CN-115994402-B - Method for determining a containment test period, readable storage medium and computer device

CN115994402BCN 115994402 BCN115994402 BCN 115994402BCN-115994402-B

Abstract

The invention discloses a method for determining a containment test period. The method comprises the steps of obtaining historical data of test results of a containment test, and determining whether the containment test period can be prolonged according to the historical data of the test results of the containment test. If not, the current containment test period is maintained. If yes, obtaining a first candidate value of the containment test period according to historical data of test results of the containment test and acceptance criteria of safety margin of the containment test. And obtaining a second candidate value of the containment test period according to the historical data of the test result of the containment test, the reference value of the risk index and the acceptance standard of the risk index. And determining a determined value of the containment test period according to the first candidate value of the containment test period and the second candidate value of the containment test period, and taking the determined value of the containment test period as the next containment test period.

Inventors

LIU YU
LU WENKUI
LI WENJING
TIAN QIWEI
WEI WEI
LIU YONG
YU XINLI
YANG XIAOYAN
LIU JING
DU JINYAN
WANG GAOPENG

Assignees

中国核电工程有限公司

Dates

Publication Date: 20260508
Application Date: 20230128

Claims (12)

1. A method of determining a containment test period, the method comprising: Acquiring historical data of a test result of a containment test; Obtaining a first candidate value of a containment test period through a regression prediction method according to historical data of test results of the containment test and acceptance criteria of safety margin of the containment test; Obtaining a second candidate value of the containment test period according to the historical data of the test result of the containment test and the acceptance standard of a first risk index, wherein the first risk index comprises the early high-level radioactive release frequency and the containment condition failure probability, and And determining a determined value of the containment test period according to the first candidate value of the containment test period and the second candidate value of the containment test period, and taking the determined value of the containment test period as the next containment test period.
2. The method of determining a safe shell test period according to claim 1, wherein the obtaining the historical data of the test results of the containment test includes obtaining the historical data of the test results of the containment test and determining whether to extend the containment test period based on the historical data of the test results of the containment test.
3. The method of determining a safe shell test period according to claim 2, wherein the obtaining historical data of test results of the safe shell test comprises: acquiring historical data of test results of two continuous containment tests; The determining whether to extend the containment test period according to the historical data of the test result of the containment test comprises: judging whether the historical data of the test results of the two continuous containment tests meet the acceptance criterion of the safety margin of the containment test; if yes, determining to prolong the containment test period; If not, determining not to extend the containment test period.
4. The method for determining a safe shell test period according to claim 1, wherein the obtaining the first candidate value of the safe shell test period by a regression prediction method based on the history data of the test result of the safe shell test and the acceptance criterion of the safety margin of the safe shell test comprises: setting a data threshold of a test result of the containment test according to an acceptance criterion of a safety margin of the containment test; According to historical data of a test result of a containment test, obtaining an aging correction factor of the containment, and according to the aging correction factor of the containment, obtaining a prediction result of the containment test by a regression prediction method, wherein the prediction result of the containment test comprises a containment service time and prediction data of a test result of the containment test corresponding to the containment service time, and Selecting first prediction data from prediction data of test results of the containment test corresponding to the service time of the containment according to a data threshold of the test results of the containment test, and determining a time interval between the service time of the containment corresponding to the first prediction data and the time of the last containment test as a first candidate value of a containment test period, wherein the first prediction data is smaller than the data threshold of the test results of the containment test.
5. The method of determining a safe shell test period according to claim 1, wherein the obtaining a second candidate value of a safe shell test period based on historical data of test results of the safe shell test and acceptance criteria of a first risk indicator comprises: setting a threshold value of a first risk index increment of the containment test according to an acceptance standard of the first risk index; Obtaining a reference value of a second risk index according to historical data of test results of the containment test by a statistical method or a probability safety analysis method, wherein the second risk index comprises a reactor core damage frequency, a large amount of radioactivity release frequency and an excessive risk leakage risk probability, and And determining a second candidate value of the containment test period according to the reference value of the second risk index and the threshold value of the first risk index increment.
6. The method of determining a safe shell test period according to claim 5, wherein the determining a second candidate value of a safe shell test period based on the reference value of the second risk indicator and the threshold value of the first risk indicator increment comprises: Acquiring a third candidate value of the containment test period according to the reference value of the second risk index, the threshold value of the early massive radioactivity release frequency increment, the reference value of the risk probability of excessive risk leakage and the current containment test period; obtaining a fourth candidate value of the containment test period according to the reference value of the core damage frequency and the threshold value of the containment condition failure probability increment, and And acquiring a second candidate value of the containment test period according to the third candidate value of the containment test period and the fourth candidate value of the containment test period, wherein the second candidate value of the containment test period is the minimum value of the third candidate value of the containment test period and the fourth candidate value of the containment test period.
7. The method of determining a safe shell test period according to any one of claims 1 to 6, wherein the determined value of the safe shell test period is a minimum of a first candidate value of the safe shell test period and a second candidate value of the safe shell test period.
8. The method of determining a safe shell test period according to claim 7, further comprising obtaining in real time containment temperature, containment pressure, containment leak rate real time monitoring results and penetration leak rate monitoring results; Performing early warning setting and alarm setting according to the containment temperature, the containment pressure, the containment leak rate real-time monitoring result and the penetration leak rate monitoring result, and When early warning or alarming occurs, emergency treatment measures are adopted.
9. The method of determining a safe shell test period of claim 8, further comprising: and under the condition that emergency treatment measures are adopted when early warning or alarming occurs, determining values of the containment test period are determined again.
10. The method of determining a safe shell assay period according to any one of claims 1-6, further comprising: Multiple visual inspection and multiple prestress steel beam monitoring are added between the current containment test and the next containment test; if the visual inspection results are not acceptable, corrective action is taken until an acceptable criterion is reached, and And verifying whether the pressure bearing performance meets the requirement according to the monitoring result of the prestress steel beam, if so, taking the determined value of the containment test period as the next containment test period, and if not, maintaining the current containment test period.
11. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the method of determining a safe shell test period according to any one of claims 1 to 10 when executing the computer program.
12. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, performs the method of determining a safe shell test period according to any one of claims 1 to 10.

