阅读说明：本技术 一种用于核设施碘吸附器吸附效率测试的设备及其方法 (Equipment and method for testing adsorption efficiency of iodine adsorber of nuclear facility ) 是由 俞杰 李永国 张计荣 任宏正 陈建利 杨彪 高琳锋 孔海霞 吴波 丘丹圭 刘群 于 2019-09-03 设计创作，主要内容包括：本发明涉及一种用于核设施碘吸附器吸附效率测试的设备,包括与碘吸附器进气端连接的试验试剂导入组件以及与碘吸附器出气端连接的试验试剂导出组件,试验试剂导入组件包括与碘吸附器进气端连接的试验试剂导入管,试验试剂导入管的端部连接进风风机,试验试剂导入管连接上游采集管和试验试剂注入管；所述试验试剂导出组件包括与碘吸附器出气端连接的试验试剂导出管,试验试剂导出管端部连接出风风机,试验试剂导出管连接下游采集管；所述上游采集管和下游采集管均连接试验试剂收集组件。本发明采用非放射性碘甲烷作为试验试剂对碘吸附器进行效率测试,不仅可以避免在碘吸附器效率试验中的放射性操作,降低操作风险,减少操作人员集体受照剂量。(The invention relates to equipment for testing the adsorption efficiency of an iodine adsorber of a nuclear facility, which comprises a test reagent lead-in component connected with the air inlet end of the iodine adsorber and a test reagent lead-out component connected with the air outlet end of the iodine adsorber, wherein the test reagent lead-in component comprises a test reagent lead-in pipe connected with the air inlet end of the iodine adsorber, the end part of the test reagent lead-in pipe is connected with an air intake fan, and the test reagent lead-in pipe is connected with an upstream collection pipe and a test reagent injection pipe; the test reagent leading-out assembly comprises a test reagent leading-out pipe connected with the air outlet end of the iodine adsorber, the end part of the test reagent leading-out pipe is connected with an air outlet fan, and the test reagent leading-out pipe is connected with a downstream collection pipe; the upstream collection tube and the downstream collection tube are both connected to a test reagent collection assembly. The invention adopts the nonradioactive methyl iodide as the test reagent to carry out the efficiency test on the iodine adsorber, thereby not only avoiding the radioactive operation in the efficiency test of the iodine adsorber, reducing the operation risk and reducing the collective irradiated dose of operators.)

1. A device for testing the adsorption efficiency of an iodine adsorber of a nuclear facility comprises a test reagent leading-in component connected with the air inlet end of the iodine adsorber and a test reagent leading-out component connected with the air outlet end of the iodine adsorber, and is characterized in that the test reagent leading-in component comprises a test reagent leading-in pipe connected with the air inlet end of the iodine adsorber, the end part of the test reagent leading-in pipe is connected with an air intake fan, and the test reagent leading-in pipe is connected with an upstream collection pipe and a test reagent injection pipe; the test reagent leading-out assembly comprises a test reagent leading-out pipe connected with the air outlet end of the iodine adsorber, the end part of the test reagent leading-out pipe is connected with an air outlet fan, and the test reagent leading-out pipe is connected with a downstream collection pipe; the upstream collection tube and the downstream collection tube are both connected to a test reagent collection assembly.

2. The device for testing the adsorption efficiency of the iodine adsorber of the nuclear facility as claimed in claim 1, wherein the test reagent is nitrogen or air mixed gaseous methyl iodide, and the concentration of the test reagent is 1-5000 ppm.

3. The apparatus of claim 1, wherein the test reagent is ethanol mixed liquid nonradioactive methyl iodide with a volume concentration of 0.005-99.5%.

4. The device for testing the adsorption efficiency of the iodine adsorber of the nuclear facility as claimed in claim 2 or 3, wherein the test reagent introducing pipe is provided with a filter, a heater and a turbulator; the test reagent delivery pipe is provided with a regulating valve, and the carrier gas flow of the detected iodine adsorber system is 50-100000m³/h。

5. The apparatus for testing adsorption efficiency of the iodine adsorber in the nuclear plant according to claim 4, wherein the test reagent injection pipe is connected with the methyl iodide injection device, and methyl iodide gas is introduced into the test reagent introduction pipe by using a continuous stable injection or pulse injection method, and the concentration of methyl iodide in the gas flow of the test reagent introduction pipe is in the range of 1ppb to 1000 ppm.

