A reactor startup method and system based on a neutron generator

Abstract

The application discloses a reactor startup method and system based on a neutron generator, and the method comprises the following steps: establishing a reactor theoretical model and performing model checking by using a reactor physics calculation program; counting the count rate of the neutrons generated by the neutron generator after passing through the reactor core at a neutron detector, and determining the neutron yield of the neutron generator meeting the reactor startup requirements; replacing the reactor startup neutron source with the neutron generator, opening the neutron generator and maintaining the stable neutron yield emission state before lifting the control rod in the reactor startup process, and performing the reactor startup operation. The application eliminates the inherent risk of radioactive neutron sources by using the neutron generator for reactor startup, and is more conducive to optimizing the reactor physics startup process because the neutrons generated by the neutron generator are controllable and adjustable in intensity, and the safety performance of the reactor core can be improved while optimizing the arrangement of the reactor core.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nuclear power technology, in particular to a reactor startup method and system based on a neutron generator, which uses a neutron generator to replace a traditional radioactive neutron source and is applied to reactor startup process, and is suitable for various solid, liquid and gaseous research reactors, and is particularly suitable for critical devices. BACKGROUND

[0002] In the reactor startup process, various materials in the reactor can be combined in a certain way to gradually increase the number of neutrons generated in the reactor or gradually reduce the number of neutrons that disappear, so that the number of neutrons generated is equal to the number of neutrons that disappear, that is, k eff = 1 or p = 0.

[0003] In the first startup process of research reactors such as critical devices, the "neutron count reciprocal extrapolation method" is used to gradually raise the control rods to approach criticality. Before raising the control rods, a radioactive neutron source needs to be added to the reactor. When raising the control rods to extrapolate criticality, first raise a control rod to a height H1 and record the count rate N1 of the neutron detector, then raise a control rod to a height H2 and record the count rate N2 of the neutron detector. According to the two neutron count rates and the control rod height difference, it can be extrapolated that the reaction needs to add a certain amount of p to make the core critical, and then the next step is to add the reaction according to the "1 / 2 principle", that is, to introduce the reaction equivalent of a certain amount of p / 2 by raising the subsequent control rods. After repeating the extrapolation operation several times, the core k eff can reach 0.996. At this time, the neutron source is removed from the reactor, and the control rods are fine-tuned to make the core critical, that is, the reactor startup operation is completed.

[0004] The reactor arranges nuclear fuel, control rods, poison rods, etc. according to certain rules. The nuclear fuel is mainly composed of fissile nuclides and fissionable nuclides. The newly arranged reactor is in a deep subcritical state. It is necessary to introduce a certain amount of positive reactivity to the reactor by raising the control rods to generate enough neutron signals for the neutron detector to distinguish. For the newly arranged reactor, since the control rod critical rod position is unknown, the control rods cannot be blindly raised.

[0005] It is necessary to add a startup neutron source before raising the control rods, which plays a "ignition" role in the reactor. The change trend of the neutron signal emitted by the neutron source after passing through the reactor can be obtained through the neutron detector. Then, the change trend of the above-mentioned neutron signal is analyzed and processed by using a rear-end neutron count measurement device (common neutron count measurement devices include a startup neutron count device, a neutron count supervision device, etc.), and the current state of the reactor can be obtained. Under the condition of effectively monitoring the state of the reactor, the control rods are gradually raised to make the reactor transition from a subcritical state to a critical state, and the reactor startup operation is realized. At this time, the number of neutrons generated in the reactor is equal to the number of neutrons that disappear.

[0006] Different reactors have different requirements for the intensity of the start-up neutron source, and the intensity of the start-up neutron source is generally between 1-5Ci, and the neutron emitted by the start-up neutron source is required to have a count rate of not less than 0.5cps when passing through the core to the neutron detector.

