A passive start-up method for high temperature gas-cooled reactor

Abstract

The present invention discloses a passive start method for a high temperature gas-cooled reactor. The present invention adopts passive start technology, eliminates the need for neutron sources during reactor loading and startup, and significantly reduces the construction cost of the high temperature gas-cooled reactor. The neutron source itself is highly radioactive, and eliminating the neutron source reduces a large amount of high-level radioactive waste; the high temperature gas-cooled reactor of the present invention adopts passive start and eliminates the neutron source, which can avoid the risk of "stuck neck" in the procurement of californium powder.

Description

Technical Field

[0001] The invention relates to the technical field of reactor debugging and operation, and in particular to a passive starting method for a high-temperature gas-cooled reactor. Background Art

[0002] "Passive start-up" refers to the process in which the reactor, in the absence of an external neutron source, uses only the neutrons released by the spontaneous fission of nuclear fuel as a starting neutron source to achieve a self-sustaining chain fission reaction of the nuclear fuel in the reactor and bring the reactor to an initial critical state.

[0003] The Russian-designed VVER reactor uses a unique passive start-up technology. Since the Soviet Union first successfully used this technology in the 1960s, all VVER reactors have used passive start-up for physical startup.

[0004] The No. 1 and No. 2 units of the first phase of my country's Tianwan Nuclear Power Station were successfully passively started in December 2005 and May 2007, respectively, and the No. 3 and No. 4 units of the second phase were successfully passively started in May 2017 and September 2018, respectively.

[0005] High temperature gas-cooled reactors have many advantages, such as inherent safety, high temperature resistance of fuel elements (1620℃), and passive residual heat removal. They are called "reactors that will not melt down" and have become the safest and most commercialized fourth-generation nuclear power technology in my country. Compared with VVER reactors, high temperature gas-cooled reactors have different core designs and different characteristics in loading and starting: first, there is a temporary physical starting system during the first loading and criticality process, which can insert neutron detectors into the core reflector layer, so that it is easier to obtain the neutron detection count of the core and effectively monitor the loading process; second, because high temperature gas-cooled reactors use spherical fuel elements, the uranium loading of each fuel element is very small, and the control rods are located in the side reflector layer outside the core, and the value of a single rod is very small. Therefore, during the loading and starting process, the positive reactivity introduced by the mis-addition of fuel elements or the mis-extraction of rods is very low, and there will be no rapid introduction of positive reactivity events; coupled with the inherent safety of high temperature gas-cooled reactors, it is ensured that even if a positive reactivity mis-introduction event occurs, the reactor itself will not have major accident consequences. The above characteristics are the advantages of high temperature gas-cooled reactors over VVER reactors in core loading and startup monitoring, and are also the basis for the development and utilization of passive startup technology. In theory, high temperature gas-cooled reactors using passive startup technology are safer than VVER type isopause reactors.

[0006] At present, the national nuclear safety regulatory authorities also support the active exploration of the research and application of passive start-up technology in non-VVER reactors under the premise of ensuring safety. Therefore, the passive start-up of high-temperature gas-cooled reactors is a technology with great application prospects. It can not only provide support for the further development of high-temperature gas-cooled reactors, but also provide important reference for the application of passive start-up technology of other reactor types. It is necessary to propose a passive start-up method for high-temperature gas-cooled reactors. Summary of the invention

[0007] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0008] To this end, an embodiment of the present invention provides a passive startup method for a high temperature gas-cooled reactor.

