Research pile test loop element damage monitoring system and method

Abstract

The invention discloses a research reactor test loop element damage monitoring system and method, and relates to the technical field of research reactor irradiation, and the research reactor test loop element damage monitoring system comprises a damage detection heat exchanger, a first control valve, a delayed neutron monitor, a total gamma monitor and an online nuclide monitor which are connected in sequence; a cooling inlet of the breaking and exploring heat exchanger is communicated with the test loop, and a cooling outlet of the breaking and exploring heat exchanger is connected with a water inlet of the delayed neutron monitor through a first control valve; the water outlet of the delayed neutron monitor is connected with the water inlet of the total gamma monitor; the water outlet of the total gamma monitor is connected with the water inlet of the online nuclide monitor; a water outlet of the online nuclide monitor is connected with a regeneration inlet of the breaking and exploring heat exchanger through a first flow regulating valve; a regeneration outlet of the breaking detection heat exchanger is communicated with the test loop; the system can accurately judge whether the fuel element is damaged or not.

Description

Technical Field

[0001] The present invention relates to the field of irradiation technology for research reactors, and in particular to a system and method for monitoring damage of test loop components of a research reactor. Background Art

[0002] The research reactor test loop, also known as the irradiation test loop, is a fuel element performance verification platform. It simulates the actual operating conditions of the fuel elements in the reactor and completes the fuel element performance verification through fine control of the main parameters of the loop system such as temperature, pressure, and flow.

[0003] That is, the test loop is mainly used to release heat from the components within the reactor and to extract waste heat from the system. However, during the operation of the loop, the integrity of the fuel elements cannot be absolutely guaranteed because the fuel elements are under extremely harsh working conditions such as high temperature and high pressure. If the fuel elements are damaged and not discovered in time and appropriate countermeasures are not taken, the radioactive medium will spread in large quantities, causing pollution to the loop system, resulting in huge economic losses, and the operating safety of the reactor and the loop will also be affected.

[0004] At present, the most mature method for damage detection of research reactor test loops is the heat carrier ray separation method which combines the heat carrier delayed neutron method and the heat carrier total gamma method. This method monitors the integrity of fuel elements by simultaneously monitoring the delayed neutrons and total gamma in the water of the first loop. Among them, the delayed neutron method measures the fission products of 235U, 238U, and 239U in the loop through a delayed neutron detector, which can directly monitor whether the fuel elements are damaged, but due to the stability and sensitivity of the detector itself, false alarms may occur; and the total gamma monitoring method monitors the total gamma in the loop through a total gamma monitor, which can indirectly reflect whether the fuel elements are damaged, but in addition to the damage of the fuel elements, the loop equipment or pipelines will also release a small amount of gamma rays due to long-term operation accumulation, resulting in false alarms.

[0005] Therefore, the two are usually combined and verified to improve system reliability. In order to match the delayed neutron monitor and further improve the stability of the system, the total gamma monitor usually uses a NaI scintillator detector with an effective monitoring energy range of less than 800keV.

[0006] However, in the design and actual operation of the test loop element damage monitoring system, the delayed neutron decay period is very short, 0.2s to 54.5s, and the interference of 16N and 19O must be avoided. The measurement conditions are very harsh, which greatly increases the difficulty of designing the system equipment and pipelines and selecting the measurement position. In addition, since there are many types of key nuclides with energy below 800kev and they will affect each other, it is very difficult to distinguish each nuclide. Therefore, this method is only suitable for detecting whether the fuel element is damaged and monitoring the total γ level, and does not have the function of monitoring the content of radioactive nuclides.

[0007] Therefore, we propose a component damage monitoring system that can accurately determine the results. Summary of the invention

[0008] In order to overcome the deficiencies in the background technology, the present invention discloses a system and method for monitoring damage of a test loop component of a research reactor.

[0009] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0010] A research reactor test loop component damage monitoring system comprises a damage detection heat exchanger, a first control valve, a delayed neutron monitor, a total gamma monitor and an online nuclide monitor connected in sequence;

[0011] The cooling inlet of the blast heat exchanger is connected to the test circuit, and the cooling outlet of the blast heat exchanger is connected to the water inlet of the delayed neutron monitor through the first control valve;

[0012] The water outlet of the delayed neutron monitor is connected to the water inlet of the total gamma monitor;

[0013] The water outlet of the total γ monitor is connected to the water inlet of the online nuclide monitor;

[0014] The water outlet of the online nuclide monitor is connected to the regeneration inlet of the heat exchanger through a first flow regulating valve;

[0015] The regeneration outlet of the heat exchanger is connected to the test circuit.

