Nuclear power compartment radiation shielding control method and system and shielding design method

Abstract

According to the nuclear power compartment radiation shielding control method and system and the shielding design method, the holes are divided according to the shielding conditions of the holes, and the holes comprise the open holes, the hollow pipeline holes and the filled pipeline holes. On the basis of the scattering dose rate of the open hole, equivalently calculating the average density of the filled pipeline partition as the filler density, and respectively calculating to obtain the scattering dose rate of the hollow pipeline hole and the unblocked hole of the filled pipeline hole; on the basis of the initial scattering dose rate of the open hole, according to the filler density of the first pore partition and the filler density of the second pore partition, the scattering dose rates of the blocked hollow pipeline hole and the filled pipeline hole are obtained through calculation. According to the method, the scattering dose rates before and after hole plugging are quantified, quantitative analysis and evaluation of the hole plugging effect are achieved, the quantification result is used for controlling the radiation dose rate of the compartment, and the radiation dose rate of the compartment can be accurately controlled.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power technology, and in particular to a nuclear power compartment radiation shielding control method and system (quantifying the influence of hole scattering) and a shielding design method. Background Art

[0002] The radioactive building of a nuclear power plant is equipped with radiation sources (this technical book refers to the building equipped with γ radiation sources). The radiation source continuously emits γ-ray particles, which creates a harmful radiation field in the space. In order to protect the workers from the radiation hazards of the radiation source, the nuclear power plant arranges the high-radiation source equipment in an independent compartment, relying on the biological wall (i.e. concrete wall, called biological wall in the control area of ​​the nuclear power plant) for shielding, reducing the radiation of the source compartment to the surrounding compartments, so that the weakened penetrating radiation dose rate meets the compartment dose rate acceptance requirements.

[0003] However, the compartment is not only affected by the penetrating radiation of the adjacent compartments, but also by the scattered radiation of the adjacent compartments through the holes if there are holes in the wall; in addition, if the compartment itself has a radiation source arranged inside, it is also affected by the radiation of the equipment in the compartment. According to regulatory standards, radiation shielding design should be used to ensure that the combined impact of these three types of radiation, that is, the total radiation dose rate, meets the dose rate acceptance requirements of the radiation partition where the compartment is located. If the compartment dose rate acceptance requirement is defined as D WAC , the dose rate contributed by the equipment in the compartment is D in , the total dose rate of adjacent compartments penetrating radiation contribution is The initial scattered total dose rate of the adjacent compartment holes is

[0004] The current industry adopts a "semi-quantitative + semi-empirical" design method. Specifically, the dose rate contributed by the equipment in the compartment D in and adjacent compartments penetrating radiation contribution dose rate A quantitative analysis was performed to ensure that the sum of the two is lower than the acceptance requirement of the compartment dose rate D WAC , that is, a certain margin is reserved. The margin factor is determined according to the specific situation, and is generally around 0.5. In the absence of quantitative analysis of the impact of hole scattering, the margin factor is only established based on design experience, which is uncertain and poses a greater radiation risk, posing a radiation hazard to workers entering the compartment. Summary of the invention

[0005] In view of some of the shortcomings of the above-mentioned prior art, the present invention provides a nuclear power compartment radiation shielding control method and system and a shielding design method, which solves the problem of quantifying the hole scattering dose rate, and based on the quantified hole scattering dose rate, enables the compartment to meet the radiation dose rate control requirements of the radiation zone in which it is located, thereby ensuring the safety of operators.

[0006] To achieve the above-mentioned and other related purposes, the present invention includes a nuclear power compartment radiation shielding control method, comprising the following steps:

[0007] Obtain the types of all holes on the partition wall, and calculate the scattered dose rates of other types of holes based on the scattered dose rates of open holes;

[0008] The hole and pipe layout is adjusted based on the scattered dose rate of the holes so that the sum of the scattered dose rates of all holes on the compartment wall meets the radiation dose rate control requirements of the compartment.

[0009] As one embodiment of the present invention, the hole pipe arrangement includes:

[0010] Filter the types and quantity of all holes on the partition walls, and adjust the shielding settings of the holes;

[0011] Based on the shielding setting of the holes, the sum of the scattered dose rates of all holes is calculated, and the radiation dose rate of the compartment is obtained by adding the penetration dose rate of the adjacent compartment and the equipment dose rate of the equipment in the compartment, so that the radiation dose rate is not greater than the preset radiation dose rate value;

[0012] Among them, the preset value of the radiation dose rate is obtained from the radiation partition where the compartment is located.

[0013] As one embodiment of the present invention, the hole further includes a hollow pipe hole, and the hollow pipe hole includes a first pore partition and a hollow pipe partition; the shielding setting of the hollow pipe hole includes unblocked and blocked;

[0014] When the holes in the hollow pipe are not blocked, the scattered dose rate is the sum of the initial scattered dose rates of the first pore partition and the hollow pipe partition;

[0015] When the holes in the hollow pipe are plugged, the scattered dose rate is the sum of the scattered dose rate of the first pore partition and the initial scattered dose rate of the hollow pipe partition;

[0016] The scattered dose rate of the first pore partition is calculated from its initial scattered dose rate.

