A method and system for controlling a pressurized water reactor critical process
Patent Information
- Application Number
- CN202311577784.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-23
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2043-11-23
AI Technical Summary
Traditional reactor criticality process control methods cannot accurately determine the state of the reactor before and during criticality, resulting in a heavy workload for operators, high human risk, and difficulty in achieving precise control of the reactor startup process.
By controlling the position of the control rods and the reactor cycle in stages, and collecting the first characteristic information in real time, the reactor criticality process is automatically controlled by using technical means through continuous rod lifting in the first stage and fast and slow step-up rod lifting in the second stage, based on the first and second characteristic information.
It reduces the burden on operators and human-caused risks, improves the automation and intelligence level of the reactor start-up process, and achieves precise control of the reactor critical process.
Smart Images
Figure CN117369395B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of reactor start-up control technology, and more specifically to a method and system for controlling the critical process of a pressurized water reactor. Background Technology
[0002] Reactor criticality control is one of the most important control technologies in reactor startup control, playing a crucial role in the normal and rapid commissioning of nuclear power plants. The reactor criticality process is characterized by nonlinearity, rapid response, and high risk, making reactor criticality control differ from conventional control processes and complicating automatic control methods. Furthermore, during the reactor criticality stage, the core power level is low, making reactor power level measurement difficult and preventing it from being used as an effective control input, further increasing the difficulty of control.
[0003] Traditional methods for controlling the critical process of nuclear reactors involve measuring the neutron flux level in the reactor before introducing reactivity; introducing reactivity into the reactor by raising rods, diluting, or loading / unloading refueling; waiting for the neutron flux level to stabilize and for the doubling period to be greater than 2000 seconds; and then using critical extrapolation calculations to obtain extrapolated critical parameters to determine the critical state.
[0004] The patent, "Power Control Device and Power Control Method for Reactors," describes a power control device and method for nuclear reactors. The power control device includes: an input module configured to receive a target power value input by a user; a measurement module configured to measure the actual power value of the nuclear reactor; a control module configured to calculate a relative power deviation based on the target power value and the actual power value, and to obtain operating information of control rods based on the relative power deviation; and a drive module configured to drive the control rods to operate based on the operating information. Summary of the Invention
[0005] The technical problem this invention aims to solve is that, since the current reactor criticality process is manually controlled, the operators bear a heavy burden and face significant human-caused risks. Traditional methods of controlling the nuclear reactor criticality process through criticality extrapolation calculations cannot accurately determine the reactor's state before and during criticality, making it difficult to achieve precise control of the reactor startup process. The purpose of this invention is to provide a pressurized water reactor (PWR) reactor criticality process control method and system. Based on existing PWR reactor criticality process control technology, this invention improves the method by controlling the position of the control rods and the phased control of the control rod lifting during the reactor cycle, thus solving the problem of automatic control during the reactor criticality process.
[0006] This invention is achieved through the following technical solution:
[0007] This solution provides a method for controlling the critical processes of a pressurized water reactor, including:
[0008] Phase 1: Real-time acquisition of first feature information, including the position of the control rod and the reactor cycle. Based on the first feature information, the control rod is continuously raised in real time to continuously introduce reactivity until a certain amount is reached and the reactor enters the critical cycle identification zone.
[0009] The second stage: After the reactor enters the critical cycle identification zone, the second characteristic information is collected in real time. The second characteristic information includes the position of the control rod, the reactor cycle, and the rate of change of the reactor cycle. Based on the second characteristic information, the control rod is first lifted in a fast step and then lifted in a slow step to linearly introduce reactivity until the reactor reaches criticality.
[0010] The working principle of this solution: The operation of a reactor criticality process is complex and involves significant human risk. Traditional methods for controlling the criticality process of a nuclear reactor through criticality extrapolation calculations cannot accurately determine the state of the reactor before and at criticality, making it difficult to achieve precise control of the reactor startup process. The purpose of this invention is to provide a method and system for controlling the criticality process of a pressurized water reactor. Based on existing pressurized water reactor criticality process control technology, this invention improves the method by controlling the position of the control rods and the phased control of the control rod lifting during the reactor cycle, thus solving the problem of automatic control during the reactor criticality process.
