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

Abstract

The invention discloses a method and a device for determining an alarm threshold value of a dose rate in a fresh air chamber, and a method and a system for determining an alarm threshold value of a monitoring instrument, and relates to the technical field of nuclear industry. The method for determining the alarm threshold value of the dosage rate in the fresh air chamber comprises the steps that the average activity concentration # imgabs0 # of radionuclide i in a master control room when a first accident is in an initial release time period T3 is obtained, and a first external irradiation dosage rate limiting value Dex, l allowed by the master control room is determined according to the average activity concentration # imgabs1 #; and according to the first external irradiation dose rate limit value Dex, l, a first alarm threshold value Dvent, l of the dose rate in the fresh air cell is determined. According to the embodiment of the invention, the method can reasonably determine the first alarm threshold value Dvent, l of the dosage rate in the fresh air cell, and provides possibility for reasonably determining the alarm threshold value of the monitoring instrument through the first alarm threshold value Dvent, l of the dosage rate in the fresh air cell subsequently.

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 is the control center of the nuclear power plant operation. Its main function is to ensure the safe operation of the reactor under normal conditions and to achieve safe shutdown under abnormal and accident conditions. In accident conditions, after the plant area is contaminated by radioactivity, in order to ensure the realization of the main control room function and maintain its habitability, it is necessary to use an emergency ventilation system with filtering function to ventilate and purify the main control room.

[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 requirements. The instrument is equipped with two levels of alarms, of which the first level alarm 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 is an important indicator of whether the radiation monitoring system issues an alarm signal and is the core operating parameter of the radiation monitoring system. The alarm threshold affects the switching time of the ventilation system, which in turn affects the exposure dose of the personnel in the main control room. The first-level alarm does not trigger the switching action. When the second-level alarm threshold is reached, the normal ventilation system will be switched to the emergency ventilation system. During this period, the main control room still maintains normal ventilation. At this time, the radioactive substances in the outdoor smoke plume enter the main control room through the ventilation system, causing the personnel in the main control room to be exposed to radiation. Since the main control room is close to the reactor core, normal ventilation for a short period of time can lead to higher dose consequences. If the alarm threshold is set too low, it is easy to cause false alarms, and if it is set too high, it may cause excessive radiation exposure to the personnel in the main control room. Determining a reasonable alarm threshold for the ventilation system monitoring instrument can ensure that the ventilation system of the main control room is switched to the emergency ventilation system as soon as possible under accident conditions.

[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 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 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 the dose rate in a fresh air room in view of the above-mentioned deficiencies in the prior art. 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 providing the possibility for reasonably determining 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 the radionuclide i in the main control room during the initial release period T3 of the first accident is obtained. The method comprises: obtaining the first activity concentration C(t) of the radioactive nuclide 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, 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 time T1 and the third time 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, a 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 a 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 , 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 , 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 implementations 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 activity Q of the released nuclides 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 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 .

[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. 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 implementations of the first aspect, obtaining a first shielding coefficient GF in a first free volume of the main control room includes: obtaining the first free volume V of the main control room 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 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: placing 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; Formula (11) includes:

[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 a first shielding coefficient GF in the first free volume of the main control room, and a 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, a 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, an embodiment of the present application further provides a method for determining an alarm threshold of a monitoring instrument, comprising: determining a first alarm threshold D of a dose rate in a fresh air room corresponding to a plurality of first accidents according to the method for determining an alarm threshold of a dose rate in a 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 vent,l Determined as the target allowable dose rate limit R L ; At 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 second level 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 the third aspect, the embodiment of the present application provides an alarm threshold determination device for the dose rate in a fresh air room, comprising: a first acquisition module for 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 The first determination module is connected to the first acquisition 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 A second determination module, connected to the first determination module, is used to determine 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 time t of the first accident, as well as a second time T1 and a third time 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 time T1 and the third time T2 into formula (1) for calculation, and 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 determination module is specifically configured to: Determine the first effective dose D l , the first effective dose D l is 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 .

[0044] In some embodiments of the third aspect, the second determination module may be specifically used to: obtain a first shielding coefficient GF in a first free volume of the main control room and a second shielding coefficient GF in a 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 comprises: a third determination module connected to the alarm threshold determination device of the dose rate in the fresh air room, 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 and is used to determine the dose rate limit R according to the target L , determine the second alarm threshold L of the monitoring instrument d .