[0009] The present invention proposes a passive startup method for a high temperature gas-cooled reactor, comprising the following steps:

[0010] (1) A temporary physical start-up system is arranged in the graphite reflector layer on the core side, and the neutron injection rate and neutron energy spectrum outside the core are theoretically calculated for different fuel loadings. The neutron response at different positions is simulated and analyzed. According to the strength of the neutron response, a high-sensitivity neutron measurement device and a source range detector are arranged outside the reactor pressure vessel to obtain the neutron counting rate under deep subcriticality conditions;

[0011] (2) Establish a core state calculation model, simulate and analyze the first loading and passive startup process, and give the core fuel loading and K eff and the relationship diagram of the source range detector and the high-sensitivity neutron measuring device under a specific core state are provided; during the first loading process, the reaction characteristics of the high-sensitivity neutron measuring device and the source range detector are verified by the temporary physical start-up system, and the arrangement position of the high-sensitivity neutron measuring device is adaptively adjusted;

[0012] (3) Lift all the adjustment rods and compensation rods horizontally until they are close to the critical state, where K eff =0.998;

[0013] (4) The regulating rods and the compensating rods are lifted one by one step by step, with the height of each rod being less than 50 mm. After each rod is lifted, it is stabilized for more than 1 minute until the core achieves the first criticality.

[0014] In some embodiments, the high-sensitivity neutron measurement device cooperates with the source range detector to monitor changes in the core neutron fluence rate to reduce the blind area of ​​neutron fluence rate monitoring.

[0015] In some embodiments, the rod lifting speed is controlled so that the time interval from the near-critical state to the critical state is greater than 60 minutes, and the high temperature gas-cooled reactor is controlled to reach +0.2β from the critical state. eff The time interval is greater than 10 minutes.

[0016] In some embodiments, before step (3), the temporary physical startup system is dismantled to heat, dehumidify and switch the atmosphere of the high temperature gas-cooled reactor.

[0017] In some embodiments, the step of verifying the response characteristics of the high-sensitivity neutron measurement device and the source range detector by the temporary physical start-up system during the first loading process and adaptively adjusting the arrangement position of the high-sensitivity neutron measurement device comprises the following steps:

[0018] Loading the core with mixed fuel of 1 / 3 of the theoretical initial full fuel loading amount, and after the counting is stable, recording the counting rates of the temporary physical start-up system, the source range detector and the high-sensitivity neutron measurement device and comparing and analyzing them with theoretical values;

[0019] According to the 1 / 3 loading principle, 2 / 9 of the theoretical initial full fuel loading amount of mixed fuel is loaded into the core. After the counting is stable, the counting rates of the temporary physical start-up system, the source range detector and the high-sensitivity neutron measurement device are recorded and compared with the theoretical values ​​for analysis;

[0020] Subsequently, according to the 1 / 3 loading principle, a mixed fuel of 1 / 3 of the difference between the theoretical initial full fuel loading and the current total core loading is sequentially loaded. After each loading is completed and the counting is stable, the counting rate of each neutron detector is recorded and compared and analyzed until the core is initially fully loaded;

[0021] The neutron characteristic analysis of the high-sensitivity neutron measuring device during the first loading process is performed to determine the arrangement position of the high-sensitivity neutron measuring device.

[0022] In some embodiments, during the first loading process, if the neutron count rate of any neutron detector in the temporary physical start system, the source range detector, or the high-sensitivity neutron measurement device reaches 0.5cps, 1 / 3 extrapolated loading is performed based on the neutron detector of the system to complete the initial full loading.

[0023] In some embodiments, in step (3), the 1 / 3 rod lifting principle is adopted to lift all the adjustment rods and the compensation rods horizontally to a theoretical rod position close to the critical state.

[0024] In some embodiments, when the high temperature gas-cooled reactor reaches a critical state, the core achieves passive startup for the first time criticality.

[0025] In some embodiments, the step of lifting all the adjusting rods and the compensating rods to a near critical state comprises the following steps:

[0026] Lift all the regulating rods and compensating rods to the height of the bottom of the core active area, and record the position of each control rod and the count rate of each neutron counting tube after the count rates of the source range detector and the high-sensitivity neutron measuring device are stabilized;

[0027] All the adjustment rods and the compensation rods are lifted horizontally by 200 mm, and after the counting rates of the source range detector and the high-sensitivity neutron measuring device are stabilized, the positions of the control rods and the counting rates of the neutron counting tubes are recorded;

[0028] Subsequently, according to the 1 / 3 rod lifting principle, all the regulating rods and compensating rods are lifted horizontally one by one, and the rod lifting height is the smaller of 1 / 3 of the difference between the theoretical critical rod position and the current rod position and 200 mm. After each rod lifting is completed and the counting is stable, the counting rate of each neutron detector is recorded until the average rod position of the regulating rods and the compensating rods is close to the reactor K eff =0.998 theoretical critical rod position.

