Method and device for judging dilution stop point in critical process of pressurized water reactor

Abstract

This application belongs to the field of reactor physics of nuclear power plants, and specifically relates to a method and device for judging the dilution stop point in the critical process of a pressurized water reactor. The method includes: obtaining the theoretical reactivity #imgabs0# of the reactor core before dilution and the theoretical reactivity #imgabs1# of the reactor core at the dilution stop point in the critical process of the pressurized water reactor; calculating the 1 / M at the dilution stop point corresponding to the target critical state according to #imgabs2# and #imgabs3#; calculating the target source range count rate #imgabs5# of the i-th source range channel at the dilution stop point according to 1 / M and the source range count rate #imgabs4# of the i-th source range channel before dilution; when the source range count rate of the i-th source range channel in the out-of-core nuclear measurement system during the dilution process rises to #imgabs6#, it is determined that the dilution stop point has been reached, and the dilution is stopped. This application judges the dilution stop point by the target source range count rate of the source range channel in the out-of-core nuclear measurement system during the real-time dilution process, so as to solve the technical problem that the reactivity at the end of the control rod group deviates greatly from the expected value during the existing final criticality.

Description

Technical Field

[0001] This application belongs to the field of reactor physics of nuclear power plants, and specifically relates to a method and device for judging the dilution stop point in the critical process of a pressurized water reactor. Background Art

[0002] Reactor criticality is the process of guiding the reactor from a subcritical state to a critical state to achieve a self-sustaining chain fission reaction. Most domestic pressurized water reactor nuclear power units still use the method of reaching criticality by withdrawing control rods. Judging the dilution stop point is the key to the process of reaching criticality by withdrawing control rods. The accuracy of controlling the dilution stop point directly determines whether the reactor can reach criticality near the target critical state (the reactivity of the control rod bank end is 60 pcm), and even affects whether the reactor can become critical.

[0003] Currently, there are mainly two methods for judging the dilution stop point of reaching criticality by withdrawing control rods:

[0004] Judgment method 1: Stop dilution when the deviation between the boron concentration in the current state calculated from the dilution water volume and the extrapolated critical boron concentration from the dilution water volume reaches an expected value, and this expected value is obtained by converting the sum of the reactivity introduced from the current rod position to the target critical rod position and core homogenization;

[0005] Judgment method 2: The neutron inverse count rate ratio 1 / M reaches a certain value, and this value is obtained from historical test data and does not change with the core loading scheme.

[0006] For the existing two judgment methods, due to the change of the existing dilution method and the differences in different cycle core loading schemes, the reactivity of the control rod bank end deviates greatly from the expected value (60 pcm) at the final criticality, and the deviation is generally about 100 - 200 pcm, thus affecting the implementation of subsequent zero-power performance tests. Summary of the Invention

[0007] In view of this, this application is committed to providing a method and device for judging the dilution stop point in the critical process of a pressurized water reactor, and judges the dilution stop point through the target source range count rate of the source range channel in the out-of-core nuclear measurement system during the real-time dilution process, so as to solve the technical problem that the reactivity of the control rod bank end deviates greatly from the expected value at the final criticality due to the change of the dilution method and the differences in different cycle core loading schemes.

[0008] The first aspect of this application provides a method for judging the dilution stop point in the critical process of a pressurized water reactor, and this method for judging the dilution stop point in the critical process of a pressurized water reactor includes:

[0009] Step 1: Obtain the theoretical reactivity of the core before dilution in the critical process of the pressurized water reactor according to the design report of the current core loading scheme, the core state before dilution, the core state at the dilution stop point, and the target critical state and the theoretical reactivity of the core at the dilution stop point 。

[0010] Step 2: According to the theoretical reactivity of the core before dilution and the theoretical reactivity of the core at the dilution stop point , combine with Formula 1 to calculate the 1 / M at the dilution stop point corresponding to the target critical state