[0016] Preferably, the test heat exchanger adopts a regenerative heat exchanger, and the heat exchanger includes a primary cooling circuit and a secondary cooling circuit, wherein the cooling inlet of the primary cooling circuit is connected to the main water inlet of the test circuit, and the cooling outlet of the primary cooling circuit is connected to the cooling inlet of the secondary cooling circuit; the regeneration inlet of the primary cooling circuit is connected to the outlet of the online nuclide monitor, and the regeneration inlet of the primary cooling circuit is connected to the main water outlet of the test circuit;

[0017] The cooling outlet of the secondary cooling circuit is connected to the first control valve, the regeneration inlet of the secondary cooling circuit is connected to the secondary water circuit inlet of the test circuit through the second flow regulating valve, and the regeneration outlet of the secondary cooling circuit is connected to the secondary water circuit drain outlet of the test circuit.

[0018] Preferably, the flow rate adjustment range of the first flow rate regulating valve is 0m 3 / h~1m 3 / h.

[0019] Preferably, the flow rate adjustment range of the second flow rate regulating valve is 0m 3 / h~4m 3 / h.

[0020] Preferably, a second control valve is connected in parallel to the total gamma monitor, and a third control valve is connected in parallel to the online nuclide monitor.

[0021] Preferably, the delayed neutron detector adopts a digital BF3 counter tube detector, and the energy range of the detector is thermal neutron to 2Mev.

[0022] Preferably, the total gamma monitor uses a NaI scintillator detector, the energy range of which is 100kev to 800kev and the measurement range is 3.7×106Bq / m 3 ~3.7×1010Bq / m 3 .

[0023] Preferably, the online nuclide monitor uses a HPGe detector, the energy range of which is 100kev to 3Mev and the measurement range is 3.7×106Bq / m 3 ~3.7×1012Bq / m 3 .

[0024] Preferably, the key nuclides selected by the online nuclide monitoring instrument are 138 Cs, 92 Sr. 135 I. 89 Rb, 134 I. 142 La, 133 I. 138 Xe.

[0025] A method for monitoring damage of a test circuit component of a research reactor, comprising the following specific steps:

[0026] 1) Use the test heat exchanger to cool the water in the test circuit;

[0027] 2) The cooled water passes through the delayed neutron monitor, total gamma monitor and online nuclide monitor in sequence to measure whether the water contains radioactive nuclides;

[0028] 3) The measured water returns to the test circuit through the heat exchanger;

[0029] 4) The host computer determines whether the fuel elements in the test loop are damaged based on the measurement results of the delayed neutron monitor, total gamma monitor and online nuclide monitor, and decides whether to stop the operation of the test loop.

[0030] Due to the adoption of the above-mentioned technical solution, the present invention has the following beneficial effects:

[0031] The present invention discloses a research reactor test loop component damage monitoring system and method, which can perform secondary measurement on the nuclides measured by the delayed neutron monitor and the total gamma monitor by introducing an online nuclide monitor, thereby improving the accuracy of the nuclide measurement and thus improving the reliability of the component damage monitoring system;

[0032] In addition, the heat exchanger can effectively reduce the temperature difference between the primary cooling circuit and the secondary cooling circuit, thereby reducing the thermal stress caused by excessive temperature difference;

[0033] In addition, the flow rate of water in the main water channel of the test loop can be adjusted through the first flow regulation, which reduces the difficulty of obtaining delayed neutrons and makes it easy to select the installation position of the delayed neutron monitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A structural schematic diagram of the present invention.