[0029] In some embodiments, if the counting rates of all neutron detectors in the source range detector and the high-sensitivity neutron measurement device reach above 0.5cps during the rod lifting process, and the core has not yet reached criticality, the counting rates of each neutron detector are used to perform criticality operations according to the 1 / 3 rod lifting principle until the core achieves first criticality.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] The present invention adopts passive start-up technology, eliminates the need for neutron sources during reactor loading and startup, and significantly reduces the construction cost of high-temperature gas-cooled reactors. Neutron sources themselves are highly radioactive, and eliminating neutron sources reduces a large amount of high-level radioactive waste.

[0032] The high-temperature gas-cooled reactor of the present invention adopts passive start-up and eliminates the neutron source, thereby avoiding the "bottleneck" risk of purchasing californium powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0034] Figure 1 A schematic diagram of the arrangement of neutron detectors related to the passive start-up of a high-temperature gas-cooled reactor;

[0035] Figure 2 This is the flow chart for the first loading and passive startup of the high-temperature gas-cooled reactor. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0037] The following describes a passive startup method for a high temperature gas-cooled reactor according to an embodiment of the present invention with reference to the accompanying drawings.

[0038] The high temperature gas-cooled reactor passive startup method of the present invention comprises the following steps:

[0039] (1) A temporary physical start-up system is arranged in the graphite reflector layer on the core side, and the neutron injection rate and neutron energy spectrum outside the core are theoretically calculated for different fuel loadings. The neutron response at different positions is simulated and analyzed. According to the strength of the neutron response, a high-sensitivity neutron measurement device and a source range detector are arranged outside the reactor pressure vessel to obtain the neutron counting rate under deep subcriticality conditions;

[0040] (2) Establish a core state calculation model, simulate and analyze the first loading and passive startup process, and give the core fuel loading and K eff The relationship diagram of the source range detector and the high-sensitivity neutron measuring device is provided, and the neutron reaction characteristics of the source range detector and the high-sensitivity neutron measuring device under specific core conditions are given. During the first loading process, the reaction characteristics of the high-sensitivity neutron measuring device and the source range detector are verified through a temporary physical start-up system, and the layout position of the high-sensitivity neutron measuring device is adaptively adjusted;

[0041] (3) Dismantle the temporary physical startup system to heat, dehumidify and switch the atmosphere of the HTGR;

[0042] (4) Lift all the adjustment rods and compensation rods horizontally until they are close to the critical state. The critical state is K eff =0.998;

[0043] (5) Lift the regulating rods and compensating rods one by one step by step. The height of each rod should be less than 50 mm. Each rod should be stabilized for more than 1 minute after being lifted until the core achieves the first criticality.

[0044] The temporary physical start-up system is an original system of the high-temperature gas-cooled reactor. On this basis, the present invention adds a high-sensitivity neutron measuring device and sets the position of the high-sensitivity neutron measuring device according to theoretical calculations.

[0045] Specifically, in addition to arranging a temporary physical start-up system in the graphite reflector layer on the core side, extrapolating and supervising during the first loading process, a high-sensitivity neutron measurement device is arranged outside the reactor pressure vessel. During passive startup, the high-sensitivity neutron measurement device cooperates with the source range detector to monitor the change of the core neutron injection rate to reduce the blind area of ​​the neutron injection rate monitoring. The neutron injection rate and neutron energy spectrum outside the core are theoretically calculated when different fuels are loaded, and the neutron response at different positions is accurately simulated and analyzed. According to the strength of the neutron response, the high-sensitivity neutron measurement device and the source range detector are reasonably arranged to obtain neutron counts as much as possible under the condition of deeper subcriticality.

