An on-line continuous monitoring system and method for i-129 and kr-85

Abstract

The application discloses an I-129 and Kr-85 online continuous monitoring system and method, relates to the technical field of spent fuel reprocessing radiation monitoring, and comprises a Kr-85 sampling detection device, an input of a first I-129 sampling detection device, and an output of a Kr-85 sampling detection device; a second I-129 sampling detection device, an output of a Kr-85 sampling detection device, and an input of a flushing interface; and a flushing interface, an output of a first I-129 sampling detection device and a second I-129 sampling detection device, and an input of an electrical control box. The application controls the on-off state of solenoid valves YV2-YV5 through the electrical control box. The application can remove Kr-85 in sampling gas through air flushing and differential measurement, and can realize I-129 and Kr-85 online continuous measurement when the concentration difference between Kr-85 and I-129 is more than 10 9 times.

Description

Technical Field

[0001] This invention relates to the field of radiation monitoring technology for spent fuel reprocessing, and in particular to an online continuous monitoring system and method for I-129 and Kr-85. Background Technology

[0002] At the nuclear fuel element reprocessing site, after prolonged cooling, the radioactive gases in the fission products are mainly Kr-85 and I-129, with I-129 having a half-life as long as 1.57 × 10⁻⁶. 7 I-129 poses a long-term hazard to human health and the environment. Therefore, to ensure the safety of the environment and operators, it is essential to monitor the radioactivity of I-129 in the gaseous effluent from the process piping in nuclear fuel element reprocessing sites.

[0003] However, due to the extremely low content of I-129 in fission gases, and its activity differing from that of Kr-85 by at least 10, 6 On the order of magnitude, for example, a fuel rod with a burnup of 62 GW, after being cooled for five years, would have a Kr-85 activity of 7.06 × 10⁻⁶. 12 Bq, I-129 activity is 3.726 × 10⁻⁶ 6 Therefore, when continuously monitoring the activity concentration of I-129 in the gaseous effluent from the process pipelines of nuclear fuel element reprocessing sites, the influence of Kr-85 must be eliminated.

[0004] I-129 emits beta rays with a maximum energy of 151.2 keV with 100% probability, and simultaneously emits characteristic X-rays at 29.458 keV (branching ratio 19.9%), 29.779 keV (branching ratio 36.9%), 33.6 keV (branching ratio 13.1%), and 39.578 keV (branching ratio 7.5%), with a half-life of 1.57 × 10⁻⁶. 7 Kr-85 emits beta rays with a maximum energy of 687.1 keV with a 99.56% probability and beta rays with a maximum energy of 173.1 keV with a 0.44% probability during its decay process, accompanied by gamma rays of 513.9 keV. Its half-life is 10.73 years. Because beta decay exhibits a continuous spectrum, simply using beta counting methods cannot detect and distinguish Kr-85 from I-129 in a gas mixture; furthermore, because the concentration of Kr-85 is 10 times that of I-129... 6The strong β and γ fields generated by Kr-85 significantly interfere with the detection of low-energy rays from low-content I-129. Even considering only the 513.9 keV γ-ray emitted with a 0.44% probability during Kr-85 decay, its activity is 2 to 3 orders of magnitude higher than that of I-129. Therefore, when performing online continuous measurements of I-129 activity concentration, characteristic X-rays at 29.458 keV (branching ratio 19.9%), 29.779 keV (branching ratio 36.9%), 33.6 keV (branching ratio 13.1%), and 39.578 keV (branching ratio 7.5%) are used.

[0005] Existing equipment can achieve a concentration difference of 10 between Kr-85 and I-129 activity. 6 Online continuous measurement of I-129 activity concentration at times. If the difference between Kr-85 and I-129 activity concentrations is 10... 9 When the concentration of I-129 is multiples or higher, the online continuous measurement of I-129 activity concentration is significantly affected by Kr-85. Existing equipment cannot achieve online continuous measurement of I-129 activity concentration, nor can it achieve online monitoring of both I-129 and Kr-85 activity concentrations. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an online continuous monitoring system and method for I-129 and Kr-85, solving the problem that existing equipment cannot monitor Kr-85 and I-129 activity concentration differences of up to 10%. 9 The problem of achieving online monitoring of I-129 activity concentration and Kr-85 activity concentration in environments with concentrations of 100% or higher.

