Method and system for estimating concentration of radioactive iodine species in containment after accident

Abstract

The invention discloses a method and system for estimating the concentration of radioactive iodine species in a containment after an accident, and the method comprises the steps: inputting the content of gaseous iodine in the atmosphere of the containment, and calculating the acid content in the wall surface of the containment and the liquid phase of a pit; on the basis of the content of acid in the pit liquid phase and the content of a medicine added into the pit in advance, the pH value in the pit liquid phase is calculated through a pH model; determining the content of iodine which enters the liquid phase of the pit and does not participate in the chemical reaction of the liquid phase; on the basis of the content and the pH value of iodine which can be subjected to chemical reaction in the pool, combining an iodine water chemical equation, and calculating through a liquid phase chemical reaction model to obtain the concentrations of different iodine species in a liquid phase; calculating the mass transfer amount of gaseous iodine in the gas phase between the containment atmosphere and the pit water based on a pool mass transfer model; the content of gaseous iodine in the containment atmosphere is calculated through a gaseous iodine radiolysis and ionization model; determining the content of iodine deposited on the dry wall surface of the containment based on a gaseous iodine deposition model; and finally outputting the concentration of each iodine species in the gas liquid.

Description

Technical Field

[0001] The invention belongs to the technical field of severe accident analysis of pressurized water reactors, and in particular relates to a method and system for estimating the concentration of radioactive iodine species in a containment vessel after an accident. Background Art

[0002] In the event of a serious accident at a nuclear power plant, the migration of radioactive iodine has a special significance for risk prevention and control. Based on the unique physical and chemical properties of elemental iodine and its chemical form transformation between the aqueous phase and the gas phase, more than 90% of the radioactive iodine exists in the containment atmosphere in gaseous form (I2, HOI, etc.) after the accident. In order to suppress the risk of radioactive release, the internationally accepted method is to use the "alkaline trap" effect (when the pit water pH is ≥7.5, the iodine partition coefficient can be significantly increased to 10 3 Accurately assessing the gaseous iodine concentration within the containment vessel is directly related to source term prediction and emergency decision-making in the "iodine spike" release scenario.

[0003] A large number of experimental and computational studies have been conducted both domestically and internationally on the assessment of radioactive iodine concentrations in nuclear power plant containments. Although mainstream international integrated severe accident analysis tools are capable of simulating multi-physics coupling phenomena during accident processes, existing computational models generally do not fully cover key processes such as gaseous iodine mass transfer at the gas-liquid interface, wall adsorption effects, and liquid film absorption within the containment. This modeling defect significantly underestimates the effect of liquid phase retention on the removal of radioactive iodine, ultimately resulting in a deviation of 1-2 orders of magnitude between the predicted and actual values ​​of the airborne iodine concentration. Due to the inadequate characterization of the dynamic equilibrium characteristics of iodine in the complex gas-liquid two-phase system, existing methods are unable to accurately reflect the distribution patterns of different iodine species within the containment, limiting the credibility and engineering applicability of post-accident radioactive consequence assessments. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and provide a method and system for estimating the concentration of radioactive iodine species in the containment vessel after an accident, so as to solve the technical problems of poor calculation accuracy of iodine species in the gas and liquid of the containment vessel after an accident, few considerations, and low reliability, and provide a reference for evaluating the removal of radioactive iodine after a pressurized water reactor accident and analyzing accident sources.

[0005] The present invention adopts the following technical solutions:

[0006] A method for estimating the concentration of radioactive iodine species in a containment vessel after an accident comprises the following steps:

[0007] Input the concentration of gaseous iodine in the containment atmosphere I 2(atm) , based on the atmospheric and cable dose rates in the containment and The acid content C in the containment atmosphere, wall and pit liquid phase was calculated by the acid generation and mass transfer model. atm,acid , C p,acid and C w,acid,n ;

[0008] Based on the acid content C in the liquid phase of the pit p,acid and the concentration of the drug pre-added to the pit x NaP , the pH value of the liquid phase in the pit was calculated by pH model;

[0009] The iodine-silver model is used to determine the content of iodine that does not participate in the liquid phase chemical reaction and enters the pit liquid phase, and the concentration of iodine that can undergo chemical reaction in the pool is updated. 2(aq) ;

[0010] Based on the content and pH value of iodine that can undergo chemical reactions in the pool, combined with the iodine water chemical equation, the concentrations of different iodine species in the liquid phase are calculated through the liquid phase chemical reaction model; the mass transfer of gaseous iodine between the containment atmosphere and the pit water in the gas phase is calculated, and then the radioactive iodine concentration I in the gas and liquid phases is updated. 2(atm) and I 2(aq) ;

[0011] Combined hydrogen, ozone and radiolytic reduction coefficient k TIH , k TIO and k RI Calculate and update the concentration of gaseous iodine in the containment atmosphere I 2(atm) ; Determine the iodine concentration I deposited on the dry wall of the containment vessel 2(wall) ; Output the concentration or content of each iodine species in the gas and liquid.

