Method and device for determining alarm threshold value of dose rate in fresh air chamber, and method and system for determining alarm threshold value of monitoring instrument

Abstract

The present application discloses a method and device for determining the alarm threshold of the dose rate in a fresh air room, and a method and system for determining the alarm threshold of a monitoring instrument, which relate to the technical field of the nuclear industry. The method for determining the alarm threshold of the dose rate in a fresh air room comprises: obtaining the average activity concentration of the radioactive nuclide i in the main control room during the initial release period T3 of the first accident, and determining the first external exposure dose rate limit D allowed in the main control room based on the average activity concentration. ex,l ; According to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l According to the embodiment of the present application, the method can reasonably determine the first alarm threshold value D of the dose rate in the fresh air room. vent,l , is the first alarm threshold D of the subsequent fresh air indoor dose rate vent,l , which provides the possibility to reasonably determine the alarm threshold of the monitoring instrument.

Description

Technical Field

[0001] The present application belongs to the field of nuclear industry technology, and specifically relates to a method and device for determining an alarm threshold value of a dose rate in a fresh air chamber, and a method and system for determining an alarm threshold value of a monitoring instrument. Background Art

[0002] The main control room (MCR) is the control center for nuclear power plant operations. Its primary function is to ensure the safe operation of the reactor under normal conditions and to achieve safe shutdown under abnormal and accident conditions. In the event of an accident, if the plant is contaminated with radioactivity, an emergency ventilation system with filtering capabilities is required to ventilate and purify the MCR to ensure its functionality and maintain its habitability.

[0003] The main control room is equipped with a normal ventilation system and an emergency ventilation system, and radiation monitoring instruments are installed at the air intakes of the ventilation systems. The dose monitoring instrument installed at the normal air intake of the main control room is used to monitor in real time the air absorption dose rate level in the ventilation chamber caused by the radioactive nuclides in the fresh air introduced into the main control room. If the dose rate level at this location does not exceed the alarm threshold, the fresh air enters the air duct and then enters the main control room. If the dose rate level at this location exceeds the alarm threshold, it means that the staff in the main control room may be exposed to a dose exceeding the standard requirement. The instrument is equipped with two levels of alarms, of which the first level is used for warning, and the second level alarm is linked to the air intake isolation valve to switch the ventilation system, that is, once the second level alarm threshold is exceeded, the ventilation system will automatically switch to the emergency air intake to introduce fresh air.

[0004] The alarm threshold, a key indicator of whether the radiation monitoring system issues an alarm signal, is a core operating parameter of the radiation monitoring system. The alarm threshold affects the ventilation system switching time, which in turn affects the radiation dose to personnel in the main control room. A level 1 alarm does not trigger a switchover. Reaching the level 2 alarm threshold triggers a switchover from the normal ventilation system to the emergency ventilation system. During this period, the main control room maintains normal ventilation. During this period, radioactive material from the outdoor smoke plume enters the main control room through the ventilation system, exposing personnel to radiation. Due to the main control room's proximity to the reactor core, even a short period of normal ventilation can result in high radiation doses. Setting the alarm threshold too low can easily lead to false alarms, while setting it too high can result in excessive radiation exposure to personnel in the main control room. Determining appropriate alarm thresholds for ventilation system monitoring instruments ensures that, in the event of an emergency, the main control room ventilation system switches to the emergency ventilation system as quickly as possible.

[0005] In the prior art, the alarm threshold of the monitoring instrument is usually determined manually based on experience, which is highly subjective and lacks scientific basis support, resulting in unreasonable determination of the alarm threshold of the monitoring instrument. Summary of the Invention

[0006] The technical problem to be solved by the present application is to address the above-mentioned deficiencies in the prior art and to provide a method and device for determining the alarm threshold of the dose rate in a fresh air room, and a method and system for determining the alarm threshold of a monitoring instrument. The method for determining the alarm threshold of the dose rate in a fresh air room can reasonably determine the first alarm threshold of the dose rate in the fresh air room, thereby making it possible to reasonably determine the alarm threshold of the monitoring instrument through the first alarm threshold of the dose rate in the fresh air room.

[0007] In the first aspect, the embodiment of the present application provides a method for determining the alarm threshold of the dose rate in the fresh air room, comprising: obtaining the average activity concentration of the radioactive nuclide i in the main control room during the initial release period T3 of the first accident According to the average activity concentration Determine the first external radiation dose rate limit D allowed in the main control room ex,l ; According to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l .

[0008] In some embodiments of the first aspect, the average activity concentration of radioactive nuclide i in the main control room during the initial release period T3 of the first accident is obtained. The method includes: obtaining the first activity concentration C(t) of the radioactive nuclide in the main control room at the first moment t of the first accident, as well as the second moment T1 and the third moment T2 of the first accident, t and T1 are both less than the end time T of the first accident, and T2 is less than or equal to the end time T; substituting the first activity concentration C(t), the second moment T1 and the third moment T2 into formula (1) for calculation, and obtaining the average activity concentration of the radioactive nuclide i in the main control room during the duration of the first accident. Formula (1) includes:

[0009]

[0010] In some embodiments of the first aspect, obtaining a first activity concentration C(t) of a radioactive nuclide in a main control room at a first time t of a first accident includes: obtaining a second time T1 of the first accident, a second activity concentration C(T1) of the radioactive nuclide in the main control room at the second time T1, the first time t, a first parameter value p, and a second parameter value q; substituting the second time T1, the second activity concentration C(T1), the first time t, the first parameter value p, and the second parameter value q into formula (2) for calculation to obtain a first activity concentration C(t) of the radioactive nuclide i in the main control room during the first time t of the first accident; formula (2) includes:

[0011]

[0012] In some embodiments of the first aspect, obtaining the first parameter value p includes: obtaining the nuclide activity decay rate λ caused by decay i , Normal air volume Q u and the volume V of the ventilation area of ​​the main control room; the nuclide activity decay rate λ i , Normal air volume Q u Substitute the volume V of the ventilation area of ​​the main control room into formula (3) to calculate and obtain the first parameter value p; formula (3) includes:

[0013]

[0014] Alternatively, obtaining the second parameter value q includes: obtaining the normal air volume Q u , atmospheric diffusion factor (χ / Q) at the air intake of the main control room and activity release rate R to the environment during the initial release period T3; the normal air volume Q u , atmospheric diffusion factor (χ / Q) and activity release rate R are substituted into formula (4) to calculate the second parameter value q; formula (4) includes:

[0015] q=Q u *(x / Q)*R (4).

[0016] In some embodiments of the first aspect, obtaining the activity release rate R to the environment during the initial release period of the accident includes: obtaining the activity Q of the released nuclides to the environment during the initial release period T3 of the first accident; substituting the initial release period T3 and the released nuclide activity Q into formula (5) for calculation to obtain the activity release rate R to the environment during the initial release period T3; formula (5) includes:

[0017] R=Q / T3 (5).

[0018] In some embodiments of the first aspect, according to the average activity concentration Determine the first external radiation dose rate limit D allowed in the main control room ex,l , including: based on the average activity concentration Determine the first effective dose D l , the first effective dose D l is the maximum allowable effective dose per unit time; according to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l .

[0019] In some embodiments of the first aspect, according to the average activity concentration Determine the first effective dose D l , including: based on the average activity concentration Determine the exposure dose of personnel in the main control room under normal ventilation conditions. The exposure dose includes the total effective dose D, which includes the external radiation dose D. ex and internal radiation dose D in ; According to the total effective dose D and the effective dose limit D L , determine the first effective dose D l .