[0017] As one embodiment of the present invention, the hole also includes a filled pipe hole, and the filled pipe hole includes a second pore partition and a filled pipe partition; the shielding setting of the filled pipe hole includes unblocked and blocked;

[0018] When the filled pipe is not blocked, its scattered dose rate is the sum of the scattered dose rate of the filled pipe partition and the initial scattered dose rate of the second pore partition;

[0019] When the pipeline is filled and plugged, its scattered dose rate is the sum of the scattered dose rate of the filled pipeline partition and the scattered dose rate of the second pore partition;

[0020] The scattered dose rate of the filled pipe partition is calculated from its initial scattered dose rate, and the scattered dose rate of the second pore partition is calculated from its initial scattered dose rate.

[0021] As one embodiment of the present invention, the initial scattered dose rates of the first pore partition, the hollow pipe partition, the second pore partition and the filled pipe partition are all the scattered dose rates of the open holes when they are equivalently calculated as open holes.

[0022] As one embodiment of the present invention, the calculation of the scattered dose rate of the filled pipeline partition or the first pore partition or the second pore partition includes:

[0023] Obtaining an average density of a filled pipe partition or a plugging filler density of a first pore partition or a plugging filler density of a second pore partition;

[0024] Based on the average density or plugging filler density, the attenuation factor between it and the initial dose rate is obtained;

[0025] The scattered dose rate of the filled pipe partition or the first pore partition or the second pore partition is calculated in combination with the initial scattered dose rate.

[0026] As one embodiment of the present invention, when the open hole, the hollow pipe hole, or the filled pipe hole is a fully shielded hole, the scattered dose rate is 0.

[0027] As one embodiment of the present invention, the present invention also includes a nuclear power compartment radiation shielding control system, including:

[0028] The data acquisition module obtains the types of all holes on the partition wall and calculates the scattered dose rates of other types of holes based on the scattered dose rates of the open holes;

[0029] The dynamic adjustment module adjusts the hole pipe arrangement based on the scattered dose rate of the holes so that the sum of the scattered dose rates of all holes on the compartment wall meets the radiation dose rate control requirements of the compartment.

[0030] As one embodiment of the present invention, the present invention also includes a nuclear power compartment radiation shielding design method, comprising the following steps:

[0031] According to the radiation zoning of the compartment, the radiation dose rate control requirements of the compartment are obtained, and the initial value of the wall thickness of the compartment is determined;

[0032] Based on the initial value of wall thickness, the initial value of penetration dose rate in adjacent compartments is obtained;

[0033] And obtain the initial values ​​of the scattered dose rate of all holes on the partition wall and the equipment dose rate of the partition equipment to determine whether it meets the radiation dose rate control requirements of the partition;

[0034] If it does not meet the requirements, use one or both of the following two adjustment methods to repeat the adjustment until the radiation dose rate control requirements are met:

[0035] Method 1: Shield the holes in the partition wall according to their types to reduce the scattered dose rate of the holes;

[0036] Method 2: Adjust the thickness of the compartment wall to reduce the penetration dose rate of adjacent compartments.

[0037] As one embodiment of the present invention, the dose rate control requirements include: the sum of the scattered dose rate, the penetration dose rate, and the equipment radiation dose rate of all holes in the compartment wall is not greater than the radiation dose rate preset value of the compartment, and the radiation dose rate preset value is obtained by the radiation partition where the compartment is located.

[0038] As one embodiment of the present invention, the shielding setting of holes by type includes:

[0039] The holes in the hollow pipe and the holes in the filled pipe are blocked in turn, and the scattered dose rate of the blocked hollow pipe holes and the scattered dose rate of the filled pipe holes are obtained respectively; combined with the scattered dose rate, the initial value of the penetration dose rate, and the equipment dose rate of other types of holes, it is determined in turn whether the radiation dose rate control requirements of the compartment are met;

[0040] When it is determined that the requirements are not met, shielding baffles are installed on the corresponding walls around the open holes, hollow pipe holes and holes filled with pipe holes to make the scattered dose rate of all holes 0, and determine whether the dose rate control requirements are met.

[0041] As one embodiment of the present invention, adjusting the thickness of the partition wall includes:

[0042] Obtain the penetration dose rates corresponding to the six walls of the compartment respectively;

[0043] According to the penetration dose rate, the corresponding wall thickness is adjusted in turn to reduce its penetration dose rate;

[0044] The sum of the penetration dose rates of the six walls, as well as the equipment dose rate and scattered dose rate are obtained. Based on the radiation partitioning of the compartment, it is determined in turn whether the radiation dose rate control requirements of the compartment are met.

[0045] The beneficial technical effects of the present invention include at least:

[0046] (1) A method and system for controlling radiation shielding of nuclear power compartments of the present invention achieves the purpose of controlling the radiation dose rate of the compartments by quantifying the radiation scattering effect of holes. Specifically, based on the scattering dose rate of open holes, the scattering dose rates of hollow pipe holes and filled pipe holes are calculated respectively; then the arrangement of the hole pipes is adjusted, including adjusting the number of holes of different types and shielding them, including filling the holes with fillers or fully shielding the holes, so that the sum of the scattering dose rates of all holes on the compartment wall meets the radiation dose rate control requirements of the compartment. Therefore, by quantifying the scattering dose rates before and after the hole plugging, a quantitative analysis and evaluation of the hole plugging effect is achieved, and the quantified results are used in the radiation dose rate control of the compartment, so that the radiation dose rate of the compartment can be accurately controlled.

