Multiphysics coupling hardware-in-the-loop device for pressurized water reactor core oxide corrosion product deposition

Abstract

A hardware-in-the-loop device for multi-physics coupling of oxidation and corrosion product deposition in pressurized water reactor cores includes: an accelerated deposition system for corrosion products, an online elemental testing system, and an axial power offset digital mirroring system. This invention can realize the complex process of multi-physics coupling involving water chemistry, material corrosion, flow heat transfer, and neutron physics in the deposition of oxidation and corrosion products, avoid offline data transmission between individual physical fields, directly obtain the growth law of the deposition layer, analyze the deposition mechanism of oxidation and corrosion products, and improve the shortcomings of existing devices that cannot be physically verified and cannot obtain the elemental concentration and distribution inside the corrosion product deposition layer.

Description

Technical Field

[0001] This invention relates to a technology in the field of reactor control, specifically a hardware-in-the-loop device for multi-physics coupling of pressurized water reactor core oxidation corrosion product deposition. Background Technology

[0002] Due to the high temperature, high pressure, and high radioactivity within nuclear reactors, it is impossible to directly analyze the multi-physics coupling processes involved in the deposition of core oxidation and corrosion products, or the deposition mechanism of these products, through in-reactor measurements. Currently, the most representative research method is offline characterization, which involves extracting fuel assemblies from the reactor core for external cooling and oxidation, cutting the cladding, and preparing samples of the oxidation and corrosion product deposition layer for microscopic characterization by electron microscopy (SEM) and elemental analysis by energy dispersive spectroscopy (EDS). Based on this, the deposition mechanism of oxidation and corrosion products on the cladding, and the influence of oxidation and corrosion product deposition on cladding heat transfer and elemental distribution, can be deduced through data transfer between individual physical fields. However, the aforementioned data transfer method between individual physical fields cannot realize the multi-physics coupling processes involved in the deposition of oxidation and corrosion products. Furthermore, since the solubility of the materials constituting the oxide corrosion product deposition layer (such as NiO, NiFe2O4 and Li2B4O7) is closely related to temperature, the deposition layer materials may dissolve or precipitate again during the preparation of oxide corrosion product deposition layer samples, leading to deviations in the measurement of oxide corrosion product deposition and element migration behavior. Therefore, it is impossible to accurately analyze the deposition mechanism of oxide corrosion products in the reactor core. Summary of the Invention

[0003] To address the aforementioned shortcomings of existing technologies, this invention proposes a hardware-in-the-loop device for multi-physics coupling in the deposition of oxidation and corrosion products in pressurized water reactor cores. This device can realize the complex process of multi-physics coupling involved in the deposition of oxidation and corrosion products, including water chemistry, material corrosion, flow heat transfer, and neutron physics. It avoids offline data transmission between individual physical fields, directly obtains the growth law of the deposition layer, and analyzes the deposition mechanism of oxidation and corrosion products. This invention overcomes the shortcomings of existing devices that cannot be physically verified and cannot obtain the elemental concentration and distribution inside the corrosion product deposition layer.

[0004] This invention is achieved through the following technical solution:

[0005] This invention relates to a hardware-in-the-loop (HIL) device for multi-physics coupling of oxidation and corrosion product deposition in a pressurized water reactor core, comprising: an accelerated deposition system for corrosion products, an online elemental testing system, and an axial power offset digital mirroring system. The accelerated deposition system rapidly deposits precursors onto the cladding to obtain an oxidation and corrosion product deposition layer. The online elemental testing system uses transient gamma activation technology to analyze the growth pattern and elemental distribution within the deposition layer. The axial power offset digital mirroring system calculates the cross-sectional information of neutron flux based on the elemental distribution of the deposition layer, thereby calculating the axial power distribution and controlling the heat transfer boundary on the cladding surface of the heating unit, achieving coupling of oxidation and corrosion product deposition, elemental migration and distribution, and axial power offset.

[0006] This invention relates to a control method based on the above-described system, comprising:

[0007] Step 1: Accelerate the preparation of deposition precursors, specifically including:

[0008] 1.1 By simulating the reactor coolant loop and the charging and discharging loop of the chemical and volumetric system, and based on the Gibbs free energy change under typical pressurized water reactor conditions, the thermochemical equilibrium constants of each reaction in the high-permeability solution are determined, thereby obtaining the substance concentration and pH value in the Li-B-D2O system. Specifically, the Gibbs free energy change in the high-permeability solution is given by the formula... Confirmed, among which: Gibbs free energy of formation after modification of reactants under high temperature and high pressure Obtained by doing something else.