[0020] In some embodiments of the first aspect, according to the total effective dose D and the effective dose limit D L , determine the first effective dose D l , including: in D ≥ D L In the case of L and the duration of the first accident T T Substitute into formula (6) to calculate and obtain the first effective dose D l ; Formula (6) includes:

[0021]

[0022] In some embodiments of the first aspect, according to the average activity concentration Determine the exposure dose of personnel in the main control room under normal ventilation conditions, including: obtaining the first shielding factor GF in the first free volume of the main control room, the air immersion external radiation dose conversion factor DCF i,air , the duration of the first accident T T , inhalation internal radiation dose conversion factor DCF i,in and breathing rate BR; the first shielding factor GF, air immersion external radiation dose conversion factor DCF i,air , average activity concentration and duration T T , substitute into formula (7) to calculate and obtain the external radiation dose D ex ; Formula (7) includes:

[0023]

[0024] Where I represents the number of radionuclides;

[0025] Inhalation internal radiation dose conversion factor DCF i,in , average activity concentration Duration T T and respiratory rate BR, and substitute them into formula (8) to calculate the internal radiation dose D in ; Formula (8) includes:

[0026]

[0027] The external radiation dose Dex and internal radiation dose D in Substitute into formula (9) to calculate and obtain the total effective dose D; formula (9) includes:

[0028] D=D ex +D in (9).

[0029] In some embodiments of the first aspect, obtaining a first shielding coefficient GF in a first free volume of the main control chamber includes: obtaining the first free volume V of the main control chamber r ; The first free volume V r Substituting into formula (10) for calculation, the first shielding coefficient GF in the first free volume of the main control room is obtained; formula (10) includes:

[0030]

[0031] In some embodiments of the first aspect, the first external radiation dose rate limit D ex,l Including the first lower limit value D ex,D and the first upper limit value D ex,TH According to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l , comprising: administering a first effective dose D l Substitute the first ratio into formula (11) to calculate and obtain the first lower limit value D ex,D , the first ratio K is the external radiation dose D ex The ratio of the total effective dose D is:

[0032] D ex,D =D l ×K (11).

[0033] In some embodiments of the first aspect, according to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l , including: obtaining the first shielding coefficient GF in the first free volume of the main control room and the second shielding coefficient GF in the second free volume of the fresh air room vent ; The first shielding coefficient GF, the second shielding coefficient GF vent , and the first external radiation dose rate limit D ex,l Substituting into formula (12), we can get the first alarm threshold value D of the fresh air indoor dose rate: vent,l ; Formula (12) includes:

[0034]

[0035] In some embodiments of the first aspect, the second shielding coefficient GF in the second free volume of the fresh air chamber is obtained. vent , including: obtaining the second free volume V of the fresh air chamber vent ; The second free volume V vent Substitute into formula (13) to calculate and obtain the second shielding coefficient GF in the second free volume of the fresh air chamber: vent ; Formula (13) includes:

[0036] GF vent =352 / V vent 0.338 (13).

[0037] Based on the same inventive concept, in a second aspect, the embodiment of the present application further provides a method for determining an alarm threshold value of a monitoring instrument, comprising: determining a first alarm threshold value D of the dose rate in the fresh air room corresponding to a plurality of first accidents according to the method for determining an alarm threshold value of the dose rate in the fresh air room of any one of the first aspects; vent,l ; According to all first alarm thresholds D vent,l , determine the target allowable dose rate limit R L ; According to the target allowable dose rate limit R L , determine the second alarm threshold L of the monitoring instrument d .

[0038] In some embodiments of the second aspect, according to all first alarm thresholds D vent,l , determine the target allowable dose rate limit R L , including: obtaining the maximum radiation dose rate D0 allowed by the environmental background measurement; the first alarm threshold D with the minimum value vent,l When the radiation dose rate is greater than twice the high radiation dose rate D0, the first alarm threshold D with the smallest value is set to vent,l Determined as the target allowable dose rate limit R L ; The first alarm threshold D with the minimum value vent,l When the dose rate is less than or equal to twice the high radiation dose rate D0, the dose rate D0 is determined as the target allowable dose rate limit R L .

[0039] In some embodiments of the second aspect, the second alarm threshold L d Including the first level alarm threshold L d1 and the secondary alarm threshold L d2 ; According to the target allowable dose rate limit R L , determine the second alarm threshold L of the monitoring instrument d , including: setting the target allowable dose rate limit R L Determined as the first level alarm threshold L d1; Twice the target allowable dose rate limit R L Determined as the second level alarm threshold L d2 .

[0040] Based on the same inventive concept, in a third aspect, an embodiment of the present application provides a device for determining an alarm threshold value of a dose rate in a fresh air room, comprising: a first acquisition module for obtaining the average activity concentration of radioactive nuclides i in the main control room during the initial release period T3 of the first accident; The first determination module is connected to the first acquisition module and is used to determine the average activity concentration Determine the first external radiation dose rate limit D allowed in the main control room ex,l A second determination module, connected to the first determination module, for determining the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l .

[0041] In some embodiments of the third aspect, the first acquisition module is specifically used to: obtain a first activity concentration C(t) of the radioactive nuclide in the main control room at the first moment t of the first accident, as well as a second moment T1 and a third moment T2 of the first accident, t and T1 are both less than the end time T of the first accident, and T2 is less than or equal to the end time T; substitute the first activity concentration C(t), the second moment T1, and the third moment T2 into formula (1) for calculation to obtain the average activity concentration of the radioactive nuclide i in the main control room during the duration of the first accident Formula (1) includes:

[0042]

[0043] In some embodiments of the third aspect, the first determining module is specifically configured to: Determine the first effective dose D l , the first effective dose D l is the maximum allowable effective dose per unit time; according to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l .

[0044] In some embodiments of the third aspect, the second determining module may be specifically configured to obtain a first shielding coefficient GF within the first free volume of the main control room and a second shielding coefficient GF within the second free volume of the fresh air room. vent ; The first shielding coefficient GF, the second shielding coefficient GF vent , and the first external radiation dose rate limit D ex,l Substituting into formula (12), we can get the first alarm threshold value D of the fresh air indoor dose rate: vent,l ; Formula (12) includes:

[0045]

[0046] Based on the same inventive concept, in a fourth aspect, an embodiment of the present application provides an alarm threshold determination system for a monitoring instrument, comprising: an alarm threshold determination device for a dose rate in a fresh air room as in any one of the third aspects; and an alarm threshold determination device for a monitoring instrument; wherein the alarm threshold determination device for a dose rate in a fresh air room is used to determine a first alarm threshold value D of a dose rate in a fresh air room corresponding to a plurality of first accidents. vent,l ;

[0047] The alarm threshold determination device of the monitoring instrument includes: a third determination module connected to the alarm threshold determination device of the fresh air indoor dose rate, for determining the alarm threshold according to all the first alarm thresholds D vent,l , determine the target allowable dose rate limit R L The fourth determination module is connected to the third determination module for determining the dose rate limit R according to the target L , determine the second alarm threshold L of the monitoring instrument d .

[0048] In some embodiments of the fourth aspect, the third determination module is specifically configured to: obtain the maximum radiation dose rate D0 allowed by the environmental background measurement; and at the first alarm threshold D with the minimum value; vent,l When the radiation dose rate is greater than twice the high radiation dose rate D0, the first alarm threshold D with the smallest value is set to vent,l Determined as the target allowable dose rate limit R L ; The first alarm threshold D with the minimum value vent,l When the dose rate is less than or equal to twice the high radiation dose rate D0, the dose rate D0 is determined as the target allowable dose rate limit R L .

[0049] In some embodiments of the fourth aspect, the second alarm threshold L d Including the first level alarm threshold L d1 and the secondary alarm threshold L d2 The fourth determination module is specifically used to: set the target allowable dose rate limit R L Determined as the first level alarm threshold L d1 ; Twice the target allowable dose rate limit R L Determined as the second level alarm threshold L d2 .

[0050] According to the method and device for determining the alarm threshold of the fresh air indoor dose rate and the method and system for determining the alarm threshold of the monitoring instrument provided in the embodiments of the present application, by obtaining the average activity concentration Determine the first external radiation dose rate limit D allowed in the main control roomex,l , and then according to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l Since the monitoring instrument monitors the real-time dose rate of external radiation dose, the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l , taking into account the first alarm threshold D of the external radiation and fresh air indoor dose rate vent,l Therefore, the first alarm threshold D of the fresh air indoor dose rate can be reasonably determined. vent,l , is the first alarm threshold D of the subsequent fresh air indoor dose rate vent,l , which provides the possibility to reasonably determine the alarm threshold of the monitoring instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A flow chart showing a method for determining an alarm threshold value of a dose rate in a fresh air room provided by an embodiment of the present application is shown;

[0052] Figure 2 A schematic diagram illustrating a flow chart of a method for determining an alarm threshold value of a monitoring instrument provided in an embodiment of the present application;

[0053] Figure 3 Another flowchart of a method for determining an alarm threshold value of a monitoring instrument provided in an embodiment of the present application is shown;

[0054] Figure 4 A schematic diagram illustrating a structure of a device for determining an alarm threshold value of a dose rate in a fresh air room provided by an embodiment of the present application;

[0055] Figure 5 A structural diagram of a system for determining an alarm threshold value of a monitoring instrument provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0057] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present application and are not configured to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0058] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article, or device comprising the elements.