[0047] (2) The radiation shielding design method for nuclear power compartments of the present invention quantifies the scattered dose rate of holes to obtain the sum of the scattered dose rates of holes before and after plugging, and uses the value to determine whether it meets the radiation dose rate control requirements of the compartment; and adjusts the plugging status of different types of holes according to the determination results to gradually reduce the scattered dose rate of the holes, quantifies the scattered dose rate of the holes according to the plugging status, and then determines whether it meets the dose rate control requirements, until shielding plates are installed on the corresponding walls around all holes, at which time the scattered dose rate of the holes is zero, and determines whether it meets the dose rate control requirements; if it does not meet the control requirements, then according to the size of the corresponding penetration dose rate of the wall, the thickness of the wall is increased in turn to obtain the corresponding penetration dose rate, and then determines whether it meets the dose rate control requirements of the compartment. Therefore, the radiation shielding design method of the present invention includes adjusting the sealing condition of the holes to gradually reduce the scattered dose rate of the holes, and increasing the wall thickness to gradually reduce the penetration dose rate. The radiation dose rate of the compartment is adjusted by the above two methods until the radiation dose rate control requirements of the radiation partition where the compartment is located are met. Therefore, the obtained result is more accurate, which not only ensures that the compartment strictly meets its radiation dose rate control requirements, but also saves resources, and the design of pipeline arrangement and wall thickening of the compartment holes can meet the dose rate control requirements of the compartment. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A flow chart of a nuclear power compartment radiation shielding control method provided by one embodiment of the present invention;

[0049] Figure 2 A schematic diagram of an open hole, a hollow pipe hole, and a filled pipe hole provided in one embodiment of the present invention;

[0050] Figure 3 A system block diagram of a nuclear power compartment radiation shielding control system provided by one embodiment of the present invention;

[0051] Figure 4A schematic diagram of blocking a first pore partition of a hollow pipe hole provided by an embodiment of the present invention;

[0052] Figure 5 A schematic diagram of plugging a first pore partition of a pipeline hole provided by an embodiment of the present invention;

[0053] Figure 6 A schematic diagram of installing a shielding plate on a wall corresponding to a hole around a hole provided by an embodiment of the present invention;

[0054] Figure 7 A flow chart of a method for designing radiation shielding for a nuclear power compartment provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0056] See also Figure 1 to Figure 7 It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportion relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0057] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0058] It should be noted that the compartment dose rate control needs to satisfy the following formula:

[0059]

[0060] Among them, D WAC To define the dose rate acceptance requirement of the compartment, it is obtained from the radiation zone where the compartment is located; D in The sum of the dose rates contributed by the equipment in the compartment, is the sum of the scattered dose rates of the holes, i represents the partition wall with adjacent compartments, and j represents the hole arranged on the partition wall i; is the sum of the penetrating radiation dose rates of the six walls of the compartment, and i represents the adjacent compartment.

[0061] At present, the dose rate contributed by the equipment in the compartment and the penetrating radiation dose rate have been quantitatively analyzed. The above formula is equivalent to:

[0062]

[0063] Among them, the margin factor is defined as f (0 < f < 1), and is generally taken as about 0.5, and no quantitative analysis is performed on the scattered dose rate of the hole. The margin factor is only determined based on experience, which poses a great safety hazard to the radiation dose rate control of the compartment.

[0064] See also Figure 1 The present invention includes a nuclear power compartment radiation shielding control method, comprising the following steps:

[0065] Obtain the types of all holes on the partition wall, and calculate the scattered dose rates of other types of holes based on the scattered dose rates of open holes;

[0066] The hole and pipe layout is adjusted based on the scattered dose rate of the holes so that the sum of the scattered dose rates of all holes on the compartment wall meets the radiation dose rate control requirements of the compartment.

[0067] It should be noted that obtaining the scattered dose rate of open holes includes: obtaining the area of ​​the open hole, the relative elevation, and the parameters of the radiation partitions of the compartments on both sides of the wall where the hole is located, and calculating the scattered dose rate of the open hole based on the Monte Carlo method. Specifically, the Monte Carlo method is used to calculate the reference paper "Theoretical Evaluation of the Scattering Effects of Holes in γ-Radioactive Buildings of Nuclear Power Plants Based on the Monte Carlo Method" (China Nuclear Power, 2023 Vol. 16 Supplement 1), based on reasonable assumptions and convergence techniques, and gives the scattered dose rate of open holes under different values ​​(ranges) of the three input parameters of "hole area", "hole (relative to the floor) elevation" and "radiation partitions on both sides of the wall where the hole is located". This is the specific content of Table 1 in "Theoretical Evaluation of the Scattering Effects of Holes in γ-Radioactive Buildings of Nuclear Power Plants Based on the Monte Carlo Method".

[0068] As one embodiment of the present invention, the types of holes include open holes, hollow pipe holes and filled pipe holes, wherein the hollow pipe holes include a first pore partition and a hollow pipe partition, and the filled pipe holes include a second pore partition and a filled pipe partition.