[0009] 1.2 Control the temperature of the coolant and regulate the concentrations of boron, lithium, and oxidation corrosion products in the circuit. Determine the stable phase distribution of Fe and Ni through the chemical equilibrium of minimizing the Gibbs free energy of the multi-component solute-solvent system. This allows for the adjustment of the ratio of soluble Fe, Ni, and suspended particles to form precursors for oxidation corrosion products. Specifically, the concentrations of each component at equilibrium are obtained by solving the equilibrium equations, element mass conservation equations, and charge conservation equations of each reaction simultaneously using Newton-Raphson iterative calculations.

[0010] 1.3 Accelerated deposition of corrosion products: According to the parameters obtained in step 1.2, the prepared precursor is added to the coolant circuit to accelerate deposition on the cladding and form an oxide corrosion product deposition layer.

[0011] Step 2: Irradiate the oxide corrosion product deposit layer obtained in Step 1 with a neutron beam. Based on the different energies of transient gamma rays released by the nuclear reactions of different elements with neutrons, calculate the three-dimensional distribution of Fe, Ni, and B. Specifically, this includes:

[0012] 2.1 Using a total internal reflection neutron lens, the focusing behavior of the radiation was simulated using the Monte Carlo method to calculate the optimal focusing and gain conditions. The oxide corrosion product deposit layer obtained in step one was irradiated with a cold neutron beam with the optimal focusing gain, resulting in transient gamma activation.

[0013] 2.2 A high-purity germanium detector was used to receive activated gamma rays and obtain the activated gamma spectrum of the oxidation corrosion products. By identifying the characteristic peaks of each element and combining them with the background, the content information of each element in the deposition layer of oxidation corrosion products was calculated.

[0014] 2.3 A Compton camera is used to receive activated gamma rays, causing Compton scattering within the gamma rays. The obtained Compton scattering information is analyzed and calculated to output the location of gamma activation within the oxide corrosion product deposit layer and the spatial distribution information of each element within the oxide corrosion product deposit layer.

[0015] Step 3: Based on the spatial distribution information of each element, a data-driven intrinsic orthogonal decomposition (POD) order reduction algorithm is used to obtain the three-dimensional axial power distribution of the fuel rod, thereby realizing feedback control of the heat flux on the cladding surface and actively adjusting the deposition of corrosion products and the migration distribution of elements. Specifically, this includes:

[0016] 3.1 Based on the spatial distribution information of each element, a multi-dimensional multi-group neutron cross-section database is constructed using the background grid mixing layer cross-section homogenization method.

[0017] 3.2 Based on the background mesh method, and using the multi-dimensional multi-group neutron cross-section database obtained by the variational principle and the background mesh mixed layer cross-section homogenization method, full-order matrix equations representing the neutron equilibrium relationship inside the finite element block and the neutron continuity relationship on the block surface are obtained respectively.

[0018] 3.3 A data-driven intrinsic orthogonal decomposition algorithm for order reduction is employed to construct a reduced-order model for neutron transport simulation and solve for the reduced-order basis. Methods such as linear interpolation, Gaussian process regression, decision trees, and neural networks are used to obtain a predictive model between parameters and coefficients. Using the reduced-order basis obtained from the algorithm and the trained predictive model, the order reduction of the full-order matrix obtained in step 3.2 can be accelerated, thereby enabling rapid prediction of the three-dimensional power distribution of fuel rods under different oxide corrosion product deposition layer thicknesses.

[0019] 3.4 Based on the power distribution information predicted in step 3.3, the power supply is set and the heating power is adjusted to achieve feedback control, thereby adjusting the deposition of oxidation corrosion products and the migration distribution of elements in real time.