[0011] Formula 1

[0012] Step 3: According to 1 / M and the source range count rate of the i-th source range channel before dilution , combine with Formula 2 to calculate the target source range count rate of the i-th source range channel at the dilution stop point ,

[0013] Formula 2

[0014] Step 4: When the source range count rate of the i-th source range channel in the out-of-core nuclear measurement system during the dilution process rises to the target source range count rate of the i-th source range channel at the dilution stop point , it is determined that the dilution stop point has been reached, and the dilution is stopped

[0015] In a specific embodiment of the present application, the above Step 1 includes the following Steps 1-1 and 1-2

[0016] Step 1-1: According to the design report of the current core loading scheme and the core state before dilution, combine with Formula 3 to calculate the theoretical reactivity of the core before dilution ;

[0017] Formula 3

[0018] In Formula 3 is the theoretical reactivity introduced by the control rod group from the fully withdrawn state to the rod position before dilution is the boron concentration of the core before dilution is the theoretical critical boron concentration in the fully withdrawn state of the control rod group; DBC is the theoretical boron differential worth under the conditions of the initial stage of the core life, hot zero power, and critical boron concentration

[0019] Step 1-2: According to the design report of the current core loading scheme, the core state at the dilution stop point, and the target critical state, calculate the theoretical reactivity of the core at the dilution stop point ;

[0020] Formula 4

[0021] In Formula 4 The theoretical reactivity introduced by the control rod group from the all-rod-out state (ARO) to the expected target critical rod position.

[0022] In a specific embodiment of the present application, step 2 above includes the following steps 2-1 and 2-2.

[0023] Step 2-1: Obtain the theoretical reactivity of the core before dilution, the theoretical reactivity of the core at the dilution stop point, and the relationship between 1 / M at the dilution stop point corresponding to the target critical state according to the 1 / M extrapolation formula and the subcritical formula. The theoretical reactivity of the core at the dilution stop point. And the relationship of 1 / M at the dilution stop point corresponding to the target critical state.

[0024] Step 2-2: Calculate the 1 / M at the dilution stop point corresponding to the target critical state (such as the reactivity of the end of the control rod group being 60 pcm) according to the theoretical reactivity of the core before dilution, the theoretical reactivity of the core at the dilution stop point, and the relationship between 1 / M at the dilution stop point corresponding to the target critical state. The theoretical reactivity of the core at the dilution stop point. And the relationship of 1 / M at the dilution stop point corresponding to the target critical state.

[0025] In a specific embodiment of the present application, step 3 above includes the following steps 3-1 and 3-2. Step 4 above includes the following step 4-1.

[0026] Step 3-1: Calculate the target source range count rate of the 1st source range channel at the dilution stop point according to 1 / M and the source range count rate of the 1st source range channel before dilution, in combination with Formula VIII. Combined with Formula VIII, calculate the target source range count rate of the 1st source range channel at the dilution stop point. .

[0027] Formula VIII.

[0028] Step 3-2: Calculate the target source range count of the 2nd source range channel at the dilution stop point according to 1 / M and the source range count rate of the 2nd source range channel before dilution, in combination with Formula IX. Combined with Formula IX, calculate the target source range count of the 2nd source range channel at the dilution stop point. .

[0029] Formula IX.

[0030] Step 4-1: When the source range count rate of the 1st source range channel of the in-core nuclear measurement system during the dilution process rises to , and the source range count rate of the 2nd source range channel rises to , it is determined that the dilution stop point has been reached and the dilution is stopped.

[0031] The second aspect of the present application provides a device for judging the dilution stop point in the critical process of a pressurized water reactor. The device for judging the dilution stop point in the critical process of a pressurized water reactor includes an acquisition module, a calculation module, and a determination module.

[0032] An acquisition module, configured to acquire the theoretical reactivity of the core before dilution in the critical process of a pressurized water reactor according to the design report of the current core loading scheme, the core state before dilution, the core state at the dilution stop point, and the target critical state and the theoretical reactivity of the core at the dilution stop point .