[0059] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0060] In order to better understand the method and device for determining the alarm threshold value of the fresh air indoor dose rate and the method and system for determining the alarm threshold value of the monitoring instrument provided in the embodiments of the present application, the existing technologies that may be involved in the embodiments of the present application are first explained.

[0061] The alarm threshold primarily considers whether the total dose received by personnel meets the control value (including internal and external exposure). Regarding the dose standard for control room personnel in the event of an accident, my country's nuclear safety guideline "Emergency Preparedness and Response for Nuclear Power Plant Operating Organizations" (HAD 002 / 01-2019) requires that key emergency facilities, such as the main control room, meet the habitability criteria: during the designated continuous emergency response period (generally 30 days), the effective dose received by personnel must not exceed 50 mSv, and the thyroid equivalent dose must not exceed 500 mSv. The "Design Guidelines for On-Site Emergency Facilities in Nuclear Power Plants" also requires consideration of the frequency of operator rotations. The time fraction of personnel in the habitable area is set as follows: 100% within 24 hours after the accident, 60% for 1 to 4 days, and 40% after 4 days. Under the condition that the personnel dose control value is met, the dose rate at the location of the radiation monitoring instruments is calculated based on the design of the main control room ventilation system, the installation location of the monitoring instruments, and the composition of the accident source term, thereby determining the switching threshold for the air intake.

[0062] Extensive research by the inventors revealed that, because the walls and roof of the main control room are sufficiently thick to attenuate gamma radiation from outside, the external exposure from the smoke plume and ground deposition outside the control room contributes minimally. The effective dose to the control room personnel primarily comes from external exposure from the smoke plume entering the control room and internal exposure from inhalation. The monitoring instrument measures the real-time dose rate of external gamma ray exposure. Therefore, the relationship between external exposure and effective dose needs to be considered when determining the alarm threshold for the monitoring instrument.

[0063] The following describes a method and device for determining an alarm threshold value of a dose rate in a fresh air room, and a method and system for determining an alarm threshold value of a monitoring instrument, provided in an embodiment of the present application.

[0064] Example 1

[0065] Figure 1 A flow chart of a method for determining an alarm threshold value of a fresh air indoor dose rate provided in an embodiment of the present application is shown.

[0066] The method for determining the alarm threshold value of the dose rate in the fresh air room provided in the embodiment of the present application can be performed by an apparatus for determining the alarm threshold value of the dose rate in the fresh air room and an electronic device. The following description will be made using the method for determining the alarm threshold value of the dose rate in the fresh air room performed by an electronic device as an example.

[0067] It should be noted that the fresh air chamber is a facility used to control and regulate the air quality inside a nuclear power plant.

[0068] like Figure 1 As shown, the method for determining the alarm threshold value of the dose rate in the fresh air room provided in the embodiment of the present application may include steps S110 to S130.

[0069] S110: Obtain the average activity concentration of radioactive nuclide i in the main control room during the initial release period T3 of the first accident.

[0070] S120, based on the average activity concentration Determine the first external radiation dose rate limit D allowed in the main control room ex,l .

[0071] S130, according to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l .

[0072] According to the method for determining the alarm threshold of the fresh air indoor dose rate provided in the embodiment of the present application, the average activity concentration is obtained. Determine the first external radiation dose rate limit D allowed in the main control room ex,l , and then according to the first external radiation dose rate limit D ex,l, determine the first alarm threshold D of the fresh air indoor dose rate vent,l Since the monitoring instrument monitors the real-time dose rate of external radiation dose, the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l , taking into account the first alarm threshold D of the external radiation and fresh air indoor dose rate vent,l Therefore, the first alarm threshold D of the fresh air indoor dose rate can be reasonably determined. vent,l , is the first alarm threshold D of the subsequent fresh air indoor dose rate vent,l , which provides the possibility to reasonably determine the alarm threshold of the monitoring instrument.

[0073] The specific implementation of each of the above steps is introduced below.

[0074] In step S110 , the first accident may be any radioactive accident.

[0075] The activity of a radionuclide can be expressed as the number of nuclear decays that occur per unit time interval.

[0076] The initial release period T3 may be a period between the start time and the end time T of the first accident.

[0077] The main control room may include I types of radionuclides, and radionuclide i can represent any radionuclide among the I types of radionuclides, where i is a positive integer.

[0078] Average activity concentration It can be the average value of the activity concentration of radionuclide i in the main control room during the entire period after the first accident occurs.

[0079] In some embodiments, the electronic device may pre-store the average activity concentration of radioactive nuclide i in the main control room during the initial release period T3 of the first accident. For subsequent direct calls.

[0080] In other embodiments, the electronic device may determine the average activity concentration of radioactive nuclide i in the main control room during the initial release period T3 of the first accident in response to the first input operation of the user. The first input operation can be to input the average activity concentration For example, the first input operation may be to input the average activity concentration in the input box displayed by the electronic device. For another example, the first input operation may be selecting an average activity concentration from a plurality of preset average activity concentration options displayed on the electronic device. operation.

[0081] In some other embodiments, the average activity concentration of radioactive nuclide i in the main control room during the initial release period T3 of the first accident is obtained. This may include:

[0082] Obtain the first activity concentration C(t) of the radioactive nuclides in the main control room at the first time t of the first accident, as well as the second time T1 and the third time T2 of the first accident, where t and T1 are both less than the end time T of the first accident, and T2 is less than or equal to the end time T;

[0083] Substitute the first activity concentration C(t), the second time T1 and the third time T2 into formula (1) to calculate the average activity concentration of radionuclide i in the main control room during the first accident period.

[0084] Formula (1) includes:

[0085]

[0086] The first activity concentration C(t) may be the activity of the radioactive nuclides in the main control room at the first moment t of the first accident.

[0087] The first time t may be any time within the initial release period T3.

[0088] The second time T1 may be any time other than the first time t within the initial release period T3. For example, the second time T1 may be the start time of the first accident.

[0089] The third time T2 may be any time other than the first time t and the second time T1 within the initial release period T3 and later than the second time T1. For example, the third time T2 may be the end time T of the first accident.

[0090] In some examples, the electronic device pre-stores the first activity concentration C(t) of the radioactive nuclides in the main control room at the first moment t of the first accident, as well as the second moment T1 of the first accident and the third moment T2 of the first accident for subsequent direct retrieval.

[0091] In other examples, the electronic device may determine the first activity concentration C(t) of the radioactive nuclides in the main control room at the first moment t of the first accident, as well as the second moment T1 and the third moment T2 of the first accident in response to a second input operation by the user. The second input operation may be an operation of inputting the first activity concentration C(t), as well as the second moment T1 and the third moment T2 of the first accident. For example, the second input operation may be an operation of inputting the first activity concentration C(t), as well as the second moment T1 and the third moment T2 of the first accident in an input box displayed by the electronic device. For another example, the second input operation may be an operation of selecting the first activity concentration C(t), as well as the second moment T1 and the third moment T2 of the first accident from a plurality of preset activity concentration options displayed by the electronic device.

[0092] In some other examples, obtaining a first activity concentration C(t) of radionuclides in a main control room at a first time t of a first accident may include:

[0093] Obtaining a second time T1 of the first accident, a second activity concentration C(T1) of the radioactive nuclide in the main control room at the second time T1, a first time t, a first parameter value p, and a second parameter value q;

[0094] Substitute the second time T1, the second activity concentration C(T1), the first time t, the first parameter value p, and the second parameter value q into formula (2) to calculate the first activity concentration C(t) of the radioactive nuclide i in the main control room during the first time t of the first accident;

[0095] Formula (2) includes:

[0096]

[0097] The second activity concentration C(T1) may be the activity concentration of the radioactive nuclides in the main control room at the second time T1.