[0020] Technical effect

[0021] This invention employs an analytical system that integrates multiple physical processes such as water chemistry, material corrosion, flow heat transfer, and neutron physics, along with a hardware-in-the-loop device for multi-physical coupling of oxidative corrosion product deposition. This system enables the analysis of the growth patterns and deposition mechanisms of oxidative corrosion product deposits. Furthermore, it allows for online measurement of oxidative corrosion product deposition, avoiding measurement errors caused by changes in the properties of the deposited layer due to environmental variations (temperature, pressure, etc.) during offline measurements. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the system of the present invention;

[0023] Figure 2 Schematic diagram of an accelerated deposition system for corrosion products;

[0024] In the diagram: 1. Preheater, 2. Centrifugal pump, 3. Heat exchanger, 4. Pressure regulator, 5. Control and acquisition system, 6. Plate heat exchanger, 7. Injection pump, 8. Water chemistry instrument box, 9. Precursor, 10. Boron-containing water, 11. Lithium-containing water, 12. Pressure gauge, 13. Pressure relief valve, 14. Flow meter.

[0025] Figure 3 A schematic diagram of an online element testing system;

[0026] Figure 4 This is a schematic diagram of the neutron algorithm order reduction model and the heating unit. Detailed Implementation

[0027] like Figure 1 As shown in this embodiment, a hardware-in-the-loop device for multi-physics coupling of oxidation and corrosion product deposition in a pressurized water reactor core includes: an accelerated deposition system for corrosion products to reproduce the water chemistry and flow heat transfer environment in a typical pressurized water reactor primary loop system and provide a scenario for the deposition of oxidation and corrosion products on the cladding surface; an online element testing system for real-time measurement of elemental distribution information within the deposition layer of oxidation and corrosion products; and an axial power offset digital mirroring system for realizing the coupling of corrosion product deposition, elemental migration distribution, and axial power offset.

[0028] like Figure 2As shown, the accelerated deposition system for corrosion products includes: a control and acquisition system 6, a neutron spectrometer 1, a preheater 2, a centrifugal pump 3, a heat exchanger 4 connected in sequence to form a loop, a voltage regulator 5 located between the neutron spectrometer 1 and the heat exchanger 4, an injection pump 8 located between the centrifugal pump 3 and the heat exchanger 4, a water chemistry instrument box 9, a pressure relief valve 14, and a plate heat exchanger 7. The precursor 10, boron-containing water 11, and lithium-containing water 12 are sequentially located between the injection pump 8 and the water chemistry instrument box 9. The control and acquisition system 6 is connected to the valves, pumps, measuring instruments, and other devices of the entire system, acquiring information such as loop temperature, flow rate, pressure, and chemical parameters, and performing real-time monitoring of loop information and terminal control of loop devices.

[0029] The neutron spectrometer 1, preheater 2, centrifugal pump 3, heat exchanger 4, and voltage stabilizer 5 constitute the coolant circuit of the simulated reactor; the plate heat exchanger 7, injection pump 8, water chemistry instrument box 9, precursor 10, boron-containing water 11, and lithium-containing water 12 constitute the charging and discharging circuit of the chemical capacity system, which controls the temperature of the coolant and regulates the concentration of boron, lithium, and oxidation corrosion products in the circuit.

[0030] Due to the strict water chemistry control of pressurized water reactors, the deposition of oxidation and corrosion products in the coolant on the fuel cladding surface is a lengthy solute migration process. As the online testing technology for transient gamma activation is dependent on the experimental reactor resources, the online testing system for matching elements needs to accelerate the deposition of oxidation and corrosion products.

[0031] The accelerated deposition process involves preparing Fe and Ni suspended particles using ferric ammonium sulfate dodecahydrate, tetramethylammonium hydroxide, and nickel chloride hexahydrate. Soluble Fe and Ni are then synthesized using ethylenediaminetetraacetic acid, ammonia, ultrafine Fe powder, and nickel hydroxide, respectively. Heavy water is used as the solvent for dissolving the oxidation corrosion products (a high-permeability neutron solvent) to reduce interference with the neutron beam and enable online elemental measurement. The Helgeson-Kirkham-Flowers equation is used to obtain the Gibbs free energy of the multi-component mixture in heavy water under high temperature and pressure, thereby determining the reaction equilibrium constant. The stable phase distribution of Fe and Ni is determined through a chemical equilibrium that minimizes the Gibbs free energy of the multi-component solute-solvent system. This allows for adjustment of the ratio of soluble Fe and Ni to the suspended particles. Soluble Fe and Ni meeting the target ratio are dissolved in the heavy water solvent, and then chemical reagents containing elements such as B and Li are added to complete the preparation of a high-concentration, high-permeability oxidation corrosion product deposition precursor.