[0033] A calculation module, configured to calculate the 1 / M at the dilution stop point corresponding to the target critical state according to the theoretical reactivity of the core before dilution and the theoretical reactivity of the core at the dilution stop point , in combination with Formula 1

[0034] Formula 1;

[0035] and according to the 1 / M and the source range count rate of the i-th source range channel before dilution , calculate the target source range count rate of the i-th source range channel at the dilution stop point in combination with Formula 2 ,

[0036] Formula 2

[0037] A determination module, configured to determine that the dilution stop point has been reached and stop dilution when the source range count rate of the i-th source range channel in the out-of-core nuclear measurement system during the dilution process rises to the target source range count rate of the i-th source range channel at the dilution stop point .

[0038] The third aspect of the present application provides a computer device. The computer device includes a processor and a memory. The processor is configured to execute a method for judging the dilution stop point in the critical process of a pressurized water reactor according to the first aspect of the present application. The memory is configured to store executable instructions of the processor

[0039] The fourth aspect of the present application provides a computer-readable storage medium, on which executable instructions of a computer are stored. When the executable instructions are executed by a processor, a method for judging the dilution stop point in the critical process of a pressurized water reactor according to the first aspect of the present application is implemented

[0040] The fifth aspect of the present application provides a computer program product, including a computer program / instructions. When the computer program / instructions are executed by a processor, a method for judging the dilution stop point in the critical process of a pressurized water reactor according to the first aspect of the present application is implemented

[0041] The beneficial effects of the technical solution of this application are as follows: By using the method for judging the dilution stop point in the critical process of a pressurized water reactor, the dilution stop point in the process of raising the control rods to criticality in a pressurized water reactor can be judged more accurately. Moreover, this judgment method is simple, stable and reliable, and can be widely used. When the unit reaches the critical state by using this method for judging the dilution stop point in the critical process of a pressurized water reactor, the reactivity at the end of the control rod assembly is close to 60 pcm, which is convenient for carrying out subsequent zero-power performance tests. Description of the Drawings

[0042] Figure 1 The following shows a schematic flowchart of a method for judging the dilution stop point in the critical process of a pressurized water reactor provided by an embodiment of this application. Detailed Embodiments

[0043] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the protection scope of this application.

[0044] At least one embodiment of this application provides a method for judging the dilution stop point in the critical process of a pressurized water reactor. The execution subject of this method for judging the dilution stop point in the critical process of a pressurized water reactor can be a processor, a server, etc. Hereinafter, the processor will be used as an example for illustration. Refer to Figure 1 , and the method for judging the dilution stop point in the critical process of a pressurized water reactor includes the following steps.

[0045] Step 1: According to the design report of the current core loading scheme, the core state before dilution, the core state at the dilution stop point, and the target critical state, obtain the theoretical reactivity of the core before dilution in the critical process of the pressurized water reactor and the theoretical reactivity of the core at the dilution stop point .

[0046] In some embodiments, it can be that the user calculates the theoretical reactivity of the core before dilution in the critical process of the pressurized water reactor and the theoretical reactivity of the core at the dilution stop point according to the design report of the current core loading scheme, the core state before dilution, the core state at the dilution stop point, and the target critical state, and manually input and into the computer device, so that the processor of the computer device can directly obtain the theoretical reactivity of the core before dilution in the critical process of the pressurized water reactor and the theoretical reactivity of the core at the dilution stop point .

[0047] In some other embodiments, the processor of the computer device can directly identify or call the corresponding parameters from the design report of the current core loading scheme, the core state before dilution, the core state at the dilution stop point, and the target critical state, and calculate the theoretical reactivity of the pressurized water reactor core before dilution according to the corresponding parameters. and the theoretical reactivity of the core at the dilution stop point .

[0048] It should be noted that and are both in pcm.

[0049] Step 2: According to the theoretical reactivity of the core before dilution and the theoretical reactivity of the core at the dilution stop point , combine with Formula 1 to calculate the 1 / M at the dilution stop point corresponding to the target critical state.