[0098] The first parameter value p can be the nuclide activity decay rate λ i The sum of the reduction rate of radionuclides caused by exhaust from the control room to the environment. Among them, the reduction rate of radionuclides caused by exhaust from the control room to the environment can be the normal air volume Q u The ratio of the volume V of the ventilation area of ​​the main control room.

[0099] The second parameter value q can be the normal air volume Q u The product of the atmospheric diffusion factor (χ / Q) and the activity release rate R.

[0100] Exemplarily, the second activity concentration C(T1) may be zero.

[0101] In some examples, the second activity concentration C(T1), the first time t, the first parameter value p, and the second parameter value q may be pre-stored in the electronic device for subsequent direct retrieval.

[0102] In some other examples, obtaining the first parameter value p may include:

[0103] Get the nuclide activity decay rate λ caused by decay i , Normal air volume Q u and the volume V of the ventilation area of ​​the main control room;

[0104] The activity decay rate of the nuclide λ i , Normal air volume Q u Substitute the volume V of the ventilation area of ​​the main control room into formula (3) to calculate and obtain the first parameter value p;

[0105] Formula (3) includes:

[0106]

[0107] Nuclide activity decay rate λ i It can be the rate of decay of nuclide activity caused by decay.

[0108] For example, the electronic device may pre-store the nuclide activity decay rate λ caused by decay. i , Normal air volume Q u and the ventilation area volume V of the main control room for subsequent direct call.

[0109] In some other examples, obtaining the second parameter value q includes:

[0110] Get normal air volume Q u , the atmospheric diffusion factor (χ / Q) at the air intake of the main control room and the activity release rate R to the environment during the initial release period T3;

[0111] The normal air volume Q u , atmospheric diffusion factor (χ / Q) and activity release rate R are substituted into formula (4) to calculate the second parameter value q;

[0112] Formula (4) includes:

[0113] q=Q u *(x / Q)*R (4).

[0114] The atmospheric diffusion factor (χ / Q) at the air intake of the main control room may be the atmospheric diffusion factor (χ / Q) at the air intake of the main control room during normal ventilation.

[0115] As an example, the electronic device may pre-store the atmospheric diffusion factor (χ / Q) at the air intake of the main control room and the activity release rate R to the environment during the initial release period T3 for subsequent retrieval.

[0116] As another example, the atmospheric diffusion factor (χ / Q) at the air intake of the main control room can be determined based on hourly meteorological data throughout the year.

[0117] As another example, obtaining the activity release rate R to the environment during the initial release period of the accident includes:

[0118] Obtaining the activity Q of nuclides released into the environment during the initial release period T3 of the first accident;

[0119] Substitute the initial release period T3 and the activity Q of the released nuclides into formula (5) to calculate the activity release rate R to the environment during the initial release period T3;

[0120] Formula (5) includes:

[0121] R=Q / T3 (5).

[0122] For example, the electronic device may pre-store the activity Q of nuclides released into the environment during the initial release period T3 of the first accident for subsequent retrieval.

[0123] In step S120, the electronic device obtains the average activity concentration of radioactive nuclide i in the main control room during the initial release period T3 of the first accident. Afterwards, the average activity concentration Determine the first external radiation dose rate limit D allowed in the main control room ex,l .

[0124] In some embodiments, based on the average activity concentration Determine the first external radiation dose rate limit D allowed in the main control room ex,l , which may include:

[0125] According to the average activity concentration Determine the first effective dose D l , the first effective dose D l The maximum permissible effective dose per unit time;

[0126] According to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l .

[0127] The first external radiation dose rate limit D ex,l Including the first lower limit value D ex,D and the first upper limit value D ex,TH .

[0128] In some examples, based on the average activity concentration Determine the first effective dose D l ,include:

[0129] According to the average activity concentration Determine the exposure dose of personnel in the main control room under normal ventilation conditions. The exposure dose includes the total effective dose D, which includes the external radiation dose D. ex and internal radiation dose D in ;

[0130] According to the total effective dose D and the effective dose limit D L , determine the first effective dose D l .

[0131] For example, the first effective dose D l It can be the maximum allowable effective dose per unit time.

[0132] For example, the external radiation dose D ex It can be the external radiation dose of plume immersion; the internal radiation dose D in It may be an internal radiation dose from inhalation.

[0133] For example, the electronic device pre-stores an effective dose limit D L , so that it can be called directly later.

[0134] In some examples, based on the average activity concentration Determining the radiation dose to personnel in the main control room under normal ventilation conditions may include:

[0135] Obtain the first shielding coefficient GF and air immersion external radiation dose conversion factor DCF in the first free volume of the main control room i,air , the duration of the first accident T T , inhalation internal radiation dose conversion factor DCF i,in and respiratory rate BR;

[0136] The first shielding factor GF, air immersion external radiation dose conversion factor DCF i,air , average activity concentration and duration T T , substitute into formula (7) to calculate and obtain the external radiation dose D ex ;

[0137] Formula (7) includes:

[0138]

[0139] Where I represents the number of radionuclides;

[0140] Inhalation internal radiation dose conversion factor DCF i,in , average activity concentration Duration T T and respiratory rate BR, and substitute them into formula (8) to calculate the internal radiation dose D in ;

[0141] Formula (8) includes:

[0142]

[0143] The external radiation dose D ex and internal radiation dose D in Substitute into formula (9) to calculate and obtain the total effective dose D;

[0144] Formula (9) includes:

[0145] D=D ex +D in (9).

[0146] In some examples, the electronic device may pre-store the first shielding coefficient GF in the first free volume of the main control room, the air immersion external radiation dose conversion factor DCF i,air , the duration of the first accident T T , inhalation internal radiation dose conversion factor DCF i,in And the respiratory rate BR for subsequent direct call.

[0147] In other examples, the duration of the first accident is T T Meet T T =T2-T1. That is, the duration of the first accident T can be determined by the second time T2 and the third time T3. T .

[0148] In some other examples, obtaining a first shielding coefficient GF in a first free volume of the main control room includes:

[0149] Get the first free volume V of the main control room r ;

[0150] The first free volume V r Substituting into formula (10) for calculation, we can obtain the first shielding coefficient GF in the first free volume of the main control room;

[0151] Formula (10) includes:

[0152]

[0153] For example, the electronic device may store a first free volume V of the main control chamber. r , so that it can be called directly later.

[0154] In some examples, the first external radiation dose rate limit D ex,l Including the first lower limit value D ex,D and the first upper limit value D ex,TH ;

[0155] According to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l ,include:

[0156] The first effective dose D l Substitute the first ratio into formula (11) to calculate and obtain the first lower limit value D ex,D , the first ratio K is the external radiation dose D ex The ratio of the total effective dose D;

[0157] Formula (11) includes:

[0158] D ex,D =D l ×K (11).

[0159] For example, the first ratio K may satisfy: K=D ex D.

[0160] In other examples, the air immersion external radiation dose conversion factor (DCF) can be obtained from the guidelines and standards that are regularly published and updated by international and regional nuclear safety and radiation protection agencies, such as the International Atomic Energy Agency (IAEA), the U.S. Nuclear Regulatory Commission (NRC), and the European Atomic Energy Community (EURATOM). i,air , inhalation internal radiation dose conversion factor DCF i,in and respiratory rate BR.

[0161] In some examples, based on the total effective dose D and the effective dose limit D L , determine the first effective dose D l ,include:

[0162] In D≥D L In the case of L and the duration of the first accident T T Substitute into formula (6) to calculate and obtain the first effective dose D l ;

[0163] Formula (6) includes:

[0164]

[0165] It should be noted that when D≥D LWhen D<D L During the entire accident period, even with normal ventilation, the exposure dose to personnel in the main control room can still meet the dose limit requirements. This first accident is not used as the basis for setting the monitoring threshold.