[0012] Preferably, the acid content C in the containment atmosphere, wall and pit liquid phase is atm,acid , C p,acid and C w,acid,n They are:

[0013]

[0014]

[0015] Among them, k eff,acid t is V atm for, is the acid generation rate, k w,acid,n is the mass transfer coefficient of acid from the atmosphere to the wall n, is the acid generation rate per unit time, k p,acid is the mass transfer coefficient of the acid.

[0016] Preferably, the pH value in the pit liquid phase is calculated by a pH model, specifically:

[0017] The initial pH is obtained by initial charge balance, and the H in the liquid phase is obtained based on the initial pH and the physical properties of water. + and OH - Ion concentration;

[0018] Based on the input of each substance and the hydrolysis reaction equation in the liquid phase, the ion concentration of each species is obtained, and the ion concentration of each species is brought into the total electron balance formula to calculate the new H + The concentration and pH are compared with the initial pH and iterated until the convergence condition is met to complete the pH calculation.

[0019] Preferably, when the charge concentration ΔZ>0, is the hydroxide concentration, is the hydrogen ion concentration, is the ionic product constant of water;

[0020] When the charge concentration ΔZ = 0,

[0021] When the charge concentration ΔZ < 0,

[0022] Preferably, the charge concentration ΔZ is:

[0023]

[0024] Among them, x NaP is the phosphate concentration, x Cs is the cesium ion concentration, is the nitric acid concentration, x HCl is the concentration of hydrochloric acid.

[0025] Preferably, the radioactive iodine mass transfer equation between the atmosphere and the cell is specifically:

[0026]

[0027] Among them, I 2(atm) is the concentration of radioactive iodine in the atmosphere, k pool is the mass transfer coefficient of radioactive iodine from the cell surface to the atmosphere, A pool is the interface area between the atmosphere and the pool surface, V atm is the volume of atmosphere, I 2(aq) is the concentration of radioactive iodine in the pool, is the distribution coefficient of radioactive iodine.

[0028] Preferably, the partition coefficient of radioactive iodine is

[0029] Preferably, the reduction reaction of radioactive iodine in the atmosphere is as follows:

[0030]

[0031] Among them, k TIH is the reduction coefficient of the reaction between hydrogen and radioactive iodine, k TIO is the reduction coefficient of the reaction between ozone and radioactive iodine, k RI is the radiolysis reduction coefficient; is the atmospheric dose rate, [H2] and [O3] are the concentrations of hydrogen and ozone, kmole / m 3 ; T is the atmospheric temperature.

[0032] Preferably, the deposition of radioactive iodine on the containment wall is specifically as follows:

[0033]

[0034] Among them, I 2(atm) is the concentration of radioactive iodine in the atmosphere, I 2(wall) is the radioactive iodine concentration on the wall, k ad is the radioiodine adsorption coefficient, k de is the desorption coefficient of radioactive iodine.

[0035] In a second aspect, an embodiment of the present invention provides a system for estimating the concentration of radioactive iodine species in a containment vessel after an accident, comprising:

[0036] Acid generation and mass transfer module, input the concentration of gaseous iodine in the containment atmosphere I 2(atm) , based on the atmospheric and cable dose rates in the containment and The acid content C in the containment atmosphere, wall and pit liquid phase was calculated by the acid generation and mass transfer model. atm,acid , C p,acid and C w,acid,n ;

[0037] pH module, based on the acid content C in the pit liquid phase p,acid and the concentration of the drug pre-added to the pit x NaP , the pH value in the pit liquid phase was calculated using the pH model;

[0038] The iodine-silver module determines the content of iodine that does not participate in the liquid phase chemical reaction in the pit through the iodine-silver model, and updates the concentration of iodine that can undergo chemical reaction in the pool. 2(aq) ;

[0039] The liquid phase module calculates the concentration of different iodine species in the liquid phase based on the content and pH value of iodine that can undergo chemical reactions in the pool, combined with the iodine water chemical equation, through the liquid phase chemical reaction model; calculates the mass transfer of gaseous iodine between the containment atmosphere and the pit water in the gas phase, and then updates the radioactive iodine concentration I in the gas and liquid phases. 2(atm) and I2(aq) ;

[0040] Estimation module combining hydrogen, ozone and radiolytic reduction coefficient k TIH , k TIO and k RI Calculate and update the concentration of gaseous iodine in the containment atmosphere I 2(atm) ; Determine the iodine concentration I deposited on the dry wall of the containment vessel 2(wall) ; Output the concentration or content of each iodine species in the gas and liquid.

[0041] In a third aspect, a computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the above-mentioned method for estimating the concentration of radioactive iodine species in a containment vessel after an accident are implemented.

[0042] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium comprising a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for estimating the concentration of radioactive iodine species in a containment vessel after an accident.

[0043] In a fifth aspect, a chip comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the above-mentioned method for estimating the concentration of radioactive iodine species in the containment vessel after an accident are implemented.

[0044] In a sixth aspect, an embodiment of the present invention provides an electronic device comprising a computer program, which, when executed by the electronic device, implements the steps of the above-mentioned method for estimating the concentration of radioactive iodine species in a containment vessel after an accident.