[0011] In the process of a pressurized water reactor moving from subcritical to critical state, the determination of reactor criticality is crucial. In actual criticality processes, it is not possible to determine whether the reactor has reached criticality by measuring reactivity. However, this scheme calculates the introduction of reactivity based on the measured changes in reactor cycle and the position of control rods, thereby determining whether the reactor has reached criticality.
[0012] Considering the critical process of an external neutron source, the reactor period does not tend to infinity and will have a positive period for a certain period of time. Since the neutron density in the reactor is in a stable state before the introduction of reactivity, the reactor period tends to infinity. Near the criticality, the reactor period will enter the critical period identification region (reactor period T∈(T1,T2)), and the closer the reactor is to the criticality, the longer the reactor period stays in the critical period identification region. When the reactor stays in the critical period identification region for more than a certain period of time, it can be determined that the reactor has reached the criticality.
[0013] A further optimized scheme is as follows: the real-time control of the control rods based on the first feature information continuously raises the rods, continuously introducing reactivity until the reactor enters the critical cycle identification zone, including the following method:
[0014] S1, raise the D group control rod at the first rod speed until the position of the D group control rod reaches the D group threshold, then proceed to step S2.
[0015] S2, raise the control rod of group E1 at the second rod speed, and determine whether the position of the control rod of group E1 has reached the threshold of group E1. If yes, proceed to step S3; otherwise, proceed to step S4.
[0016] S3, raise the E2 group control rod at the third rod speed, and determine whether the position of the E2 group control rod has reached the E2 group threshold. If so, the reactor enters the critical period identification zone and ends the introduction of reactivity; otherwise, proceed to S5.
[0017] S4. Determine whether the reactor cycle has reached the cycle threshold. If so, the reactor enters the critical cycle identification zone and the introduction of reactivity ends; otherwise, return to step S2.
[0018] S5, determine whether the reactor cycle has reached the cycle threshold. If so, the reactor enters the critical cycle identification zone and the introduction of reactivity ends; otherwise, return to step S3.
[0019] During this process, the reactor cycle is monitored, and the process should be stopped when the cycle is less than 80 seconds.
[0020] A further optimized solution is that the speed of the first rod is greater than the speeds of the second and third rods.
[0021] A further optimized solution is that the first bar speed is a 3-speed bar speed, and the second and third speeds are both 2-speed bar speeds.
[0022] A further optimized solution is that the rapid stepping rod lifting method includes:
[0023] M1, step-lift C-group control bar;
[0024] M2, determine whether the current reactor cycle is less than the given cycle value T1, and whether the rate at which the reactor cycle decreases is greater than the given cycle rate value dT1. If so, proceed to step M3; otherwise, proceed to step M4.
[0025] M3, maintain the current rod lifting of control rod C until the reactor cycle is greater than the cycle setpoint T2, then complete the current rod lifting and proceed to the next rod lifting step;
[0026] M4: Determine if the current reactor cycle is within the cycle constraint range. If yes, proceed to step M3. Otherwise, determine if the current rod lifting height is less than the height threshold H. If yes, complete the fast-step rod lifting. Otherwise, proceed to M5.
[0027] M5 determines whether the current position of the control rod in group C has reached the estimated critical position. If so, the rod is lifted quickly; otherwise, it returns to M1.
[0028] A further optimization scheme is to set the period constraint interval to (30s, 80s).
[0029] A further optimized solution is that the slow step-up lifting method includes:
[0030] G1, step-up C-group control bar;
[0031] G2: Determine whether the reactor period is less than the given period value T4 and the rate at which the reactor period decreases is greater than the given period rate value dT2. If so, proceed to G3; otherwise, proceed to G4.
[0032] G3: Maintain the current lifting of the control rods in group C and determine whether the reactor cycle meets the critical condition: the reactor cycle is stable within the critical cycle threshold range for more than 30 seconds; if so, the reactor has reached criticality; otherwise, proceed to G5.
[0033] G4: Determine whether the reactor cycle is stable within the critical cycle threshold range. If yes, proceed to step G3; otherwise, return to step G1.
[0034] G5 checks if the reactor period is greater than the given period value T3. If so, the current rod lifting is completed and the next rod lifting is performed; otherwise, it returns to G3.
[0035] A further optimization scheme is that the critical period threshold range is (30, 80) s.