[0046] After arranging the high-sensitivity neutron measurement device and the source range detector according to the strength of the theoretically calculated neutron response, it is necessary to verify the neutron response characteristics of the high-sensitivity neutron measurement device and the source range detector.

[0047] Specifically, a core state calculation model is established to conduct a comprehensive simulation analysis of the first loading and passive startup process, and the core fuel loading and k eff The relationship diagram is shown, and the neutron reaction characteristics of the source range detector and the high-sensitivity neutron measurement device under specific core conditions are given. During the first loading process, the reaction characteristics of the high-sensitivity neutron measurement device and the source range detector are verified by temporarily physically starting the system, and the layout of the high-sensitivity neutron measurement device is adaptively adjusted.

[0048] In some embodiments, the 1 / 3 loading principle is adopted to complete the initial full loading of the core. During the first loading process, the response characteristics of the high-sensitivity neutron measurement device and the source range detector are verified by a temporary physical startup system, and the layout position of the high-sensitivity neutron measurement device is adaptively adjusted, including the following steps:

[0049] Load the core with mixed fuel of 1 / 3 of the theoretical initial full fuel load. After the counts stabilize, record the count rates of the temporary physical start-up system, source range detector and high-sensitivity neutron measurement device and compare and analyze them with the theoretical values;

[0050] According to the 1 / 3 loading principle, 2 / 9 of the theoretical initial full fuel loading amount of mixed fuel is loaded into the core. After the counting is stable, the counting rates of the temporary physical start-up system, source range detector and high-sensitivity neutron measurement device are recorded and compared with the theoretical values ​​for analysis;

[0051] Subsequently, according to the 1 / 3 loading principle, a mixed fuel of 1 / 3 of the difference between the theoretical initial full fuel loading and the current total core loading is sequentially loaded. After each loading is completed and the counting is stable, the counting rate of each neutron detector is recorded and compared and analyzed until the core is initially fully loaded;

[0052] Conduct neutron characteristic analysis of the high-sensitivity neutron measuring device during the initial loading process and determine the layout of the high-sensitivity neutron measuring device.

[0053] In addition, during the first loading process, if the neutron count rate of any neutron detector in the temporary physical start-up system, source range detector, and high-sensitivity neutron measurement device reaches 0.5cps, 1 / 3 extrapolated loading is performed based on the neutron detector of the system to complete the initial full loading.

[0054] It can be understood that if the counting rate of the high-sensitivity neutron measuring device is close to the theoretical value, there is no need to adjust the layout position of the high-sensitivity neutron measuring device; if the counting rate of the high-sensitivity neutron measuring device is significantly different from the theoretical value, the layout position of the high-sensitivity neutron measuring device is adjusted.

[0055] After determining the location of the high-sensitivity neutron measurement device, the temporary physical start-up system is dismantled, and the high-temperature gas-cooled reactor is heated, dehumidified, and the atmosphere is switched to facilitate the subsequent passive start-up process.

[0056] Use the 1 / 3 rod lifting principle to lift all adjustment rods and compensation rods to the theoretical rod position close to the critical state. The critical state is K eff =0.998. Specifically, the following steps are included:

[0057] Lift all regulating rods and compensating rods to the bottom height of the core active area. After the counting rates of the source range detector and the high-sensitivity neutron measuring device are stable, record the position of each control rod and the counting rate of each neutron counting tube.

[0058] Lift all adjustment rods and compensation rods horizontally by 200mm. After the counting rate of the source range detector and high-sensitivity neutron measuring device is stable, record the position of each control rod and the counting rate of each neutron counting tube;

[0059] Subsequently, according to the 1 / 3 rod lifting principle, all the regulating rods and compensating rods are lifted horizontally one by one. The rod lifting height is the smaller of 1 / 3 of the difference between the theoretical critical rod position and the current rod position and 200 mm. After each rod lifting is completed and the counting is stable, the counting rate of each neutron detector is recorded until the average rod position of the regulating rods and compensating rods is close to the reactor k eff =0.998 theoretical critical rod position.