[0048] In some implementations of the fourth aspect, the third determination module is specifically used to: obtain the maximum radiation dose rate D0 allowed by the environmental background measurement; vent,l When the radiation dose rate is greater than twice the high radiation dose rate D0, the first alarm threshold D vent,l Determined as the target allowable dose rate limit R L ; At 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 second level 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 C i , determine the first external radiation dose rate limit D allowed by 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 allowed by the main control room is 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 , providing the possibility to reasonably determine the alarm threshold of the monitoring instrument. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0055] Figure 5 A structural schematic diagram of an alarm threshold determination system for 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 only 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 article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0059] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after 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 prior art that may be involved in the embodiments of the present application is first described.

[0061] The alarm threshold mainly considers whether the total dose of personnel meets the control value requirements (including internal and external exposure). Regarding the dose standard of personnel in the control room in the event of an accident, my country's nuclear safety guideline "Emergency Preparedness and Emergency Response of Nuclear Power Plant Operating Units" (HAD 002 / 01-2019) requires that the habitability criteria for important emergency facilities such as the main control room should be met: during the set continuous emergency response period (generally 30 days), the effective dose received by the staff is not more than 50mSv, and the thyroid equivalent dose is not more than 500mSv. In the "Design Criteria for On-site Emergency Facilities of Nuclear Power Plants", it is required to consider the shift frequency of operators, and the time share of personnel in the habitable area is: 100% within 24 hours after the accident, 60% for 1 to 4 days, and 40% after 4 days. Under the condition of meeting the personnel dose control value, the dose rate at the location of the radiation monitoring instrument is calculated according to the relevant design of the ventilation system of the main control room, the installation location of the monitoring instrument, the composition of the accident source item, and other conditions, and then the switching threshold of the air intake is determined.

[0062] The inventors have found through extensive research that since the walls and roof of the main control room have sufficient concrete thickness to reduce the gamma radiation from the outside, the external exposure of the smoke plume outside the main control room and the ground deposition exposure contribute very little, and the effective dose received by the main control room personnel mainly comes from the external exposure caused by the smoke plume entering the main control room and the internal exposure caused by inhalation. The monitoring instrument monitors the real-time dose rate of gamma ray external exposure. Therefore, when determining the alarm threshold of the monitoring instrument, the corresponding relationship between external exposure and effective dose needs to be considered.

[0063] The following describes 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 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 dose rate in a fresh air chamber provided in an embodiment of the present application is shown.

[0066] The method for determining the alarm threshold of the dose rate in the fresh air room provided in the embodiment of the present application can be performed by a device for determining the alarm threshold of the dose rate in the fresh air room and an electronic device, etc. The following takes the method for determining the alarm threshold of the dose rate in the fresh air room performed by an electronic device as an example for description.

[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 of the dose rate in the fresh air chamber provided in the embodiment of the present application may include steps S110 to S130.

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

[0070] S120, according to the average activity concentration C i , determine the first external radiation dose rate limit D allowed by 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, by obtaining the average activity concentration C i , determine the first external radiation dose rate limit D allowed by 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 allowed by the main control room is 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 , providing the possibility to reasonably determine the alarm threshold of the monitoring instrument.

[0073] The specific implementation methods of the above steps are 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 may represent any radionuclide among the I types of radionuclides, where i is a positive integer.

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

[0079] In some embodiments, the electronic device may pre-store the average activity concentration C of the radionuclide i in the main control room during the initial release period T3 of the first accident. i , so that it can be called directly later.

[0080] In other embodiments, the electronic device may determine, in response to a first input operation by a user, an average activity concentration C of the radioactive nuclide i in the main control room during the initial release period T3 of the first accident. i The first input operation can be to input the average activity concentration C i 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 by 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] Substituting the first activity concentration C(t), the second time T1 and the third time T2 into formula (1) for calculation, the average activity concentration of radionuclide i in the main control room during the first accident is obtained.

[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 time 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 the user's second input operation. 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 and obtain 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 dispersion 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 call.

[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 nuclide activity decay rate caused by decay.