[0069] It should be noted that during the pouring of the biowall, holes (generally with a circular or square cross-section) will be reserved for the penetration and installation of various items (also referred to as penetrations in this article), including cable trays, electrical instruments and process pipelines. According to the type and function of the penetration items, penetrations are divided into gas pipelines, and holes for liquid pipelines with extremely low flow frequency and extremely short time (for example, once a year, only one hour at a time) are called "hollow pipeline holes", and holes for penetrations for irregularly flowing liquid pipelines and other penetrations are called "filled pipeline holes". There are also some holes that do not penetrate any items, but simply connect the air space of two compartments for ventilation between compartments. Such holes without any penetration items can be defined as "open holes". Among them, open holes are used to connect the air space of the corresponding adjacent compartments. It is generally believed that they are filled with air, and the holes need to remain free of penetration items, that is, remain unblocked.

[0070] See also Figure 2 The hollow pipe holes include a first pore partition and a hollow pipe partition, and the filled pipe holes include a second pore partition and a filled pipe partition. Figure 2 A is a schematic diagram of an open hole. Figure 2 B is a schematic diagram of the holes in the hollow pipe, in which the middle is the hollow pipe. Figure 2 The C in the figure is a schematic diagram of a filled pipe hole, with the filled pipe in the middle. The hole is represented by a rectangle. Figure 2 The area between the rectangle and the hollow pipe in B represents the first pore partition, Figure 2 The area between the rectangle and the filled pipe in C represents the second pore partition.

[0071] According to the above division method, the open holes, the first pore partition, the hollow pipe partition, the second pore partition, and the filled pipe partition are obtained respectively, and the initial scattered dose rates of the first pore partition, the hollow pipe partition, the second pore partition, and the filled pipe partition are obtained according to the calculation method of the scattered dose rate of the open holes. That is, the first pore partition, the hollow pipe partition, the second pore partition, and the filled pipe partition are equivalently calculated as open holes, and the scattered dose rate of the open holes can be obtained by referring to Table 1 in "Theoretical Evaluation of Scattering Impact of Holes in γ-Radioactive Buildings of Nuclear Power Plants Based on Monte Carlo Method".

[0072] As one embodiment of the present invention, the hole pipe arrangement includes: screening the types of all holes on the partition wall and the number of holes of each type, and adjusting the shielding settings of the holes;

[0073] Based on the shielding setting of the holes, the sum of the scattered dose rates of all holes is calculated, and the radiation dose rate of the compartment is obtained by adding the penetration dose rate of the adjacent compartment and the equipment dose rate of the equipment in the compartment, so that the radiation dose rate is not greater than the preset radiation dose rate value;

[0074] Among them, the preset value of the radiation dose rate is obtained from the radiation partition where the compartment is located.

[0075] As one embodiment of the present invention, as one embodiment of the present invention, the hole also includes a hollow pipe hole, the hollow pipe hole includes a first pore partition and a hollow pipe partition; the shielding setting of the hollow pipe hole includes unblocked and blocked;

[0076] When the holes in the hollow pipe are not blocked, the scattered dose rate is the sum of the initial scattered dose rates of the first pore partition and the hollow pipe partition;

[0077] When the holes in the hollow pipe are plugged, the scattered dose rate is the sum of the scattered dose rate of the first pore partition and the initial scattered dose rate of the hollow pipe partition;

[0078] The scattered dose rate of the first pore partition is calculated from its initial scattered dose rate.

[0079] It should be noted that since the density of penetrations in hollow pipe holes is extremely low, the scattered dose rate, i.e. the initial scattered dose rate, of hollow pipe holes that have not been shielded can be directly calculated as the scattered dose rate of the corresponding open holes, as shown in Table 1 of “Theoretical Evaluation of Scattering Impacts of Holes in Gamma-Radioactive Buildings of Nuclear Power Plants Based on the Monte Carlo Method”.

[0080] Furthermore, the area of ​​the hollow pipe hole is regarded as the "hole area" of the open hole, and the elevation of the hollow pipe hole relative to the floor is regarded as the "elevation of the hole relative to the floor" of the open hole. Combined with Table 2 in "Theoretical Evaluation of Scattering Effects of Holes in Gamma-Radioactive Buildings of Nuclear Power Plants Based on Monte Carlo Method", the specific value of the initial scattering dose rate of the hollow pipe hole can be obtained.

[0081] It should be noted that the scattered dose rate of the blocked hollow pipe holes is the sum of the scattered dose rate of the first pore partition and the initial scattered dose rate of the hollow pipe partition.

[0082] The area of ​​the hollow pipe partition is regarded as the "hole area" of the open hole, and the elevation of its penetration relative to the floor is regarded as the "elevation of the hole relative to the floor" of the open hole. Combined with Table 1 in "Theoretical Evaluation of Scattering Effects of Holes in Gamma-Radioactive Buildings of Nuclear Power Plants Based on Monte Carlo Method", the specific value of the initial scattering dose rate of the hollow pipe partition can be obtained.

[0083] The calculation method of the initial scattered dose rate of the first pore partition when it is not blocked is the same as above.

[0084] Table 2 is a table showing the relationship between the scattered dose rate and the attenuation multiple of the initial scattered dose rate when the open holes are filled with fillers of different densities.

[0085] Calculation of scattered dose rate of the first pore partition after plugging: According to Table 2, the filler density of the first pore partition is ρ f For example, when ρ i <ρ f <ρ i+1 , ρ f Take the smaller value of the adjacent packing density, that is, ρ i , then the scattered dose rate of the first pore partition is the initial scattered dose rate of the first pore partition and ρ i The ratio of the corresponding attenuation multiples.