[0036] This solution provides a critical process control system for a pressurized water reactor, used to implement the aforementioned critical process control method for a pressurized water reactor, including:
[0037] The acquisition module is used to acquire first feature information in real time, the first feature information including the position of the control rods and the reactor cycle;
[0038] The first control module is used to control the continuous lifting of the control rod based on the first feature information in real time, continuously introducing reactivity until the reactor enters the critical cycle identification zone.
[0039] The acquisition module is also used to acquire second feature information in real time after the reactor enters the critical cycle identification zone. The second feature information includes the position of the control rod, the reactor cycle, and the reactor cycle change rate.
[0040] The second control module is used to control the control rods in real time based on the second feature information, first by rapidly raising the rods, then by slowly raising them, linearly introducing reactivity until the reactor reaches criticality.
[0041] A further optimized solution is that the acquisition module includes a rod position measuring device and a period measuring device;
[0042] Both the first control module and the second control module are connected to the reactor. The rod position measuring device is used to measure the position of the control rods and is connected to both the first control module and the second control module. The period measuring device is used to measure the reactor period and is connected to both the first control module and the second control module.
[0043] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0044] This invention provides a method for controlling the critical process of a pressurized water reactor (PWR). Based on existing PWR critical process control technology, the method improves upon existing techniques by dividing the reactivity introduction control into two stages. This is achieved by controlling the position of the control rods and the staged lifting of the control rods according to the reactor cycle. The introduction of reactivity is calculated based on measured reactor cycle changes and the control rod positions, thereby determining whether the reactor has reached a critical state. This invention solves the problem of automatic control during the reactor critical process.
[0045] This invention provides a critical process control method for pressurized water reactors. Addressing the nonlinear, fast-response, and high-risk characteristics of the reactor critical process, this method uses the reactor source region cycle as the control input and designs an expert control rule based on operator or expert experience. Automatic control rules are designed according to different stages, and an automatic control scheme is proposed to achieve automatic control of reactor criticality, thereby improving the automation and intelligence level of reactor startup control. Attached Figure Description
[0046] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:
[0047] Figure 1 This is a schematic diagram of the critical process control method for pressurized water reactors;
[0048] Figure 2 Schematic diagram of the first stage continuous rod lifting control process;
[0049] Figure 3 Schematic diagram of the control structure in the first stage;
[0050] Figure 4 Schematic diagram of the rapid stepping rod lifting control process in the second stage;
[0051] Figure 5 The control structure diagram for the second stage;
[0052] Figure 6 A schematic diagram of the slow and fast step-up control process for the second stage. Detailed Implementation
[0053] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.
[0054] This invention provides the following embodiments of an automatic control method for reactor criticality, which reduces the number of operators and their workload during reactor criticality, reduces human error, and improves safety; further improving the automation and intelligence level of the reactor criticality process during reactor cold start.
[0055] Example 1
[0056] This embodiment provides a method for controlling the critical process of a pressurized water reactor, dividing the reactivity introduction control into two stages: The first stage involves continuously introducing reactivity by raising the control rods when the reactor is far from criticality; the second stage involves introducing reactivity by rapidly raising the control rods in stages when the reactor is close to criticality. Figure 1 As shown;
[0057] Phase 1: Real-time acquisition of first characteristic information, including the position of the control rods and the reactor cycle. Based on the first characteristic information, the control rods are continuously raised in real time to continuously introduce reactivity until the reactor enters the critical cycle identification zone. During this process, the position of the control rods and the reactor cycle are monitored. The reactor cycle will decrease accordingly. After a certain amount of reactivity is continuously introduced (by continuously raising the control rods), the reactor will enter the critical cycle identification zone.
[0058] Based on the first characteristic information, the control rods are continuously raised in real time to continuously introduce reactivity until the reactor enters the critical cycle identification zone, such as... Figure 2 As shown, the methods include:
[0059] S1, raise the D group control rod at the first rod speed until the position of the D group control rod reaches the D group threshold, then proceed to step S2.
[0060] S2, raise the control rod of group E1 at the second rod speed, and determine whether the position of the control rod of group E1 has reached the threshold of group E1. If yes, proceed to step S3; otherwise, proceed to step S4.
[0061] S3, raise the E2 group control rod at the third rod speed, and determine whether the position of the E2 group control rod has reached the E2 group threshold. If so, the reactor enters the critical period identification zone and ends the introduction of reactivity; otherwise, proceed to S5.