[0050] Formula 1.

[0051] Step 3: According to 1 / M and the source range count rate of the i-th source range channel before dilution , combine with Formula 2 to calculate the target source range count rate of the i-th source range channel at the dilution stop point .

[0052] Formula 2.

[0053] Specifically, according to Formula 2, , from which the target source range count rate of the i-th source range channel at the dilution stop point can be calculated .

[0054] Step 4: When the source range count rate of the i-th source range channel in the out-of-core nuclear measurement system during the dilution process rises to the target source range count rate of the i-th source range channel at the dilution stop point , it is determined that the dilution stop point has been reached, and the dilution is stopped.

[0055] It should be noted that the neutron measurement in the reactor source range characterizes the neutron flux density and power level by the source range count rate. The source range count rate is a kind of pulse count rate.

[0056] According to the technical solution provided by the embodiments of the present application, by according to the theoretical reactivity of the core before dilution and the theoretical reactivity of the core at the dilution stop point , calculate 1 / M corresponding to the target critical state's dilution stop point, thus achieving no longer using empirical values to determine 1 / M and improving the accuracy of 1 / M. By designing that when the source range count rate of the source range channel in the out-of-core nuclear measurement system during the dilution process rises to the dilution stop point, the source range count rate of the source range channel at this time, it is determined that the dilution stop point has been reached and the dilution is stopped. Judging the dilution stop point in this way makes it possible that after waiting for the core to be well mixed and the control rods are lifted to criticality, the reactivity at the end of the control rod group during actual criticality should basically conform to the expectation, thereby reducing the state adjustment time before the subsequent zero-power performance test and effectively shortening the main overhaul line. In addition, the method for judging the dilution stop point in the critical process of this pressurized water reactor updates the judgment conditions for the dilution stop point according to the differences in the core loading methods of different cycles of the pressurized water reactor unit, enabling the reactor to reach criticality more accurately near 60 pcm of the reactivity at the end of the control rod group. The method for judging the dilution stop point in the critical process of this pressurized water reactor can judge the dilution stop point by the target source range count rate of the source range channel in the out-of-core nuclear measurement system during the dilution process in real time. Compared with the existing method of judging the dilution stop point by extrapolation every 5 minutes or 15 minutes, it effectively avoids the delay in judgment resulting in not stopping the dilution in time. The method for judging the dilution stop point in the critical process of this pressurized water reactor can make the reactivity at the end of the control rod group closer to 60 pcm by accurately controlling the target critical rod position, reducing the state adjustment time before the subsequent zero-power performance test and effectively shortening the main overhaul line.

[0057] In at least one embodiment of the present application, step 1 above includes the following steps 1-1 and step 1-2.

[0058] Step 1-1: According to the design report of the current core loading scheme and the core state before dilution, calculate the theoretical reactivity of the core before dilution in combination with Formula III ;

[0059] Formula III.

[0060] In Formula III, is the theoretical reactivity introduced by the control rod group from the fully lifted state to the rod position before dilution; is the boron concentration of the core before dilution; is the theoretical critical boron concentration in the fully lifted state of the control rod group; DBC is the theoretical boron differential worth under the conditions of the beginning of core life (BOL), hot zero power (HZP), and critical boron concentration.

[0061] It should be noted that , and DBC can all be obtained from the design report of the current core loading scheme, It can be obtained from the core state before dilution. The all-rods-out state is the state where all control rod clusters are withdrawn from the core (All Rods Clusters Out, ARO). The units of and are both pcm, and the unit of DBC is pcm / ppm.

[0062] Step 1-2: Calculate the theoretical reactivity of the core at the dilution stop point according to the design report of the current core loading scheme, the core state at the dilution stop point, and the target critical state. ;

[0063] Formula Four.

[0064] In Formula Four, is the theoretical reactivity introduced by the control rod group from the all-rods-out state (ARO) to the expected target critical rod position.