[0086] Table 2

[0087]

[0088]

[0089] As one embodiment of the present invention, the hole also includes a filled pipe hole, and the filled pipe hole includes a second pore partition and a filled pipe partition; the shielding setting of the filled pipe hole includes unblocked and blocked;

[0090] When the filled pipe is not blocked, its scattered dose rate is the sum of the scattered dose rate of the filled pipe partition and the initial scattered dose rate of the second pore partition;

[0091] When the pipeline is filled and plugged, its scattered dose rate is the sum of the scattered dose rate of the filled pipeline partition and the scattered dose rate of the second pore partition;

[0092] The scattered dose rate of the filled pipe partition is calculated from its initial scattered dose rate, and the scattered dose rate of the second pore partition is calculated from its initial scattered dose rate.

[0093] It should be noted that the scattered dose rate of the unsealed filled pipe holes is the sum of the scattered dose rate of the filled pipe partition and the initial scattered dose rate of the second pore partition.

[0094] The second pore partition is equivalent to an open hole. According to Table 1 in "Theoretical Evaluation of Scattering Impact of Holes in γ-Radioactive Buildings of Nuclear Power Plants Based on Monte Carlo Method", the initial scattering dose rate of the second pore partition and the initial scattering dose rate of the filled pipe partition are obtained.

[0095] Specifically, the initial scattered dose rate of the second pore partition only needs to regard the area of ​​the second pore partition as the "hole area" of the open hole, and regard the elevation of the second hole relative to the floor as the "elevation of the hole relative to the floor" of the open hole.

[0096] The initial scattered dose rate of the filled pipe partition can be obtained by simply considering the area of ​​the filled pipe partition as the "hole area" of the open hole, and the elevation of the filled pipe partition relative to the floor as the "hole elevation of the open hole relative to the floor". The specific value can be obtained by combining Table 1 of "Theoretical Evaluation of Hole Scattering Effects of γ-Radioactive Plants in Nuclear Power Plants Based on Monte Carlo Method".

[0097] Scattered dose rate of filled pipe partitions: Filled pipe partitions can be considered as open holes filled with a certain filler (penetrations). Therefore, the average density of penetrations can be regarded as the filler density and is ρ i The calculation method is the same as the calculation method of the scattered dose rate of the first pore partition after plugging. At this time, the scattered dose rate of the filled pipeline hole is the sum of the scattered dose rate of the filled pipeline partition and the initial scattered dose rate of the second pore partition.

[0098] The calculation method of the scattered dose rate of the second pore partition after plugging is the same as the calculation method of the scattered dose rate of the first pore partition after plugging mentioned above.

[0099] It should be noted that the scattered dose rate of the filled pipeline hole after plugging is the scattered dose of the second pore partition. Rate and fill The sum of the scattered dose rates in the solid pipeline partitions.

[0100] As one embodiment of the present invention, when a shielding baffle is provided on the corresponding compartment wall around the open hole or the hollow pipe hole or the filled pipe hole, the hole is a completely shielded hole, and the scattered dose rate of the hole is 0.

[0101] See also Figure 3 As one embodiment of the present invention, the present invention also includes a nuclear power compartment radiation shielding control system, including:

[0102] The data acquisition module obtains the types of all holes on the partition wall and calculates the scattered dose rates of other types of holes based on the scattered dose rates of the open holes;

[0103] The dynamic adjustment module adjusts the hole pipe arrangement based on the scattered dose rate of the holes so that the sum of the scattered dose rates of all holes on the compartment wall meets the radiation dose rate control requirements of the compartment.

[0104] As one embodiment of the present invention, the present invention also includes a nuclear power compartment radiation shielding design method, comprising the following steps:

[0105] According to the radiation zoning of the compartment, the radiation dose rate control requirements of the compartment are obtained, and the initial value of the wall thickness of the compartment is determined;

[0106] Based on the initial value of wall thickness, the initial value of penetration dose rate in adjacent compartments is obtained;

[0107] And obtain the initial values ​​of the scattered dose rate of all holes on the partition wall and the equipment dose rate of the partition equipment to determine whether it meets the radiation dose rate control requirements of the partition;

[0108] If it does not meet the requirements, use one or both of the following two adjustment methods to repeat the adjustment until the radiation dose rate control requirements are met:

[0109] Method 1: Shield the holes in the partition wall according to their types to reduce the scattered dose rate of the holes;

[0110] Method 2: Adjust the thickness of the compartment wall to reduce the penetration dose rate of adjacent compartments.

[0111] As one embodiment of the present invention, the dose rate control requirements include: the sum of the scattered dose rate, the penetration dose rate, and the equipment radiation dose rate of all holes in the compartment wall is not greater than the radiation dose rate preset value of the compartment, and the radiation dose rate preset value is obtained by the radiation partition where the compartment is located.