[0166] In step S130, the electronic device Determine the first external radiation dose rate limit D allowed in the main control room ex,l Afterwards, the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l .

[0167] In some embodiments, according to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l , which may include:

[0168] Get the first shielding coefficient GF in the first free volume of the main control room and the second shielding coefficient GF in the second free volume of the fresh air room vent ;

[0169] The first shielding coefficient GF and the second shielding coefficient GF vent , and the first external radiation dose rate limit D ex,l Substituting into formula (12), we can get the first alarm threshold value D of the fresh air indoor dose rate: vent,l ;

[0170] Formula (12) includes:

[0171]

[0172] In some examples, the electronic device stores a second shielding coefficient GF in the second free volume of the fresh air chamber. vent , so that it can be called directly later.

[0173] It is understandable that by substituting formula (10) and formula (13) into formula (12), we can get

[0174] It should be noted that the first alarm threshold D vent,l A second lower limit value D may be included vent,D and the second upper limit value D vent,TH , the second lower limit value D vent,D satisfy: Second upper limit value D vent,TH satisfy:

[0175] In other examples, the second shielding coefficient GF in the second free volume of the fresh air chamber is obtained. vent ,include:

[0176] Get the second free volume V of the fresh air chamber vent ;

[0177] The second free volume V vent Substitute into formula (13) to calculate and obtain the second shielding coefficient GF in the second free volume of the fresh air chamber: vent ;

[0178] Formula (13) includes:

[0179] GF vent =352 / V vent 0.338 (13).

[0180] For example, the electronic device stores the second free volume V of the fresh air chamber. vent , so that it can be called directly later.

[0181] To facilitate understanding of the method for determining the alarm threshold of a monitoring instrument provided in an embodiment of the present application, a specific embodiment is described below.

[0182] like Figure 2 As shown, the method for determining the alarm threshold of a monitoring instrument provided in an embodiment of the present application may include steps S201 to S212.

[0183] S201. Obtain the activity Q of the nuclide released in the accident;

[0184] S202, determining the nuclide release rate R=Q / T (i.e., the activity release rate R);

[0185] S203, obtaining hourly meteorological data throughout the year;

[0186] S204. Obtain the atmospheric diffusion factor X / Q at the air intake of the main control room during normal ventilation;

[0187] S205. Determine the average activity concentration of the nuclides at the air intake after the accident based on the nuclide release rate and the atmospheric diffusion factor X / Q at the air intake of the main control room;

[0188] S206. Determine the radiation dose D inside and outside the main control room based on the average activity concentration. in (ie, internal radiation dose D in );

[0189] S207. Determine the radiation dose D inside and outside the main control room based on the average activity concentration. ex (ie, external radiation dose D ex );

[0190] S208, according to the radiation dose D inside and outside the main control room in And the radiation dose inside and outside the main control room D ex , determine the total effective dose D = D in +D ex ;

[0191] S209, based on the total effective dose D and the indoor and outdoor irradiation dose D ex , determine the proportion of external radiation to the total effective dose K = D ex / D (i.e., the first ratio K);

[0192] S210, according to the ratio K of external radiation to total effective dose, determine the maximum allowable effective dose per unit time D in the main control room l (ie the first effective dose D l );

[0193] S211, according to the maximum allowable effective dose per unit time D in the main control room l , determine the maximum allowable external radiation dose rate D in the main control room ex,l (i.e. the first external radiation dose rate limit D ex,l );

[0194] S212, according to the maximum allowable external radiation dose rate D ex,l , determine the fresh air indoor dose rate alarm threshold D vent,l (ie the first alarm threshold D vent,l ).

[0195] Based on the same inventive concept, an embodiment of the present application further provides a method for determining an alarm threshold value of a monitoring instrument. The method for determining an alarm threshold value of a monitoring instrument provided in an embodiment of the present application is introduced below with reference to the accompanying drawings.

[0196] Example 2

[0197] The monitoring instrument alarm threshold determination method provided in the embodiment of the present application can be executed by a monitoring instrument alarm threshold determination device and an electronic device, etc. The following description will be made using the monitoring instrument alarm threshold determination method executed by an electronic device as an example.

[0198] like Figure 3 As shown, the method for determining the alarm threshold of a monitoring instrument provided in an embodiment of the present application may include steps S310 to S330.

[0199] S310: Determine the first alarm threshold value D of the dose rate in the fresh air room corresponding to the first accidents according to the method for determining the alarm threshold value of the dose rate in the fresh air room in any one of the embodiments 1. vent,l .

[0200] S320, according to all first alarm thresholds D vent,l , determine the target allowable dose rate limit R L .

[0201] S330, according to the target allowable dose rate limit R L , determine the second alarm threshold Ld of the monitoring instrument.

[0202] According to the alarm threshold determination method of the monitoring instrument provided in the embodiment of the present application, firstly, the first alarm threshold value D of the fresh air indoor dose rate corresponding to multiple first accidents is reasonably determined by the alarm threshold determination method of the fresh air indoor dose rate in any one of the embodiments 1. vent,l , then according to the first alarm threshold D vent,l , reasonably determine the target allowable dose rate limit R L , and then according to the target allowable dose rate limit R L , reasonably determine the second alarm threshold Ld of the monitoring instrument.

[0203] The specific implementation methods of the above steps are introduced below.

[0204] In step S310, the electronic device may store a plurality of first accidents, and then sequentially execute the method for determining the alarm threshold value of the dose rate in the fresh air room in Example 1 for each of the plurality of first accidents to determine the first alarm threshold value D of the dose rate in the fresh air room corresponding to the plurality of first accidents. vent,l For the implementation of the method for determining the alarm threshold value of the fresh air indoor dose rate in Example 1 executed by the electronic device, please refer to the detailed description in Example 1, which will not be repeated here.

[0205] In step S320, the electronic device determines the first alarm threshold value D of the fresh air indoor dose rate corresponding to the first accidents. vent,l Afterwards, according to the first alarm threshold D vent,l , determine the target allowable dose rate limit R L .

[0206] For example, the target allowable dose rate limit R L The minimum permissible dose rate limit that can be monitored in a power plant.

[0207] In some embodiments, according to the total first alarm threshold D vent,l , determine the target allowable dose rate limit R L, which may include:

[0208] Obtain the maximum radiation dose rate D0 allowed for environmental background measurement;

[0209] The first alarm threshold D with the minimum value vent,l When the radiation dose rate is greater than twice the high radiation dose rate D0, the first alarm threshold D with the smallest value is set to vent,l Determined as the target allowable dose rate limit R L ;

[0210] The first alarm threshold D with the minimum value vent,l When the dose rate is less than or equal to twice the high radiation dose rate D0, the dose rate D0 is determined as the target allowable dose rate limit R L .

[0211] In some examples, the electronic device may pre-store the maximum radiation dose rate D0 allowed for environmental background measurement for subsequent direct retrieval.

[0212] In other examples, the ratio of the maximum allowable effective dose limit for the public in the target year to 365*24 can be used to determine the maximum radiation dose rate D0 allowed for ambient background measurements. The target year can be any single year. For example, if the maximum allowable effective dose limit for the public in a single year is 5 mSv, then the maximum allowable radiation dose rate for ambient background measurements corresponding to the maximum allowable effective dose limit of 5 mSv is D0 = 5 mSv / 365 / 24 = 0.57 uSv / h.

[0213] That is, the target allowable dose rate limit R L Satisfy R L =max[min(D vent,l ), 2×D0].

[0214] In step S330, the electronic device performs the following operations according to the first alarm threshold D vent,l , determine the target allowable dose rate limit R L Afterwards, the target allowable dose rate limit R L , determine the second alarm threshold L of the monitoring instrument d .

[0215] For example, the second alarm threshold L d Including the first level alarm threshold L d1 and the secondary alarm threshold L d2 Among them, the first level alarm threshold L d1 It is an alarm, but does not trigger the ventilation system switching action; the second level alarm threshold L d2 Ventilation system switching action.