[0035] In the figure: 1. Explosion heat exchanger; 11. Primary cooling circuit; 12. Secondary cooling circuit; 2. First control valve; 3. Delayed neutron monitor; 4. Total gamma monitor; 5. Online nuclide monitor; 6. First flow regulating valve; 7. Second flow regulating valve; 8. Second control valve; 9. Third control valve; 10. Test circuit; 101. Main water circuit; 102. Secondary water circuit. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be described below in conjunction with the drawings in the embodiments of the present invention. In the description, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right" and the like indicating directions or positional relationships, they are only corresponding to the drawings of the present invention, for the convenience of describing the present invention, and do not indicate or imply that the devices or components referred to must have a specific direction:

[0037] Embodiment 1 is:

[0038] Combined with Figure 1 The research reactor test loop component damage monitoring system comprises a damage detection heat exchanger 1, a first control valve 2, a delayed neutron monitor 3, a total gamma monitor 4 and an online nuclide monitor 5 which are connected in sequence;

[0039] The cooling inlet of the cracking heat exchanger 1 is connected to the test circuit 10, and the cooling outlet of the cracking heat exchanger 1 is connected to the water inlet of the delayed neutron monitor 3 through the first control valve 2;

[0040] The cooling inlet of the damage detection heat exchanger 1 is connected to the test circuit 10 through the fourth control valve and the fifth control valve, and the fourth and fifth control valves are used to open or close the operation of the damage monitoring system;

[0041] It should be noted that the first control valve 2 and the delayed neutron monitor 3 are also provided with a flow meter and a thermometer for detecting the flow rate and water temperature of the water flowing into the delayed neutron monitor 3;

[0042] In addition, the delayed neutron monitor 3 is used to measure whether there are delayed neutrons generated by fission products of fuel elements in the water of the test loop 10, and the detector uses paraffin as a neutron moderation material and is equipped with a coil inside to measure the delayed neutrons in the water;

[0043] In addition, the distance between the inlet of the delayed neutron monitor 3 and the cooling outlet pipeline of the blast heat exchanger 1 should be no less than 300m, so that the total time from the outlet of the test loop 10 to the delayed neutron monitor 3 after passing through the blast heat exchanger 1 is approximately 50s, ensuring the monitoring accuracy of the delayed neutron monitor 3;

[0044] According to the needs, the delayed neutron detector adopts a digital BF3 counter tube detector, and the energy range of the detector is thermal neutron ~ 2Mev, which is mainly used for the relatively short half-life of 0.2~55s. 235 U. 238 U. 239 Fission products of U 87 Br, 137 I. 88 The delayed neutrons of Br are monitored. In the HFETR reactor, this type of delayed neutron monitor 3 has a good monitoring effect.

[0045] The water outlet of the delayed neutron monitor 3 is connected to the water inlet of the total γ monitor 4, and the total γ monitor 4 is used to measure whether the total γ content in the water of the test loop 10 exceeds the standard;

[0046] In addition, the total γ monitor 4 adopts a NaI scintillator detector with an energy range of 100kev to 800kev and a measurement range of 3.7×10 6 Bq / m 3~3.7×10 10 Bq / m 3 , 87 Br, 137 I. 88 The decay energy of nuclides such as B is within this energy range. When the delayed neutron detector alarms, the NaI scintillator will also alarm at the same time, which can improve the reliability of the system.

[0047] The water outlet of the total gamma monitor 4 is connected to the water inlet of the online nuclide monitor 5, and the online nuclide monitor 5 is used to measure whether the content of a specific radioactive nuclide in the water of the test loop 10 exceeds the standard;

[0048] In addition, the online nuclide monitor 5 adopts a HPGe detector, the energy range of which is 100kev~3Mev and the measurement range is 3.7×106Bq / m 3 ~3.7×1012Bq / m 3 , mainly used to measure the fission products with relatively long half-life, high decay energy and high content in HFETR reactors, such as 38 Cs, 92 Sr. 135 When the delayed neutron detector fails to monitor due to lack of suitable installation position, the damage of fuel element cladding can be monitored through the nuclide online monitoring system;

[0049] And the key nuclides selected by the online nuclide monitor 5 are 138 Cs, 92 Sr. 135 I. 89 Rb, 134 I. 142 La, 133 I. 138 Xe, the above nuclide has a relatively high content in the main water channel 101 of the test loop 10 of the HFETR reactor and can be used as a key characteristic nuclide for monitoring the integrity of the fuel cladding.

