阅读说明：本技术 一种脉冲萃取柱有机相着火事故源项估算方法 (Pulse extraction column organic phase ignition accident source item estimation method ) 是由 梁博宁 张建岗 杨亚鹏 王任泽 冯宗洋 贾林胜 王宁 刘一宁 闫峰 于 2020-11-26 设计创作，主要内容包括：本发明涉及一种脉冲萃取柱有机相着火事故源项估算方法,所述方法包括以下步骤：(1)启动；(2)获取工艺参数；(3)估算当前泄漏的溶剂质量和燃烧池表面积；(4)计算燃料燃烧产生的第x种烟气质量；(5)计算烟气经过过滤器过滤与管道沉降,第x种烟气的剩余质量；(6)计算烟气经过过滤器过滤与管道沉降,第x种烟气已释放的活度及所有种烟气的总释放活度；(7)剩余氧气含量估算,返回步骤(4)重新估算；(8)如果燃料燃尽,计算结束。所述方法通过分析乏燃料后处理设施中脉冲萃取柱所处环境特点及可用状态参数,基于脉冲萃取柱有机相(磷酸三丁脂-煤油混合溶液)的着火规律,提出合理的估算方法,为应急响应和应急决策提供输入条件。(The invention relates to a method for estimating an organic phase fire accident source item of a pulse extraction column, which comprises the following steps: (1) starting; (2) acquiring process parameters; (3) estimating the mass of the solvent leaked at present and the surface area of the combustion pool; (4) calculating the mass of the x-th smoke generated by fuel combustion; (5) calculating the residual mass of the xth flue gas after the flue gas is filtered by a filter and is settled by a pipeline; (6) calculating the activity of the released xth smoke and the total release activity of all kinds of smoke after the smoke is filtered by a filter and is settled by a pipeline; (7) estimating the residual oxygen content, and returning to the step (4) for re-estimation; (8) if the fuel is burned out, the calculation ends. According to the method, a reasonable estimation method is provided by analyzing the environmental characteristics and available state parameters of a pulse extraction column in a spent fuel post-treatment facility and based on the ignition rule of an organic phase (tributyl phosphate-kerosene mixed solution) of the pulse extraction column, and input conditions are provided for emergency response and emergency decision.)

1. A method for estimating the source term of an organic phase fire accident of a pulse extraction column is characterized by comprising the following steps:

(1) judging whether the pulse extraction column has a fire accident or not, and starting calculation if the pulse extraction column has the fire accident;

(2) acquiring process parameters;

(3) estimating the mass M of the solvent leaked at present according to the data of the pulse extraction column quality on-line monitoring device and the sump liquid level alarm device_f,0And the surface area S of the combustion chamber_pool；

(4) Calculating the x-th smoke mass m generated by fuel combustion at the current time step_x,a,t；

(5) Calculating the residual mass m of the x-th smoke filtered by the filter of the exhaust pipeline and settled by the pipeline at the current time step_x,a,t,J；

(6) Calculating the activity A of the released x type of smoke at the current time step after the smoke is filtered by a filter of the exhaust pipeline and is settled by the pipeline_x,tAnd the total release activity A of all kinds of smoke at the current time step_t；

(7) Judging whether the fuel is burnt out or not, if not, calculating the mass of the residual available oxygen in the equipment room at the current time stepAnd initial available oxygen massReturning to the step (4) for recalculation;

(8) and if the fuel is burnt out, calculating the total activity A of the organic phase ignition release at all time steps, and finishing the calculation.

2. The method as claimed in claim 1, wherein the start-up modes in step (1) include a manual start-up mode and an automatic start-up mode in which the start-up mode is automatically started up when the combustion of the pulsed extraction column is detected by drift behavior of a process monitoring instrument and a rise in activity of an aerosol in an equipment room.