6. The apparatus of claim 5, wherein the test reagent collection component is a methyl iodide analyzer, and the methyl iodide concentration measurement value in the gas flow is measured by introducing the sample gas directly into the methyl iodide analyzer through a sampling pump built in the methyl iodide analyzer.

7. The device for testing the adsorption efficiency of the iodine adsorber in the nuclear facility as claimed in claim 5, wherein the test reagent collecting component is an atmospheric sampling bag or an atmospheric sampling tank, and the methyl iodide gas in the upstream collecting pipe and the downstream collecting pipe is collected and measured by directly storing the sample gas in the atmospheric sampling bag or the atmospheric sampling tank through a sampling pump, and then the sample gas is introduced into the measuring instrument to measure the methyl iodide concentration measurement value in the gas flow, wherein the sampling volume is 0.1L-5L.

8. The device for testing the adsorption efficiency of the iodine adsorber in the nuclear facility as claimed in claim 5, wherein the methyl iodide gas in the upstream collection pipe and the downstream collection pipe is collected by collecting a sample into the sampling device through a low-temperature enrichment method, and the enriched sample is desorbed from the sampling device through a thermal desorption method and is introduced into the measuring instrument during measurement, so that the measured value of the methyl iodide concentration in the gas flow is measured.

9. The device for testing the adsorption efficiency of the iodine adsorber of the nuclear facility as claimed in claim 5, wherein the adsorption efficiency of the iodine adsorber is calculated according to the following formula:

efficiency of

C_up-concentration of nonradioactive methyl iodide gas (ppb or ppm) in upstream collection tubes

C_down-non-radioactive methyl iodide gas concentration (ppb or ppm) in downstream collection tubes.

10. A method for testing the adsorption efficiency of an iodine adsorber of a nuclear facility is characterized by comprising the following steps:

s1, connecting an air inlet end of an iodine adsorber to be tested with a test reagent lead-in pipe, and connecting an air outlet end of the iodine adsorber to be tested with a test reagent lead-out pipe;

s2, opening an air inlet fan and an air outlet fan, adjusting the air quantity of the system to be within +/-10% of the rated air quantity of the iodine adsorber, enabling the relative humidity of air flow to be not higher than 40%, and starting a heater to reduce the relative humidity if the relative temperature does not meet the requirement;

s3, starting a methyl iodide injection device after the air flow conditions meet the requirements, introducing methyl iodide gas into a test reagent introduction pipe by the methyl iodide injection device by adopting a continuous stable injection or pulse injection method, and collecting gas samples through an upstream collection pipe and a downstream collection pipe by a test reagent collection assembly;

s4, stopping collecting the gas sample, and respectively testing the concentration of methyl iodide gas in the gas sample of the upstream collecting pipe and the gas sample of the downstream collecting pipe through the test reagent collecting assembly;

and S5, calculating the adsorption efficiency of the iodine adsorber to be tested according to an efficiency formula.

Technical Field

The invention relates to the technical field of nuclear industry, in particular to equipment and a method for testing adsorption efficiency of an iodine adsorber of a nuclear facility.

Background

The nuclear power plant inevitably generates gaseous radioactive iodine in normal operation or in an accident state, although the concentration of the radioactive iodine is very low, the release of the radioactive iodine can cause great harm to the health of a human body because the thyroid of the human body has very strong absorption and enrichment capacity to the radioactive iodine, so that an iodine adsorber is usually arranged in ventilation systems of nuclear facilities such as a large-scale nuclear power plant and the like and is used for removing the gaseous iodine generated in normal operation or in an accident condition so as to ensure that working personnel, the public and the environment are prevented from radiation damage. The effectiveness of the iodine adsorber needs to be evaluated after the iodine adsorber is installed or replaced for the first time, and the effectiveness verification needs to be carried out after the iodine adsorber operates for a period of time so as to ensure the integrity and the reliability of the iodine removing and filtering functions of the iodine adsorber.