[0065] It should be noted that The unit of

[0066] In at least one embodiment of the present application, the above Step 2 includes the following Steps 2-1 and 2-2.

[0067] Step 2-1: Obtain the theoretical reactivity of the core before dilution, the theoretical reactivity of the core at the dilution stop point, and the relationship of 1 / M at the dilution stop point corresponding to the target critical state according to the 1 / M extrapolation formula and the subcritical formula.

[0068] Specifically, the subcritical formula is as follows, Formula Five:

[0069] Formula Five.

[0070] In Formula Five, n is the neutron flux density; S is the external neutron source intensity; is the effective multiplication factor; is the neutron mean lifetime.

[0071] The 1 / M extrapolation formula is as follows, Formula Six:

[0072] Formula Six.

[0073] Substitute Formula Five into Formula Six to obtain Formula Seven:

[0074] Formula Seven.

[0075] In Formula Seven, is the effective multiplication factor at the dilution stop point; is the effective multiplication factor before dilution.

[0076] It should be noted that the units of n, n0, and n1 are all n / cm 3 ; the unit of S is Bq; is in s. Both Equation 7 and Equation 1 are the theoretical reactivity of the core before dilution , the theoretical reactivity of the core at the dilution stop point and the relationship of 1 / M at the dilution stop point corresponding to the target critical state. Equation 1 is the simplified formula of Equation 7.

[0077] Step 2-2: According to the theoretical reactivity of the core before dilution , the theoretical reactivity of the core at the dilution stop point and the relationship of 1 / M at the dilution stop point corresponding to the target critical state, calculate the 1 / M at the dilution stop point corresponding to the target critical state (such as the reactivity of the control rod bank end being 60 pcm).

[0078] The number of source range channels of different types of pressurized water reactors may be different. For example, some pressurized water reactors have 2 source range channels, and some have 4 source range channels. The following takes the number of source range channels of a pressurized water reactor being 2 as an example for illustration.

[0079] In at least one embodiment of the present application, the above Step 3 includes the following Steps 3-1 and 3-2. The above Step 4 includes the following Steps 4-1 and 4-2.

[0080] Step 3-1: According to 1 / M and the source range count rate of the No. 1 source range channel before dilution , combined with Equation 8, calculate the target source range count rate of the No. 1 source range channel at the dilution stop point .

[0081] Equation 8.

[0082] Step 3-2: According to 1 / M and the source range count rate of the No. 2 source range channel before dilution , combined with Equation 9, calculate the target source range count of the No. 2 source range channel at the dilution stop point .

[0083] Equation 9.

[0084] It should be noted that , , and are all in cps.

[0085] Step 4-1: When the source range count rate of the No. 1 source range channel of the in-core nuclear measurement system during the dilution process rises to , and the source range count rate of the No. 2 source range channel rises to , it is determined that the dilution stop point has been reached, and the dilution is stopped.

[0086] The determination method of the dilution stop point in the critical process of this pressurized water reactor has been verified by the initial critical test data of multiple units and multiple cycles, and can enable the reactor to reach criticality more accurately near 60 pcm of the reactivity at the end of the control rod bank. Next, the determination method of the dilution stop point in the critical process of this pressurized water reactor will be illustrated with specific embodiments.

[0087] Embodiment 1: Take a certain unit of a nuclear power plant as an example

[0088] According to the design report of the current core loading scheme and the core state before dilution, the theoretical reactivity of the core before dilution is calculated to be 2144.75 pcm (corresponding to Step 1-1); <,

[0089] According to the design report of the current core loading scheme, the core state at the dilution stop point, and the target critical state (e.g., 60 pcm of the reactivity at the end of the control rod bank, critical rod position * rod bank 199 steps), the theoretical reactivity of the core at the dilution stop point is calculated to be 524 pcm (corresponding to Step 1-2);

[0090] 3. According to the 1 / M extrapolation principle and the subcritical formula, calculate 1 / M = 0.244 corresponding to the dilution stop point of the target critical state (60 pcm of the reactivity at the end of the control rod bank, critical rod position * rod bank 199 steps) (corresponding to Steps 2-1 and 2-2);