3. The method for estimating the source item of the organic phase fire accident of the pulse extraction column as recited in claim 1, wherein the process parameters in the step (2) comprise fixed process parameters, real-time process parameters and real-time monitoring parameters.

4. The method as claimed in claim 3, wherein the fixed process parameters include height of the equipment room and volume of the equipment room, the real-time process parameters include volume fraction of tributyl phosphate in the pulsed extraction column and initial mass of organic solvent in the pulsed extraction column in the current process flow, and the real-time monitoring parameters include inlet air flow and outlet air flow of the equipment room.

5. The method for estimating the source term of organic phase fire accident of pulse extraction column as claimed in claim 1, wherein the mass M of solvent currently leaked in step (3)_f,0And the surface area S of the combustion chamber_poolThe calculation method comprises the following steps:

M_f,0＝M_o-M_l

wherein M is₀Is the initial mass of the organic solvent of the pulsed extraction column of the current process flow, M₁Is the current residual organic solvent mass of the pulse extraction column, rho_fIs the density of the organic solvent, H_poolIs the height of the combustion chamber.

6. The method for estimating the source term of an organic phase fire accident of a pulse extraction column according to claim 1, wherein the specific steps of the step (4) comprise:

(41) calculating the fuel mass loss rate m'_t

Where t is the current time step, h_cFor combustion convection heat flux density, h_fFor combustion of radiant heat flux, h_rIs the surface radiant heat flux, h_lFor latent heat of vaporization of fuel, T_tFor the solution temperature at the current time step, c_f(T_t) Is the heat capacity of the fuel, T_bIs the boiling point of the fuel, T_∞In order to be at an infinite space temperature,is the mass ratio of nitrate solution;

(42) calculating the fuel combustion mass m at the current time step_tWith the mass of oxygen consumed by combustion of the fuel

m_t＝m″_t·Δt·S_pool

Wherein, Δ t is the current time step duration,mass of oxygen consumed for combustion of a unit mass of fuel;

(43) calculating the total heat quantity Q generated by combustion_tAnd the solution temperature T of the next time step_t+1

Q_t＝am_th_t

Wherein a is the heat release efficiency, h_tAs heat of combustion of fuel, M_roomAll the equipment quality (including iron on the ground, wall surface and the like) of the equipment room, c_s(T_t) The heat capacity of steel is adopted;

(44) calculating mass fraction omega of fuel combustion at the current time step_t

Wherein M is_f,tThe initial remaining fuel mass for the current time step,

mass of oxygen consumed by fuel combustion if current time stepGreater than the current remaining available oxygen massThe mass of oxygen consumed by the fuel burning at the current time stepEqual to the current remaining available oxygen massNamely, it is

(45) Calculating the x-th smoke mass m generated at the current time step_x,a,t，

m_x,a,t＝M_x,t·ω_t·γ_x

Wherein M is_x,tIs at presentResidual mass of radionuclide of x type, gamma, at time step_xThe smoke generation rate for the x-th radionuclide.

7. The method for estimating the source term of an organic phase fire accident of a pulse extraction column according to claim 1, wherein the concrete steps of the step (5) comprise:

(51) calculating the residual smoke mass of the smoke before the smoke passes through the jth filter

Wherein m is_x,a,t,j-1The mass of the residual smoke, zeta, of the xth smoke after passing through the jth-1 filter_x,jThe deposition rate per unit path of the x type flue gas in the j section of the pipeline, l_jIs the length of the pipe before the jth filter;

(52) calculating the x-th smoke mass Deltam filtered by the jth filter_x,a,t,j

Wherein the content of the first and second substances,the filtering efficiency of the jth filter on the xth type of smoke;

(53) calculating the residual smoke mass m after passing through the jth filter_x,a,t,j

Wherein, ω is_xIs the mass fraction of the x-th radionuclide in the oxide fume;