[0060] After the high temperature gas-cooled reactor reaches a near-critical state, the regulating rods and compensating rods are lifted one by one in steps, with each rod lifting height less than 50mm. After a single rod is lifted, it is stabilized for more than 1 minute until the core achieves the first criticality. When the high temperature gas-cooled reactor reaches a critical state, the core achieves the first criticality of passive startup.

[0061] In addition, if the counting rates of all neutron detectors in the source range detector and the high-sensitivity neutron measurement device reach above 0.5cps during the rod lifting process and the core has not yet reached criticality, the counting rates of each neutron detector will be used to perform criticality operations according to the 1 / 3 rod lifting principle until the core achieves first criticality.

[0062] After the high temperature gas-cooled reactor approaches the critical state, the rod lifting speed is strictly controlled so that the time interval from the critical state to the critical state is greater than 60 minutes, and the high temperature gas-cooled reactor is controlled from the critical state to +0.2β eff The time interval is greater than 10 minutes, leaving enough time for the operating personnel to correctly judge the core status and take measures to control the changes in core reactivity.

[0063] In addition, in order to strictly control the positive reactivity introduction rate, a passive start-up positive reactivity introduction rate protection or alarm signal can be set to prevent the occurrence of excessively rapid positive reactivity introduction events; increase radiation dose monitoring in key locations such as the reactor hall and reactor compartment as an additional monitoring means for changes in core reactivity; take measures to avoid unplanned reactivity introduction, such as false acceleration / start-up of the main helium fan, water / steam inlet into the primary circuit, etc.

[0064] like Figure 1-2 As shown, in some embodiments, the first loading and passive startup process of the high temperature gas-cooled reactor includes:

[0065] S1: The safety rod is at the upper limit, the regulating rod and the compensating rod are at the lower limit, and the absorbing ball is blown out of the core;

[0066] S2: Using the 1 / 3 loading principle, the initial full loading of the core is completed, and the response characteristics of the neutron detector are verified during the loading process;

[0067] S3: dismantle the temporary physical startup system, and then complete core heating, dehumidification and atmosphere switching;

[0068] S4: Use the 1 / 3 lifting principle to lift all adjustment rods and compensation rods horizontally to K eff =0.998 theoretical stick position;

[0069] S5: Lift the adjustment rods and compensation rods one by one, and strictly control the height of each rod lift and the dwell time after lifting the rod;

[0070] S6: The core achieves its first criticality through passive startup.

[0071] Specifically: put into operation the temporary physical start-up system, source range detector, high-sensitivity neutron measurement device and other systems and equipment related to the first loading of the reactor to ensure that all parameters are set reasonably and work properly. Verify the test prerequisites, ensure that the core has been loaded with the required pure graphite ball cushion, all safety rods are at the upper limit, all adjustment rods and compensation rods are at the lower limit, all absorption balls are blown out of the core, etc., and record the initial parameters such as the core temperature.

[0072] The core is loaded with mixed fuel of 1 / 3 of the theoretical initial full fuel loading amount. After the counting is stable, the counting rate of each neutron detector is recorded and compared with the theoretical reaction characteristics of the source range detector and the high-sensitivity neutron measurement device under the corresponding core state. Among them, the neutron detector refers to the neutron detector of the temporary physical start-up system, the source range detector, and the high-sensitivity neutron measurement device.

[0073] According to the 1 / 3 loading principle, the core is loaded with the remaining (1-1 / 3) 1 / 3 of the theoretical initial full fuel loading amount of mixed fuel, that is, 2 / 9 of the theoretical initial full fuel loading amount of mixed fuel. After the counting is stable, the counting rate of each neutron detector is recorded and compared and analyzed.

[0074] Subsequently, according to the 1 / 3 loading principle, a mixed fuel of 1 / 3 of the difference between the theoretical initial full fuel loading and the current total core loading is loaded in sequence. After each loading is completed and the counting is stable, the counting rate of each neutron detector is recorded and compared and analyzed until the core completes the initial full loading.