[0045] Compared with the prior art, the present invention has at least the following beneficial effects:

[0046] A method for estimating the concentration of radioactive iodine species in a containment vessel after an accident, by connecting an acid generation and mass transfer model, a pH model, an iodine-silver model, and an iodine-water chemical model in series, achieves for the first time a dynamic simulation of the entire path of iodine physical migration, chemical conversion, and interface mass transfer within the containment vessel. By introducing hydrogen, ozone, and radiolysis reduction coefficients, the method quantifies the chemical consumption of gaseous iodine by reducing substances and radiation fields, avoiding the overestimation of iodine concentration caused by neglecting reduction reactions in traditional models. By iteratively updating gas / liquid phase iodine concentrations and wall deposition, the method achieves continuous prediction of time-varying behavior after an accident, providing real-time data support for emergency decision-making. The method overcomes the limitations of traditional static models, improves the prediction accuracy of iodine volatilization risks, and supports the optimized design of iodine removal measures within the containment vessel.

[0047] Furthermore, the acid distribution mass transfer model clearly identifies acidity as the main controlling factor of iodine chemical form, providing input for subsequent pH-dependent iodine species transformation.

[0048] Furthermore, the pH dynamic iterative model accurately captures the effects of boric acid (pH buffer) and fission products on pH in the pit, ensuring the reliability of the iodine water chemical reaction path.

[0049] Furthermore, the mass transfer rate is driven by the distribution coefficient, which combines the mass transfer coefficient and the interfacial area to dynamically update the gas / liquid phase iodine concentration. The distribution coefficient is driven by experimental data, reflecting the distribution tendency of iodine between the gas and liquid phases, quantifying the cross-interfacial migration ability of iodine, and explaining why some iodine is retained in the liquid phase (reducing the risk of release) while gaseous iodine can leak out through the containment.

[0050] Furthermore, three reduction mechanisms were introduced to reveal the key path of inerting gaseous iodine, providing a theoretical basis for measures such as nitrogen filling and oxygen reduction in the containment and adding corrosion inhibitors.

[0051] Furthermore, the wall iodine concentration, q, is controlled by a dynamic adsorption-desorption equilibrium. The adsorption coefficient depends on the wall material (e.g., epoxy resin is prone to adsorption), while the desorption coefficient is affected by temperature. This quantitative analysis of the internal surface retention of the containment vessel reduces the peak gaseous iodine concentration and provides a basis for the design of decommissioning and decontamination plans.

[0052] It can be understood that the beneficial effects of the second to sixth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0053] In summary, the present invention can accurately analyze the concentration of various iodine species in the containment gas and liquid after an accident, solving the problems of poor simulation accuracy and low credibility of existing models.

[0054] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0056] Figure 1 Flowchart of the present invention;

[0057] Figure 2 Schematic diagram of iodine species migration in gas and liquid;

[0058] Figure 3 This is a comparison chart of the calculation results of the present invention;

[0059] Figure 4 A schematic diagram of a computer device provided in accordance with an embodiment of the present invention;

[0060] Figure 5 The present invention is a block diagram of an electronic device according to an embodiment of the present invention.

[0061] Among them, 60. Computer device; 61. Processor; 62. Memory; 63. Computer program; 600. Electronic device; 610. Processing unit; 620. Storage unit; 6201. Random access memory unit; 6202. Cache memory unit; 6203. Read-only memory unit; 6204. Program / Utility; 6205. Program module; 630. Bus; 640. Display unit; 650. Input / output interface; 660. Network adapter; 700. External device. DETAILED DESCRIPTION

[0062] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0063] In the description of the present invention, it is to be understood that the terms “include” and “comprise” indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0064] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0065] It should be further understood that the term "and / or" as used in the present specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0066] It should be understood that although the terms "first," "second," and "third" may be used to describe preset ranges in embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are merely used to distinguish one preset range from another. For example, without departing from the scope of embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0067] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0068] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0069] The present invention provides a method for estimating the concentration of radioactive iodine species in a containment after an accident. First, the concentration of gaseous iodine in the containment atmosphere I is input. 2(atm) , then based on the atmospheric and cable dose rates in the containment and The acid content C in the containment atmosphere, wall and pit liquid phase was calculated by the acid generation and mass transfer model. atm,acid , C p,acid and C w,acid,n ; Based on the acid content C in the liquid phase of the pit p,acid and the concentration of the drug pre-added to the pit x NaP , the pH value of the liquid phase in the pit is calculated by the pH model; then the iodine content that does not participate in the liquid phase chemical reaction is determined by the iodine silver model, and then the concentration of iodine that enters the liquid phase and can also react with iodine water is updated. 2(aq) Based on the content and pH value of iodine that can undergo chemical reactions in the pool, combined with the iodine water chemical equation, the concentrations of different iodine species in the liquid phase are calculated through the liquid phase chemical reaction model; the mass transfer of gaseous iodine between the containment atmosphere and the pit water in the gas phase is calculated, and then the radioactive iodine concentration I in the gas and liquid phases is updated. 2(atm) and I 2(aq) ; Combined hydrogen, ozone and radiolytic reduction coefficient kTIH , k TIO and k RI Calculate and update the concentration of gaseous iodine in the containment atmosphere I 2(atm) ; Determine the iodine concentration I deposited on the dry wall of the containment vessel 2(wall) Finally, the concentration or content of each iodine species in the gas and liquid phases is output. The concentration of the generated and derived products of radioactive iodine in the gas and liquid phases can be accurately calculated.