(54) calculating the effective filter mass m remaining for the jth filter_p,t,j

Wherein m is_p,t-1,jTo provide the effective filtering quality remaining for the time step preceding the jth filter,all the filtered smoke mass for the jth filter;

if the filter has a remaining effective filter mass m_p,t,jThe mass of the filtered smoke is less than or equal to the mass of the filtered smoke, and the mass of the filtered smoke is set as the residual effective filtering mass m of the filter_p,t,jAnd the filter is failed;

(55) after filtering by J filters and pipeline sedimentation, the residual mass of the x-th smoke at the current time step is m_x,a,t,J。

8. The method for estimating the source item of the organic phase fire accident of the pulse extraction column as claimed in claim 1, wherein the activity A of the released x type smoke in the current time step in the step (6)_x,tAnd the total release activity A of all kinds of smoke at the current time step_tThe calculation method comprises the following steps:

A_x,t＝a_xm_x,a,t,J

wherein, a_xThe specific activity of the X-th radionuclide is more than or equal to 1 and less than or equal to X.

9. The method for estimating the organic phase fire accident origin item of the pulse extraction column according to claim 1, wherein the available oxygen in the equipment room at the current time step in the step (7) is remainedQuality of gasAnd initial available oxygen massThe calculation method comprises the following steps:

for organic solvents, when the oxygen content in the air reaches eta, the organic solvents cannot be combusted, so that the oxygen content of the exhausted air is assumed to be eta,

wherein the content of the first and second substances,for the quality of the residual available oxygen in the equipment room at the previous time step, V_inIs the inlet air flow, ρ_inIs the intake density, V_roomIs the equipment room air volume.

10. The method for estimating the source term of an organic phase fire accident of a pulse extraction column according to claim 1, wherein the total activity A of the organic phase fire release in all time steps in the step (8) is calculated by:

wherein t is more than 0 and less than or equal to t_t,t_tThe total time for the organic phase to ignite and burn is shown.

Technical Field

The invention belongs to the technical field of nuclear and radiation emergency, and particularly relates to a pulse extraction column organic phase fire accident source item estimation method.

Background

When nuclear fuel is used in a reactor, the consumption of fissile nuclides and the generation of fission products and heavy nuclides cause the change of fuel reactivity, and finally the reactor can not maintain criticality any more, so that the nuclear fuel needs to be replaced to a certain extent. The fuel discharged after irradiation by the reactor is also called spent fuel or irradiated fuel. Spent nuclear fuel must be properly disposed of because it contains a large amount of radionuclides and is therefore highly radioactive. The spent fuel treatment mainly comprises the processes of storage, transportation, post-treatment, deep geological disposal and the like.

Spent fuel reprocessing is an important link for realizing the recycling and proper disposal of nuclear fuel. The Purex process (Purex) is a chemical process for recovering uranium and plutonium from irradiated nuclear fuel by tributyl phosphate extraction, and is the most effective and successful post-treatment process nowadays. A solvent extraction system, a solvent purification system and an equipment room in a spent fuel post-treatment facility contain a large amount of organic solvents, and potential fire accident potential of organic phase solvents exists. In the uranium and plutonium co-decontamination system, the position with the highest radioactive activity concentration of fission products is a pulse extraction column, the quantity of radioactive nuclides released from a burning solvent is the largest when solvent leakage catches fire in the device, and the main burning substance is a mixed solution of tributyl phosphate and kerosene. In the nuclear emergency condition, the source item estimation needs to be carried out on the accident so as to provide input conditions for emergency response and emergency decision.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a pulse extraction column organic phase ignition accident source item estimation method, which provides a reasonable estimation method based on the ignition rule of a pulse extraction column organic phase (tributyl phosphate-kerosene mixed solution) by analyzing the environmental characteristics and available state parameters of the pulse extraction column in a spent fuel post-treatment facility, and provides input conditions for emergency response and emergency decision.