[0216] In some embodiments, the second alarm threshold Ld Including the first level alarm threshold L d1 and the secondary alarm threshold L d2 ;

[0217] According to the target allowable dose rate limit R L , determine the second alarm threshold L of the monitoring instrument d ,include:

[0218] The target allowable dose rate limit R L Determined as the first level alarm threshold L d1 ;

[0219] Twice the target allowable dose rate limit R L Determined as the second level alarm threshold L d2 .

[0220] That is to say, for the first level alarm threshold L d1 According to the monitoring range of the monitoring instrument and the maximum radiation dose rate D0 allowed by the environmental background measurement, the minimum allowable dose rate limit can be taken; for the second-level alarm threshold L d2 , the first level alarm threshold L d1 twice, that is, 2×R L .

[0221] Based on the same inventive concept, an embodiment of the present application also provides an alarm threshold determination device for the dose rate in the fresh air room. The alarm threshold determination device for the dose rate in the fresh air room provided by the embodiment of the present application is introduced below with reference to the accompanying drawings.

[0222] Example 3

[0223] like Figure 4 As shown, the device 400 for determining the alarm threshold value of the fresh air indoor dose rate provided in the embodiment of the present application may include a first acquisition module 410 , a first determination module 420 and a second determination module 430 .

[0224] The first acquisition module 410 is used to obtain the average activity concentration of radioactive nuclide i in the main control room during the initial release period T3 of the first accident.

[0225] The first determination module 420 is connected to the first acquisition module 410 and is used to determine the average activity concentration according to the average activity concentration. Determine the first external radiation dose rate limit D allowed in the main control room ex,l ;

[0226] The second determining module 430 is connected to the first determining module 420 and is used to determine the first external radiation dose rate limit value D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l .

[0227] According to the device for determining the alarm threshold value of the dose rate in the fresh air room provided by the embodiment of the present application, the average activity concentration is obtained. Determine the first external radiation dose rate limit D allowed in the main control room ex,l , and then according to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l Since the monitoring instrument monitors the real-time dose rate of external radiation dose, the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l , taking into account the first alarm threshold D of the external radiation and fresh air indoor dose rate vent,l Therefore, the first alarm threshold D of the fresh air indoor dose rate can be reasonably determined. vent,l , is the first alarm threshold D of the subsequent fresh air indoor dose rate vent,l , which provides the possibility to reasonably determine the alarm threshold of the monitoring instrument.

[0228] In some implementations, the first acquisition module 410 is specifically configured to:

[0229] Obtain the first activity concentration C(t) of the radioactive nuclides in the main control room at the first time t of the first accident, as well as the second time T1 and the third time T2 of the first accident, where t and T1 are both less than the end time T of the first accident, and T2 is less than or equal to the end time T;

[0230] Substitute the first activity concentration C(t), the second time T1 and the third time T2 into formula (1) to calculate the average activity concentration of radionuclide i in the main control room during the first accident period.

[0231] Formula (1) includes:

[0232]

[0233] In some implementations, the first acquisition module 410 may be specifically configured to:

[0234] Obtaining a second time T1 of the first accident, a second activity concentration C(T1) of the radioactive nuclide in the main control room at the second time T1, a first time t, a first parameter value p, and a second parameter value q;

[0235] Substitute the second time T1, the second activity concentration C(T1), the first time t, the first parameter value p, and the second parameter value q into formula (2) to calculate the first activity concentration C(t) of the radioactive nuclide i in the main control room during the first time t of the first accident;

[0236] Formula (2) includes:

[0237]

[0238] In some implementations, the first acquisition module 410 may be specifically configured to:

[0239] Get the nuclide activity decay rate λ caused by decay i , Normal air volume Q u and the volume V of the ventilation area of ​​the main control room;

[0240] The activity decay rate λ i , Normal air volume Q u Substitute the volume V of the ventilation area of ​​the main control room into formula (3) to calculate and obtain the first parameter value p;

[0241] Formula (3) includes:

[0242]

[0243] Alternatively, the first acquisition module 410 may be specifically configured to:

[0244] Get normal air volume Q u , the atmospheric diffusion factor (χ / Q) at the air intake of the main control room and the activity release rate R to the environment during the initial release period T3;

[0245] The normal air volume Q u , atmospheric diffusion factor (χ / Q) and activity release rate R are substituted into formula (4) to calculate the second parameter value q;

[0246] Formula (4) includes:

[0247] q=Q u *(x / Q)*R (4).

[0248] In some implementations, the first acquisition module 410 may be specifically configured to:

[0249] Obtaining the activity Q of nuclides released into the environment during the initial release period T3 of the first accident;

[0250] Substitute the initial release period T3 and the activity Q of the released nuclides into formula (5) to calculate the activity release rate R to the environment during the initial release period T3;

[0251] Formula (5) includes:

[0252] R=Q / T3 (5).

[0253] In some implementations, the first determining module 420 may be specifically configured to:

[0254] According to the average activity concentration Determine the first effective dose D l , the first effective dose D l The maximum permissible effective dose per unit time;

[0255] According to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l .

[0256] In some implementations, the first determining module 420 may be specifically configured to:

[0257] According to the average activity concentration Determine the exposure dose of personnel in the main control room under normal ventilation conditions. The exposure dose includes the total effective dose D, which includes the external radiation dose D. ex and internal radiation dose D in ;

[0258] According to the total effective dose D and the effective dose limit D L , determine the first effective dose D l .

[0259] In some implementations, the first determining module 420 may be specifically configured to:

[0260] In D≥D L In the case of L and the duration of the first accident T T Substitute into formula (6) to calculate and obtain the first effective dose D l ;

[0261] Formula (6) includes:

[0262]

[0263] In some implementations, the first determining module 420 may be specifically configured to:

[0264] Obtain the first shielding coefficient GF and air immersion external radiation dose conversion factor DCF in the first free volume of the main control room i,air , the duration of the first accident T T , inhalation internal radiation dose conversion factor DCF i,in and respiratory rate BR;

[0265] The first shielding factor GF, air immersion external radiation dose conversion factor DCF i,air , average activity concentration and duration T T , substitute into formula (7) to calculate and obtain the external radiation dose Dex ;

[0266] Formula (7) includes:

[0267]

[0268] Where I represents the number of radionuclides;

[0269] Inhalation internal radiation dose conversion factor DCF i,in , average activity concentration Duration T T and respiratory rate BR, and substitute them into formula (8) to calculate the internal radiation dose D in ;

[0270] Formula (8) includes:

[0271]

[0272] The external radiation dose D ex and internal radiation dose D in Substitute into formula (9) to calculate and obtain the total effective dose D;

[0273] Formula (9) includes:

[0274] D=D ex +D in (9).

[0275] In some implementations, the first determining module 420 may be specifically configured to:

[0276] Obtaining a first shielding coefficient GF in a first free volume of the main control room includes:

[0277] Get the first free volume V of the main control room r ;

[0278] The first free volume V r Substituting into formula (10) for calculation, we can obtain the first shielding coefficient GF in the first free volume of the main control room;

[0279] Formula (10) includes:

[0280]

[0281] In some implementations, the first determining module 420 may be specifically configured to:

[0282] The first external radiation dose rate limit D ex,l Including the first lower limit value D ex,D and the first upper limit value D ex,TH ;

[0283] According to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l ,include:

[0284] The first effective dose D l Substitute the first ratio into formula (11) to calculate and obtain the first lower limit value D ex,D , the first ratio K is the external radiation dose D ex The ratio of the total effective dose D;

[0285] Formula (11) includes:

[0286] D ex,D =D l ×K (11).

[0287] In some implementations, the second determining module 430 is specifically configured to:

[0288] Get the first shielding coefficient GF in the first free volume of the main control room and the second shielding coefficient GF in the second free volume of the fresh air room vent ;

[0289] The first shielding coefficient GF and the second shielding coefficient GF vent , and the first external radiation dose rate limit D ex,l Substituting into formula (12), we can get the first alarm threshold value D of the fresh air indoor dose rate: vent,l ;

[0290] Formula (12) includes:

[0291]

[0292] In some implementations, the second determining module 430 is specifically configured to:

[0293] Get the second shielding coefficient GF in the second free volume of the fresh air room vent ,include:

[0294] Get the second free volume V of the fresh air chamber vent ;

[0295] The second free volume V vent Substitute into formula (13) to calculate and obtain the second shielding coefficient GF in the second free volume of the fresh air chamber: vent ;

[0296] Formula (13) includes:

[0297] GF vent =352 / V vent 0.338 (13).