[0007] However, the high radioactivity of the radioactive neutron source will have a safety impact on the relevant operating personnel; the radioactive neutron source will continuously emit radiation outward, the intensity of the neutron source is uncontrollable, the radiation safety hazard is large, the transfer and installation process is complex, involves cumbersome management approval, and it can only be used for a certain specific reactor. If a fault or anomaly occurs or the performance does not meet the requirements, only the neutron source can be replaced, which is high in cost. SUMMARY

[0008] In order to solve the problems existing in the traditional start-up of the reactor using the radioactive neutron source, the application provides a reactor start-up method and system based on a neutron generator. The reactor start-up method and system based on a neutron generator can eliminate the inherent risk of the radioactive neutron source without configuring the traditional radioactive neutron source in the reactor core or near the periphery, and the neutron generated by the neutron generator is controllable and adjustable in intensity, which is more conducive to optimizing the reactor physical start-up process, thereby optimizing the arrangement of the reactor core and improving the safety performance of the core.

[0009] The application is implemented by the following technical solutions:

[0010] A reactor start-up method based on a neutron generator, the reactor start-up method comprising:

[0011] establishing a reactor theoretical model using a reactor physics calculation program and performing model checking;

[0012] statistically counting the count rate of the neutron generated by the neutron generator at the neutron detector after passing through the core using the checked reactor theoretical model, and determining the neutron yield of the neutron generator that meets the reactor start-up requirements;

[0013] using the neutron generator with the neutron yield that meets the reactor start-up requirements to replace the start-up neutron source, opening the neutron generator and maintaining it in a stable neutron yield emission state before lifting the control rod in the reactor start-up process, and performing reactor start-up operation.

[0014] In some embodiments, the reactor theoretical model is established using a reactor physics calculation program, specifically comprising:

[0015] Using the Monte Carlo-based reactor physics calculation program, the reactor core, neutron detector, and neutron generator are modeled in detail from the inside out and in a step-by-step manner. During the modeling process, all control rods are set to move freely up and down.

[0016] In some embodiments, the model verification specifically includes:

[0017] The reactor theoretical model is calibrated and verified using multiple critical rod position measured values, and the calibration and verification conditions satisfy that the deviation between the measured value and the calculated value does not exceed a preset value.

[0018] In some embodiments, the neutron yield of the neutron generator that meets the reactor startup requirements is specifically:

[0019] The counting rate of the neutrons generated by the neutron generator at the neutron detector after passing through the core is generally not less than 0.5 cps.

[0020] In some embodiments, the maximum neutron yield of the neutron generator is generally higher than 1×10 9 n / s, and the neutron yield of the neutron generator can be freely adjusted between 0 and the maximum neutron yield.

[0021] In some embodiments, the reactor startup operation specifically includes:

[0022] Completing the installation and commissioning of the neutron generator outside the core;

[0023] After the neutron generator is installed, the neutron yield of the neutron generator is adjusted to the numerically calculated value and maintained in a stable neutron yield emission state, ensuring that the measured count rate of the rear-end neutron detector is greater than 0.5 cps;

[0024] Reactivity was added according to the 1 / 2 principle, and rod lifting and extrapolation experiments were carried out to bring the core to a critical state.

[0025] In some embodiments, the installation and commissioning of the neutron generator outside the core specifically includes:

[0026] The neutron generator and the neutron detector are respectively located on two opposite sides of the core, and the neutron generator is arranged outside the reactor barrel. The target core component of the neutron generator, the core and the centers of the neutron detector are arranged collinearly.

[0027] In some embodiments, the rod lifting and extrapolation experiment specifically includes:

[0028] Determine the core critical rod position based on the measured value;

[0029] According to the core critical rod position, the extrapolation operation is repeated multiple times according to the 1 / 2 principle, so that the core k eff The neutron generator is cut off when the core k reaches 0.996.

[0030] The control rod is finely adjusted to make the core reach the critical state.

[0031] In some embodiments, the neutron generator is a device that generates a neutron beam by particle bombardment of target nuclei.

[0032] In another aspect, the present application provides a reactor startup system based on a neutron generator, which comprises:

[0033] A model construction module configured to establish a reactor theoretical model using a reactor physics calculation program and perform model verification;

[0034] A numerical calculation module configured to use the verified reactor theoretical model to count the count rate of the neutrons generated by the neutron generator after passing through the core at the neutron detector, and determine the neutron yield of the neutron generator that meets the reactor startup requirements;

[0035] And a reactor startup module configured to use the neutron generator with a neutron yield that meets the reactor startup requirements to replace the reactor startup neutron source, open the neutron generator and maintain a stable neutron yield emission state before lifting the control rod in the reactor startup process, and perform reactor startup operation.