[0032] The Helgeson-Kirkham-Flowers equations are as follows: ,in: This is a correction value for the Gibbs free energy of formation at the target temperature T (K) and target pressure P (bar). and For reference temperature and reference pressure, values ​​of 298.15 K and 1 bar are used, respectively. To provide the Gibbs free energy of formation at the reference temperature and pressure, For reference temperature and pressure, the absolute entropy value, This is the solvent pressure parameter, with a value of 2600 bar; This is the solvent temperature parameter, with a value of 228 K. , , and It is the volume integral constant; and It is the integral constant of specific heat; It is the Born constant; It is the dielectric constant of water; The Born function typically takes the following values: .

[0033] like Figure 3 As shown, the online elemental testing system includes: a neutron beam focusing unit and a transient gamma activation testing unit, wherein: the neutron beam focusing unit focuses the cold neutron beam extracted from the research reactor to obtain an amplified cold neutron beam, and irradiates it onto the oxide corrosion product deposition layer; the transient gamma activation testing unit detects the transient gamma rays generated by the interaction between the cold neutrons and the deposition layer, obtains the axial concentration distribution of Fe, Ni and B elements in the deposition layer, and calculates the thickness of the deposition layer.

[0034] The neutron beam focusing unit in the aforementioned online element testing system employs an ellipsoidal total internal reflection neutron lens to enhance the neutron beam intensity, achieving neutron beam focusing and neutron flux density gain. To expand the range of neutron capture angles, a concentric multi-level ellipsoidal nesting system is used. Multiple concentric large ellipsoids are superimposed around the original small ellipsoid to achieve hierarchical screening, thereby achieving better focusing gain.

[0035] The instantaneous gamma activation testing unit in the aforementioned online elemental testing system utilizes instantaneous gamma activation technology to characterize Fe, Ni, and B elements in the oxide corrosion product deposition layer. The content of Fe, Ni, and B is determined by measuring the intensity of characteristic gamma rays, and the thickness of the oxide corrosion product deposition layer is determined by the total amount of Fe and Ni elements, thereby analyzing the deposition mechanism of the oxide corrosion products. This is achieved by detecting the intensity of characteristic gamma rays and... 10 The abundance of B can determine the boron content, thus providing reference data for neutron cross-section database calculations in the power distribution unit of the axial power offset digital mirror system.

[0036] like Figure 4As shown, the axial power offset digital mirror system includes a power distribution unit and a heating unit. The power distribution unit obtains the three-dimensional axial power distribution information of the fuel rod by using a high-resolution neutron algorithm and combining the elemental distribution of the deposition layer as the cross-sectional input information of the neutron flux. The heating unit controls the heat flow on the cladding surface in real time based on the power distribution information calculated by the digital mirror system.

[0037] The power distribution unit is based on the elemental distribution of the oxide corrosion product deposit layer obtained from transient gamma activation analysis. A multi-dimensional, multi-group neutron cross-section database is constructed using a background mesh mixed-layer cross-section homogenization method. By introducing the simplification of mixed materials, the same finite element mesh is used to describe axial grid elements of deposit layers with different thicknesses, directly mapping the physical parameters between axial grids. This improves the quality of the finite element mesh without requiring circumferential refinement, while avoiding the accuracy loss in high-fidelity simulation caused by complete homogenization of the deposit layer and background material. Based on the background mesh method, and according to the variational principle, full-order matrix equations representing the neutron equilibrium relationship inside the finite element block and the neutron continuity relationship on the block surface are obtained. A data-driven intrinsic orthogonal decomposition (POD) reduction algorithm is used to construct a reduced-order model for neutron transport simulation within a certain parameter space. Based on this, linear interpolation, Gaussian process regression, decision trees, and neural networks are used to obtain a predictive model between parameters and coefficients. By using the trained prediction model and the reduced-order basis, the above full-order model is accelerated to achieve rapid prediction of the three-dimensional power distribution of fuel rods under different oxide corrosion product deposition layer thicknesses.

[0038] The full-order matrix equation is specifically as follows: ,in: , , , , This is the response matrix.