[0007] The present invention adopts the following technical solution: In a first aspect, the present invention provides an online continuous monitoring system for I-129 and Kr-85, comprising: The sampling inlet interface is connected to one end of the side wall of the process exhaust pipe. The input of the Kr-85 sampling and detection device is connected to the output of the sampling inlet interface; The input of the first I-129 sampling and detection device is connected to the output of the Kr-85 sampling and detection device. A shut-off valve V6, a solenoid valve YV2, and a shut-off valve V7 are provided between the output of the Kr-85 sampling and detection device and the input of the first I-129 sampling and detection device. The input of the second I-129 sampling and detection device is connected to the output of the Kr-85 sampling and detection device. A shut-off valve V6, a solenoid valve YV4, and a shut-off valve V8 are provided between the output of the Kr-85 sampling and detection device and the input of the second I-129 sampling and detection device. The flushing interface has its input connected to the air purging interface and its output connected to the input of the first I-129 sampling and detection device and the second I-129 sampling and detection device. A shut-off valve V2, a solenoid valve YV3 and a shut-off valve V7 are provided between the output of the flushing interface and the input of the first I-129 sampling and detection device, and a shut-off valve V2, a solenoid valve YV5 and a shut-off valve V8 are provided between the output of the flushing interface and the input of the second I-129 sampling and detection device. The electrical control box controls the on / off state of solenoid valves YV2 to YV5. The sampling return interface has its input connected to the output of the first I-129 sampling detection device and the second I-129 sampling detection device, and its output connected to the other side wall of the process exhaust pipe.

[0008] Preferably, both the first I-129 sampling and detection device and the second I-129 sampling and detection device include an iodine box, a main detector, and a compensation detector; the upper layer of the iodine box adopts a carbon fiber isolation layer, and the lower layer of the iodine box adopts a stainless steel shielding layer.

[0009] Preferably, the Kr-85 sampling and detection device includes a sampling measurement chamber, a sodium iodide detector, and a multichannel module. The input and output of the Kr-85 sampling and detection device are also equipped with a shut-off valve V5.

[0010] Preferably, a solenoid valve YV1, a shut-off valve V3, and a shut-off valve V4 are provided between the output of the sampling inlet interface and the input of the Kr-85 sampling and detection device.

[0011] Preferably, an aerosol filter is provided between the solenoid valve YV1 and the shut-off valve V3.

[0012] Preferably, a flow meter FM1, a flow regulating valve VR1, a switching shut-off valve V10, a sampling pump PU1, a shut-off valve V11, and a shut-off valve V14 are provided between the output of the first I-129 sampling and detection device and the input of the sampling return interface; a flow meter FM2, a flow regulating valve VR2, a shut-off valve V10, a sampling pump PU1, a shut-off valve V11, and a shut-off valve V14 are provided between the output of the second I-129 sampling and detection device and the input of the sampling return interface.

[0013] Preferably, a stop valve V12, a sampling pump PU2, and a stop valve V13 are further provided between the flow regulating valves VR1 and VR2 and the stop valve V14.

[0014] Preferred options also include: A thermometer is installed between shut-off valves V3 and V4. A pressure gauge is installed between the shut-off valve V6 and the solenoid valve YV2; The electrical control box is also used to control solenoid valve YV1, sampling pump PU1, sampling pump PU2, flow meter FM1, flow meter FM2, thermometer and pressure gauge; The data processing unit is used to process the data output by the Kr-85 sampling and detection device, the first I-129 sampling and detection device, and the second I-129 sampling and detection device.

[0015] Secondly, the present invention provides a monitoring method for an I-129 and Kr-85 online continuous monitoring system, comprising the following steps: Under the action of sampling pumps PU1 and PU2, the sampling inlet interface samples the gas, and the aerosol filtration device filters the aerosols in the sampled gas. The sodium iodide detector in the Kr-85 sampling and detection device measures the gamma rays of Kr-85 in the filtered sampled gas to obtain the active concentration measurement value of Kr-85. The electrical control box controls the on / off state of solenoid valves YV1-YV5. The first I-129 sampling detection device enters a sampling cycle, while the second I-129 sampling detection device simultaneously enters a rinsing cycle; or the second I-129 sampling detection device enters a sampling cycle, while the first I-129 sampling detection device simultaneously enters a rinsing cycle. During the sampling cycle, Kr-85 and I-129 in the filtered sampling gas are adsorbed and sampled using an iodine box. During the rinsing cycle, the iodine box is purged with air, and the first count rate is tested using the main detector, while the second count rate is tested using a compensation detector. The measured gas is then discharged back to the process exhaust pipe via the sampling return interface. The data processing unit calculates the difference between the first count rate and the second count rate, and combines the difference result with the flow information from the flow meter to obtain the activity concentration value of I-129.