In order to achieve the above purposes, the invention adopts a technical scheme that: a method for estimating the source term of an organic phase fire accident of a pulse extraction column comprises the following steps:

(1) judging whether the pulse extraction column has a fire accident or not, and starting calculation if the pulse extraction column has the fire accident;

(2) acquiring process parameters;

(3) estimating the mass M of the solvent leaked at present according to the data of the pulse extraction column quality on-line monitoring device and the sump liquid level alarm device_f,0And the surface area S of the combustion chamber_pool；

(4) Calculating the x-th smoke mass m generated by fuel combustion at the current time step_x,a,t；

(5) Calculating the residual mass m of the x-th smoke filtered by the filter of the exhaust pipeline and settled by the pipeline at the current time step_x,a,t,J；

(6) Calculating the activity A of the released x type of smoke at the current time step after the smoke is filtered by a filter of the exhaust pipeline and is settled by the pipeline_x,tAnd the total release activity A of all kinds of smoke at the current time step_t；

(7) Judging whether the fuel is burnt out or not, if not, calculating the mass of the residual available oxygen in the equipment room at the current time stepAnd initial available oxygen massReturning to the step (4) for recalculation;

(8) and if the fuel is burnt out, calculating the total activity A of the organic phase ignition release at all time steps, and finishing the calculation.

Further, one embodiment of the step (1) is to manually start the calculation.

Further, another embodiment in step (1) is to automatically start the calculation by detecting the occurrence of combustion in the pulsed extraction column through drift behavior of the process monitoring instrument and the increase of radioactivity of the aerosol in the equipment room.

Further, the process parameters in the step (2) include fixed process parameters, real-time process parameters and real-time monitoring parameters.

Further, the fixed process parameters comprise the height of the equipment room and the volume of the equipment room, the real-time process parameters comprise the volume fraction of tributyl phosphate and the initial mass of the organic solvent of the pulse extraction column in the current process flow, and the real-time monitoring parameters comprise the inlet air flow and the outlet air flow of the equipment room.

Further, the mass M of the solvent currently leaked in the step (3)_f,0And the surface area S of the combustion chamber_poolThe calculation method comprises the following steps:

M_f,0＝M_o-M_l

wherein M is₀Is the initial mass of the organic solvent of the pulsed extraction column of the current process flow, M₁Is the current residual organic solvent mass of the pulse extraction column, rho_fIs the density of the organic solvent, H_poolIs the height of the combustion chamber.

Further, the specific steps of the step (4) include:

(41) calculating the fuel mass loss rate m'_t

Where t is the current time step, h_cFor combustion convection heat flux density, h_fFor combustion of radiant heat flux, h_rIs the surface radiant heat flux, h_lFor latent heat of vaporization of fuel, T_tFor the solution temperature at the current time step, c_f(T_t) Is the heat capacity of the fuel, T_bIs the boiling point of the fuel, T_∞In order to be at an infinite space temperature,is the mass ratio of nitrate solution;

(42) calculating the fuel combustion mass m at the current time step_tWith the mass of oxygen consumed by combustion of the fuel

m_t＝m"_t·Δt·S_pool

Wherein, Δ t is the current time step duration,mass of oxygen consumed for combustion of a unit mass of fuel;

(43) calculating the total heat quantity Q generated by combustion_tAnd the solution temperature T of the next time step_t+1

Q_t＝am_th_t

Wherein a is the heat release efficiency, h_tAs heat of combustion of fuel, M_roomIs an equipment roomAll equipment masses (including iron on the ground, wall, etc.), c_s(T_t) The heat capacity of steel is adopted;

(44) calculating mass fraction omega of fuel combustion at the current time step_t

Wherein M is_f,tThe initial remaining fuel mass for the current time step,

mass of oxygen consumed by fuel combustion if current time stepGreater than the current remaining available oxygen massThe mass of oxygen consumed by the fuel burning at the current time stepEqual to the current remaining available oxygen massNamely, it is

(45) Calculating the x-th smoke mass m generated at the current time step_x,a,t，

m_x,a,t＝M_x,t·ω_t·γ_x

Wherein M is_x,tFor the remaining mass of the x-th radionuclide, gamma, at the current time step_xThe smoke generation rate for the x-th radionuclide.