[0091] 4. According to 1 / M = 0.244 and the source range count rate of the No. 1 source range channel before dilution = 50.7 cps, substitute it into Formula 2 to calculate the source range count rate of the No. 1 source range channel at the dilution stop point = 207.8 cps. According to 1 / M = 0.244 and the source range count rate of the No. 2 source range channel before dilution = +46.6 cps, substitute it into Formula 2 to calculate the source range count rate of the No. 2 source range channel at the dilution stop point = 191.0 cps.

[0092] 5. During the dilution process, when the source range count rate of the No. 1 source range channel reaches 207.8 cps and the source range count rate of the No. 2 source range channel reaches 191.0 cps, stop the dilution (corresponding to step 4-1). After waiting for the core to be well mixed, raise the control rods to criticality. Finally, when actually critical, the reactivity at the end of the control rod group is 35 pcm, and the deviation from the expected 60 pcm is only 25 pcm, which is much smaller than the deviation of the existing judgment method (100 pcm - 200 pcm).

[0093] The deviation between the final reactivity at the end and the target of the judgment method for the dilution stop point in the critical process of this pressurized water reactor is 25 pcm, and the converted boron concentration deviation is only 3.8 ppm. By adjusting the control rod group through dilution, the reactivity at the end is made between 50 pcm and 60 pcm. Since the change in boron concentration is small, there is basically no need to wait, which can meet the core uniformity condition, reduce the core state adjustment time before the subsequent zero-power performance test, effectively shorten the main overhaul time by about 1 hour, and increase the economic benefits of the unit.

[0094] At least one embodiment of the present application also provides a judgment device for the dilution stop point in the critical process of a pressurized water reactor. The judgment device for the dilution stop point in the critical process of a pressurized water reactor includes an acquisition module, a calculation module, and a determination module.

[0095] The acquisition module is used to obtain the theoretical reactivity of the core before dilution in the critical process of the pressurized water reactor according to the design report of the current core loading scheme, the core state before dilution, the core state at the dilution stop point, and the target critical state and the theoretical reactivity of the core at the dilution stop point .

[0096] The calculation module is used to calculate the 1 / M at the dilution stop point corresponding to the target critical state according to the theoretical reactivity of the core before dilution and the theoretical reactivity of the core at the dilution stop point , in combination with Formula 1.

[0097] Formula 1;

[0098] And according to 1 / M and the source range count rate of the i-th source range channel before dilution , calculate the target source range count rate of the i-th source range channel at the dilution stop point in combination with Formula 2 .

[0099] Formula 2.

[0100] The determination module is used to determine that when the source range count rate of the i-th source range channel in the out-of-core nuclear measurement system during the dilution process rises to the target source range count rate of the i-th source range channel at the dilution stop point When it reaches this point, it is determined that the dilution stop point has been reached, and the dilution is stopped.

[0101] The determination device for the dilution stop point in the critical process of the pressurized water reactor is the determination device corresponding to the method for determining the dilution stop point in the critical process of the pressurized water reactor provided in any of the above embodiments of the present application. It includes the technical features corresponding to the method for determining the dilution stop point in the critical process of the pressurized water reactor, and can achieve the corresponding technical effects, which will not be elaborated here.

[0102] At least one embodiment of the present application also provides a computer device, which includes a processor and a memory. The processor is used to execute the method for determining the dilution stop point in the critical process of the pressurized water reactor provided in any of the above embodiments of the present application. The memory is used to store the executable instructions of the processor, such as application programs. The number of processors can be one or more. The application programs stored in the memory can include one or more modules corresponding to each set of instructions. In addition, the processor is configured to execute instructions to execute the above method for determining the dilution stop point in the critical process of the pressurized water reactor.