[0050] The water outlet of the online nuclide monitor 5 is connected to the regeneration inlet of the probe heat exchanger 1 through the first flow regulating valve 6; since the delayed neutron monitor 3 has very high requirements on environmental conditions, especially sensitive to temperature, if the water temperature is too high, it may cause the paraffin material in the delayed neutron monitor 3 to melt, affecting the performance of the monitor; therefore, it is necessary to control the water temperature before entering the delayed neutron monitor 3 within a suitable range, usually this temperature should be lower than 40°C, so by adjusting the water flow rate returning to the test loop 10, the water temperature and flow rate entering the delayed neutron monitor 3 can be indirectly controlled, thereby ensuring that the monitor works under optimal conditions, and also making it easier for workers to find the best installation position for the delayed neutron monitor 3, reducing the design complexity of the equipment and pipelines;

[0051] In addition, the first flow regulating valve 6 is an electric regulating valve, which enables the water temperature regulating mechanism to dynamically adjust the flow rate as needed to adapt to different monitoring requirements of the delayed neutron monitor 3 and improve the overall performance and reliability of the monitoring system;

[0052] It should be noted that the flow rate adjustment range of the first flow rate control valve 6 is 0m 3 / h~1m 3 / h.

[0053] The regeneration outlet of the heat exchanger 1 is connected to the test circuit 10;

[0054] In one example, the damage detection heat exchanger 1 is connected to the test circuit 10 through a thermometer, a sixth control valve and a seventh control valve in sequence, wherein the thermometer is used to detect the temperature of the water flow in the damage monitoring system to determine whether the water temperature will affect the measurement result of the delayed neutron monitor 3; and the sixth control valve and the seventh control valve are used to open or close the operation of the damage monitoring system;

[0055] That is, when the fourth, fifth, sixth and seventh control valves are all opened, the main water channel 101 of the test circuit 10 will be connected to the damage detection system to form a loop, and the water in the main water channel 101 will be cooled by the damage detection heat exchanger 1, and then pass through the delayed neutron monitor 3, the total gamma monitor 4 and the online nuclide monitor 5 in turn to measure the nuclides in the water, so as to determine whether the fuel elements in the test circuit 10 have leaked radioactive nuclides due to damage to the outer shell, and the water in the main water channel 101 flows continuously, thereby achieving the purpose of damage monitoring.

[0056] Embodiment 2 is:

[0057] On the basis of Example 1, the test heat exchanger 1 is further defined, that is, the test heat exchanger 1 adopts a regenerative heat exchanger, and the heat exchanger includes a primary cooling circuit 11 and a secondary cooling circuit 12, wherein the cooling inlet of the primary cooling circuit 11 is connected to the water inlet of the main water channel 101 of the test circuit 10, and the cooling outlet of the primary cooling circuit 11 is connected to the cooling inlet of the secondary cooling circuit 12; the regeneration inlet of the primary cooling circuit 11 is connected to the water outlet of the online nuclide monitor 5, and the regeneration inlet of the primary cooling circuit 11 is connected to the water outlet of the main water channel 101 of the test circuit 10;

[0058] The cooling outlet of the secondary cooling circuit 12 is connected to the first control valve 2, the regeneration inlet of the secondary cooling circuit 12 is connected to the water inlet of the secondary water circuit 102 of the test circuit 10 through the second flow regulating valve 7, and the regeneration outlet of the secondary cooling circuit 12 is connected to the drain outlet of the secondary water circuit 102 of the test circuit 10;

[0059] The regenerative heat exchanger can effectively reduce the temperature difference between the primary cooling circuit 11 and the secondary cooling circuit 12, thereby reducing the thermal stress caused by the large temperature difference between the two cooling circuits and ensuring the safety and stability of the system.

[0060] It should be noted that the primary outlet temperature of the regenerative heat exchanger is controlled below 40 degrees Celsius, which can prevent the paraffin material in the delayed neutron monitor 3 from melting due to overheating, thereby further ensuring the accuracy and reliability of the monitoring system.

[0061] In addition, the primary cooling circuit 11 is connected to the main water circuit 101 and is responsible for cooling the high-temperature water in the main water circuit 101 to provide a suitable working environment for the subsequent delayed neutron monitor 3, the total gamma monitor 4 and the online nuclide monitor 5; and the secondary cooling circuit 12 is connected to the independent secondary water circuit 102 in the test circuit 10, which helps to maintain the cooling efficiency and the stability of the system;

[0062] It should be noted that the flow rate adjustment range of the second flow rate control valve 7 is 0m 3 / h~4m 3 / h;

[0063] In addition, an eighth control valve and a thermometer are sequentially provided between the second flow regulating valve 7 and the secondary water circuit 102 of the test circuit 10, and a ninth control valve, a tenth control valve and a thermometer are sequentially provided between the regeneration outlet of the secondary cooling circuit 12 and the drain outlet of the secondary water circuit 102 of the test circuit 10;

[0064] Among them, the second flow regulating valve 7, the eighth control valve, the ninth control valve and the tenth control valve are used to control the start or stop of the secondary cooling circuit 12 of the heat exchanger 1; and the two thermometers in the secondary cooling circuit 12 can judge the cooling effect of the secondary cooling circuit 12 of the heat exchanger 1 by the reading difference, so as to facilitate the calculation of the temperature difference between the secondary cooling circuit 12 and the primary cooling circuit 11.