[0070] Example 1

[0071] See also Figure 1 The present invention provides a method for estimating the concentration of radioactive iodine species in a containment vessel after an accident, comprising the following steps:

[0072] S1, acid content in containment atmosphere, wall and pit liquid phase;

[0073] Acid generation rate Specifically:

[0074]

[0075] in,

[0076]

[0077] in, are the acid generation rate, nitric acid generation rate, and hydrochloric acid generation rate, kg-mole / s, respectively; is the mass of nitrogen in the atmosphere, kg; is the atmospheric dose rate, MRad / h; M cable is the mass of the cable in the control volume, kg; is the cable dose rate, MRad / h.

[0078] After the acid in the atmosphere is generated, it can be deposited on the water film on the wet wall of the containment. The deposition equation is as follows:

[0079]

[0080] Among them, C w,acid,n is the molar amount of acid on wall n, kg-mole; k w,acid,n is the mass transfer coefficient of acid from atmosphere to wall n, m / s; C atm,acid is the molar amount of acid in the atmosphere, kg-mole.

[0081] The acid in the atmosphere transfers mass to the wetted wall and the pool, so the acid in the atmosphere can be calculated using the following formula:

[0082]

[0083] Among them, k w,acid,nA is the mass transfer coefficient of acid from the atmosphere to the wall n, m / s; w,n is the area of ​​wall n, m 2 ;k p,acid A is the mass transfer coefficient of acid from the atmosphere to the pool, m / s; pool is the contact area between the atmosphere and the pool, m 2 ; V atm is the volume of atmosphere, m 3 ; is the acid generation rate, kg-mole / s.

[0084] Adding the time term, the change of the molar amount of acid in the atmosphere with time is as follows:

[0085]

[0086] Similarly, the change in the molar amount of acid on the wet wall and in the pool over time is as follows:

[0087]

[0088] in,

[0089]

[0090] S2. Calculate the liquid pH;

[0091] The initial charge balance in the liquid phase is specifically:

[0092]

[0093] Where ΔZ is the charge concentration, kmole / m 3 ;x NaP is the phosphate concentration, kmole / m 3 ;x Cs is the cesium ion concentration, kmole / m 3 ; is the nitric acid concentration, kmole / m 3 ;x HCl is the concentration of hydrochloric acid, kmole / m 3 .

[0094] When ΔZ>0, it is considered that:

[0095]

[0096] When ΔZ=0, it is considered that:

[0097]

[0098] When ΔZ<0, it is considered that:

[0099]

[0100] In the liquid phase, the total electron balance is:

[0101]

[0102] in,

[0103]

[0104] Among them, [A + ] is the kilomolar number of Na3PO4; K w is the ionization constant of water, (moles / kg) 2 ;K w,p is the ionization constant of water at different temperatures, (kmole / m 3 ) 2 ρ w is the density of water, kg / m 3 ; T is the liquidus temperature, ℃.

[0105] In the liquid phase, it is believed that H2CO3 formed by the dissolution of Na3PO4, B(OH)3 and CO2 in water will affect the pH of the water. The concentration of each ion can be obtained based on the input of the three substances and the ionization equation in the liquid phase. Below, M(P), M(B) and M(C) are used to represent the collection of substances containing phosphorus, boron and carbon in the liquid phase.

[0106]

[0107] in,

[0108]

[0109] in,

[0110]

[0111] in,

[0112]

[0113] in,

[0114]

[0115] Where k1~k6 are the reaction rate constants; T is the liquidus temperature, ℃; γ(i) is the activity coefficient of ion i; Z(i) is the absolute value of the charge carried by the ion; b is an empirical constant, taken as 0.2; l is the ionic strength; ε is the dielectric constant of water, F / m.

[0116] During the pH calculation process, the initial pH is obtained by initial charge balance, and the H in the liquid phase is obtained based on the initial pH and the physical properties of water. +and OH - ion concentration, and then based on the input of each substance and the hydrolysis reaction equation in the liquid phase, the ion concentration of each species is obtained, and the ion concentration of each species is brought into the total electron balance formula to calculate the new H + The concentration and pH are compared with the initial pH and iterated until the convergence condition is met and the pH calculation is completed.

[0117] S3. Calculate the concentration of iodine element that enters the liquid phase and can participate in the iodine water reaction;

[0118] The specific equation for the reaction between iodine and silver is:

[0119] 2Ag+I2=2AgI↓

[0120] Ag + +I - =AgI↓

[0121] The iodine element and iodide ions in the liquid phase will react with silver to form a precipitate. The silver content in the liquid phase can be specified manually. After the silver iodide precipitate is formed, the iodine in it will no longer participate in other related calculations.

[0122] S4. Calculate the concentrations of different iodine species in the liquid phase;

[0123] The specific process of radioactive iodine in water is as follows:

[0124]

[0125] The concentration of the derived iodine species in the liquid phase within a single step is calculated using the above chemical equation and related data.