[0036] The reactor startup method and system based on a neutron generator provided by the present application use a neutron generator to replace the traditional radionuclide neutron source, which can eliminate the inherent risks of the radionuclide neutron source (such as the adverse effects of high radioactivity on personnel, etc.); At the same time, since the neutrons generated by the neutron generator are controllable and adjustable in intensity, it is more conducive to optimizing the reactor physics startup process, thereby improving the safety performance of the core while optimizing the arrangement of the core;

[0037] Compared with the uncontrollable radionuclide neutron source, which can only be used for specific reactors and can only be replaced with a radionuclide neutron source in case of failure or other situations, the neutron generator used in the present application has the advantages of generating single-energy neutrons, controllable yield, mobility, and reusability, which can greatly reduce costs and has great economic value.

[0038] The reactor startup method and system based on a neutron generator provided by the present application has a wide range of applications and can be applied to various types of solid, liquid, and gaseous research reactors, and is particularly suitable for critical devices. BRIEF DESCRIPTION OF DRAWINGS

[0039] The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0040] Figure 1 A schematic diagram of a neutron generator structure according to an embodiment of the application;

[0041] Figure 2 A flowchart of a reactor startup method according to an embodiment of the application;

[0042] Figure 3 A side view of a reactor and neutron generator arrangement according to an embodiment of the application;

[0043] Figure 4 A top view of a reactor and neutron generator arrangement according to an embodiment of the application;

[0044] Figure 5 A top view of a reactor and radioactive neutron source arrangement according to an embodiment of the application;

[0045] Figure 6 A flowchart of installation and commissioning of a critical assembly and neutron generator according to an embodiment of the application;

[0046] Figure 7 A schematic diagram of a critical assembly core arrangement according to an embodiment of the application;

[0047] Figure 8 A flowchart of a neutron generator enabling reactor startup according to an embodiment of the application;

[0048] Figure 9 A principle block diagram of a reactor startup system according to an embodiment of the application.

[0049] Reference signs and corresponding component names:

[0050] 1 - moving platform, 2 - control system, 3 - target nuclear component, 4 - acceleration unit, 5 - ion source, 6 - high-voltage cavity, 7 - reactor body support, 8 - core base, 9 - neutron detector, 10 - core, 11 - core barrel, 12 - control rod, 13 - upper grid plate, 14 - control rod drive mechanism, 15 - steel platform, 16 - neutron generator, 17 - radioactive neutron source. DETAILED DESCRIPTION

[0051] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and drawings, and the illustrative embodiments of the present application and their descriptions are only used to explain the present application and do not constitute any limitation to the present application.

[0052] Embodiments:

[0053] In the reactor startup process, it is usually necessary to add a startup neutron source before lifting the control rod, and through the neutron detector, the change trend of the neutron signal emitted by the neutron source after passing through the reactor is collected, and then the change trend of the neutron signal is analyzed and processed by using the rear-end neutron counting measurement device, so that the current state of the reactor can be obtained. However, there are safety hazards, uncontrollability and limited application range and other problems in configuring traditional radionuclide neutron sources in or outside the reactor core. In view of this, the embodiment proposes a reactor startup method based on a neutron generator. The method proposed in the embodiment can optimize the configuration of the research reactor by using the neutron generator for reactor startup, without the need to configure traditional radionuclide neutron sources in or near the reactor core, thereby eliminating the inherent risks of radioactive neutron sources. At the same time, since the neutron generator generates neutrons that are controllable and adjustable in intensity, it is more conducive to optimizing the reactor physical startup process, thereby improving the safety performance of the reactor core while optimizing the arrangement of the reactor core. In addition, the neutron generator has many advantages such as single-energy neutron generation, controllable yield, mobility and reusability, which can greatly reduce equipment costs and have huge economic benefits, providing safer, more effective and more economical technical support for reactor startup.