[0062] S4. Determine whether the reactor cycle has reached the cycle threshold. If so, the reactor enters the critical cycle identification zone and the introduction of reactivity ends; otherwise, return to step S2.
[0063] S5, determine whether the reactor cycle has reached the cycle threshold. If so, the reactor enters the critical cycle identification zone and the introduction of reactivity ends; otherwise, return to step S3.
[0064] The speed of the first rod is greater than the speeds of the second and third rods.
[0065] The first speed is 3, and the second and third speeds are both 2.
[0066] During this process, the positions of the control rods and the reactor cycle are monitored to prevent accidents. If the reactor cycle becomes too low, such as less than 80 seconds, the process should be stopped. Therefore, the controller input should be the given rod positions and cycles for each group of rods. Referring to the manual rod lifting procedure, when lifting group D rods, a rod speed of level 3 is used; when lifting groups E1 and E2 rods, a rod speed of level 2 is used. The control structure diagram for the first stage is as follows: Figure 3 As shown.
[0067] The second stage: After the reactor enters the critical cycle identification zone, the second characteristic information is collected in real time. The second characteristic information includes the position of the control rod, the reactor cycle, and the rate of change of the reactor cycle. Based on the second characteristic information, the control rod is first lifted in a fast step and then lifted in a slow step to linearly introduce reactivity until the reactor reaches criticality.
[0068] like Figure 4 As shown, the rapid stepping bar lifting method includes:
[0069] M1, step-lift C-group control bar;
[0070] M2, determine whether the current reactor cycle is less than the given cycle value T1, and whether the rate at which the reactor cycle decreases is greater than the given cycle rate value dT1. If so, proceed to step M3; otherwise, proceed to step M4.
[0071] M3, maintain the current rod lifting of control rod C until the reactor cycle is greater than the cycle setpoint T2, then complete the current rod lifting and proceed to the next rod lifting step;
[0072] M4: Determine if the current reactor cycle is within the cycle constraint range. If yes, proceed to step M3. Otherwise, determine if the current rod lifting height is less than the height threshold H. If yes, complete the fast-step rod lifting. Otherwise, proceed to M5.
[0073] M5 determines whether the current position of the control rod in group C has reached the estimated critical position. If so, the rod is lifted quickly; otherwise, it returns to M1.
[0074] The periodic constraint interval is (30s, 80s).
[0075] This process involves lifting rod C in a discontinuous, step-by-step manner. The introduction of reactivity can be considered as a linear introduction during the lifting process, and a constant introduction between lifting intervals. The termination condition for each lifting step is: the period enters the range of 30-80 seconds; or, the period is less than a given value T1, and the rate of period decrease is greater than the given period rate dT1. The starting condition for the next lifting step is that the period is greater than the given period value T2.
[0076] like Figure 6 As shown, the slow step-by-step lifting method includes:
[0077] G1, step-up C-group control bar;
[0078] G2: Determine whether the reactor period is less than the given period value T4 and the rate at which the reactor period decreases is greater than the given period rate value dT2. If so, proceed to G3; otherwise, proceed to G4.
[0079] G3: Maintain the current lifting of the control rods in group C and determine whether the reactor cycle meets the critical condition: the reactor cycle is stable within the critical cycle threshold range for more than 30 seconds; if so, the reactor has reached criticality; otherwise, proceed to G5.
[0080] G4: Determine whether the reactor cycle is stable within the critical cycle threshold range. If yes, proceed to step G3; otherwise, return to step G1.
[0081] G5 checks if the reactor period is greater than the given period value T3. If so, the current rod lifting is completed and the next rod lifting is performed; otherwise, it returns to G3.
[0082] The critical period threshold range is (30, 80) s.
[0083] In this process, the height of each bar lift is very small, and the time spent in the 30-80 second range of the cycle will become longer and longer. The condition for starting each bar lift is that the cycle is greater than the given cycle value T3. The condition for ending each bar lift is that the cycle enters the 30-80 second range; or the given cycle value T4, and the rate of decrease of the cycle is greater than the given cycle rate value dT2.