[0075] If the neutron counting rate of any neutron detector in the temporary physical start-up system, source range detector, and high-sensitivity neutron measurement device can reach 0.5cps, 1 / 3 extrapolated loading can be performed based on the neutron detector of the system to complete the initial full loading.

[0076] The neutron characteristics of the high-sensitivity neutron measurement device during the initial loading process are analyzed to determine the layout positions of the device's four neutron detectors (such as He-3 counter tubes) during the passive startup process.

[0077] The temporary physical startup system was dismantled, and then the reactor was heated, dehumidified, and the atmosphere switched.

[0078] Put into use systems and equipment such as source range detectors and high-sensitivity neutron measurement devices related to reactor passive start-up to ensure that all parameters are set reasonably and work normally.

[0079] Verify the test prerequisites, that all safety rods are at the upper limit, all regulating rods and compensating rods are at the lower limit, all absorption balls are blown out of the core, etc., and record initial parameters such as core temperature.

[0080] Lift all adjustment rods and compensation rods to the bottom height of the core active area (the uppermost part of the pure graphite ball cushion layer), and after the counting rates of the source range detector and the high-sensitivity neutron measuring device are stable, record the position of each control rod and the counting rate of each neutron counting tube.

[0081] Lift all adjustment rods and compensation rods horizontally by 200mm, and after the neutron counting tube count rate of the source range detector and high-sensitivity neutron measuring device is stable, record the position of each control rod and the neutron counting tube count rate.

[0082] Subsequently, according to the 1 / 3 rod lifting principle, all the regulating rods and compensating rods are lifted horizontally one by one. The rod lifting height is the smaller of 1 / 3 of the difference between the theoretical critical rod position and the current rod position and 200 mm. After each rod lifting is completed and the counting is stable, the counting rate of each neutron detector is recorded until the average rod position of the regulating rods and compensating rods is close to (less than 50 mm) the reactor k eff =0.998 theoretical critical rod position.

[0083] Lift the adjustment rods and compensation rods one by one step by step. The lifting height should be less than 50mm each time. After lifting a single rod, it should be stable for more than 1 minute. Pay close attention to the changes in the neutron count rate of the source range detector and the high-sensitivity neutron measuring device until the core achieves the first criticality.

[0084] If the counting rates of all six neutron detectors in the source range detector and the high-sensitivity neutron measuring device reach above 0.5cps during the rod lifting process and the core is not yet critical, the counting rates of each neutron detector can be used to perform criticality operations according to the 1 / 3 rod lifting principle until the core achieves first criticality.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms may be for different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0086] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0087] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A passive startup method for a high temperature gas-cooled reactor, characterized in that: The following steps are involved: (1) A temporary physical start-up system is arranged in the graphite reflector layer on the core side, and the neutron injection rate and neutron energy spectrum outside the core are theoretically calculated for different fuel loadings. The neutron response at different positions is simulated and analyzed. According to the strength of the neutron response, a high-sensitivity neutron measurement device and a source range detector are arranged outside the reactor pressure vessel to obtain the neutron counting rate under deep subcriticality conditions; (2) Establish a core state calculation model, simulate and analyze the first loading and passive startup process, and give the core fuel loading and K eff and the relationship diagram of the source range detector and the high-sensitivity neutron measuring device under a specific core state are provided; during the first loading process, the reaction characteristics of the high-sensitivity neutron measuring device and the source range detector are verified by the temporary physical start-up system, and the arrangement position of the high-sensitivity neutron measuring device is adaptively adjusted; (3) Lift all the adjustment rods and compensation rods horizontally until they are close to the critical state, where K eff =0.998; (4) Lift the regulating rods and compensating rods one by one step by step, with each rod lifting to a height of less than 50 mm. Each rod should be stabilized for more than 1 minute after lifting until the core achieves first criticality. The process of verifying the response characteristics of the high-sensitivity neutron measuring device and the source range detector by the temporary physical start-up system during the first loading process and adaptively adjusting the arrangement position of the high-sensitivity neutron measuring device comprises the following steps: Loading the core with mixed fuel of 1 / 3 of the theoretical initial full fuel loading amount, and after the counting is stable, recording the counting rates of the temporary physical start-up system, the source range detector and the high-sensitivity neutron measurement device and comparing and analyzing them with theoretical values; According to the 1 / 3 loading principle, 2 / 9 of the theoretical initial full fuel loading amount of mixed fuel is loaded into the core. After the counting is stable, the counting rates of the temporary physical start-up system, the source range detector and the high-sensitivity neutron measurement device are recorded and compared with the theoretical values ​​for analysis; Subsequently, according to the 1 / 3 loading principle, a mixed fuel of 1 / 3 of the difference between the theoretical initial full fuel loading and the current total core loading is sequentially loaded. After each loading is completed and the counting is stable, the counting rate of each neutron detector is recorded and compared and analyzed until the core is initially fully loaded; Perform neutron characteristic analysis on the high-sensitivity neutron measuring device during the first loading process to determine the layout position of the high-sensitivity neutron measuring device. If the count rate of the high-sensitivity neutron measuring device is close to the theoretical value, there is no need to adjust the layout position of the high-sensitivity neutron measuring device. If the count rate of the high-sensitivity neutron measuring device is significantly different from the theoretical value, adjust the layout position of the high-sensitivity neutron measuring device.