[0016] Preferably, the electrical control box controls solenoid valve YV1 to open when de-energized, solenoid valves YV3 and YV4 to close when energized, and solenoid valves YV2 and YV5 to open when de-energized, so that the first I-129 sampling and detection device enters the sampling cycle, and the second I-129 sampling and detection device enters the flushing cycle simultaneously; the electrical control box controls solenoid valve YV1 to open when de-energized, solenoid valves YV3 and YV4 to open when de-energized, and solenoid valves YV2 and YV5 to close when energized, so that the second I-129 sampling and detection device enters the sampling cycle, and simultaneously controls the first I-129 sampling and detection device to enter the flushing cycle.

[0017] Compared with the prior art, the above-mentioned at least one technical solution adopted by the present invention can achieve the following beneficial effects: The continuous monitoring system of this invention includes a Kr-85 sampling detection device, a first I-129 sampling detection device, and a second I-129 sampling detection device. A shut-off valve V6, a solenoid valve YV2, and a shut-off valve V7 are provided between the output of the Kr-85 sampling detection device and the input of the first I-129 sampling detection device, and a shut-off valve V6, a solenoid valve YV4, and a shut-off valve V8 are provided between the output of the flushing interface and the input of the first I-129 sampling detection device, and a shut-off valve V2, a solenoid valve YV3, and a shut-off valve V7 are provided between the output of the flushing interface and the input of the first I-129 sampling detection device, and a shut-off valve V2, a solenoid valve YV5, and a shut-off valve V8 are provided between the output of the flushing interface and the input of the second I-129 sampling detection device. The on / off states of solenoid valves YV2-YV5 are controlled by an electrical control box, so that one of the first I-129 sampling detection device and the second I-129 sampling detection device is in sampling mode, and the other is in air blowing mode. Kr-85 was removed from the sampled gas using both air rinsing and differential measurement, achieving a concentration difference of less than 10 between Kr-85 and I-129. 9 It can achieve online continuous measurement of I-129 and Kr-85 by more than 10 times. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of an online continuous monitoring system for I-129 and Kr-85 according to the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides an online continuous monitoring and radionuclide analysis system for I-129 and Kr-85 under a high activity concentration of Kr-85 background. It aims to solve the problems of existing technologies that cannot perform radionuclide analysis, cannot perform online continuous monitoring, cannot simultaneously monitor the activity concentrations of Kr-85 and I-129, and cannot achieve high concentration differences (10⁻⁶) between Kr-85 and I-129. 9Issues such as achieving I-129 monitoring under the background of (multiple times or more).

[0022] Reference Figure 1 The I-129 and Kr-85 online continuous monitoring system of the present invention includes an external interface (including a sampling inlet interface and a sampling return interface), solenoid valves YV1-YV5, shut-off valves V1-V14, flow regulating valves VR1-VR2, an aerosol filter, a thermometer T, a pressure gauge PS1, flow meters FM1-FM2, and an inert gas sampling and detection device (including an integrated lead chamber, a sampling and measurement chamber, and a...). The system includes a 50×50 sodium iodide detector and a multi-channel module, an I-129 sampling and detection device (including an integrated lead chamber, two iodine samples, two main detectors, two compensation detectors and four programmable single channels), two sampling pumps PU1-PU2, an electrical control box and a data processing unit.

[0023] V5 is the maintenance bypass valve for the inert gas sampling and detection device. When the inert gas sampling and detection device malfunctions and requires maintenance, shut-off valve V5 is opened, and shut-off valves V4 and V6 are closed to ensure the normal operation of the subsequent I-129 sampling and detection device. V2 is the air flushing valve for the I-129 sampling and detection device, used to flush iodine box 1 or iodine box 2 after sampling. The four solenoid valves YV2 to YV5 are used to achieve the requirement of dual-path gas alternation measurement. V10, V11 and V12, V13 are the inlet and outlet valves of the two sampling pumps. They are all open during normal operation to ensure automatic switching to the other sampling pump when the equipment fails. At the same time, when replacing the faulty pump, it is only necessary to close the valves corresponding to the inlet and outlet of the faulty pump to replace the faulty pump without interrupting the measurement.