The radioactive methyl iodide method commonly used for the efficiency test method of the iodine adsorber is that I-131 labeled methyl iodide is used as a test reagent, radioactive methyl iodide gas is continuously and stably injected into the iodine adsorber far enough upstream of the ventilation system, and simultaneously, radioactive methyl iodide gas samples are collected by activated carbon boxes at the upstream and the downstream of the iodine adsorber. And (3) obtaining the purification capacity value of the iodine adsorber to the radioactive methyl iodide through activity measurement analysis calculation of upstream and downstream radioactive iodine samples to evaluate the performance of the iodine adsorber. The radioactive methyl iodide method has the advantages that the measurement sensitivity is extremely high, an accurate measurement result can be obtained by adding a very small amount of test reagent, the consumption of the test on the adsorption capacity of an iodine adsorber can be completely ignored, in addition, the methyl iodide marked by I-131 has a very obvious characteristic peak, and the anti-interference capability of the test measurement is strong, so the radioactive methyl iodide method is widely adopted. However, when the method is used for carrying out the efficiency test of the iodine adsorber on the site, certain defects exist, such as the risks of personnel and environmental pollution after radioactive leakage whether the radioactive source is purchased, transported, stored and managed or radioactive operation on the test site. While various measures have been taken to prevent the occurrence of an event and reduce injury to personnel, the objective presence of a source of danger makes the occurrence of a radiological handling event merely a probabilistic problem and does not fundamentally eliminate the potential safety hazard. Therefore, the development of a safe and reliable non-radioactive test method of the iodine adsorber, which is friendly to workers and the environment, is of great significance.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides equipment and a method for testing the adsorption efficiency of an iodine adsorber of a nuclear facility.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a device for testing the adsorption efficiency of an iodine adsorber of a nuclear facility comprises a test reagent leading-in component connected with the air inlet end of the iodine adsorber and a test reagent leading-out component connected with the air outlet end of the iodine adsorber, wherein the test reagent leading-in component comprises a test reagent leading-in pipe connected with the air inlet end of the iodine adsorber, the end part of the test reagent leading-in pipe is connected with an air inlet fan, and the test reagent leading-in pipe is connected with an upstream collection pipe and a test reagent injection pipe; the test reagent leading-out assembly comprises a test reagent leading-out pipe connected with the air outlet end of the iodine adsorber, the end part of the test reagent leading-out pipe is connected with an air outlet fan, and the test reagent leading-out pipe is connected with a downstream collection pipe; the upstream collection tube and the downstream collection tube are both connected to a test reagent collection assembly.

Further, the test reagent is nitrogen or air mixed gaseous methyl iodide, and the concentration of the test reagent is 1-5000 ppm.

Further, the test reagent is ethanol mixed liquid nonradioactive methyl iodide, and the volume concentration is 0.005-99.5%.

Further, a filter, a heater and a turbulator are arranged on the test reagent introducing pipe; the test reagent delivery pipe is provided with a regulating valve, and the carrier gas flow of the detected iodine adsorber system is 50-100000m³/h。

Furthermore, the test reagent injection pipe is connected with a methyl iodide injection device, methyl iodide gas is introduced into the test reagent introduction pipe by adopting a continuous stable injection or pulse injection method, and the concentration of methyl iodide in the gas flow of the test reagent introduction pipe is in the range of 1ppb to 1000 ppm.

Further, the test reagent collecting component is a methyl iodide analysis measuring instrument, a sampling pump is arranged in the methyl iodide analysis measuring instrument to directly guide the sample gas into the methyl iodide analysis measuring instrument, and the methyl iodide concentration measurement value in the gas flow is measured.

Furthermore, the test reagent collecting assembly is an atmospheric sampling bag or an atmospheric sampling tank, and the methyl iodide gas in the upstream collecting pipe and the methyl iodide gas in the downstream collecting pipe are collected and measured by directly storing the sample gas in the atmospheric sampling bag or the atmospheric sampling tank through a sampling pump and then guiding the sample gas into a measuring instrument to measure the methyl iodide concentration measurement value in the gas flow, wherein the sampling volume is 0.1L-5L.

Further, the methyl iodide gas in the upstream collecting pipe and the downstream collecting pipe is collected into the sampling device through a low-temperature enrichment method, and the enriched sample is desorbed from the sampling device through a thermal desorption method and is introduced into the measuring instrument during measurement, so that the measured value of the methyl iodide concentration in the gas flow is measured.

Further, the adsorption efficiency of the iodine adsorber is calculated as follows:

efficiency of

C_up-concentration of nonradioactive methyl iodide gas (ppb or ppm) in upstream collection tubes

C_down-non-radioactive methyl iodide gas concentration (ppb or ppm) in downstream collection tubes.