[0054] Among them, the neutron generator used in the embodiment refers to a device that can generate a neutron beam through particle bombardment of target nuclei effects, mainly including ion source 5, high-voltage cavity 6, acceleration unit 4, control system 2, mobile platform 1 and target nuclear component 3 and other components, as shown in Figure 1 The function of the neutron generator is to generate a strong and controllable energy single neutron beam, which can be used for neutron cross-section measurement, neutron irradiation breeding, neutron detector calibration, neutron photography, neutron activation analysis and other nuclear technology application work. For example, the neutron beam generated by the neutron generator is nearly monochromatic, which is suitable for measuring the neutron cross-section data of different materials, and the strong neutron beam can be used to calibrate the neutron detectors used in the nuclear measurement system, control protection system and test measurement system of the reactor, to measure the sensitivity of each neutron detector and confirm that the neutron detector is in good working condition.

[0055] As shown in Figure 2 The reactor startup method proposed in the embodiment specifically includes the following steps:

[0056] Step 100, establishing a reactor theoretical model and performing model checking by using a reactor physics calculation program.

[0057] The step 100 establishes a reactor theoretical model by using a Monte Carlo-based reactor physics calculation program. In modeling, the reactor physics calculation program is used to model the reactor core (including nuclear fuel, control rods, poison rods, and moderators), neutron detectors, neutron generators, and other components in turn according to the principle of step-by-step refinement from inside to outside. In the modeling process, all control rods are set to be freely movable up and down in order to find different control rod critical rod positions. After the reactor theoretical model is established, a plurality of critical rod position measured values are used to check and verify the reactor theoretical model. The verification condition is that the deviation between the measured value and the calculated value does not exceed a preset value.

[0058] Specifically, the step 100 takes a general critical device as an example, and uses a reactor physics calculation program to model the core 10, core base 8, core body support 7, steel platform 15, neutron generator 16, neutron detector 9, core barrel 11, control rod 12, upper grid plate 13, and control rod drive mechanism 14 of the critical device. The combination of the above components is shown in FIGS. 1 and 2. Figure 3 and Figure 4

[0059] After the reactor theoretical model is established, the reactor theoretical model is checked by using seven critical rod position measured values. Table 1 shows the comparison between the K eff measured values and the calculated values of the reactor theoretical model. As shown in Table 1, the maximum deviation between the measured values and the calculated values is 3.53‰, indicating that the established reactor theoretical model is correct.

[0060] Table 1 Comparison between K eff measured values and calculated values

[0061] Critical rod position number Measured value Calculated value deviation(‰) 1 1.0 1.00083 0.83 2 1.0 1.00164 1.64 3 1.0 0.99921 -0.79 4 1.0 1.00374 3.74 5 1.0 0.99873 -1.27 6 1.0 0.99906 -0.94 7 1.0 1.00257 2.57

[0062] In step 200, the counting rate of the neutrons generated by the neutron generator and passing through the core at the neutron detector is counted by using the checked reactor theoretical model, and the neutron yield of the neutron generator that meets the reactor startup requirement is determined.

[0063] After the reactor theoretical model is checked and verified, the neutron yield of the neutron generator is adjusted, and the counting rate of the neutrons generated by the neutron generator and passing through the core at the neutron detector is obtained. The counting rate of the neutrons generated by the neutron generator and passing through the core at the neutron detector is not less than 0.5 cps, so as to determine the minimum requirement of the neutron yield of the neutron generator, i.e., to determine the neutron yield of the neutron generator that can meet the reactor startup requirement.

[0064] Specifically, the step 200 takes a general critical device as an example, and uses a reactor physics calculation program to model the core 10, core base 8, core body support 7, steel platform 15, neutron generator 16, neutron detector 9, core barrel 11, control rod 12, upper grid plate 13, and control rod drive mechanism 14 of the critical device. The combination of the above components is shown in FIGS. 1 and 2. Figure 3 and Figure 4 ​The reactor theoretical model shown is an example, in which the yield of the neutron generator can be 5×10 8 n / s. Comparing the calculation results of the AmBe neutron source with the actual reactor test, the neutron yield of the neutron generator is evaluated to meet the requirements of the reactor startup. The AmBe neutron source is applied to the startup process of the general type critical assembly, and the AmBe neutron source is located in the barrel about 30 cm away from the edge of the core, and the neutron detector is located on the other side of the core, as shown in Figure 5 , the center of the neutron detector, the core and the neutron source are almost collinearly arranged. When the neutron generator is replaced by the neutron source, the neutron source is removed, and the neutron generator is arranged outside the barrel, and the target nuclear component of the neutron generator is opposite to the core, as shown in Figure 4 , the center of the neutron detector, the core and the neutron generator are almost collinearly arranged.