[0024] The sampling gas enters through the sampling inlet interface and first passes through an aerosol filter. The aerosol filter filters out aerosols in the sampling gas to prevent them from affecting subsequent monitoring. During the sampling process, solenoid valve YV1 is de-energized and opened, shut-off valves V2, V3, V4, V6, V7, V8, V10, V11, V12, V13, and V14 are opened, shut-off valves V1, V5, and V9 are closed, and regulating valves VR1 and VR2 are opened.

[0025] The sampled gas, after passing through the aerosol filter, enters the inert gas sampling and detection device. Because the Kr-85 activity concentration in the inert gas is high, therefore... A 50×50 sodium iodide detector measures 513.9 keV gamma rays with a branching ratio of 0.44% in Kr-85. This sampling and detection device also includes a multi-channel module for monitoring and analyzing other radionuclides that may be present in the sampled gas. The device employs an integrated lead chamber to shield the sampling measurement cavity and sodium iodide detector with 4π lead. The effective shielding thickness of the lead chamber is 50 mm, reducing the environmental dose rate by 200 times, avoiding the influence of external radiation fields on the equipment, and lowering the measurement limit. The sensitive volume of the sampling measurement cavity is approximately 1 L, and its well-type design effectively improves the sensitivity of the equipment.

[0026] The I-129 sampling and detection device can measure the activity concentration of I-129. The device uses an iodine box to adsorb I-129 in the sampled gas. Since the iodine box itself will retain inert gases to a certain extent, and this retention can be removed by air rinsing, but this removal becomes very slow as the rinsing time increases. Therefore, this part uses two measures, air rinsing and differential measurement, to remove Kr-85 from the sampled gas. The working mode of dual-channel gas alternation measurement is adopted to realize the online continuous monitoring of I-129.

[0027] Kr-85 removal from the sampled gas is achieved through a combination of air rinsing and differential measurement. Specifically, the iodine box first undergoes sampling at a period of T, followed by air rinsing at a period of T to remove Kr-85 adsorbed within the iodine sampler cavity and the iodine box itself. During the air rinsing period of T, the upper layer of the iodine box is designed with a carbon fiber isolation layer. The main detector above can detect the radioactivity of I-129 and Kr-85, and the count rate measured by the main detector at this time is... + The lower layer of the iodine box is designed with a stainless steel shielding layer, preventing the passage of I-129 low-energy rays. The compensation detector below can only detect the radioactivity of Kr-85, and at this point, the count rate measured by the compensation detector is... Then, the main detector count rate is used. + Deduct compensation detector count rate The I-129 count rate on the iodine box can be obtained. .

[0028] This monitoring system includes iodine container 1 and iodine container 2. The two iodine containers are sampled alternately at a period T. Therefore, the valves in this monitoring system have two on / off states. In one on / off state, iodine container 1 is sampling while iodine container 2 is being air-purified. In this state, the valve status is as follows: solenoid valve YV1 is de-energized and open; shut-off valves V2, V3, V4, V6, V7, V8, V10, V11, V12, V13, and V14 are open; shut-off valves V1, V5, and V9 are closed; regulating valves VR1 and VR2 are open; and solenoid valve YV3... In one scenario, YV4 is energized and closed, while solenoid valves YV2 and YV5 are de-energized and open. In another scenario, iodine box 2 is sampled and iodine box 1 is air-purged. In this scenario, solenoid valve YV1 is de-energized and open, shut-off valves V2, V3, V4, V6, V7, V8, V10, V11, V12, V13, and V14 are open, shut-off valves V1, V5, and V9 are closed, regulating valves VR1 and VR2 are open, solenoid valves YV2 and YV5 are energized and closed, and solenoid valves YV3 and YV4 are de-energized and open.

[0029] Since measurements can only be taken during air purging, sampling stops during this process. This prevents the sampling gas from being sampled during air purging, thus making radioactivity monitoring impossible. Therefore, a dual-channel gas alternation measurement mode is designed to achieve continuous measurement. Specifically, the I-129 gas sampling pipeline consists of two channels: channel 1 and channel 2. Channel 1 is connected to iodine sampling 1 (iodine box 1), and channel 2 is connected to iodine sampling 2 (iodine box 2). The dual-channel gas switching time is determined by the dual-channel gas switching measurement cycle T. Within a certain time T, the system controls solenoid valves YV3 and YV4 to be energized and engaged, while YV2 and YV5 are de-energized, so that the sampling gas passes through pipeline 1 and iodine sampling 1 (iodine box 1), and the purge air passes through pipeline 2 and iodine sampling 2 (iodine box 2). After time T, the system controls solenoid valves YV2 and YV5 to be energized and engaged, while YV3 and YV4 are de-energized, so that the sampling gas passes through pipeline 2 and iodine sampling 2 (iodine box 2), and the purge air passes through pipeline 1 and iodine sampling 1 (iodine box 1).