[0065] Embodiment 3 is:

[0066] On the basis of Example 1, the control loop of the total γ monitor 4 and the online nuclide monitor 5 is further limited, wherein the total γ monitor 4 is connected in parallel with a second control valve 8, and the online nuclide monitor 5 is connected in parallel with a third control valve 9;

[0067] During the operation of the damage monitoring system, when the total gamma monitor 4 fails, the second control valve 8 can be opened to allow water to flow through the second control valve 8, and the total gamma monitor can be isolated and repaired to prevent the overall failure of the system; and when the line nuclide monitor 5 fails, the third control valve 9 can be opened to isolate and repair the line nuclide monitor 5 to prevent the overall failure of the system, further ensuring that the damage monitoring system can accurately measure the nuclides in the water.

[0068] As a specific example: based on Example 1, when the delayed neutron monitor 3 fails to monitor the delayed neutron due to the lack of a suitable installation position, if the total γ monitor 4 alarms and the key nuclides of the nuclide online monitoring system do not show a significant increase and do not alarm, it is judged that the fuel element cladding is intact, and the γ increment comes from the equipment or process pipeline, and the damaged element monitoring system does not alarm;

[0069] As another specific example: based on Example 1, when the delayed neutron monitor 3 fails to monitor the delayed neutron due to the lack of a suitable installation location, if the total gamma monitor 4 alarms and the key nuclides in the nuclide online monitoring system increase significantly and alarm, it is judged that the fuel element cladding is damaged and the gamma increment comes from the fuel element. The operation and maintenance personnel can judge the damage of the element and evaluate the consequences of the incident based on the key nuclide content and take corresponding emergency measures.

[0070] A method for monitoring damage of a test circuit component of a research reactor, comprising the following specific steps:

[0071] 1) Using the heat exchanger 1 to cool the water in the test loop 10;

[0072] It should be noted that in the two cooling circuits of the test heat exchanger 1, the water in the main water channel 101 of the test circuit 10 is cooled by the primary cooling circuit 11, and the subsequent nuclide measurement is also for the water in the main water channel 101, while the secondary cooling circuit 12 cools the independent secondary water channel 102 in the test circuit 10 to reduce the thermal stress caused by the large temperature difference between the two cooling circuits;

[0073] Specifically, the fourth, fifth, sixth and seventh control valves are opened to connect the test loop 10 with the damage detection heat exchanger 1 to form a loop, and the water in the test loop 10 will flow in the damage monitoring system;

[0074] 2) The cooled water passes through the delayed neutron monitor 3, the total gamma monitor 4 and the online nuclide monitor 5 in sequence to measure whether the water contains radioactive nuclides;

[0075] 3) The measured water returns to the test circuit 10 through the heat exchanger 1;

[0076] Achieve continuous monitoring of the flowing water in the test loop 10;

[0077] 4) The host computer determines whether the fuel element in the test loop 10 is damaged based on the measurement results of the delayed neutron monitor 3, the total gamma monitor 4 and the online nuclide monitor 5, and decides whether to stop the operation of the test loop 10;

[0078] In addition, when one of the delayed neutron monitor 3 and the total gamma monitor 4 fails, the online nuclide monitor 5 can also independently measure whether there are nuclides in the water, thereby determining whether the fuel element of the test loop is damaged; when the online nuclide monitor 5 fails alone, the delayed neutron monitor 3 and the total gamma monitor 4 can work together to measure whether there are nuclides in the water. 87 Br, 137 I or 88 Delayed neutrons from the Br nuclide, and 87 Br, 137 I or 88 The decay energy of nuclides such as Br, that is, whether the water contains radioactivity, thereby judging whether the fuel element of the test loop 10 is damaged;

[0079] Since the delayed neutron monitor 3, the total gamma monitor 4 and the on-line nuclide monitor 5 are working online at the same time, any failure of the two monitoring systems will not affect the continuous measurement of water in the test loop 10, thereby ensuring the accuracy of the damage monitoring method.