[0039] The heating unit employs a distributed heating ring with a spatial resolution of 10 mm to control the axial heat flux density in real time. A special Bragg (FBG) optical fiber, fabricated with an ultraviolet-written grating and a polyimide coating, is used to achieve quasi-three-dimensional measurement of the cladding temperature, accurately obtaining the cladding surface temperature boundary under axial power offset. Based on the elemental distribution obtained through transient gamma activation technology, combined with the axial power distribution of the power distribution unit, independent dynamic control of the axial power of the heating unit is achieved. Furthermore, based on the cladding wall temperature and the thickness of the oxide corrosion product deposition layer, the mechanism of oxide corrosion product deposition in the pressurized water reactor core is analyzed.

[0040] Compared with existing technologies, this device can realize online measurement and characterization of the oxide corrosion product deposit layer, obtain the content and distribution of elements in the deposit layer, and then study the deposition mechanism of oxide corrosion products. Through the digital mirror system, this device can calculate the axial power offset in real time and quickly feed it back to the physical heating element, so as to control the heat flux density on the shell surface in a timely and accurate manner.

[0041] The above-described specific implementations can be partially adjusted by those skilled in the art in different ways without departing from the principles and purpose of the present invention. The scope of protection of the present invention is defined by the claims and is not limited to the above-described specific implementations. All implementation schemes within the scope of the claims are bound by the present invention.

Claims

1. A hardware-in-the-loop device for multi-physics coupling of oxidation corrosion product deposition in a pressurized water reactor core, characterized in that, include: The system comprises an accelerated deposition system for corrosion products, an online elemental analysis system, and an axial power offset digital mirroring system. The accelerated deposition system rapidly deposits precursors onto a cladding layer to obtain an oxidative corrosion product deposition layer. The online elemental analysis system uses transient gamma activation technology to analyze the growth pattern and elemental distribution within the deposition layer. The axial power offset digital mirroring system calculates the neutron flux cross-sectional information based on the elemental distribution of the deposition layer, calculates the axial power distribution, controls the heat transfer boundary on the cladding surface of the heating unit, and achieves the coupling of oxidative corrosion product deposition, elemental migration and distribution, and axial power offset. The corrosion product accelerated deposition system includes: a control and acquisition system, a neutron spectrometer, a preheater, a centrifugal pump, a heat exchanger, a pressure regulator located between the neutron spectrometer and the heat exchanger, an injection pump, a water chemistry instrument box, a pressure relief valve, and a plate heat exchanger located between the centrifugal pump and the heat exchanger. The precursor, boron-containing water, and lithium-containing water are located between the injection pump and the water chemistry instrument box. The control and acquisition system is connected to the valves, pumps, and measuring instruments of the entire system to acquire information on loop temperature, flow rate, pressure, and chemical indicators, and to perform real-time monitoring of loop information and terminal control of loop devices. The accelerated deposition process involves preparing Fe and Ni suspended particles using ferric ammonium sulfate dodecahydrate, tetramethylammonium hydroxide, and nickel chloride hexahydrate; synthesizing soluble Fe and Ni using ethylenediaminetetraacetic acid, ammonia, ultrafine Fe powder, and nickel hydroxide; using heavy water as a high-permeability neutron solvent to dissolve the oxidation corrosion products, reducing interference with the neutron beam and enabling online elemental measurement; using the Helgeson-Kirkham-Flowers equation to obtain the Gibbs free energy of multiple components in heavy water under high temperature and pressure, thereby determining the reaction equilibrium constant; determining the stable phase distribution of Fe and Ni through the chemical equilibrium of minimizing the Gibbs free energy of the multi-component solute-solvent system; adjusting the ratio of soluble Fe and Ni to the suspended particles; dissolving soluble Fe and Ni in the heavy water solvent to the target ratio; and then adding chemical reagents containing B and Li elements to complete the preparation of a high-concentration, high-permeability oxidation corrosion product deposition precursor. The Helgeson-Kirkham-Flowers equations are as follows: ,in: This is a correction value for the Gibbs free energy of formation at the target temperature T (K) and target pressure P (bar). and For reference temperature and reference pressure, To provide the Gibbs free energy of formation at the reference temperature and pressure, For reference temperature and pressure, the absolute entropy value, Solvent pressure parameters Solvent temperature parameters , , and Volume integral constant; and Specific heat integral constant; Born constant; Dielectric constant of water; Born function ; The axial power offset digital mirror system includes a power distribution unit and a heating unit. The power distribution unit obtains the three-dimensional axial power distribution information of the fuel rod by using a high-resolution neutron algorithm and combining the elemental distribution of the deposition layer as the cross-sectional input information of the neutron flux. The heating unit controls the heat flow on the cladding surface in real time based on the power distribution information calculated by the digital mirror system.