A method for testing the adsorption efficiency of an iodine adsorber of a nuclear facility comprises the following steps:

s1, connecting an air inlet end of an iodine adsorber to be tested with a test reagent lead-in pipe, and connecting an air outlet end of the iodine adsorber to be tested with a test reagent lead-out pipe;

s2, opening an air inlet fan and an air outlet fan, adjusting the air quantity of the system to be within +/-10% of the rated air quantity of the iodine adsorber, enabling the relative humidity of air flow to be not higher than 40%, and starting a heater to reduce the relative humidity if the relative temperature does not meet the requirement;

s3, starting a methyl iodide injection device after the air flow conditions meet the requirements, introducing methyl iodide gas into a test reagent introduction pipe by the methyl iodide injection device by adopting a continuous stable injection or pulse injection method, and collecting gas samples through an upstream collection pipe and a downstream collection pipe by a test reagent collection assembly;

s4, stopping collecting the gas sample, and respectively testing the concentration of methyl iodide gas in the gas sample of the upstream collecting pipe and the gas sample of the downstream collecting pipe through the test reagent collecting assembly;

and S5, calculating the adsorption efficiency of the iodine adsorber to be tested according to an efficiency formula.

The invention has the beneficial effects that: the method adopts the non-radioactive methyl iodide as the test reagent to carry out the efficiency test on the iodine adsorber, so that the radioactive operation in the efficiency test of the iodine adsorber can be avoided, the operation risk is reduced, the collective irradiated dose of operators is reduced, and the condition of radioactive gas discharge caused by unqualified adsorption efficiency or misoperation of the iodine adsorber in the test process is eliminated; and the links of purchasing, transporting, storing and the like of the radioactive source in the efficiency test of the iodine adsorber can be avoided, and the production management cost of the power station is reduced.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Detailed Description

As shown in fig. 1, an apparatus for testing adsorption efficiency of an iodine adsorber of a nuclear facility comprises a test reagent introduction assembly connected with an air inlet end of an iodine adsorber 1 and a test reagent introduction assembly connected with an air outlet end of the iodine adsorber 1, wherein the test reagent introduction assembly comprises a test reagent introduction pipe 2 connected with the air inlet end of the iodine adsorber 1, an air intake fan is connected with an end part of the test reagent introduction pipe 2, and the test reagent introduction pipe 2 is connected with an upstream collection pipe 3 and a test reagent injection pipe 4; the test reagent leading-out component comprises a test reagent leading-out pipe 5 connected with the air outlet end of the iodine adsorber 1, the end part of the test reagent leading-out pipe 5 is connected with an air outlet fan 6, and the test reagent leading-out pipe 5 is connected with a downstream collection pipe 7; both the upstream collection tube 3 and the downstream collection tube 7 are connected to a test reagent collection assembly.

In the invention, the test reagent is nitrogen or air mixed gaseous methyl iodide, and the concentration of the test reagent is 1-5000 ppm. The test reagent is ethanol mixed liquid nonradioactive methyl iodide with the volume concentration of 0.005-99.5%.

Further, a filter 8, a heater 9 and a turbulator 10 are mounted on the test reagent introduction tube 2; the test reagent delivery pipe 5 is provided with an adjusting valve 11, and the system carrier gas flow of the detected iodine adsorber 1 is 50-100000m³H is used as the reference value. The filter 8 plays a role in filtering gas, the heater 9 plays a role in dehumidifying gas, and the turbulator 10 ensures the stability of gas flow. In addition, a differential pressure gauge 12 may be connected between the test reagent introduction tube 2 and the test reagent discharge tube 5 at both ends of the iodine adsorber 1, and the differential pressure gauge 12 may monitor the pressure difference at both ends of the iodine adsorber 1.

The test reagent injection pipe 4 is connected with a methyl iodide injection device, methyl iodide gas is introduced into the test reagent introduction pipe by adopting a continuous stable injection or pulse injection method, and the concentration of methyl iodide in the gas flow of the test reagent introduction pipe is in the range of 1 ppb-1000 ppm.

In the invention, the test reagent collecting component is a methyl iodide analysis measuring instrument, and a sampling pump is arranged in the methyl iodide analysis measuring instrument to directly introduce the sample gas into the methyl iodide analysis measuring instrument and measure the methyl iodide concentration measurement value in the gas flow;

the test reagent collecting assembly can also be an atmospheric sampling bag or an atmospheric sampling tank, and the methyl iodide gas in the upstream collecting pipe 3 and the downstream collecting pipe 7 is collected and measured by directly storing the sample gas in the atmospheric sampling bag or the atmospheric sampling tank through a sampling pump and then introducing the sample gas into a measuring instrument to measure the methyl iodide concentration measurement value in the gas flow, wherein the sampling volume is 0.1L-5L.