Further, the specific steps of the step (5) include:

(51) calculating the residual smoke mass of the smoke before the smoke passes through the jth filter

Wherein m is_x,a,t,j-1The mass of the residual smoke, zeta, of the xth smoke after passing through the jth-1 filter_x,jThe deposition rate per unit path of the x type flue gas in the j section of the pipeline, l_jIs the length of the pipe before the jth filter;

(52) calculating the x-th smoke mass Deltam filtered by the jth filter_x,a,t,j

Wherein the content of the first and second substances,the filtering efficiency of the jth filter on the xth type of smoke;

(53) calculating the residual smoke mass m after passing through the jth filter_x,a,t,j

Wherein, ω is_xIs the mass fraction of the x-th radionuclide in the oxide fume;

(54) calculating the effective filter mass m remaining for the jth filter_p,t,j

Wherein m is_p,t-1,jTo provide the effective filtering quality remaining for the time step preceding the jth filter,all flue gases filtered for jth filterQuality;

if the filter has a remaining effective filter mass m_p,t,jThe mass of the filtered smoke is less than or equal to the mass of the filtered smoke, and the mass of the filtered smoke is set as the residual effective filtering mass m of the filter_p,t,jAnd the filter is failed;

(55) after filtering by J filters and pipeline sedimentation, the residual mass of the x-th smoke at the current time step is m_x,a,t,J。

Further, the activity A released by the xth smoke in the current time step in the step (6)_x,tAnd the total release activity A of all kinds of smoke at the current time step_tThe calculation method comprises the following steps:

A_x,t＝a_xm_x,a,t,J

wherein, a_xThe specific activity of the X-th radionuclide is more than or equal to 1 and less than or equal to X.

Further, the quality of the oxygen remaining available in the equipment room at the current time step in the step (7)And initial available oxygen massThe calculation method comprises the following steps:

for organic solvents, when the oxygen content in the air reaches eta, the organic solvents cannot be combusted, so that the oxygen content of the exhausted air is assumed to be eta,

wherein the content of the first and second substances,for the quality of the residual available oxygen in the equipment room at the previous time step, V_inIs the inlet air flow, ρ_inIs the intake density, V_roomIs the equipment room air volume.

Further, the method for calculating the total activity a of the organic phase released on fire in the step (8) comprises the following steps:

wherein t is more than 0 and less than or equal to t_t,t_tThe total time for the organic phase to ignite and burn is shown.

The invention has the beneficial effects that: the method provides a reasonable estimation method by analyzing the environmental characteristics and available state parameters of a pulse extraction column in the spent fuel post-treatment facility and based on the ignition rule of an organic phase (tributyl phosphate-kerosene mixed solution) of the pulse extraction column, and provides input conditions for emergency response and emergency decision.

Drawings

FIG. 1 is a flow chart of a method for estimating the source of an organic phase fire accident in a pulsed extraction column according to the present invention.

Detailed Description

In order to make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be further described in detail with reference to the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

FIG. 1 is a flow chart of a method for estimating the source of an organic phase fire accident in a pulsed extraction column according to the present invention, the method comprising the following steps:

(1) and judging whether the pulse extraction column has a fire accident or not, and starting calculation if the fire accident occurs.

In the starting module, no interface function is used, and the starting module is started by manual starting or by detecting that the pulse extraction column is burnt through the drifting behavior (pulse extraction column quality and sump liquid level alarm device) of a process monitoring instrument and the radioactive rising phenomenon of the aerosol in the equipment room.

(2) Obtaining process parameters

The acquired process parameters mainly comprise fixed process parameters, real-time process parameters and real-time monitoring parameters.