[0108] For example, the electronic device may pre-store the nuclide activity decay rate λ caused by the 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 the 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 and obtain 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 radionuclide activity Q released to 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 nuclide 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 radionuclides 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 the radionuclide 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, according to 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 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. 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] Exemplarily, 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 immersed in the plume; the internal radiation dose D in It can be an internal radiation dose through inhalation.

[0133] For example, the electronic device pre-stores an effective dose limit value 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 breathing 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, the first shielding coefficient GF in the first free volume of the main control room is obtained;

[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 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] Exemplarily, 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 commonly 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 could still meet the dose limit requirements. This first accident was 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] Obtain 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: The 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] In order 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., activity release rate R);

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

[0186] S204, obtaining 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 outlet after the accident based on the nuclide release rate and the atmospheric diffusion factor X / Q at the air outlet 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 (i.e. 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 irradiation dose inside and outside the main control room 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. Determine the maximum allowable effective dose per unit time D in the main control room based on the ratio K of external radiation to the total effective dose. l (i.e. 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 of the main control room ex,l , determine the dose rate alarm threshold D in the fresh air room vent,l (i.e. 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 of a monitoring instrument. The method for determining an alarm threshold of a monitoring instrument provided in an embodiment of the present application is introduced below in conjunction with 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 the monitoring instrument alarm threshold determination device and electronic device, etc. The following takes the monitoring instrument alarm threshold determination method executed by the electronic device as an example for description.

[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 method for determining the alarm threshold of the monitoring instrument provided in the embodiment of the present application, firstly, the method for determining the alarm threshold of the dose rate in the fresh air room of any one of the embodiments 1 is used to reasonably determine the first alarm threshold D of the dose rate in the fresh air room corresponding to the first accidents. 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 for each of the plurality of first accidents, sequentially execute the method for determining the alarm threshold value of the dose rate in the fresh air room in Example 1 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 The implementation of the method for determining the alarm threshold value of the dose rate in the fresh air chamber in Example 1 by the electronic device can be referred to the detailed description in Example 1, which will not be described in detail here.

[0205] In step S320, the electronic device determines the first alarm threshold D of the dose rate in the fresh air chamber corresponding to the first accidents. vent,l Afterwards, according to all the first alarm thresholds 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 for a power plant.

[0207] In some embodiments, according to the 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 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 determined as the maximum radiation dose rate D0 allowed for environmental background measurement. 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 5mSv, then the maximum radiation dose rate allowed for environmental background measurement corresponding to the maximum allowable effective dose limit of 5mSv is D0=5mSv / 365 / 24=0.57uSv / 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 generates a warning signal 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 second level alarm threshold L d2 Among them, the first level alarm threshold L d1 It is an alarm, and 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 second level 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 a device for determining an alarm threshold value of the dose rate in a fresh air chamber. The device for determining an alarm threshold value of the dose rate in a fresh air chamber provided by an embodiment of the present application is introduced below in conjunction with the accompanying drawings.

[0222] Example 3

[0223] like Figure 4 As shown, the device 400 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 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 determination module 430 is connected to the first determination 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 in the embodiment of the present application, by obtaining the average activity concentration 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 allowed by the main control room is 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 , providing 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] Substituting the first activity concentration C(t), the second time T1 and the third time T2 into formula (1) for calculation, the average activity concentration of radionuclide i in the main control room during the first accident is obtained.

[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 and obtain 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 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;

[0241] Formula (3) includes:

[0242]

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

[0244] Get the 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 and obtain 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 radionuclide activity Q released to 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 nuclide 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. 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, the first shielding coefficient GF in the first free volume of the main control room is obtained;

[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 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 third determination module 430 is specifically configured to:

[0288] Obtain 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 third determination module 430 is specifically configured to:

[0293] Get the second shielding factor 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 chamber 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 chamber, 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 chamber 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 chamber in the above Example 1, which will not be repeated in this embodiment.