[0112] As one embodiment of the present invention, plugging the hole includes the following steps:

[0113] See also Figure 4 , the first pore partition of the hollow pipe hole is blocked to obtain the scattered dose rate of the hole, and based on the radiation partition of the compartment, combined with the initial value of the penetration dose rate and the radiation dose rate, it is determined whether it meets the dose rate control requirements of the compartment;

[0114] See also Figure 5, plug the second pore partition that fills the pipeline hole, obtain the scattered dose rate of the hole, and determine whether it meets the dose rate control requirements of the compartment based on the radiation partition of the compartment, combined with the initial value of the penetration dose rate and the radiation dose rate;

[0115] See also Figure 6 , shielding plates are installed on the corresponding walls around the open holes, hollow pipe holes and filled pipe holes. The shape of the shielding plates is set according to needs. Generally, they are bent plates and completely cover the hole openings, so that the scattered dose rates of the open holes, hollow pipe holes and filled pipe holes are all 0. Based on the radiation zoning of the compartment, combined with the initial value of the penetration dose rate and the radiation dose rate, it is determined whether the dose rate control requirements of the compartment are met;

[0116] It should be noted that the holes in the hollow pipes can be blocked to obtain the scattered dose rate of all the holes after blocking to determine whether they meet the dose rate control requirements; when they do not meet the requirements, the holes in the filled pipes can be blocked to obtain the scattered dose rate of all the holes after further blocking to determine whether they meet the dose rate control requirements; when they do not meet the requirements, shielding plates are installed on the corresponding walls around the open holes, the holes in the hollow pipes, and the holes in the filled pipes. At this time, the scattered dose rate of the holes after the shielding plates are installed is 0, and then it is determined whether it meets the dose rate control requirements. The recommended range of hole shielding and plugging can also be obtained according to NB / T20596-2021, specifically according to Figure A.1 of the biological shielding and plugging judgment flow chart, after the holes are blocked, the scattered dose rate of the blocked holes is obtained according to the quantitative method of the present invention, and then it is determined whether it meets the dose rate control requirements.

[0117] As one embodiment of the present invention, increasing the wall thickness of the partition includes the following:

[0118] Obtain the penetrating radiation dose rates corresponding to the six walls of the compartment;

[0119] According to the magnitude of the penetrating radiation dose rate, the corresponding wall thickness is adjusted in sequence to reduce the corresponding penetrating radiation dose rate, and the penetrating radiation dose rate under the corresponding wall thickness is obtained;

[0120] The sum of the penetrating radiation dose rates corresponding to the six walls, as well as the equipment radiation dose rate and scattered dose rate are obtained. Based on the radiation partitioning of the compartments, it is determined in turn whether they meet the dose rate control requirements.

[0121] As one embodiment of the present invention, see Figure 7 The nuclear power compartment radiation shielding design method of the present invention may specifically include the following steps:

[0122] (1) Plant compartment division and main equipment layout. Based on the plant scale, process flow and system equipment size, the compartments are divided and the main equipment is arranged;

[0123] (2) Calculation of the dose rate contribution of the equipment in the compartment. Based on the equipment layout in the compartment and the input of the equipment radiation source, the shielding calculation tool is used to calculate the equipment dose rate of the equipment in the compartment;

[0124] (3) Establish radiation zoning for the compartment and obtain the dose rate acceptance requirements. Based on the radiation dose rate of the equipment in the compartment, the entry and exit requirements of the compartment and the dose control requirements for the staff, combined with the zoning guidelines of "NB / T 20185 Design Guidelines for Radiation Zoning in Pressurized Water Reactor Nuclear Power Plants", a relatively conservative radiation zoning is established for the compartment, and the radiation acceptance dose rate corresponding to the zoning is obtained, that is, the radiation dose rate control requirements for the compartment;

[0125] (4) Determine the initial wall thickness. Determine the wall thickness of the compartment based on the radiation zoning;

[0126] (5) Hole and pipe layout design of partition walls. Generate information such as "hole type", "hole size" and "hole elevation relative to the floor";

[0127] (6) For the evaluation of the scattered dose rate of holes without any shielding measures, the detailed method is as mentioned above; then, taking the compartment as the unit, all the holes in the compartment are screened out, and the sum of the scattered dose rates of all the holes in the compartment is calculated as the scattered dose rate of the unblocked holes;

[0128] (7) Calculation of radiation dose rate of adjacent compartments. Based on the radiation source information of adjacent compartments, use the shielding calculation tool to calculate the dose rate of the adjacent compartment to the compartment at the corresponding wall thickness;

[0129] (8) Determine whether the radiation dose rate control requirements of the compartment are met; that is, whether formula (Formula 1) is satisfied.

[0130] (9) If the result of the determination is negative, a shielding and plugging design is carried out around the holes to gradually reduce the scattered dose rate of the holes. Specifically, the holes are first plugged to gradually reduce the scattered dose rate of the holes. The scattered dose rate after plugging has been described. It should be noted that when all the holes that can be plugged still do not satisfy Formula (Formula 1) after plugging, a shielding baffle is set outside the hole. At this time, the scattered dose rate of all holes can be considered to be 0.

[0131] (10) After the hole is sealed, determine again whether equation (Equation 1) is satisfied.

[0132] (11) If the judgment result is no, the wall thickness should be increased in sequence according to the walls of the compartments corresponding to the penetration dose rate from high to low, and the penetration dose rate should be re-evaluated until formula (Formula 1) is satisfied.

[0133] (12)The process ends.

[0134] It should be pointed out that although the above process has achieved a closed-loop design, it adopts a sequential approach of first sealing the holes and then increasing the wall thickness. This approach may have the problem of insufficient optimization of resource allocation.