The methyl iodide gas in the upstream collection pipe 3 and the downstream collection pipe 7 is collected by collecting a sample into a sampling device through a low-temperature enrichment method, and the enriched sample is desorbed from the sampling device through a thermal desorption method and is introduced into a measuring instrument during measurement, so that the measured value of the methyl iodide concentration in the gas flow is measured.

Further, the adsorption efficiency of the iodine adsorber is calculated as follows:

efficiency of

C_up-concentration of nonradioactive methyl iodide gas (ppb or ppm) in upstream collection tubes

C_down-non-radioactive methyl iodide gas concentration (ppb or ppm) in downstream collection tubes.

The method for testing the adsorption efficiency of the iodine adsorber of the nuclear facility comprises the following steps:

s1, connecting an air inlet end of an iodine adsorber to be tested with a test reagent lead-in pipe, and connecting an air outlet end of the iodine adsorber to be tested with a test reagent lead-out pipe;

s2, opening an air inlet fan and an air outlet fan, adjusting the air quantity of the system to be within +/-10% of the rated air quantity of the iodine adsorber, enabling the relative humidity of air flow to be not higher than 40%, and starting a heater 9 to reduce the relative humidity if the relative temperature does not meet the requirement;

s3, starting a methyl iodide injection device after the air flow conditions meet the requirements, introducing methyl iodide gas into the test reagent introducing pipe 2 by the methyl iodide injection device by adopting a continuous stable injection or pulse injection method, and collecting gas samples through the upstream collecting pipe 3 and the downstream collecting pipe 7 by the test reagent collecting assembly;

s4, stopping collecting the gas sample, and respectively testing the concentration of methyl iodide gas in the gas sample of the upstream collecting pipe and the gas sample of the downstream collecting pipe through the test reagent collecting assembly;

and S5, calculating the adsorption efficiency of the iodine adsorber to be tested according to the efficiency formula.

The measurement method specifically comprises two methods:

method one (off-line measurement method): and when the air flow condition meets the requirement, starting the gas injection device, injecting methyl iodine gas into the ventilation system at the injection port of the system in a pulse or continuous stable injection mode, and simultaneously collecting gas samples by using a low-temperature enrichment method at the upstream collection pipe 3 and the downstream collection pipe 7 of the iodine adsorber, or directly collecting the gas samples in an atmosphere sampling bag or a sampling tank with the inner surface subjected to special treatment. After the methyl iodide injection was completed, sample collection was stopped. And (4) bringing the sample back to the laboratory for methyl iodide concentration measurement, and calculating the adsorption efficiency of the iodine adsorber to be tested according to an efficiency formula.

Method two (on-line measurement): when the gas flow conditions meet the requirements, a methyl iodide injection device is connected to an injection port of the system, an upstream collection pipe 3 and a downstream collection pipe 7 of the iodine adsorber are respectively connected with a methyl iodide analysis measuring instrument, the analysis measuring instrument is started, when the detector works stably, the methyl iodide gas injection device is started, methyl iodide gas is injected into a ventilation system in a pulse or continuous stable injection mode, and simultaneously, the measured values of the methyl iodide concentration in the upstream gas flow and the downstream gas flow are respectively recorded. And after the injection is finished, calculating the total injection amount and the total penetration amount of the methyl iodide in the upstream and downstream gas flow according to the concentration value. And calculating the adsorption efficiency of the iodine adsorber to be tested according to an efficiency formula.

The method adopts the non-radioactive methyl iodide as the test reagent to carry out the efficiency test on the iodine adsorber, so that the radioactive operation in the efficiency test of the iodine adsorber can be avoided, the operation risk is reduced, the collective irradiated dose of operators is reduced, and the condition of radioactive gas discharge caused by unqualified adsorption efficiency or misoperation of the iodine adsorber in the test process is eliminated; and the links of purchasing, transporting, storing and the like of the radioactive source in the efficiency test of the iodine adsorber can be avoided, and the production management cost of the power station is reduced.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are merely illustrative of the principles of the invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.