[0065] The count rate of the neutron detector on the other side is calculated when the neutron generator and the neutron source exist alone, respectively. In the modeling calculation, all the control rods are inserted to the bottom, the intensity of the AmBe neutron source is about 1.1×10 7 n / s, the neutron yield of the neutron generator is 5×10 8 n / s, and the sensitivity of the neutron detector is selected as 80 n / cm -2 ·s -1 , and the calculation results are shown in Table 2.

[0066] Table 2 Count rate at the neutron detector

[0067]

[0068] As can be seen from Table 2, when the yield of the neutron generator is selected as 5×10 8 n / s, the count rate generated at the rear end neutron detector is equivalent to the AmBe neutron source with a source intensity of about 1.1×10 7 n / s, and the count rate meets the reactor startup requirement of greater than 0.5 cps. The size of the neutron yield is proportional to the count rate of the neutron detector, that is, the larger the neutron yield, the greater the corresponding count rate. Therefore, in order to be applicable to as many different types and sizes of reactors as possible, the maximum neutron yield of the neutron generator can be selected to be higher than 1×10 9 n / s, and the neutron yield of the neutron generator can be freely adjusted between 0 and the maximum neutron yield, so that the neutron generator can be applied to various reactors, and only the required neutron yield needs to be adjusted according to the actual needs.

[0069] Step 300, using a neutron generator with sufficient neutron yield (a neutron yield meeting the reactor startup requirement) to replace the startup neutron source, opening the neutron generator and maintaining a stable neutron yield emission state before lifting the control rods in the reactor startup process, and performing the reactor startup operation.

[0070] After determining the neutron yield of the neutron generator by numerical calculation, the neutron generator with sufficient neutron yield is replaced with the start-up neutron source to realize the start-up operation of the reactor. Specifically, it includes:

[0071] Step 301, installation and debugging of the neutron generator outside the core are completed. The neutron generator and the neutron detector are located on opposite sides of the core, and the neutron generator is arranged outside the core barrel. The target nuclear component of the neutron generator is opposite to the core, and the center of the neutron detector, the core and the target nuclear component are almost collinearly arranged. Taking the above critical device as an example, the installation and debugging process is as shown in Figure 6 First, the core arrangement is performed and the critical device commissioning is completed, including installation of in-core components such as lower grid plate and surrounding plate, installation of neutron detectors and measuring instruments on the core, installation of fuel assemblies, control rods and poison rods, installation of control rod drive mechanism, and system commissioning of critical device nuclear measurement, control protection and drive mechanism; then, the neutron generator is installed and debugged, including fixed-point arrangement and debugging of the neutron generator outside the core, and commissioning of the neutron generator and the neutron detector on the core. It should be noted that the installation and debugging techniques are conventional technical means in the art, and specific installation and debugging methods will not be described here.

[0072] Step 302, after the neutron generator is installed, the neutron yield of the neutron generator is adjusted to the numerical calculation value and maintained in a stable neutron yield emission state, ensuring that the measured count rate at the rear-end neutron detector is greater than 0.5 cps.

[0073] In order to be applicable to as many different types and sizes of reactor start-up requirements as possible, the neutron generator is generally required to have a continuous stable working time limit longer than 1 hour. When there is an external neutron source (i.e. the neutron generator) to maintain the criticality of the reactor, the number of neutrons produced is comparable to the number of neutrons lost, so there is a requirement for the stability of the neutron beam generated by the neutron generator. Considering the statistical fluctuation of neutrons, the stability deviation of the neutron beam generated by the neutron generator is required to be within 1%.

[0074] The neutron beam stability requirement of the neutron generator acting as the start-up neutron source is that the continuous stable working time limit is longer than 1 hour under the condition of the start-up neutron yield, and the neutron beam deviation is within 1% at this time.