The fixed process parameters comprise the height of the equipment chamber, the volume of the equipment chamber and the like, the real-time process parameters comprise the volume fraction of tributyl phosphate, the initial mass of the organic solvent of the pulse extraction column in the current process flow and the like, and the real-time monitoring parameters comprise the inlet air flow, the outlet air flow and the like of the equipment chamber.

(3) Estimating the mass M of the solvent leaked at present according to the data of the pulse extraction column quality on-line monitoring device and the sump liquid level alarm device_f,0(i.e., initial mass of fuel) and combustion bowl surface area S_poolThe calculation method comprises the following steps:

M_f,0＝M_o-M_l

wherein the content of the first and second substances,

M₀the initial mass of the organic solvent of the pulse extraction column in the current process flow is Kg;

M₁the unit is Kg, which is the mass of the current residual organic solvent of the pulse extraction column;

ρ_fis the density of the organic solvent and has the unit of Kg/m³；

H_poolIs the height of the combustion chamber in m.

(4) Calculating the x-th smoke mass m generated by fuel combustion at the current time step_x,a,tThe method comprises the following specific steps:

(41) first combining the heat balance formula with combustionThe fuel mass loss rate m' is calculated by empirical rate formula and approximately considering the influence of the nitric acid solution on the combustion rate "_tThe calculation method comprises the following steps:

wherein the content of the first and second substances,

t is the current time step and is dimensionless;

h_cfor combustion convective heat flow density, in Kw/m²；

h_fThe density of heat flow of combustion radiation is given in Kw/m²；

h_rIs the surface radiant heat flux density in Kw/m²；

h_lThe unit is Kj/Kg, which is the latent heat of fuel evaporation;

T_tthe solution temperature at the current time step is given in units of ℃;

c_f(T_t) The heat capacity of the fuel is Kj/(Kg. DEG C);

T_bis the fuel boiling point, in units of ℃;

T_∞is an infinite space temperature in units of;

is the mass ratio of the nitrate solution and has no dimension.

(42) The fuel combustion quality m at the current time step can be obtained_tWith the mass of oxygen consumed by combustion of the fuelThe calculation method comprises the following steps:

m_t＝m_t"·Δt·S_pool

wherein the content of the first and second substances,

delta t is the duration of the current time step, and the unit is s;

is the mass of oxygen consumed by the combustion of unit mass of fuel, and has no dimension;

(43) the total heat quantity Q generated by combustion_tAnd the solution temperature T of the next time step_t+1Comprises the following steps:

Q_t＝am_th_t

wherein the content of the first and second substances,

a is the heat release efficiency, and is dimensionless;

h_tthe unit is Kj/Kg as the combustion heat of the fuel;

M_roomthe unit is Kg, which is the mass (including iron on the ground, wall and the like) of all equipment in the equipment room;

c_s(T_t) The heat capacity of the steel is Kj/(Kg. DEG C);

(44) the mass fraction omega of the fuel combustion at the current time step can be obtained_tComprises the following steps:

wherein M is_f,tThe initial residual fuel mass in Kg at the current time step;

mass of oxygen consumed by fuel combustion if current time stepGreater than the current remaining available oxygen massThe fuel combustion at the current time step is eliminatedMass of oxygen consumedEqual to the current remaining available oxygen massNamely, it is

(45) Calculating the x-th smoke mass m generated at the current time step_x,a,t

The smoke generated by X radioactive substances and the smoke generated by an organic solvent are shared, wherein the X +1 term is the smoke generated by solvent combustion, the smoke has no radioactivity, and the mass m of the X smoke generated by the current time step_x,a,tComprises the following steps:

m_x,a,t＝M_x,t·ω_t·γ_x

wherein the content of the first and second substances,

M_x,tthe residual mass of the x-th radionuclide in the current time step is Kg;

γ_xthe smoke generation rate of the x-th radionuclide is dimensionless.