[0135] Increasing the wall thickness can reduce the penetration dose rate, which means reducing the amount of shielding baffles and hole plugging required around the holes, which is a consideration of economic cost. In addition, there are differences between the "adjusting the thickness of the wall" and "implementing hole plugging measures" solutions in terms of implementation difficulty and construction progress. At the same time, on the premise of meeting the personnel protection requirements of national regulations and standards, the radiation dose control requirements of the compartments are improved, thereby increasing the "wall thickness" and "hole shielding measures margin" at the same time. This is a consideration of the dimensions of "radiation safety", "economy", and "construction progress". Therefore, in the specific implementation, a comparison and optimization can be carried out in combination with the above process. The comparison and optimization steps are as follows:

[0136] (1) Select and formulate an optimal solution that is reasonable and feasible;

[0137] (2) Key factors affecting the change process of the plan;

[0138] (3) Develop a comparison matrix and rate the degree of influencing factors of each option (1-5 points);

[0139] (4) The best solution is obtained through final scoring. The scoring table is shown in Table 4.

[0140] Table 4

[0141] Solution 1 Solution 2 Solution 3 …… Radiation safety Economical Feasibility Progress Cycle …… Total score

[0142] As shown in Table 4, scores can be given based on radiation safety, economy, feasibility, etc. The plan with the highest score can be used to identify the specific implementation plan.

[0143] In summary, the present invention solves the problem of quantifying the hole (radiation) scattering dose rate, further solves the problem of controlling the compartment (radiation) dose rate, and specifically achieves the following beneficial technical effects:

[0144] (1) The radiation shielding control method and system of nuclear power compartments of the present invention, the holes include open holes, hollow pipe holes and filled pipe holes, the hollow pipe holes include hollow pipe partitions and first pore partitions, and the filled pipe holes include filled pipe partitions and second pore partitions. Different types of holes are shielded and blocked or shielding baffles are set for complete shielding, and the scattered dose rates of the holes before and after blocking are calculated. The specific calculation method includes taking the scattered dose rate of the open holes as the basis, calculating the average density of the (penetrating parts) of the filled pipe partition as the filler density, respectively calculating the initial scattered dose rates of the hollow pipe holes and filled pipe holes before blocking, and calculating the scattered dose rates of the hollow pipe holes and filled pipe holes after blocking according to the filler density of the first pore partition and the first pore partition. The scattered dose rates before and after the hole blocking are quantified, so as to realize the quantitative analysis and evaluation of the hole blocking effect, and the quantified results are used in the radiation dose rate control of the compartment, so as to accurately control the radiation dose rate of the compartment.

[0145] (2) The nuclear power compartment radiation shielding design method of the present invention obtains the value of the hole scattered dose rate based on the quantitative analysis of the hole scattered dose rate, and brings the value into the determination whether it meets the dose rate control requirements of the compartment; and according to the determination result, the blocking state of different types of holes is adjusted to gradually reduce the hole scattered dose rate, and the hole scattered dose rate is quantified according to the blocking state, and then it is determined whether it meets the radiation dose rate control requirements, until shielding plates are installed on the corresponding walls around all holes, at which time the hole scattered dose rate is zero, and it is determined whether it meets the dose rate control requirements; if it does not meet the control requirements, then according to the wall, the scattered dose rate of the hole is quantified, and then it is determined whether it meets the dose rate control requirements. The corresponding penetration dose rate is obtained by increasing the thickness of the wall in turn. Determine whether it meets Dose rate control requirements of the compartment. Therefore, the control method of the present invention gradually reduces the scattered dose rate of the hole by blocking the hole, and gradually reduces the penetration dose rate by increasing the wall thickness until the radiation dose rate control requirements of the radiation partition where the compartment is located are met. Therefore, the result obtained is more accurate on the basis of quantifying the scattered dose rate of the hole, which not only ensures that the compartment strictly meets its radiation dose rate control requirements, but also saves resources, and the design of pipeline arrangement and wall thickening of the compartment holes meets the radiation dose rate control requirements of the compartment. An optimized solution is obtained between economy and safety.

[0146] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for controlling radiation shielding of a nuclear power compartment, characterized in that: The following steps are involved: Obtain the types of all holes on the partition wall, and calculate the scattered dose rates of other types of holes based on the scattered dose rates of open holes; The hole pipe arrangement is adjusted based on the scattered dose rate of the holes so that the sum of the scattered dose rates of all the holes on the compartment wall meets the radiation dose rate control requirement of the compartment.

2. The method for controlling radiation shielding of nuclear power compartments according to claim 1, characterized in that: The hole pipe arrangement includes: Screening the types of all the holes on the partition wall and the number of holes of each type, and adjusting the shielding settings of the holes; Based on the shielding setting of the holes, the sum of the scattered dose rates of all the holes is calculated, and the radiation dose rate of the compartment is obtained by adding the sum of the penetration dose rate of the adjacent compartment and the equipment dose rate of the equipment in the compartment, so that the radiation dose rate is not greater than the preset radiation dose rate value; Wherein, the preset value of the radiation dose rate is obtained from the radiation partition in which the compartment is located.