[0075] Step 303, according to the 1 / 2 principle, add reactivity and carry out the rod lifting extrapolation experiment to make the core reach the critical state. The rod lifting extrapolation experiment specifically includes: determining the core critical rod position according to the measured value; according to the core critical rod position, repeatedly performing the extrapolation operation according to the 1 / 2 principle to make the core k effWhen the value reaches 0.996, the neutron generator is cut off; then the control rods are finely adjusted to make the core transition to supercriticality, and finally the core is adjusted to the critical state by the power stabilization method, at which time the number of neutrons generated is equal to the number of neutrons lost, i.e., the reactor startup operation is completed.

[0076] Specifically, the above critical device is taken as an example, and the reactor startup operation is performed using the neutron generator to verify whether the neutron generator can sequentially realize the reactor startup. In the above critical device, the core includes two groups of safety rods (A1, A2) and six groups of regulation rods (K1, K2, K3, K4, K5, K6), and the core is arranged as shown in Figure 7

[0077] According to the preliminary measured value, the core critical rod position is: A1, A2, K1, K2, K3 rods are raised to the top, K4 rod is raised to 450 mm, and K5, K6 are at the bottom. According to this critical rod position, after the neutron generator is installed, the neutron yield of the neutron generator is adjusted to 5×10 8 n / s, to ensure that the measured count rate at the back-end neutron detector is greater than 0.5 cps, and then according to the "1 / 2 principle", the reactivity is added, and the rod lifting extrapolation experiment is carried out according to the steps as shown in Figure 8

[0078] A1 rod is lifted to the top, and the moderator is injected into the core;

[0079] A2 and K2 rods are lifted to the top;

[0080] K2 rod is lifted to the top, and the neutron count rate is recorded;

[0081] K3 rod is lifted to half height, and the neutron count rate is recorded;

[0082] According to the extrapolation result of the above step, K3 rod is lifted according to the 1 / 2 principle;

[0083] After K3 rod is lifted to the top, K4 rod is continued to be lifted according to the 1 / 2 principle for extrapolation;

[0084] When the extrapolation result k eff When the value reaches 0.996, the neutron generator is cut off;

[0085] K4 rod is finely adjusted to maintain the core criticality.

[0086] ​​After the above steps are completed, the core is successfully brought to a critical state by using the neutron generator, that is, the neutron generator can replace the traditional radioactive neutron source to realize the reactor startup. When the reactor startup is performed by using the neutron generator in the embodiment, the traditional radioactive nuclide neutron source does not need to be arranged in the reactor core or near the periphery, the arrangement of the research reactor is optimized, the inherent risk of the radioactive neutron source is eliminated, and because the neutrons generated by the neutron generator are controllable and adjustable in intensity, the reactor physical startup process is more optimized, and thus the arrangement of the reactor core is optimized and the safety performance of the reactor core is improved. In addition, the neutron generator generates monochromatic neutrons, the yield is controllable, the neutron generator is movable and reusable, and many other conveniences are provided, which has great economic benefits for the reactor startup and is of great significance. The method provided in the embodiment is applicable to various types of research reactors, including but not limited to various types of solid-state, liquid-state and gaseous research reactors, and is particularly suitable for critical devices.

[0087] Based on the same technical concept, the embodiment further provides a reactor startup system based on a neutron generator, as shown in Figure 9 The reactor startup system provided in the embodiment specifically includes:

[0088] A model construction module configured to establish a reactor theoretical model by using a reactor physics calculation program and perform model checking.

[0089] A numerical calculation module configured to count the count rate of neutrons generated by the neutron generator and passing through the core at the neutron detector, and determine the neutron yield of the neutron generator that meets the reactor startup requirement.

[0090] And a reactor startup module configured to replace the reactor startup neutron source with the neutron generator with sufficient neutron yield (the neutron yield that meets the reactor startup requirement), turn on the neutron generator and maintain a stable neutron yield emission state before lifting the control rod in the reactor startup process, and perform the reactor startup operation.

[0091] It should be noted that the specific implementation process of each functional module in the reactor startup system provided in the embodiment is described in the above method, and will not be described in detail here.