[0080] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the appended claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure marks in the claims should not be regarded as limiting the claims involved.

Claims

1. A research reactor test loop component damage monitoring system, characterized by: It comprises a probe heat exchanger (1), a first control valve (2), a delayed neutron monitor (3), a total gamma monitor (4) and an online nuclide monitor (5) which are connected in sequence; The cooling inlet of the detection heat exchanger (1) is connected to the test circuit (10), and the cooling outlet of the detection heat exchanger (1) is connected to the water inlet of the delayed neutron monitor (3) through the first control valve (2); The water outlet of the delayed neutron monitor (3) is connected to the water inlet of the total gamma monitor (4); The water outlet of the total gamma monitor (4) is connected to the water inlet of the online nuclide monitor (5); The water outlet of the online nuclide monitor (5) is connected to the regeneration inlet of the heat exchanger (1) via a first flow regulating valve (6); The regeneration outlet of the probing heat exchanger (1) is in communication with the test circuit (10).

2. The research reactor test circuit component damage monitoring system according to claim 1, characterized in that: The detection heat exchanger (1) adopts a regenerative heat exchanger, and the heat exchanger includes a primary cooling circuit (11) and a secondary cooling circuit (12), wherein the cooling inlet of the primary cooling circuit (11) is connected to the water inlet of the main water channel (101) of the test circuit (10), and the cooling outlet of the primary cooling circuit (11) is connected to the cooling inlet of the secondary cooling circuit (12); the regeneration inlet of the primary cooling circuit (11) is connected to the water outlet of the online nuclide monitor (5), and the regeneration inlet of the primary cooling circuit (11) is connected to the water outlet of the main water channel (101) of the test circuit (10); The cooling outlet of the secondary cooling circuit (12) is connected to the first control valve (2), the regeneration inlet of the secondary cooling circuit (12) is connected to the water inlet of the secondary water circuit (102) of the test circuit (10) through the second flow regulating valve (7), and the regeneration outlet of the secondary cooling circuit (12) is connected to the drain outlet of the secondary water circuit (102) of the test circuit (10).

3. The research reactor test circuit component damage monitoring system according to claim 2, characterized in that: The flow rate regulating range of the first flow rate regulating valve (6) is 0m 3 / h~1m 3 / h.

4. The research reactor test circuit component damage monitoring system according to claim 2, characterized in that: The flow rate regulating range of the second flow rate regulating valve (7) is 0m 3 / h~4m 3 / h.

5. The research reactor test circuit component damage monitoring system according to claim 1, characterized in that: A second control valve (8) is connected in parallel to the total gamma monitor (4), and a third control valve (9) is connected in parallel to the online nuclide monitor (5).

6. The research reactor test circuit component damage monitoring system according to claim 1, characterized in that: The delayed neutron detector adopts a digital BF3 counter tube detector, and the energy range of the detector is thermal neutron to 2Mev.

7. The research reactor test circuit component damage monitoring system according to claim 1, characterized in that: The total gamma monitor (4) adopts a NaI scintillator detector, the energy range of which is 100kev to 800kev and the measurement range is 3.7×106Bq / m 3 ~3.7×1010Bq / m 3 .

8. The research reactor test circuit component damage monitoring system according to claim 1, characterized in that: The online nuclide monitor (5) adopts a HPGe detector, the energy range of which is 100kev to 3Mev and the measurement range is 3.7×106Bq / m 3 ~3.7×1012Bq / m 3 .

9. The research reactor test circuit component damage monitoring system according to claim 1, characterized in that: The online nuclide monitoring instrument, the selected key nuclides are 138 Cs, 92 Sr. 135 I. 89 Rb, 134 I. 142 La, 133 I. 138 Xe.

10. A method for monitoring damage of a research reactor test circuit component, comprising the following steps: 1) using the probe heat exchanger (1) to cool the water in the test loop (10); 2) The cooled water passes through a delayed neutron monitor (3), a total gamma monitor (4) and an online nuclide monitor (5) in sequence to measure whether the water contains radioactive nuclides; 3) The measured water is then returned to the test circuit (10) through the heat exchanger (1); 4) The host computer determines whether the fuel element in the test loop (10) is damaged based on the measurement results of the delayed neutron monitor (3), the total gamma monitor (4) and the online nuclide monitor (5), and decides whether to stop the operation of the test loop (10).

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