[0298] The device for determining the alarm threshold value of the dose rate in the fresh air room provided in the embodiment of the present application can be used to execute the method for determining the alarm threshold value of the dose rate in the fresh air room, that is, it has the beneficial effects and implementation methods of the method for determining the alarm threshold value of the dose rate in the fresh air room provided in Example 1 of the present application. For details, please refer to the specific description of the method for determining the alarm threshold value of the dose rate in the fresh air room in Example 1 above, and this embodiment will not be repeated here.

[0299] Based on the same inventive concept, an embodiment of the present application further provides a system for determining an alarm threshold value of a monitoring instrument. The system for determining an alarm threshold value of a monitoring instrument provided in an embodiment of the present application is introduced below with reference to the accompanying drawings.

[0300] Example 4

[0301] like Figure 5 As shown, the alarm threshold determination system 1000 of the monitoring instrument provided in the embodiment of the present application may include the alarm threshold determination device 400 of the fresh air indoor dose rate in Example 3; and the alarm threshold determination device 500 of the monitoring instrument;

[0302] The device 400 for determining the alarm threshold value of the dose rate in the fresh air room is used to determine the first alarm threshold value D of the dose rate in the fresh air room corresponding to the first accidents. vent,l ;

[0303] The monitoring instrument alarm threshold determination device 500 includes:

[0304] The third determination module 510 is connected to the alarm threshold determination device of the dose rate in the fresh air room, and is used to determine the dose rate according to the first alarm threshold D vent,l , determine the target allowable dose rate limit R L ;

[0305] The fourth determining module 520 is connected to the third determining module and is used to determine the dose rate limit R according to the target allowable dose rate limit R L , determine the second alarm threshold L of the monitoring instrument d .

[0306] According to the alarm threshold determination system of the monitoring instrument provided in the embodiment of the present application, firstly, the first alarm threshold value D of the fresh air indoor dose rate corresponding to multiple first accidents is reasonably determined by the alarm threshold determination device of any one of the embodiments 3. vent,l , then according to the first alarm threshold D vent,l , reasonably determine the target allowable dose rate limit R L , and then according to the target allowable dose rate limit R L , reasonably determine the second alarm threshold L of the monitoring instrumentd .

[0307] In some implementations, the third determining module 510 may be specifically configured to:

[0308] Obtain the maximum radiation dose rate D0 allowed for environmental background measurement;

[0309] The first alarm threshold D with the minimum value vent,l When the radiation dose rate is greater than twice the high radiation dose rate D0, the first alarm threshold D with the smallest value is set to vent,l Determined as the target allowable dose rate limit R L ;

[0310] The first alarm threshold D with the minimum value vent,l When the dose rate is less than or equal to twice the high radiation dose rate D0, the dose rate D0 is determined as the target allowable dose rate limit R L .

[0311] In some embodiments, the second alarm threshold L d Including the first level alarm threshold L d1 and the secondary alarm threshold L d2 ;

[0312] The fourth determining module 420 may be specifically configured to:

[0313] The target allowable dose rate limit R L Determined as the first level alarm threshold L d1 ;

[0314] Twice the target allowable dose rate limit R L Determined as the second level alarm threshold L d2 .

[0315] The alarm threshold determination system for monitoring instruments provided in the embodiment of the present application can be used to execute the alarm threshold determination method for monitoring instruments, that is, it has the beneficial effects and implementation methods of the alarm threshold determination method for monitoring instruments provided in Example 2 of the present application. For details, please refer to the specific description of the alarm threshold determination method for monitoring instruments in the above Example 2, which will not be repeated in this embodiment.

[0316] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present application, and the present application is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present application, and such modifications and improvements are also considered to be within the scope of protection of the present application.

Claims

1. A method for determining an alarm threshold value of a fresh air indoor dose rate, characterized in that: include: Obtain the average activity concentration of radionuclide i in the main control room during the initial release period T3 of the first accident According to the average activity concentration Determine the first external radiation dose rate limit D allowed in the main control room ex,l ; According to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l ; The average activity concentration of radioactive nuclide i in the main control room during the initial release period T3 of the first accident is obtained. include: Obtaining a first activity concentration C(t) of radioactive nuclides in the main control room at a first time t of the first accident, as well as a second time T1 and a third time T2 of the first accident, where t and T1 are both less than an end time T of the first accident, and T2 is less than the end time T; Substitute the first activity concentration C(t), the second time T1 and the third time T2 into formula (1) to calculate the average activity concentration of radionuclide i in the main control room during the first accident period: The formula (1) includes: Obtaining the first activity concentration C(t) of radioactive nuclides in the main control room at the first time t of the first accident, including: Obtaining a second time T1 of the first accident, a second activity concentration C(T1) of the radioactive nuclide in the main control room at the second time T1, a first time t, a first parameter value p, and a second parameter value q; Substitute the second time T1, the second activity concentration C(T1), the first time t, the first parameter value p, and the second parameter value q into formula (2) to calculate the first activity concentration C(t) of the radionuclide i in the main control room during the first time t of the first accident; The formula (2) includes: Obtaining the first parameter value p includes: Get the nuclide activity decay rate λ caused by decay i , Normal air volume Q u and the volume V of the ventilation area of ​​the main control room; The activity decay rate of the nuclide λ i , the normal air volume Q u and the ventilation area volume V of the main control room are substituted into formula (3) to calculate and obtain the first parameter value p; The formula (3) includes: Alternatively, obtaining the second parameter value q includes: Get normal air volume Q u , the atmospheric diffusion factor (χ / Q) at the air intake of the main control room and the activity release rate R to the environment during the initial release period T3; The normal air volume Q u , the atmospheric diffusion factor (χ / Q) and the activity release rate R are substituted into formula (4) to calculate and obtain the second parameter value q; The formula (4) includes: q=Q u *(x / Q)*R (4)。 2. The method according to claim 1, characterized in that Obtain the activity release rate R to the environment during the initial release period of the accident, including: Obtaining the activity Q of nuclides released into the environment during the initial release period T3 of the first accident; Substituting the initial release period T3 and the released nuclide activity Q into formula (5) for calculation, the activity release rate R to the environment during the initial release period T3 is obtained; The formula (5) includes: R=Q / T3 (5).

3. The method according to claim 1, characterized in that According to the average activity concentration Determine the first external radiation dose rate limit D allowed in the main control room ex,l ,include: According to the average activity concentration Determine the first effective dose D l , the first effective dose D l The maximum permissible effective dose per unit time; According to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l .

4. The method according to claim 3, characterized in that According to the average activity concentration Determine the first effective dose D l ,include: According to the average activity concentration Determine the exposure dose of personnel in the main control room under normal ventilation conditions. The exposure dose includes the total effective dose D, which includes the external radiation dose D. ex and internal radiation dose D in ; According to the total effective dose D and the effective dose limit D L , determine the first effective dose D l .