[0126] S5. Calculate and update the iodine concentration in the gas and liquid;

[0127] The radioactive iodine mass transfer equation between the atmosphere and the cell is specifically:

[0128]

[0129] in,

[0130]

[0131] Among them, I 2(atm) is the concentration of radioactive iodine in the atmosphere, kmole / m 3 ;I 2(aq) is the concentration of radioactive iodine in the pool, kmole / m 3 ;k pool is the mass transfer coefficient of radioiodine from the cell surface to the atmosphere, m / s; is the distribution coefficient of radioactive iodine; T is the temperature, K.

[0132] S6. Calculate and update the concentration of elemental iodine in the atmosphere;

[0133] The reduction reaction of radioactive iodine in the atmosphere is as follows:

[0134]

[0135] in,

[0136]

[0137] Among them, k TIH is the reduction coefficient of the reaction between hydrogen and radioactive iodine, m 3 / kmol-s; k TIO is the reduction coefficient of the reaction between ozone and radioactive iodine, m 3 / kmol-s; k RI is the radiolysis reduction coefficient; is the atmospheric dose rate, Mrad / hr; [H2] and [O3] are the concentrations of hydrogen and ozone, kmole / m 3 ; T is the atmospheric temperature, K.

[0138] S7. Calculate the deposition of elemental iodine on the wall and update the concentration of elemental iodine in the atmosphere;

[0139] The deposition of radioactive iodine on the containment wall is as follows:

[0140]

[0141] Among them, I 2(atm) is the concentration of radioactive iodine in the atmosphere, kmole / m 3 ;I 2(wall) is the radioiodine concentration on the wall, kmole / m 2 ;k ad is the radioiodine adsorption coefficient, m / s; k de is the desorption coefficient of radioactive iodine; s -1 .

[0142] Those skilled in the art will appreciate that various aspects of the present invention may be implemented as systems, methods, or program products. Accordingly, various aspects of the present invention may be implemented in the following forms: entirely in hardware, entirely in software (including firmware, microcode, etc.), or in a combination of hardware and software, collectively referred to herein as "circuits," "modules," or "platforms."

[0143] Example 2

[0144] The present invention provides a system for estimating the concentration of radioactive iodine species in a post-accident containment shell. The system can be used to implement the above-mentioned method for estimating the concentration of radioactive iodine species in a post-accident containment shell. Specifically, the system for estimating the concentration of radioactive iodine species in a post-accident containment shell includes an acid generation and mass transfer module, a pH module, an iodine-silver module, a liquid phase module, and an estimation module.

[0145] Among them, the acid generation and mass transfer module inputs the concentration of gaseous iodine in the containment atmosphere I 2(atm) , based on the atmospheric and cable dose rates in the containment and The acid content C in the containment atmosphere, wall and pit liquid phase was calculated by the acid generation and mass transfer model. atm,acid , C p,acid and C w,acid,n ;

[0146] pH module, based on the acid content C in the pit liquid phase p,acid and the concentration of the drug pre-added to the pit x NaP , the pH value in the pit liquid phase was calculated using the pH model;

[0147] The iodine-silver module determines the content of iodine that does not participate in the liquid phase chemical reaction in the pit through the iodine-silver model, and updates the concentration of iodine that can undergo chemical reaction in the pool. 2(aq) ;

[0148] The liquid phase module calculates the concentration of different iodine species in the liquid phase based on the content and pH value of iodine that can undergo chemical reactions in the pool, combined with the iodine water chemical equation, through the liquid phase chemical reaction model; calculates the mass transfer of gaseous iodine between the containment atmosphere and the pit water in the gas phase, and then updates the radioactive iodine concentration I in the gas and liquid phases. 2(atm) and I 2(aq) ;

[0149] Estimation module combining hydrogen, ozone and radiolytic reduction coefficient k TIH , k TIO and k RI Calculate and update the concentration of gaseous iodine in the containment atmosphere I 2(atm) ; Determine the iodine concentration I deposited on the dry wall of the containment vessel 2(wall) ; Output the concentration or content of each iodine species in the gas and liquid.

[0150] Example 3

[0151] The present invention provides a terminal device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may also be other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to implement corresponding method processes or corresponding functions; the processor described in the embodiment of the present invention can be used for the operation of the method for estimating the concentration of radioactive iodine species in the containment after an accident, including:

[0152] Input the concentration of gaseous iodine in the containment atmosphere I 2(atm) , based on the atmospheric and cable dose rates in the containment and The acid content C in the containment atmosphere, wall and pit liquid phase was calculated by the acid generation and mass transfer model. atm,acid , C p,acid and C w,acid,n ; Based on the acid content C in the liquid phase of the pit p,acid and the concentration of the drug pre-added to the pit x NaP The pH value of the liquid phase in the pit is calculated by the pH model; the content of iodine that does not participate in the liquid phase chemical reaction entering the pit is determined by the iodine silver model, and the concentration of iodine that can enter the pool for chemical reaction is updated. 2(aq) Based on the content and pH value of iodine that can undergo chemical reactions in the pool, combined with the iodine water chemical equation, the concentrations of different iodine species in the liquid phase are calculated through the liquid phase chemical reaction model; the mass transfer of gaseous iodine between the containment atmosphere and the pit water in the gas phase is calculated, and then the radioactive iodine concentration I in the gas and liquid phases is updated. 2(atm) and I 2(aq) ; Combined hydrogen, ozone and radiolytic reduction coefficient k TIH , k TIO and k RI Calculate and update the concentration of gaseous iodine in the containment atmosphere I2(atm) ; Determine the iodine concentration I deposited on the dry wall of the containment vessel 2(wall) ; Output the concentration or content of each iodine species in the gas and liquid.