[0103] The computer device may further include a power supply component configured for power management of the computer device, a wired or wireless network interface configured to connect the computer device to a network, and an input / output (I / O) interface. The computer device can operate based on an operating system stored in the memory, such as Windows Server TM , Mac OSX TM , Unix TM , Linux TM , FreeBSD TM or the like.

[0104] At least one embodiment of the present application also provides a computer-readable storage medium, on which executable instructions of a computer are stored. When the executable instructions are executed by a processor, the method for determining the dilution stop point in the critical process of the pressurized water reactor provided in any of the above embodiments of the present application is implemented.

[0105] A non-transitory computer-readable storage medium, when the instructions in the storage medium are executed by the processor of the above computer device, enables the above computer device to execute the above method for determining the dilution stop point in the critical process of the pressurized water reactor. The method for determining the dilution stop point in the critical process of the pressurized water reactor is executed by an agent program.

[0106] Those of ordinary skill in the art can realize that the algorithm steps of each example described in combination with the embodiments disclosed in this application can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of this application.

[0107] At least one embodiment of this application also provides a computer program product, including computer programs / instructions, which, when executed by a processor, implement the method for judging the dilution stop point of a pressurized water reactor critical process provided in any one of the above embodiments of this application.

[0108] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of this application, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a computer program product. This computer program product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method for judging the dilution stop point of a pressurized water reactor critical process in each embodiment of this application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program verification codes.

[0109] It should be noted that the combination methods of the technical features in the embodiments of this application are not limited to the combination methods recorded in the embodiments of this application or the combination methods recorded in the specific embodiments. All the technical features recorded in this application can be freely combined or combined in any way, unless contradictions occur between them.

[0110] As shown in this application and the claims, unless the context clearly indicates an exceptional situation, words such as "a", "one kind", and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the term "including" only indicates the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0111] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0112] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for determining the dilution stop point in the critical process of a pressurized water reactor, characterized in that, Comprising: Step 1. Obtain the theoretical reactivity of the pressurized water reactor core before dilution during the critical process according to the design report of the current core loading scheme, the core state before dilution, the core state at the dilution stop point, and the target critical state. and the theoretical reactivity of the core at the dilution stop point ; Step 2: According to the theoretical reactivity of the core before dilution and the theoretical reactivity of the core at the dilution stop point , combining with Formula 1, calculate the 1 / M at the dilution stop point corresponding to the target critical state Formula 1; Step 3: Based on 1 / M and the source range count rate of the i-th source range channel before dilution and combining with Formula 2, calculate the target source range count rate of the i-th source range channel at the dilution stop point , Formula II; Step 4: When the source range count rate of the i-th source range channel in the in-core nuclear measurement system during the dilution process rises to the dilution stop point, the target source range count rate of the i-th source range channel it is determined that the dilution stop point has been reached, and the dilution is stopped; Among them, step 1 comprises: Step 1-1: Calculate the theoretical reactivity of the core before dilution according to the design report of the current core loading scheme and the core state before dilution, in combination with Formula 3. ; Formula III In Equation 3, is the theoretical reactivity introduced by the control rod group from the fully withdrawn state to the rod position before dilution; is the boron concentration in the core before dilution; is the theoretical critical boron concentration in the fully withdrawn state of the control rod group; DBC is the theoretical boron differential worth under the conditions of the initial core life cycle, hot zero power, and critical boron concentration. Step 1-2: Calculate the theoretical reactivity of the core at the dilution stop point based on the design report of the current core loading scheme, the core status at the dilution stop point, and the target critical status. ; Formula Four, In Equation 4, is the theoretical reactivity introduced by the control rod group from the fully withdrawn state (ARO) to the expected target critical rod position.

2. The method for determining the dilution stop point in the critical process of a pressurized water reactor according to claim 1, characterized in that, Step 2 comprises: Step 2-1: Obtain the theoretical reactivity of the core before dilution according to the 1 / M extrapolation formula and the subcritical formula , the theoretical reactivity of the core at the dilution stop point and the relationship of 1 / M at the dilution stop point corresponding to the target critical state; Step 2-2: According to the theoretical reactivity of the core before dilution , the theoretical reactivity of the core at the dilution stop point and the relationship formula of 1 / M at the dilution stop point corresponding to the target critical state, calculate 1 / M at the dilution stop point corresponding to the target critical state.