3. The method for controlling radiation shielding of nuclear power compartments according to claim 2, characterized in that: The holes also include hollow pipe holes, and the hollow pipe holes include a first pore partition and a hollow pipe partition; the shielding setting conditions of the hollow pipe holes include unblocked and blocked; When the holes in the hollow pipe are not blocked, the scattered dose rate is the sum of the initial scattered dose rate of the first pore partition and the initial scattered dose rate of the hollow pipe partition; When the hole of the hollow pipe is blocked, its scattered dose rate is the sum of the scattered dose rate of the first pore partition and the initial scattered dose rate of the hollow pipe partition; The scattered dose rate of the first pore partition is calculated from its initial scattered dose rate.

4. The method for controlling radiation shielding of nuclear power compartments according to claim 3, characterized in that: The holes also include filled pipe holes, and the filled pipe holes include second pore partitions and filled pipe partitions; the shielding setting conditions of the filled pipe holes include unblocked and blocked; When the filled pipe is not blocked, its scattered dose rate is the sum of the scattered dose rate of the filled pipe partition and the initial scattered dose rate of the second pore partition; When the filled pipe is blocked, its scattered dose rate is the sum of the scattered dose rate of the filled pipe partition and the scattered dose rate of the second pore partition; The scattered dose rate of the filled pipe partition is calculated from its initial scattered dose rate, and the scattered dose rate of the second pore partition is calculated from its initial scattered dose rate.

5. The method for controlling radiation shielding of nuclear power compartments according to claim 4, characterized in that: The initial scattered dose rates of the first pore partition, the hollow pipe partition, the second pore partition and the filled pipe partition are all the scattered dose rates of the open holes when they are equivalently calculated as open holes.

6. The method for controlling radiation shielding of nuclear power compartments according to claim 5, characterized in that: The calculation of the scattered dose rate of the filled pipe partition or the first pore partition or the second pore partition includes: Obtaining the average density of the filled pipe partition or the plugging filler density of the first pore partition or the plugging filler density of the second pore partition; Based on the average density or the filler density, a reduction multiple relationship between the average density or the filler density and the initial dose rate is obtained; The scattered dose rate of the filled pipe partition or the first pore partition or the second pore partition is calculated in combination with the initial scattered dose rate.

7. The method for controlling radiation shielding of nuclear power compartments according to claim 6, characterized in that: When the open hole, the hollow pipe hole or the filled pipe hole is a fully shielded hole, the scattered dose rate is 0.

8. A nuclear power compartment radiation shielding control system, characterized in that: include: The data acquisition module obtains the types of all holes on the partition wall and calculates the scattered dose rates of other types of holes based on the scattered dose rates of the open holes; The dynamic adjustment module adjusts the hole pipe arrangement based on the scattered dose rate of the holes so that the sum of the scattered dose rates of all the holes on the compartment wall meets the radiation dose rate control requirement of the compartment.

9. A method for designing radiation shielding of a nuclear power compartment, characterized in that: The following steps are involved: Obtaining the radiation dose rate control requirement of the compartment according to the radiation zoning of the compartment, and formulating the initial value of the wall thickness of the compartment; Obtaining an initial value of the penetration dose rate of the adjacent compartment based on the initial value of the wall thickness; Obtaining the initial values ​​of the scattered dose rates of all holes on the compartment wall and the equipment dose rates of the equipment in the compartment to determine whether they meet the radiation dose rate control requirements of the compartment; If not, use one or both of the following two adjustment methods to repeat the adjustment until the radiation dose rate control requirements are met: Method 1: shielding the holes in the partition wall according to their types to reduce the scattered dose rate of the holes; Method 2: adjusting the thickness of the compartment wall to reduce the penetration dose rate of adjacent compartments.

10. The method for designing radiation shielding of nuclear power compartments according to claim 9, characterized in that: The dose rate control requirements include: the sum of the scattered dose rate, the penetration dose rate, and the equipment radiation dose rate of all the holes in the compartment wall is not greater than a preset radiation dose rate value of the compartment, and the preset radiation dose rate value is obtained by the radiation partition in which the compartment is located.

11. The method for designing radiation shielding of nuclear power compartments according to claim 10, characterized in that: The holes are shielded by type and include: The hollow pipe holes and the filled pipe holes are blocked in sequence, and the scattered dose rate of the blocked hollow pipe holes and the scattered dose rate of the filled pipe holes are obtained respectively; combined with the scattered dose rate of other types of holes, the initial value of the penetration dose rate, and the equipment dose rate, it is determined in sequence whether the radiation dose rate control requirements of the compartment are met; When it is determined that the requirements are not met, shielding baffles are installed on the corresponding walls around the open holes, the hollow pipe holes and the filled pipe holes, so that the scattered dose rate of all the holes is 0, and it is determined whether the dose rate control requirements are met.

12. The method for designing radiation shielding of nuclear power compartments according to claim 11, characterized in that: Adjusting the thickness of the partition wall includes: Obtaining the penetration dose rates corresponding to the six walls of the compartment respectively; According to the magnitude of the penetration dose rate, the corresponding wall thicknesses are adjusted in sequence to reduce the penetration dose rate; The sum of the penetration dose rates of the six walls, the equipment dose rate and the scattered dose rate are obtained, and based on the radiation partitioning of the compartment, it is determined in turn whether the radiation dose rate control requirement of the compartment is met.

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