[0153] See also Figure 4 The terminal device is a computer device. The computer device 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable by the processor 61. When executed by the processor 61, the computer program 63 implements the method for estimating the concentration of radioactive iodine species in the containment vessel after an accident, as described in the embodiment. To avoid repetition, a detailed description thereof is omitted here. Alternatively, when executed by the processor 61, the computer program 63 implements the functions of each model / unit in the system for estimating the concentration of radioactive iodine species in the containment vessel after an accident, as described in the embodiment. To avoid repetition, a detailed description thereof is omitted here.

[0154] The computer device 60 may be a desktop computer, a notebook computer, a PDA, a cloud server, or other computing devices. The computer device 60 may include, but is not limited to, a processor 61 and a memory 62. It will be understood by those skilled in the art that Figure 4 This is merely an example of the computer device 60 and does not constitute a limitation of the computer device 60 . The computer device 60 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device may also include input and output devices, network access devices, buses, etc.

[0155] The processor 61 may be a central processing unit (CPU), or other general-purpose processors, a graphics processing unit (GPU), a tensor processing unit (TPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0156] The memory 62 may be an internal storage unit of the computer device 60, such as a hard disk or memory of the computer device 60. The memory 62 may also be an external storage device of the computer device 60, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device 60.

[0157] Furthermore, the memory 62 may include both an internal storage unit of the computer device 60 and an external storage device. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 may also be used to temporarily store data that has been output or is about to be output.

[0158] See also Figure 5 The terminal device is an electronic device 600, which is implemented as a general-purpose computing device. The components of the electronic device may include, but are not limited to, at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including the storage unit 620 and the processing unit 610), and a display unit 640.

[0159] The storage unit stores program codes, which can be executed by the processing unit 610, so that the processing unit 610 performs the steps according to various exemplary embodiments of the present invention described in the above method section of this specification. For example, the processing unit 610 can perform the following steps: Figure 1 Follow the steps shown in .

[0160] The storage unit 620 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 6201 and / or a cache memory unit 6202 , and may further include a read-only memory unit (ROM) 6203 .

[0161] The storage unit 620 may also include a program / utility 6204 having a set (at least one) of program modules 6205, such program modules 6205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0162] Bus 630 may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0163] The electronic device 600 may also communicate with one or more external devices 700 (e.g., a keyboard, a pointing device, a Bluetooth device, etc.), one or more devices that enable a user to interact with the electronic device 600, and / or any device that enables the electronic device 600 to communicate with one or more other computing devices (e.g., a router, a modem). Such communication may occur via an input / output interface 650. Furthermore, the electronic device 600 may also communicate with one or more networks (e.g., a local area network, a wide area network, and / or a public network, such as the Internet) via a network adapter 660. The network adapter 660 may communicate with other modules of the electronic device 600 via a bus 630. It should be understood that, although not shown in the figures, other hardware and / or software modules may be used in conjunction with the electronic device 600, including but not limited to microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms.

[0164] Example 4

[0165] The present invention also provides a storage medium, specifically a computer-readable storage medium, which is a memory device in a terminal device for storing programs and data. It is understood that the computer-readable storage medium herein may include both built-in storage media in the terminal device and, of course, extended storage media supported by the terminal device. It may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device, or component. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for being loaded and executed by a processor. These instructions may be one or more computer programs (including program code). It should be noted that more specific examples of the computer-readable storage medium herein include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical fiber, a portable compact disk read-only memory, an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0166] Computer-readable storage media also include data signals propagated in baseband or as part of a carrier wave, which carry readable program code. Such propagated data signals can take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable storage medium can also be any readable medium other than a readable storage medium, which can send, propagate, or transmit programs for use by or in conjunction with an instruction execution system, device, or device. The program code contained on the readable storage medium can be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, radio frequency, etc., or any suitable combination of the above.