[0092] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0093] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0094] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0095] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0096] The above description is only a specific implementation of the present application. It should be understood that the above description is only a specific implementation of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for starting a reactor based on a neutron generator, characterized in that: The reactor startup method comprises: Use reactor physics calculation program to establish reactor theoretical model and perform model verification; Using a verified reactor theoretical model, the counting rate of neutrons generated by the neutron generator and then passing through the core at the neutron detector is statistically analyzed to determine the neutron yield of the neutron generator that meets the reactor startup requirements. A neutron generator with a neutron yield that meets the reactor startup requirements is used to replace the reactor startup neutron source. Before the control rods are lifted during the reactor startup process, the neutron generator is turned on and maintained in a stable neutron yield emission state to perform the reactor startup operation.

2. A method for starting a reactor based on a neutron generator according to claim 1, characterized in that: The method of establishing a reactor theoretical model using a reactor physics calculation program specifically includes: Using the Monte Carlo-based reactor physics calculation program, the reactor core, neutron detector, and neutron generator are modeled in detail from the inside out and in a step-by-step manner. During the modeling process, all control rods are set to move freely up and down.

3. A method for starting a reactor based on a neutron generator according to claim 2, characterized in that: The model verification specifically includes: The reactor theoretical model is calibrated and verified using multiple critical rod position measured values, and the calibration and verification conditions satisfy that the deviation between the measured value and the calculated value does not exceed a preset value.

4. The method for starting a reactor based on a neutron generator according to claim 1, characterized in that: The neutron yield of the neutron generator that meets the reactor startup requirements is specifically: The neutrons generated by the neutron generator have a counting rate of not less than 0.5 cps at the neutron detector after passing through the core.

5. The method for starting a reactor based on a neutron generator according to claim 4, characterized in that: The maximum neutron yield of the neutron generator is higher than 1×10 9 n / s, and the neutron yield of the neutron generator can be freely adjusted between 0 and the maximum neutron yield.

6. A method for starting a reactor based on a neutron generator according to any one of claims 1 to 5, characterized in that: The reactor startup operation specifically includes: Completing the installation and commissioning of the neutron generator outside the core; After the neutron generator is installed, the neutron yield of the neutron generator is adjusted to the numerically calculated value and maintained in a stable neutron yield emission state, ensuring that the measured count rate of the rear-end neutron detector is greater than 0.5 cps; Reactivity was added according to the 1 / 2 principle, and rod lifting and extrapolation experiments were carried out to bring the core to a critical state.

7. A method for starting a reactor based on a neutron generator according to claim 6, characterized in that: The installation and commissioning of the neutron generator outside the core specifically includes: The neutron generator and the neutron detector are respectively located on two opposite sides of the core, and the neutron generator is arranged outside the reactor barrel. The target core component of the neutron generator, the core and the centers of the neutron detector are arranged collinearly.

8. The method for starting a reactor based on a neutron generator according to claim 6, characterized in that: The rod lifting and extrapolation experiment specifically includes: Determine the core critical rod position based on the measured value; According to the core critical rod position, the extrapolation operation is repeated many times according to the 1 / 2 principle to make the core k eff It reaches 0.996, at which point the neutron generator is cut off; Fine-tune the control rods to bring the core to criticality.

9. The method for starting a reactor based on a neutron generator according to claim 1, characterized in that: The neutron generator is a device that generates neutron beams through the effect of particle bombardment of target nuclei.

10. A reactor startup system based on a neutron generator, characterized in that: The reactor startup system includes: A model building module, wherein the model building module is configured to: establish a reactor theoretical model using a reactor physics calculation program and perform model verification; a numerical calculation module configured to: use a verified reactor theoretical model to calculate a count rate of neutrons generated by the neutron generator and then passed through the reactor core at a neutron detector, thereby determining a neutron yield of the neutron generator that meets the reactor startup requirements; and a start-up module, wherein the start-up module is configured to replace the start-up neutron source with a neutron generator having a neutron yield that meets the reactor startup requirements, and to turn on the neutron generator and maintain it in a stable neutron yield emission state before raising the control rods during the reactor startup process to perform the reactor startup operation.

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