[0030] The flow meter is used to measure the flow rate of the sampled gas, providing flow information for the calculation of I-129 activity concentration.

[0031] The thermometer and pressure gauge are used to monitor the temperature and pressure of the sampled gas. If the temperature remains above the upper temperature threshold or below the lower temperature threshold for a period of time, or if the pressure remains above the upper pressure threshold or below the lower pressure threshold for a period of time, the system will determine that operation under these conditions will damage the equipment. It will automatically stop the sampling pump and start the solenoid valve YV1 to protect the equipment, while also issuing a fault alarm and uploading the signal.

[0032] The sampling pump is used to provide power for the sampling gas, enabling the gas to reach the sampling detection device and be discharged into the main discharge pipeline. This design uses a chemical corrosion resistant diaphragm vacuum pump to ensure long-term stable and effective operation of the sampling pump. This system adopts a dual-pump design, which can automatically switch to the standby pump when a sampling pump failure is detected to ensure the normal operation of the equipment.

[0033] The electrical control box is the electrical control center of the system. The automatic switching control of the sampling pump and the energization and engagement of the solenoid valve are all completed by the electrical control box. At the same time, the electrical control box provides power to the data processing unit, inert gas sampling and detection device, I-129 sampling and detection device, thermometer, pressure gauge, flow meter, solenoid valve, sampling pump and other equipment, and provides various types of input / output terminals for the system.

[0034] The data processing unit is the control center of the system. Its main functions include receiving and processing data sent by the detector, calculating the I-129 activity concentration and Kr-85 activity concentration based on the detector data and the flow information of the flow meter, displaying the measurement data according to the set format and automatically switching the dimensions; and displaying or issuing corresponding status indicators or audible and visual alarm signals and uploading them according to the preset threshold.

[0035] Meanwhile, the data processing unit can automatically switch the pump, control the dual-channel gas rotation measurement cycle, and automatically stop the pump and control the solenoid valve YV1 to engage when the temperature or pressure of the sampled gas is abnormal.

[0036] This invention can achieve a concentration difference of 10 between Kr-85 and I-129. 9 This invention enables online continuous measurement of I-129 by more than 10 times; it can simultaneously achieve online continuous monitoring of Kr-85 and I-129; it can analyze the nuclide composition in the sampled gas in real time; it can perform self-diagnosis of the temperature and pressure of the sampled gas, and the equipment can automatically stop after detecting abnormalities.

[0037] In addition, since the mixed gas contains acidic substances (nitrogen oxides, single acids, or complex acids), this equipment also has acid and corrosion resistance to ensure long-term stable and reliable operation.

[0038] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0039] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An online continuous monitoring system for I-129 and Kr-85, characterized in that, include: The sampling inlet interface is connected to one end of the side wall of the process exhaust pipe. The input of the Kr-85 sampling and detection device is connected to the output of the sampling inlet interface; The input of the first I-129 sampling and detection device is connected to the output of the Kr-85 sampling and detection device. A shut-off valve V6, a solenoid valve YV2, and a shut-off valve V7 are provided between the output of the Kr-85 sampling and detection device and the input of the first I-129 sampling and detection device. The input of the second I-129 sampling and detection device is connected to the output of the Kr-85 sampling and detection device. A shut-off valve V6, a solenoid valve YV4, and a shut-off valve V8 are provided between the output of the Kr-85 sampling and detection device and the input of the second I-129 sampling and detection device. The flushing interface has its input connected to the air purging interface and its output connected to the input of the first I-129 sampling and detection device and the second I-129 sampling and detection device. A shut-off valve V2, a solenoid valve YV3 and a shut-off valve V7 are provided between the output of the flushing interface and the input of the first I-129 sampling and detection device, and a shut-off valve V2, a solenoid valve YV5 and a shut-off valve V8 are provided between the output of the flushing interface and the input of the second I-129 sampling and detection device. The electrical control box controls the on / off state of solenoid valves YV2 to YV5. The sampling return interface has its input connected to the output of the first I-129 sampling detection device and the second I-129 sampling detection device, and its output connected to the other side wall of the process exhaust pipe.

