condition information; determining whether the waste heat removal system is in a connected state with the primary circuit according to the waste heat removal system operating condition information; Determining whether the primary circuit is in a low natural circulation flow condition according to the system operating condition information related to the primary circuit; When the forced circulation functions of the three loops are lost, the waste heat removal system is not connected to the first loop, and the first loop is in the natural circulation low flow condition, it is determined that the real-time condition meets the preset box-changing condition.

3. The method for preventing the primary loop boron concentration from being accidentally diluted according to claim 2, characterized in that: The system operating condition information related to the primary loop includes the water flow of the three loops and the operating status of the main pumps of the three loops, and the operating status of the main pump includes the main pump shutdown status and the main pump operation status; the step of determining whether the forced circulation function of the three loops of the primary loop is lost according to the system operating condition information related to the primary loop includes: When the water flow rates of the three loops are all less than the set flow rates or the operating states of the main pumps of the three loops are all in the main pump shutdown state, it is determined that the forced circulation functions of the three loops are lost.

4. The method for preventing the primary loop boron concentration from being accidentally diluted according to claim 2, characterized in that: The residual heat removal system operating condition information includes a path state between the suction end of the residual heat removal system and the primary circuit; the step of determining whether the residual heat removal system and the primary circuit are in a connected state according to the residual heat removal system operating condition information includes: When the passage state between the suction end of the residual heat removal system and the primary circuit is in a closed state, it is determined that the residual heat removal system and the primary circuit are in a disconnected state.

5. The method for preventing the primary loop boron concentration from being accidentally diluted according to claim 2, characterized in that: The primary loop related system operating condition information includes reactor nuclear power, and the step of determining whether the primary loop is in a low natural circulation flow condition according to the primary loop related system operating condition information includes: When the nuclear power of the reactor drops from greater than the set power to less than the set power, the time after the first set delay time is set as the start time of the low natural circulation flow rate condition; When the nuclear power of the reactor increases from a state less than the set power to a state greater than the set power, the moment after the delay of the second set time is determined as the end moment of the low natural circulation flow rate condition; When the reactor nuclear power is within the duration between the start time and the end time, it is determined that the primary circuit is in the natural circulation low flow condition.

6. The method for preventing the primary circuit boron concentration from being accidentally diluted according to claim 2, characterized in that: The operating condition information also includes nuclear instrument operating condition information; the step of determining whether the real-time operating condition meets the preset box change operating condition according to the operating condition information also includes: Determining whether the reactor is in a shutdown state according to the primary loop related system operating condition information; Determining whether the neutron flux in the source range is greater than a set flux according to the nuclear instrument operating condition information; When the reactor is in a shutdown state and the source range neutron flux is greater than the set flux, it is determined that the real-time operating condition meets the preset tank-changing operating condition.

7. The method for preventing the primary circuit boron concentration from being accidentally diluted according to claim 1, characterized in that: The method for preventing the primary loop boron concentration from being accidentally diluted also includes: A third set time is delayed starting at the moment of outputting the switching signal, and after the delay is over, an indication signal is output to prompt the operator to allow manual switching back; Determine whether a manual switch-back signal is received; When the manual switch-back signal is received, the suction end of the charging pump is switched back from being connected to the material exchange water tank to being connected to the capacity control box.

8. The method for preventing the primary circuit boron concentration from being accidentally diluted according to any one of claims 2 to 7, characterized in that: The method for preventing the primary loop boron concentration from being accidentally diluted also includes: Determine whether the primary circuit is in a boron dilution condition or a boron water replenishment condition according to the operating condition information; When the primary circuit is in the boron dilution condition or when the primary circuit is in the boron water replenishment condition, determining whether the real-time condition meets the requirement of the prohibited dilution condition according to the condition information; When the real-time operating condition meets the requirement of the dilution-prohibited operating condition, a dilution-prohibited signal for prohibiting dilution of the boron concentration is output.

9. The method for preventing the primary circuit boron concentration from being accidentally diluted according to claim 8, characterized in that: When the primary circuit is in a boron dilution operating condition, the step of determining whether the real-time operating condition meets the dilution-prohibited operating condition according to the operating condition information comprises: Determining whether the forced circulation functions of the three loops are lost according to the system operating condition information related to the primary loop; determining whether the waste heat removal system is in a connected state with the primary circuit according to the operating condition information of the waste heat removal system; When the forced circulation functions of the three loops are all lost or the waste heat removal system is in a connected state with the first loop, it is determined that the real-time operating condition meets the dilution-prohibited operating condition.

10. The method for preventing the primary circuit boron concentration from being accidentally diluted according to claim 8, characterized in that: The primary circuit related system operating condition information also includes the primary circuit measured boron concentration, boric acid tank boron concentration, boric acid flow rate and make-up water flow rate; when the primary circuit is in the boron water make-up condition, the step of determining whether the real-time operating condition meets the prohibited dilution condition according to the operating condition information comprises: Calculate the boron concentration of the make-up water according to the boron concentration of the boric acid box, the boric acid flow rate and the make-up water flow rate, and determine whether the boron concentration of the make-up water is less than the boron concentration actually measured in the primary circuit; Calculating the deviation between the measured boron concentration of the primary loop and the boron concentration of the feed water, and determining whether the deviation of the boron concentration of the feed water is greater than a set concentration deviation; determining whether the waste heat removal system is in a connected state with the primary circuit according to the operating condition information of the waste heat removal system; When the boron concentration of the makeup water is lower than the measured boron concentration of the first loop, the deviation value of the boron concentration of the makeup water is higher than the set concentration deviation value, and the waste heat removal system is connected to the first loop, it is determined that the real-time operating condition meets the prohibited dilution condition.

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