[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 in conjunction with 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 embodiment 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 alarm threshold determination device 500 of the monitoring instrument comprises:

[0304] The third determination module 510 is connected to the alarm threshold determination device for 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 ;

[0305] The fourth determination module 520 is connected to the third determination 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 dose rate in the fresh air room corresponding to the first accidents is reasonably determined by the alarm threshold determination device of the dose rate in the fresh air room in 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 determination 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 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 second level alarm threshold L d2 ;

[0312] The fourth determination 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 the monitoring instrument provided in the embodiment of the present application can be used to execute the alarm threshold determination method for the monitoring instrument, that is, it has the beneficial effects and implementation methods of the alarm threshold determination method for the monitoring instrument provided in Example 2 of the present application. For details, please refer to the specific description of the alarm threshold determination method for the monitoring instrument in the above Example 2, which will not be repeated in this embodiment.

[0316] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present application, but the present application is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of the present application, and these 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 dose rate in a fresh air room, 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 .

2. The method according to claim 1, characterized in that The average activity concentration C of the radioactive nuclide i in the main control room during the initial release period T3 of the first accident is obtained. i ,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; Substituting the first activity concentration C(t), the second time T1 and the third time T2 into formula (1) for calculation, the average activity concentration of radionuclide i in the main control room during the first accident is obtained: The formula (1) includes:

3. The method according to claim 2, characterized in that Obtaining the first activity concentration C(t) of the 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; 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, 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 is obtained; The formula (2) includes:

4. The method according to claim 3, characterized in that 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 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; The formula (3) includes: Alternatively, obtaining the second parameter value q includes: Get the 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 a second parameter value q; The formula (4) includes: q=Q u *(x / Q)*R(4)。 5. The method according to claim 4, characterized in that Obtain the activity release rate R to the environment during the initial release period of the accident, including: Obtaining the radionuclide activity Q released 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, the activity release rate R to the environment during the initial release period T3 is obtained; The formula (5) includes: R=Q / T3(5).

6. 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 .

7. The method according to claim 6, 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, the total effective dose D 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 .

8. The method according to claim 7, 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:

9. The method according to claim 7, characterized in that: According to the average activity concentration C i , determine the radiation dose of 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 factor 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 radiation 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)。 10. The method according to claim 9, 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, the first shielding coefficient GF in the first free volume of the main control room is obtained; The formula (10) includes:

11. The method according to claim 6, characterized in that The first external radiation dose rate limit D ex,l Including the first lower limit 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)。 12. 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: Obtain 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:

13. The method according to claim 12, characterized in that Get the second shielding factor 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)。 14. A method for determining an alarm threshold of a monitoring instrument, characterized in that: include: According to the method for determining the alarm threshold value of the dose rate in the fresh air room according to any one of claims 1 to 13, a first alarm threshold value D of the dose rate in the fresh air room corresponding to a plurality of first accidents is determined. vent,l ; According to all the 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 .

15. The method according to claim 14, 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 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 .

16. The method according to claim 14, characterized in that The second alarm threshold L d Including the first level alarm threshold L d1 and the second level 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 allowable dose rate limit R L Determined as the secondary alarm threshold L d2 .

17. 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 C of the radioactive nuclide i in the main control room during the initial release period T3 of the first accident. i ; A first determining module is connected to the first obtaining module and is used to determine the average activity concentration C i , determine the first external radiation dose rate limit D allowed by the main control room ex,l ; A second determining module is connected to the first determining module 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 .

18. The device according to claim 17, characterized in that The first acquisition module is specifically used 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; Substituting the first activity concentration C(t), the second time T1 and the third time T2 into formula (1) for calculation, the average activity concentration C of the radionuclide i in the main control room during the first accident is obtained. i ; The formula (1) includes:

19. The device according to claim 17, 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 .

20. The device according to claim 17, characterized in that The second determination module may be specifically used for: Obtain 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:

21. A system for determining an alarm threshold of a monitoring instrument, characterized in that: include: The device for determining the alarm threshold value of the dose rate in the fresh air chamber according to any one of claims 17 to 20; 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 comprises: The third determination module is connected to the alarm threshold determination device for 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 determination module is connected to the third determination module and is used to determine the target allowable 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 .

22. The system according to claim 21, characterized in that The third determination module is specifically used 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 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 .

23. The system according to claim 21, characterized in that The second alarm threshold L d Including the first level alarm threshold L d1 and the second level alarm threshold L d2 ; The fourth determining module is specifically used for: 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 secondary alarm threshold L d2 .

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