[0084] The control structure diagram for the second stage is as follows: Figure 5As shown, in this process, the controller's inputs are the period, the rate of change of the period, and the measured rod position; the outputs are the control rod lifting rate and the lifting height. Each time reactivity is introduced (corresponding to one control rod lifting process), the reactor period shortens accordingly. After the reactor enters the critical period identification zone, the introduction of reactivity stops, and the reactor waits. At this time, the reactor period gradually increases. When the reactor period increases to T3, reactivity is introduced again until the reactor period re-enters the critical period identification zone, at which point the introduction of reactivity stops, and the reactor waits, gradually approaching criticality. When the reactor period is maintained within the range (T1, T2) and (30, 80) s for more than t = 30 s, the reactor is considered to have reached criticality.
[0085] Example 2
[0086] This embodiment provides a pressurized water reactor critical process control system for implementing a pressurized water reactor critical process control method of Embodiment 1, including:
[0087] The acquisition module is used to acquire first feature information in real time, the first feature information including the position of the control rods and the reactor cycle;
[0088] The first control module is used to control the continuous lifting of the control rod based on the first feature information in real time, continuously introducing reactivity until the reactor enters the critical cycle identification zone.
[0089] The acquisition module is also used to acquire second feature information in real time after the reactor enters the critical cycle identification zone. The second feature information includes the position of the control rod, the reactor cycle, and the reactor cycle change rate.
[0090] The second control module is used to control the control rods in real time based on the second feature information, first by rapidly raising the rods, then by slowly raising them, linearly introducing reactivity until the reactor reaches criticality.
[0091] The acquisition module includes a rod position measuring device and a period measuring device;
[0092] Both the first control module and the second control module are connected to the reactor. The rod position measuring device is used to measure the position of the control rods and is connected to both the first control module and the second control module. The period measuring device is used to measure the reactor period and is connected to both the first control module and the second control module.
[0093] During reactor cold start, the primary constraint on the control of reactivity addition is the reactor cycle. The reactor cycle should be no less than 30-50 seconds throughout the entire start-up process. Taking an average value of 40 seconds...
[0094] Furthermore, since the control rod lifting rate is limited, and the rate of reactivity introduction affects the neutron density and period of the reactor at criticality, there are corresponding constraints on the introduced reactivity rate. Based on the value of each set of rods, the constraints on the reactivity introduction rate when lifting different sets of control rods can be obtained.
[0095] To simplify the design and analysis process, the current research makes the following assumptions:
[0096] a. The effects of nonlinearity and dynamic characteristics (such as time constant) of the control rod drive mechanism, power amplification device, measurement components, etc., are not considered. The controlled object only includes the reactor nuclear physics process.
[0097] b. Only consider the control of reactivity of the reactor from subcritical to critical. During this process, since the reactor power is very low and the temperature changes of fuel and coolant are small, the reactivity feedback introduced by the temperature changes of both is ignored.
[0098] c. A lumped parameter model is used, without considering spatial distribution.
[0099] This invention employs an automatic reactor criticality control method based on expert control rules derived from operator or expert experience. It establishes reasonable automatic control rules and introduces appropriate reactivity at appropriate times, achieving relatively intelligent automatic reactor criticality control. This method provides a technical approach for automatic control of nuclear power reactor criticality and has promising application prospects. Addressing the nonlinear, fast-response, and high-risk characteristics of reactor criticality, this invention uses the reactor source region period as the control input and designs an expert control rule based on operator or expert experience. Automatic control rules are designed according to different stages, and an automatic control scheme is proposed to achieve automatic control of reactor criticality, thereby improving the automation and intelligence level of reactor startup control.
[0100] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for controlling the critical process of a pressurized water reactor, characterized in that, include: Phase 1: Real-time acquisition of first feature information, including the position of the control rod and the reactor cycle. Based on the first feature information, the control rod is continuously raised in real time to continuously introduce reactivity until the reactor enters the critical cycle identification zone. The second stage: After the reactor enters the critical cycle identification zone, the second characteristic information is collected in real time. The second characteristic information includes the position of the control rod, the reactor cycle, and the rate of change of the reactor cycle. Based on the second characteristic information, the control rod is first lifted in a fast step and then lifted in a slow step to linearly introduce reactivity until the reactor reaches criticality. The rapid step-up lifting method includes: M1, step-lift C-group control bar; M2, determine whether the current reactor cycle is less than the given cycle value T1, and whether the rate at which the reactor cycle decreases is greater than the given cycle rate value dT1. If so, proceed to step M3; otherwise, proceed to step M4. M3, maintain the current rod lifting of control rod C until the reactor cycle is greater than the cycle setpoint T2, then complete the current rod lifting and proceed to the next rod lifting step; M4: Determine if the current reactor cycle is within the cycle constraint range. If yes, proceed to step M3. Otherwise, determine if the current rod lifting height is less than the height threshold H. If yes, complete the fast-step rod lifting. Otherwise, proceed to M5. M5 determines whether the current position of the control rod in group C has reached the estimated critical position. If so, the rod is lifted quickly; otherwise, it returns to M1.