2. The multi-physics coupled hardware-in-the-loop device for depositing oxidation and corrosion products in a pressurized water reactor core according to claim 1, characterized in that, The neutron spectrometer, preheater, centrifugal pump, heat exchanger, and pressure regulator constitute the coolant loop of the simulated reactor; the plate heat exchanger, injection pump, water chemistry instrument box, precursor, boron-containing water, and lithium-containing water constitute the charging and discharging loop of the chemical capacity system, which controls the temperature of the coolant and regulates the concentration of boron, lithium, and oxidation corrosion products in the loop.

3. The multi-physics coupled hardware-in-the-loop device for depositing oxidation and corrosion products in a pressurized water reactor core according to claim 1, characterized in that, The aforementioned online elemental testing system includes: a neutron beam focusing unit and a transient gamma activation testing unit, wherein: the neutron beam focusing unit focuses the cold neutron beam extracted from the research reactor to obtain an amplified cold neutron beam, and irradiates it onto the oxide corrosion product deposition layer; the transient gamma activation testing unit detects the transient gamma rays generated by the interaction between the cold neutrons and the deposition layer, obtains the axial elemental concentration distribution of Fe, Ni, and B in the deposition layer, and estimates the thickness of the deposition layer.

4. The multi-physics coupled hardware-in-the-loop device for depositing oxidation and corrosion products in a pressurized water reactor core according to claim 3, characterized in that, The neutron beam focusing unit employs an ellipsoidal total reflection neutron lens and a concentric multi-level ellipsoid nesting system to enhance the neutron beam intensity. By superimposing multiple large ellipsoids with the same focus around the original small ellipsoid, hierarchical screening is achieved, thereby realizing a better focusing gain effect.

5. The multi-physics coupled hardware-in-the-loop device for depositing oxidation and corrosion products in a pressurized water reactor core according to claim 3, characterized in that, The aforementioned instantaneous gamma activation testing unit determines the contents of Fe, Ni, and B by measuring the intensity of characteristic gamma rays, and determines the thickness of the oxide corrosion product deposition layer by measuring the total amount of Fe and Ni elements, thereby analyzing the deposition mechanism of the oxide corrosion products; by detecting the intensity of characteristic gamma rays and 10 The abundance of B can determine the boron content, thus providing reference data for neutron cross-section database calculations in the power distribution unit of the axial power offset digital mirror system.

6. The multi-physics coupled hardware-in-the-loop device for depositing oxidation and corrosion products in a pressurized water reactor core according to claim 1, characterized in that, The power distribution unit is based on the elemental distribution of the oxidative corrosion product deposit layer obtained by transient gamma activation analysis, and a multi-dimensional multi-group neutron cross-section database is constructed by using the background grid mixing layer cross-section homogenization method. By introducing the simplification of hybrid materials, the same set of finite element meshes is used to describe axial grids of different thicknesses of deposition layers, directly mapping the physical parameters between axial meshes. This improves the quality of the finite element mesh without the need for circumferential refinement, while avoiding the accuracy loss in high-fidelity simulation caused by the complete homogenization of the deposition layer and background material. Based on the background mesh method, and according to the variational principle, full-order matrix equations representing the neutron balance relationship inside the finite element block and the neutron continuity relationship on the block surface are obtained. A data-driven intrinsic orthogonal decomposition (POD) reduction algorithm is used to construct a reduced-order model for neutron transport simulation within a certain parameter space. Based on this, linear interpolation, Gaussian process regression, decision trees, and neural networks are used to obtain a predictive model between parameters and coefficients. The trained predictive model and the reduced-order basis are used to accelerate the above full-order model, enabling rapid prediction of the three-dimensional power distribution of fuel rods under different thicknesses of oxidative corrosion product deposition layers. The full-order matrix equation is specifically as follows: ,in: , , , , This is the response matrix.