[0167] The program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, and the like, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a stand-alone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device via any type of network, including a local area network or a wide area network, or may be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0168] The processor may load and execute one or more instructions stored in a computer-readable storage medium to implement the corresponding steps of the method for estimating the concentration of radioactive iodine species in a containment vessel after an accident in the above embodiment. The processor may load and execute the following steps:

[0169] Input the concentration of gaseous iodine in the containment atmosphere I 2(atm) , based on the atmospheric and cable dose rates in the containment and The acid content C in the containment atmosphere, wall and pit liquid phase was calculated by the acid generation and mass transfer model. atm,acid , C p,acid and C w,acid,n ; Based on the acid content C in the liquid phase of the pit p,acid and the concentration of the drug pre-added to the pit x NaP The pH value of the liquid phase in the pit is calculated by the pH model; the content of iodine that does not participate in the liquid phase chemical reaction entering the pit is determined by the iodine silver model, and the concentration of iodine that can enter the pool for chemical reaction is updated. 2(aq)Based on the content and pH value of iodine that can undergo chemical reactions in the pool, combined with the iodine water chemical equation, the concentrations of different iodine species in the liquid phase are calculated through the liquid phase chemical reaction model; the mass transfer of gaseous iodine between the containment atmosphere and the pit water in the gas phase is calculated, and then the radioactive iodine concentration I in the gas and liquid phases is updated. 2(atm) and I 2(aq) ; Combined hydrogen, ozone and radiolytic reduction coefficient k TIH , k TIO and k RI Calculate and update the concentration of gaseous iodine in the containment atmosphere I 2(atm) ; Determine the iodine concentration I deposited on the dry wall of the containment vessel 2(wall) ; Output the concentration or content of each iodine species in the gas and liquid.

[0170] The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may include, but are not limited to, general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic units, data processing logic units based on quantum computing, and the like.

[0171] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0172] In order to verify the effectiveness of this method and system, MELCOR was used to model the SR11 experimental device in the STORM series of experiments for comparative verification.

[0173] The test conditions are shown in the table below:

[0174] Table 1 Test carrier gas mass flow rate

[0175]

[0176] The program node modeled the experimental part into 10 control volumes of equal size, each with a volume of 1.6592×10 -3 m 3, each control body is 1m long. The test part uses 1×10 5 The initial atmospheric pressure is Pa. The atmosphere is assumed to consist solely of N2 (75%) and O2 (25%). The carrier gas source is input to the first control volume gas phase of the experimental section using control functions and table functions. The atmospheric temperature in each control volume is calculated based on data from the ISP-40 report.

[0177] The atmospheric temperature, pressure and other parameters of the SR11 experiment were input into the model as boundaries, and the calculation results were compared. The corresponding simulation results were compared. Figure 3 From the comparison results, it can be seen that the method and system for estimating the concentration of radioactive iodine species in a post-accident containment shell developed by the present invention can effectively calculate the concentration of radioactive iodine in a large space control volume.

[0178] In summary, the present invention provides a method and system for estimating radioactive iodine species concentration in a post-accident containment. Through the coupling of multiple physical and chemical processes and a dynamic iteration mechanism, it achieves accurate prediction of iodine behavior within the containment after an accident. This system integrates key processes such as acid distribution, pH evolution, iodine mass transfer, redox, and wall adsorption, establishing for the first time a complete mathematical model from iodine release to form transformation, addressing the error accumulation problem of traditional segmented models. The system introduces reduction and distribution coefficients to reveal the inerting pathway of iodine. Furthermore, it improves the prediction reliability of pH-sensitive reactions through charge balance iteration and iodine-silver separation. The system outputs gas / liquid / solid three-phase iodine species concentrations to directly guide emergency measures such as alkali dosing (pH adjustment) and hydrogen igniter operation (reduction promotion). The system also features dynamic update capabilities adapted to long accident sequences, providing core input for containment integrity assessment and source term analysis. This invention significantly improves the accuracy of iodine risk control in severe accident management at nuclear power plants, moving from "empirical conservative design" to "mechanism-driven precision prevention and control," providing a key technical tool for the design of containment structures and the development of accident plans for next-generation nuclear power plants.

[0179] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0180] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0181] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the present invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0182] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical functional division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interface, indirect coupling or communication connection of devices or units, and can be electrical, mechanical, or other forms.

[0183] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0184] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0185] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0186] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices, and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0187] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0188] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0189] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for estimating the concentration of radioactive iodine species in a containment vessel after an accident, characterized in that: The following steps are involved: Input the concentration of gaseous iodine in the containment atmosphere I 2(atm) , based on the atmospheric and cable dose rates in the containment and The acid content C in the containment atmosphere, wall and pit liquid phase was calculated by the acid generation and mass transfer model. atm,acid , C p,acid and C w,acid,n ; Based on the acid content C in the liquid phase of the pit p,acid and the concentration of the drug pre-added to the pit x NaP , the pH value in the pit liquid phase was calculated using the pH model; The iodine-silver model is used to determine the content of iodine that does not participate in the liquid phase chemical reaction and enters the pit liquid phase, and the concentration of iodine that can undergo chemical reaction in the pool is updated. 2(aq) ; Based on the content and pH value of iodine that can undergo chemical reactions in the pool, combined with the iodine water chemical equation, the concentrations of different iodine species in the liquid phase are calculated through the liquid phase chemical reaction model; the mass transfer of gaseous iodine between the containment atmosphere and the pit water in the gas phase is calculated, and then the radioactive iodine concentration I in the gas and liquid phases is updated. 2(atm) and I 2(aq) ; Combined hydrogen, ozone and radiolytic reduction coefficient k TIH , k TIO and k RI Calculate and update the concentration of gaseous iodine in the containment atmosphere I 2(atm) ; Determine the iodine concentration I deposited on the dry wall of the containment vessel 2(wall) ; Output the concentration or content of each iodine species in the gas and liquid.