(5) Calculating the residual mass m of the x-th smoke filtered by the filter of the exhaust pipeline and settled by the pipeline at the current time step_x,a,t,J

Since a large amount of flue gas generated by combustion is discharged from the exhaust duct, the duct has a filter, and a part of the flue gas is deposited on the filter, it is necessary to estimate the deposition in the duct and the filter. In addition, the flue gas may cause clogging of the filter, and therefore an evaluation of the filter is also required. The method comprises the following specific steps:

(51) firstly, the residual smoke mass of the smoke before passing through the jth filter is calculated

Wherein the content of the first and second substances,

m_x,a,t,j-1the unit is Kg, which is the mass of the smoke left after the xth smoke passes through the jth-1 filter;

ζ_x,jthe deposition rate of the x type flue gas in the j section of the pipeline per unit path is m^-1；

l_jThe length of the pipeline before the jth filter is m;

(52) calculating the x-th smoke mass Deltam filtered by the jth filter_x,a,t,j

Wherein the content of the first and second substances,the filter efficiency of the jth filter to the xth type smoke is dimensionless;

(53) calculating the residual smoke mass m after passing through the jth filter_x,a,t,j

Wherein, ω is_xIs the mass fraction of the x-th radionuclide in the oxide smoke, and is dimensionless;

(54) calculating the effective filter mass m remaining for the jth filter_p,t,j

Wherein m is_p,t-1,jIs the remaining effective filtration mass in Kg for the previous time step of the jth filter;is the jth processThe unit of the mass of all the smoke filtered by the filter is Kg;

if the filter has a remaining effective filter mass m_p,t,jThe mass of the filtered smoke is less than or equal to the mass of the filtered smoke, and the mass of the filtered smoke is set as the residual effective filtering mass m of the filter_p,t,jAnd the filter fails.

After filtering by J filters and pipeline sedimentation, the residual mass of the x-th smoke at the current time step is m_x,a,t,J。

(6) Calculating the activity A of the released x type of smoke at the current time step after the smoke is filtered by a filter of the exhaust pipeline and is settled by the pipeline_x,tAnd the total release activity A of all kinds of smoke at the current time step_tThe calculation method comprises the following steps:

A_x,t＝a_xm_x,a,t,J

wherein X is more than or equal to 1 and less than or equal to X, a_xThe radioactivity of the x type radionuclide is expressed in Bq/Kg;

(7) judging whether the fuel is burnt out or not, if not, calculating the mass of the residual available oxygen in the equipment room at the current time stepAnd initial available oxygen massAnd (5) returning to the step (4) for recalculation.

For organic solvents, the organic solvent cannot be combusted when the oxygen content in the air reaches eta, so that the mass of the residual available oxygen in the equipment room at the current time step is the mass of the residual available oxygen in the equipment room at the current time step on the assumption that the oxygen content of the exhausted air is etaAnd initial available oxygen massComprises the following steps:

wherein the content of the first and second substances,

the mass of the residual available oxygen in the equipment room at the previous time step is Kg;

V_inis the intake air flow rate, and has the unit of m³/s；

ρ_inThe unit is Kg/m for the intake air density³；

V_roomIs the air volume of the equipment room, and the unit is m³。

(8) And if the fuel is burnt out, calculating the total activity A released by the ignition of the organic phase, and outputting a calculation result.

Total activity A of each radionuclide released by organic phase on fire_xComprises the following steps:

the total activity a of the organic phase on fire release was:

wherein X is more than or equal to 1 and less than or equal to X, t is more than 0 and less than or equal to t_t，t_tThe total time of the organic phase ignition combustion is expressed in s.

It will be appreciated by persons skilled in the art that the apparatus and method of the present invention are not limited to the embodiments described in the detailed description, and the detailed description is for the purpose of explanation and not limitation of the invention. Other embodiments will be apparent to those skilled in the art from the following detailed description, which is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.