2. The method for controlling the critical process of a pressurized water reactor according to claim 1, characterized in that, The method of continuously raising control rods in real time based on the first feature information to continuously introduce reactivity until the reactor enters the critical cycle identification zone includes: S1, raise the D group control rod at the first rod speed until the position of the D group control rod reaches the D group threshold, then proceed to step S2. S2, raise the control rod of group E1 at the second rod speed, and determine whether the position of the control rod of group E1 has reached the threshold of group E1. If yes, proceed to step S3; otherwise, proceed to step S4. S3, raise the E2 group control rod at the third rod speed, and determine whether the position of the E2 group control rod has reached the E2 group threshold. If so, the reactor enters the critical period identification zone and ends the introduction of reactivity; otherwise, proceed to S5. S4. Determine whether the reactor cycle has reached the cycle threshold. If so, the reactor enters the critical cycle identification zone and the introduction of reactivity ends; otherwise, return to step S2. S5, determine whether the reactor cycle has reached the cycle threshold. If so, the reactor enters the critical cycle identification zone and the introduction of reactivity ends; otherwise, return to step S3.
3. The method for controlling the critical process of a pressurized water reactor according to claim 2, characterized in that, The speed of the first rod is greater than the speeds of the second and third rods.
4. The method for controlling the critical process of a pressurized water reactor according to claim 3, characterized in that, The first bar speed is a 3-speed bar speed, and the second and third speeds are both 2-speed bar speeds.
5. The method for controlling the critical process of a pressurized water reactor according to claim 1, characterized in that, The periodic constraint interval is (30s, 80s).
6. The method for controlling the critical process of a pressurized water reactor according to claim 1, characterized in that, The slow-step lifting method includes: G1, step-up C-group control bar; G2: Determine whether the reactor period is less than the given period value T4 and the rate at which the reactor period decreases is greater than the given period rate value dT2. If so, proceed to G3; otherwise, proceed to G4. G3: Maintain the current lifting of the control rods in group C and determine whether the reactor cycle meets the critical condition: the reactor cycle is stable within the critical cycle threshold range for more than 30 seconds; if so, the reactor has reached criticality; otherwise, proceed to G5. G4: Determine whether the reactor cycle is stable within the critical cycle threshold range. If yes, proceed to step G3; otherwise, return to step G1. G5 checks if the reactor period is greater than the given period value T3. If so, the current rod lifting is completed and the next rod lifting is performed; otherwise, it returns to G3.
7. The method for controlling the critical process of a pressurized water reactor according to claim 6, characterized in that, The critical period threshold range is (30, 80) s.
8. A critical process control system for a pressurized water reactor, characterized in that, A method for controlling the critical process of a pressurized water reactor as described in any one of claims 1-7 includes: The acquisition module is used to acquire first feature information in real time, the first feature information including the position of the control rods and the reactor cycle; The first control module is used to control the continuous lifting of the control rod based on the first feature information in real time, continuously introducing reactivity until the reactor enters the critical cycle identification zone. The acquisition module is also used to acquire second feature information in real time after the reactor enters the critical cycle identification zone. The second feature information includes the position of the control rod, the reactor cycle, and the reactor cycle change rate. The second control module is used to control the control rods in real time based on the second feature information, first by rapidly raising the rods, then by slowly raising them, linearly introducing reactivity until the reactor reaches criticality.
9. A pressurized water reactor critical process control system according to claim 8, characterized in that, The acquisition module includes a rod position measuring device and a period measuring device; Both the first control module and the second control module are connected to the reactor. The rod position measuring device is used to measure the position of the control rods and is connected to both the first control module and the second control module. The period measuring device is used to measure the reactor period and is connected to both the first control module and the second control module.