3. The method for determining the dilution stop point in the critical process of a pressurized water reactor according to claim 1, characterized in that, Step 3 comprises: Step 3-1: According to 1 / M and the source range count rate of the No. 1 source range channel before dilution , and combining with Formula VIII, calculate the target source range count rate of the No. 1 source range channel at the dilution stop point , Formula VIII, Step 3-2: Based on 1 / M and the source range count rate of the No. 2 source range channel before dilution , and combined with Formula 9, calculate the target source range count of the No. 2 source range channel at the dilution stop point , Formula IX; Step 4 comprises: Step 4-1: When the source range count rate of the No. 1 source range channel of the in-core nuclear measurement system during the dilution process rises to , and the source range count rate of the No. 2 source range channel rises to , it is determined that the dilution stop point has been reached and the dilution is stopped.

4. A device for judging the dilution stop point in the critical process of a pressurized water reactor, characterized in that, Comprising an acquisition module, a calculation module and a determination module, An acquisition module, configured to acquire the theoretical reactivity of the core before dilution in the critical process of a pressurized water reactor according to the design report of the current core loading scheme, the core state before dilution, the core state at the dilution stop point, and the target critical state and the theoretical reactivity of the core at the dilution stop point , Among them, according to the design report of the current core loading scheme, the core state before dilution, the core state at the dilution stop point, and the target critical state, the theoretical reactivity of the pressurized water reactor core before dilution during the critical process is obtained and the theoretical reactivity of the core at the dilution stop point including: According to the design report of the current core loading scheme and the core state before dilution, the theoretical reactivity of the core before dilution is calculated by combining Formula 3 ; Formula III In Equation 3, is the theoretical reactivity introduced by the control rod group from the fully withdrawn state to the rod position before dilution; is the boron concentration in the core before dilution; is the theoretical critical boron concentration in the fully withdrawn state of the control rod group; DBC is the theoretical boron differential worth under the conditions of the initial core life cycle, hot zero power, and critical boron concentration. Based on the design report of the current core loading scheme, the core status at the dilution stop point, and the target critical status, the theoretical reactivity of the core at the dilution stop point is calculated. ; Formula Four, In Equation 4, is the theoretical reactivity introduced by the control rod group from the fully withdrawn state (ARO) to the expected target critical rod position; A calculation module, configured to calculate, according to the theoretical reactivity of the core before dilution and the theoretical reactivity of the core at the dilution stop point , and calculate, in combination with Formula 1, the 1 / M at the dilution stop point corresponding to the target critical state Formula 1; and based on 1 / M and the source range count rate of the i-th source range channel before dilution and combined with Formula 2 to calculate the target source range count rate of the i-th source range channel at the dilution stop point , Formula II; A determination module, which is used to determine the target source range count rate of the i-th source range channel when the source range count rate of the i-th source range channel in the out-of-core nuclear measurement system during the dilution process rises to the dilution stop point When it reaches the dilution stop point, it is determined that the dilution stop point has been reached and the dilution is stopped.

5. A computer device, characterized in that, Comprising: A processor for executing a method for judging the dilution stop point of a pressurized water reactor critical process according to any one of claims 1 to 3; And A memory for storing executable instructions of the processor.

6. A computer-readable storage medium having computer-executable instructions stored thereon, characterized in that, When the executable instructions are executed by the processor, a method for judging the dilution stop point of a pressurized water reactor critical process according to any one of claims 1 to 3 is implemented.

7. A computer program product comprising computer programs / instructions, characterized in that, When the computer program / instructions are executed by the processor, a method for judging the dilution stop point of a pressurized water reactor critical process according to any one of claims 1 to 3 is implemented.

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