Description

Method for determining a containment test period, readable storage medium and computer device Technical Field The invention relates to the field of safety analysis of nuclear power plants, in particular to a method for determining a containment test period, a readable storage medium and computer equipment. Background As a final barrier to limit the release of radioactive materials to the environment, the containment vessel of a nuclear power plant assumes the safety function of containing radioactive materials and shielding radiation under various operating conditions. In order to ensure the functional requirements of the safety shell in the service life of the unit, the tightness and the structural strength of the safety shell should be tested and verified regularly in the service life. The containment periodic test considered in the design of the nuclear power unit at the present stage comprises the following steps: containment local test (LLRT): class B tests to determine local leakage through containment specific penetrations (equipment gates, personnel gates, fuel transfer channels, electrical penetrations, etc.); class C test-local leakage through containment isolation valves is measured. Containment integrity test (ILRT): Class a test the overall leak rate of the containment was measured and during this time a strength test was performed. For the double-layer containment structure, the containment test also comprises the measurement requirement of the leakage rate of the outer containment, and the test is mainly used for being matched with the operation of an annular space ventilation system so as to maintain the negative pressure state of the annular space and limit the leakage of radioactive substances in the inner containment to the outside of the containment. The A-type test works as a key main line of the unit refueling overhaul, occupies a main line construction period, consumes a great amount of manpower and material resources, and possibly introduces unfavorable initial events in the test process to cause serious consequences, so that the A-type test becomes an important breakthrough point for greatly improving the availability and economic benefits of the unit. At present, the establishment of the safety shell test period of the domestic in-service unit refers to related requirements in domestic and foreign standards and practices, namely, the first class A test is carried out when the reactor is shut down for the first time or the second time, the first class A test is carried out for no more than 10 years later, certain requirements are met for the frequency of the class B/C test, for example, an electric penetration assembly should record at least 1 time of pressure reading of the electric penetration assembly per month, the interval between two tests of the isolation valve is no more than 2 years, and the like. However, in the case where the operation of the nuclear power plant is stable and the state of the containment remains good, there may be a case where the containment test is not required, but is performed in a fixed containment test period, and thus the fixed containment test period makes the containment test inflexible and may result in a high total cost of the nuclear power plant, which is disadvantageous in improving the economy of the nuclear power. Disclosure of Invention The invention aims to solve the technical problems that the safety shell test lacks flexibility due to the fixed safety shell test period, and the running and maintenance cost of a nuclear power plant is high, so that the nuclear power economy is not improved. In order to overcome the defects in the prior art, the invention aims to provide a method, a readable storage medium and computer equipment for determining a containment test period, which dynamically predicts a test result according to historical test data and data acquired in real time of containment tests and determines the containment test period according to the test result and acceptance criteria so as to increase the flexibility of containment tests, reduce the operation and maintenance cost of a nuclear power plant and improve the economy of nuclear power. In one aspect, the invention provides a method of determining a containment test period comprising obtaining historical data of test results of a containment test. And obtaining a first candidate value of the containment test period through a regression prediction method according to the historical data of the test result of the containment test and the acceptance criterion of the safety margin of the containment test. And obtaining a second candidate value of the containment test period according to the historical data of the test result of the containment test and the acceptance standard of a first risk index, wherein the first risk index comprises the early massive radioactive release frequency and the containment condition failure probability. And determining a determined value of the co