2. The I-129 and Kr-85 online continuous monitoring system as described in claim 1, characterized in that, Both the first I-129 sampling and detection device and the second I-129 sampling and detection device include an iodine box, a main detector and a compensation detector; the upper layer of the iodine box adopts a carbon fiber isolation layer and the lower layer of the iodine box adopts a stainless steel shielding layer.

3. The I-129 and Kr-85 online continuous monitoring system as described in claim 1, characterized in that, The Kr-85 sampling and detection device includes a sampling measurement chamber, a sodium iodide detector, and a multichannel module. The input and output of the Kr-85 sampling and detection device are also equipped with a shut-off valve V5.

4. The I-129 and Kr-85 online continuous monitoring system as described in claim 1, characterized in that, A solenoid valve YV1, a shut-off valve V3, and a shut-off valve V4 are provided between the output of the sampling inlet interface and the input of the Kr-85 sampling and detection device.

5. The I-129 and Kr-85 online continuous monitoring system as described in claim 4, characterized in that, An aerosol filter is provided between the solenoid valve YV1 and the shut-off valve V3.

6. The I-129 and Kr-85 online continuous monitoring system as described in claim 5, characterized in that, The first I-129 sampling and detection device is equipped with a flow meter FM1, a flow regulating valve VR1, a switching shut-off valve V10, a sampling pump PU1, a shut-off valve V11, and a shut-off valve V14 between its output and the input of the sampling return interface; the second I-129 sampling and detection device is equipped with a flow meter FM2, a flow regulating valve VR2, a shut-off valve V10, a sampling pump PU1, a shut-off valve V11, and a shut-off valve V14 between its output and the input of the sampling return interface.

7. The I-129 and Kr-85 online continuous monitoring system as described in claim 6, characterized in that, Between the flow regulating valves VR1 and VR2 and the shut-off valve V14, there is also a shut-off valve V12, a sampling pump PU2, and a shut-off valve V13.

8. The I-129 and Kr-85 online continuous monitoring system as described in claim 7, characterized in that, Also includes: A thermometer is installed between shut-off valves V3 and V4. A pressure gauge is installed between the shut-off valve V6 and the solenoid valve YV2; The electrical control box is also used to control solenoid valve YV1, sampling pump PU1, sampling pump PU2, flow meter FM1, flow meter FM2, thermometer and pressure gauge; The data processing unit is used to process the data output by the Kr-85 sampling and detection device, the first I-129 sampling and detection device, and the second I-129 sampling and detection device.

9. A monitoring method for the I-129 and Kr-85 online continuous monitoring system according to any one of claims 1-8, characterized in that, Includes the following steps: Under the action of sampling pumps PU1 and PU2, the sampling inlet interface samples the gas, and the aerosol filtration device filters the aerosols in the sampled gas. The sodium iodide detector in the Kr-85 sampling and detection device measures the gamma rays of Kr-85 in the filtered sampled gas to obtain the active concentration measurement value of Kr-85. The electrical control box controls the on / off state of solenoid valves YV1-YV5. The first I-129 sampling detection device enters a sampling cycle, while the second I-129 sampling detection device simultaneously enters a rinsing cycle; or the second I-129 sampling detection device enters a sampling cycle, while the first I-129 sampling detection device simultaneously enters a rinsing cycle. During the sampling cycle, Kr-85 and I-129 in the filtered sampling gas are adsorbed and sampled using an iodine box. During the rinsing cycle, the iodine box is purged with air, and the first count rate is tested using the main detector, while the second count rate is tested using a compensation detector. The measured gas is then discharged back to the process exhaust pipe via the sampling return interface. The data processing unit calculates the difference between the first count rate and the second count rate, and combines the difference result with the flow information from the flow meter to obtain the activity concentration value of I-129.

10. The monitoring method of the I-129 and Kr-85 online continuous monitoring system as described in claim 9, characterized in that, The electrical control box controls solenoid valve YV1 to open when de-energized, solenoid valves YV3 and YV4 to close when energized, and solenoid valves YV2 and YV5 to open when de-energized. This initiates the sampling cycle for the first I-129 sampling and detection device, while simultaneously initiating the flushing cycle for the second I-129 sampling and detection device. The electrical control box also controls solenoid valve YV1 to open when de-energized, solenoid valves YV3 and YV4 to open when de-energized, and solenoid valves YV2 and YV5 to close when energized. This initiates the sampling cycle for the second I-129 sampling and detection device, while simultaneously controlling the first I-129 sampling and detection device to enter the flushing cycle.

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