2. The method according to claim 1, characterized in that The high-sensitivity neutron measurement device cooperates with the source range detector to monitor the change of the core neutron injection rate to reduce the blind area of ​​the neutron injection rate monitoring.

3. The method according to claim 1, characterized in that The rod lifting speed is controlled so that the time interval from the near-critical state to the critical state is greater than 60 minutes, and the high-temperature gas-cooled reactor is controlled to reach +0.2β from the critical state. eff The time interval is greater than 10 minutes.

4. The method according to claim 1, characterized in that Prior to step (3), the temporary physical startup system is dismantled to heat, dehumidify and switch the atmosphere of the high temperature gas-cooled reactor.

5. The method according to claim 1, characterized in that During the first loading process, if the neutron count rate of any neutron detector in the temporary physical start system, the source range detector, or the high-sensitivity neutron measurement device reaches 0.5 cps, 1 / 3 extrapolated loading is performed based on the neutron detector of the system to complete the initial full loading.

6. The method according to claim 1, characterized in that In the step (3), the 1 / 3 rod lifting principle is adopted to lift all the regulating rods and the compensating rods horizontally to a theoretical rod position close to the critical state.

7. The method according to claim 1, characterized in that When the high-temperature gas-cooled reactor reaches the critical state, the core achieves the first criticality through passive startup.

8. The method according to claim 1, characterized in that The method of lifting all the adjusting rods and the compensating rods to a near critical state comprises the following steps: Lift all the regulating rods and compensating rods to the height of the bottom of the core active area, and record the position of each control rod and the count rate of each neutron counting tube after the count rates of the source range detector and the high-sensitivity neutron measuring device are stabilized; All the adjustment rods and the compensation rods are lifted horizontally by 200 mm, and after the counting rates of the source range detector and the high-sensitivity neutron measuring device are stabilized, the positions of the control rods and the counting rates of the neutron counting tubes are recorded; Subsequently, according to the 1 / 3 rod lifting principle, all the regulating rods and compensating rods are lifted horizontally one by one, and the rod lifting height is the smaller of 1 / 3 of the difference between the theoretical critical rod position and the current rod position and 200 mm. After each rod lifting is completed and the counting is stable, the counting rate of each neutron detector is recorded until the average rod position of the regulating rods and the compensating rods is close to the reactor K eff =0.998 theoretical critical rod position.

9. The method according to claim 1, characterized in that If the counting rates of all neutron detectors in the source range detector and the high-sensitivity neutron measuring device reach above 0.5cps during the rod lifting process and the core is not yet critical, the counting rates of the neutron detectors are used to perform criticality operations according to the 1 / 3 rod lifting principle until the core achieves the first criticality.

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