5. The method according to claim 4, characterized in that According to the total effective dose D and the effective dose limit D L , determine the first effective dose D l ,include: In D≥D L In the case of L and the duration of the first accident T T Substitute into formula (6) to calculate and obtain the first effective dose D l ; The formula (6) includes:

6. The method according to claim 4, characterized in that According to the average activity concentration Determine the radiation dose to personnel in the main control room under normal ventilation conditions, including: Obtain the first shielding coefficient GF and air immersion external radiation dose conversion factor DCF in the first free volume of the main control room i,air , the duration of the first accident T T , inhalation internal radiation dose conversion factor DCF i,in and respiratory rate BR; The first shielding coefficient GF, the air immersion external radiation dose conversion factor DCF i,air , the average activity concentration and the duration T T , substitute into formula (7) to calculate and obtain the external radiation dose D ex ; The formula (7) includes: Where I represents the number of radionuclides; The inhalation internal radiation dose conversion factor DCF i,in , the average activity concentration The duration T T and the respiratory rate BR, and substitute them into formula (8) to calculate the internal radiation dose D in ; The formula (8) includes: The external irradiation dose D ex and the internal radiation dose D in Substitute into formula (9) to calculate and obtain the total effective dose D; The formula (9) includes: D=D ex +D in (9)。 7. The method according to claim 6, characterized in that Obtaining a first shielding coefficient GF in a first free volume of the main control room includes: Get the first free volume V of the main control room r ; The first free volume V r Substituting into formula (10) for calculation, we can obtain the first shielding coefficient GF in the first free volume of the main control room; The formula (10) includes:

8. The method according to claim 3, characterized in that The first external radiation dose rate limit D ex,l Including the first lower limit value D ex,D and the first upper limit value D ex,TH ; According to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l ,include: The first effective dose D l Substitute the first ratio into formula (11) to calculate and obtain the first lower limit value D ex,D , the first ratio K is the external radiation dose D ex The ratio of the total effective dose D; The formula (11) includes: D ex,D =D l ×K (11)。 9. The method according to claim 1, characterized in that According to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l ,include: Get the first shielding coefficient GF in the first free volume of the main control room and the second shielding coefficient GF in the second free volume of the fresh air room vent ; The first shielding coefficient GF and the second shielding coefficient GF vent , and the first external radiation dose rate limit D ex,l Substituting into formula (12), we can get the first alarm threshold value D of the fresh air indoor dose rate: vent,l ; The formula (12) includes:

10. The method according to claim 9, characterized in that Get the second shielding coefficient GF in the second free volume of the fresh air room vent ,include: Get the second free volume V of the fresh air chamber vent ; The second free volume V vent Substitute into formula (13) to calculate and obtain the second shielding coefficient GF in the second free volume of the fresh air chamber: vent ; The formula (13) includes: GF vent =352 / V vent 0.338 (13)。 11. A method for determining an alarm threshold of a monitoring instrument, characterized in that: include: According to any one of claims 1 to 10, the method for determining the alarm threshold value of the dose rate in the fresh air room is used to determine the first alarm threshold value D of the dose rate in the fresh air room corresponding to the first accidents. vent,l ; According to the first alarm threshold D vent,l , determine the target allowable dose rate limit R L ; According to the target allowable dose rate limit R L , determine the second alarm threshold L of the monitoring instrument d .

12. The method according to claim 11, characterized in that According to the first alarm threshold D vent,l , determine the target allowable dose rate limit R L ,include: Obtain the maximum radiation dose rate D0 allowed for environmental background measurement; The first alarm threshold D with the minimum value vent,l When the radiation dose rate is greater than twice the high radiation dose rate D0, the first alarm threshold D with the smallest value is set to vent,l Determined as the target allowable dose rate limit R L ; The first alarm threshold D with the minimum value vent,l When the dose rate is less than or equal to twice the high radiation dose rate D0, the dose rate D0 is determined as the target allowable dose rate limit R L .

13. The method according to claim 11, characterized in that The second alarm threshold L d Including the first level alarm threshold L d1 and the secondary alarm threshold L d2 ; The target allowable dose rate limit R L , determine the second alarm threshold L of the monitoring instrument d ,include: The target allowable dose rate limit R L Determined as the first level alarm threshold L d1 ; Twice the target permissible dose rate limit R L Determined as the second level alarm threshold L d2 .

14. A device for determining an alarm threshold value of a dose rate in a fresh air room, characterized in that: include: The first acquisition module is used to obtain the average activity concentration of radioactive nuclide i in the main control room during the initial release period T3 of the first accident A first determining module is connected to the first acquiring module and is used to determine the average activity concentration according to the average activity concentration. Determine the first external radiation dose rate limit D allowed in the main control room ex,l ; The second determining module is connected to the first determining module and is used to determine the dose rate of the first external radiation dose rate according to the first external radiation dose rate limit D ex,l , determine the first alarm threshold D of the fresh air indoor dose rate vent,l ; The first acquisition module is specifically configured to: Obtaining a first activity concentration C(t) of radioactive nuclides in the main control room at a first time t of the first accident, as well as a second time T1 and a third time T2 of the first accident, where t and T1 are both less than an end time T of the first accident, and T2 is less than or equal to the end time T; Substitute the first activity concentration C(t), the second time T1 and the third time T2 into formula (1) to calculate the average activity concentration of radionuclide i in the main control room during the first accident period: The formula (1) includes: The first acquisition module is specifically configured to: Obtaining a second time T1 of the first accident, a second activity concentration C(T1) of the radioactive nuclide in the main control room at the second time T1, a first time t, a first parameter value p, and a second parameter value q; Substitute the second time T1, the second activity concentration C(T1), the first time t, the first parameter value p, and the second parameter value q into formula (2) to calculate the first activity concentration C(t) of the radionuclide i in the main control room during the first time t of the first accident; The formula (2) includes: The first acquisition module is specifically configured to: Get the nuclide activity decay rate λ caused by decay i , Normal air volume Q u and the volume V of the ventilation area of ​​the main control room; The activity decay rate of the nuclide λ i , the normal air volume Q u and the ventilation area volume V of the main control room are substituted into formula (3) to calculate and obtain the first parameter value p; The formula (3) includes: Alternatively, the first acquisition module is specifically configured to: Get normal air volume Q u , the atmospheric diffusion factor (χ / Q) at the air intake of the main control room and the activity release rate R to the environment during the initial release period T3; The normal air volume Q u , the atmospheric diffusion factor (χ / Q) and the activity release rate R are substituted into formula (4) to calculate and obtain the second parameter value q; The formula (4) includes: q=Q u *(x / Q)*R (4)。 15. The device according to claim 14, characterized in that The first determining module is specifically configured to: According to the average activity concentration Determine the first effective dose D l , the first effective dose D l The maximum permissible effective dose per unit time; According to the first effective dose D l , determine the first external radiation dose rate limit D allowed by the main control room ex,l .

16. The device according to claim 14, characterized in that The second determining module may be specifically configured to: Get the first shielding coefficient GF in the first free volume of the main control room and the second shielding coefficient GF in the second free volume of the fresh air room vent ; The first shielding coefficient GF and the second shielding coefficient GF vent , and the first external radiation dose rate limit D ex,l Substituting into formula (12), we can get the first alarm threshold value D of the fresh air indoor dose rate: vent,l ; The formula (12) includes:

17. A system for determining an alarm threshold value of a monitoring instrument, characterized in that: include: The device for determining the alarm threshold value of the dose rate in the fresh air room according to any one of claims 14 to 16; and a device for determining an alarm threshold value of a monitoring instrument; The device for determining the alarm threshold value of the dose rate in the fresh air room is used to determine the first alarm threshold value D of the dose rate in the fresh air room corresponding to a plurality of first accidents. vent,l ; The alarm threshold determination device of the monitoring instrument includes: The third determination module is connected to the alarm threshold determination device of the dose rate in the fresh air room, and is used to determine the dose rate according to all the first alarm thresholds D vent,l , determine the target allowable dose rate limit R L ; The fourth determining module is connected to the third determining module and is used to determine the dose rate limit R according to the target allowable dose rate limit R L , determine the second alarm threshold L of the monitoring instrument d .

18. The system according to claim 17, wherein: The third determining module is specifically configured to: Obtain the maximum radiation dose rate D0 allowed for environmental background measurement; The first alarm threshold D with the minimum value vent,l When the radiation dose rate is greater than twice the high radiation dose rate D0, the first alarm threshold D with the smallest value is set to vent,l Determined as the target allowable dose rate limit R L ; The first alarm threshold D with the minimum value vent,l When the dose rate is less than or equal to twice the high radiation dose rate D0, the dose rate D0 is determined as the target allowable dose rate limit R L .

19. The system according to claim 17, wherein: The second alarm threshold L d Including the first level alarm threshold L d1 and the secondary alarm threshold L d2 ; The fourth determining module is specifically configured to: The target allowable dose rate limit R L Determined as the first level alarm threshold L d1 ; Twice the target permissible dose rate limit R L Determined as the second level alarm threshold L d2 .

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