2. The method for estimating the concentration of radioactive iodine species in a post-accident containment vessel according to claim 1, wherein: Acid content C in containment atmosphere, wall and pit liquid phase atm,acid , C p,acid and C w,acid,n They are: Among them, k eff,acid t is V atm for, is the acid generation rate, k w,acid,n is the mass transfer coefficient of acid from the atmosphere to the wall n, is the acid generation rate per unit time, k p,acid is the mass transfer coefficient of the acid.

3. The method for estimating the concentration of radioactive iodine species in a containment vessel after an accident according to claim 1, characterized in that: The pH value in the pit liquid phase is calculated using the pH model, specifically: The initial pH is obtained by initial charge balance, and the H in the liquid phase is obtained based on the initial pH and the physical properties of water. + and OH - Ion concentration; Based on the input of each substance and the hydrolysis reaction equation in the liquid phase, the ion concentration of each species is obtained, and the ion concentration of each species is brought into the total electron balance formula to calculate the new H + The concentration and pH are compared with the initial pH and iterated until the convergence condition is met to complete the pH calculation.

4. The method for estimating the concentration of radioactive iodine species in a containment vessel after an accident according to claim 3, characterized in that: When the charge concentration ΔZ>0, is the hydroxide concentration, is the hydrogen ion concentration, is the ionic product constant of water; When the charge concentration ΔZ = 0, When the charge concentration ΔZ < 0, 5. The method for estimating the concentration of radioactive iodine species in a containment vessel after an accident according to claim 4, characterized in that: The charge concentration ΔZ is: Among them, x NaP is the phosphate concentration, x Cs is the cesium ion concentration, is the nitric acid concentration, x HCl is the concentration of hydrochloric acid.

6. The method for estimating the concentration of radioactive iodine species in a post-accident containment vessel according to claim 1, wherein: The radioactive iodine mass transfer equation between the atmosphere and the cell is specifically: Among them, I 2(atm) is the concentration of radioactive iodine in the atmosphere, k pool is the mass transfer coefficient of radioactive iodine from the cell surface to the atmosphere, A pool is the interface area between the atmosphere and the pool surface, V atm is the volume of atmosphere, I 2(aq) is the concentration of radioactive iodine in the pool, is the distribution coefficient of radioactive iodine.

7. The method for estimating the concentration of radioactive iodine species in a containment vessel after an accident according to claim 6, characterized in that: Partition coefficient of radioactive iodine 8. The method for estimating the concentration of radioactive iodine species in a containment vessel after an accident according to claim 1, wherein: The reduction reaction of radioactive iodine in the atmosphere is as follows: Among them, k TIH is the reduction coefficient of the reaction between hydrogen and radioactive iodine, k TIO is the reduction coefficient of the reaction between ozone and radioactive iodine, k RI is the radiolysis reduction coefficient; is the atmospheric dose rate, [H2] and [O3] are the concentrations of hydrogen and ozone, kmole / m 3 ; T is the atmospheric temperature.

9. The method for estimating the concentration of radioactive iodine species in a containment vessel after an accident according to claim 1, characterized in that: The deposition of radioactive iodine on the containment wall is as follows: Among them, I 2(atm) is the concentration of radioactive iodine in the atmosphere, I 2(wall) is the radioactive iodine concentration on the wall, k ad is the radioiodine adsorption coefficient, k de is the desorption coefficient of radioactive iodine.

10. A system for estimating the concentration of radioactive iodine species in a containment vessel after an accident, characterized in that: include: Acid generation and mass transfer module, input the concentration of gaseous iodine in the containment atmosphere I 2(atm) , based on the atmospheric and cable dose rates in the containment and The acid content C in the containment atmosphere, wall and pit liquid phase was calculated by the acid generation and mass transfer model. atm,acid , C p,acid and C w,acid,n ; pH module, based on the acid content C in the pit liquid phase p,acid and the concentration of the drug pre-added to the pit x NaP , the pH value in the pit liquid phase was calculated using the pH model; The iodine-silver module determines the content of iodine that does not participate in the liquid phase chemical reaction in the pit through the iodine-silver model, and updates the concentration of iodine that can undergo chemical reaction in the pool. 2(aq) ; The liquid phase module calculates the concentration of different iodine species in the liquid phase based on the content and pH value of iodine that can undergo chemical reactions in the pool, combined with the iodine water chemical equation, through the liquid phase chemical reaction model; calculates the mass transfer of gaseous iodine between the containment atmosphere and the pit water in the gas phase, and then updates the radioactive iodine concentration I in the gas and liquid phases. 2(atm) and I 2(aq) ; Estimation module combining hydrogen, ozone and radiolytic reduction coefficient k TIH , k TIO and k RI Calculate and update the concentration of gaseous iodine in the containment atmosphere I 2(atm) ; Determine the iodine concentration I deposited on the dry wall of the containment vessel 2(wall) ; Output the concentration or content of each iodine species in the gas and liquid.

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