7. A control method based on the device according to any one of claims 1-6, characterized in that, include: Step 1: Accelerate the preparation of deposition precursors, specifically including: 1.1 By simulating the reactor coolant loop and the charging and discharging loop of the chemical and volumetric system, and based on the Gibbs free energy change under typical pressurized water reactor conditions, the thermochemical equilibrium constants of each reaction in the high-permeability solution are determined, thereby obtaining the substance concentration and pH value in the Li-B-D2O system. Specifically, the Gibbs free energy change in the high-permeability solution is given by the formula... Confirmed, among which: Gibbs free energy of formation after modification of reactants under high temperature and high pressure Obtained by subtraction; 1.2 Control the temperature of the coolant and regulate the concentrations of boron, lithium, and oxidation corrosion products in the circuit. Determine the stable phase distribution of Fe and Ni through the chemical equilibrium of minimizing the Gibbs free energy of the multi-component solute-solvent system. This allows for the adjustment of the ratio of soluble Fe, Ni, and suspended particles to form precursors for oxidation corrosion products. Specifically, the concentrations of each component at equilibrium are obtained by solving the equilibrium equations, element mass conservation equations, and charge conservation equations of each reaction simultaneously using Newton-Raphson iterative calculations. 1.3 Accelerated deposition of corrosion products: According to the parameters obtained in step 1.2, the prepared precursor is added to the coolant circuit to accelerate deposition on the cladding and form an oxide corrosion product deposition layer. Step 2: Irradiate the oxide corrosion product deposit layer obtained in Step 1 with a neutron beam. Based on the different energies of transient gamma rays released by the nuclear reactions of different elements with neutrons, calculate the three-dimensional distribution of Fe, Ni, and B. Specifically, this includes: 2.1 Using a total internal reflection neutron lens, the focusing behavior of the rays was simulated by the Monte Carlo method, and the optimal focusing and gain conditions were calculated. The oxide corrosion product deposit layer obtained in step one was irradiated with a cold neutron beam after the optimal focusing gain, resulting in transient gamma activation. 2.2 A high-purity germanium detector was used to receive activated gamma rays and obtain the activated gamma spectrum of the oxidation corrosion products. By identifying the characteristic peaks of each element and combining them with the background, the content information of each element in the deposition layer of oxidation corrosion products was calculated. 2.3 Use a Compton camera to receive activated gamma rays, causing Compton scattering of the gamma rays within the gamma rays. Analyze and calculate the obtained Compton scattering information to output the location of gamma activation within the oxide corrosion product deposit layer and the spatial distribution information of each element within the oxide corrosion product deposit layer. Step 3: Based on the spatial distribution information of each element, a data-driven intrinsic orthogonal decomposition (POD) order reduction algorithm is used to obtain the three-dimensional axial power distribution of the fuel rod, thereby achieving feedback control of the heat flux on the cladding surface and actively adjusting the deposition of corrosion products and the migration distribution of elements. include: 3.1 Based on the spatial distribution information of each element, a multi-dimensional multi-group neutron cross-section database is constructed using the background grid mixing layer cross-section homogenization method; 3.2 Based on the background mesh method, and using the multi-dimensional multi-group neutron cross-section database obtained by the variational principle and the background mesh mixed layer cross-section homogenization method, full-order matrix equations representing the neutron equilibrium relationship inside the finite element block and the neutron continuity relationship on the block surface are obtained respectively. 3.3 A data-driven intrinsic orthogonal decomposition reduction algorithm is adopted to construct a reduced-order model for neutron transport simulation, solve for the reduced-order basis, and use linear interpolation, Gaussian process regression, decision tree and neural network to obtain the prediction model between parameters and coefficients. The reduced-order basis obtained by the reduction algorithm and the prediction model obtained by training are used to accelerate the reduction of the full-order matrix obtained in step 3.2, thereby realizing the rapid prediction of the three-dimensional power distribution of fuel rods under different oxide corrosion product deposition layer thicknesses. 3.4 Based on the power distribution information predicted in step 3.3, the power supply is set and the heating power is adjusted to achieve feedback control, thereby adjusting the deposition of oxidation corrosion products and the migration distribution of elements in real time.

Images