Abnormality diagnosis system

An abnormality diagnosis system diagnosing an abnormality event of a nuclear power plant based on of abnormality indication detection results acquired by an abnormality indication monitoring system detecting an abnormality indication of the nuclear power plant by monitoring indicative value summing up correlation values between two measurement parameters out a plurality of measurement parameters measured in the nuclear power plant for all combinations of said two measurement parameters, when the monitoring indicative value goes over

• a threshold value L at a first certain time T2, the first certain time T2 is set as an indication detection timing T2,
• the correlation values have respective abnormal values and when at least one of the correctional values indicates its own abnormal value at a second certain time T1 before the indication detection timing T2, the second certain time T1 is set as a non-detection timing T1, and
• an monitoring period is set as a period from the non-detection timing T1 to the indication detection timing T2 the abnormality indication detection results include, when the abnormality indication is detected, parameter transitions and parameter contributions, wherein the parameter transitions are temporal transitions of the two measurement parameters relating to the correlation value indication its own abnormal value in the monitoring period, and
• the parameter contributions are degrees of contribution of respective measurement parameters to a temporal change of the monitoring indicative value during the monitoring period,
• the parameter contributions are degrees of contribution of respective measurement parameters to a temporal change of the monitoring indicative value during the monitoring period,
• the abnormality diagnosis system comprising:
• an abnormality diagnosis control unit configured to acquire the abnormality indication detection results from the abnormality indication monitoring system, and
• a database configured to store a plurality of previous abnormality events of the nuclear power plant having occurred in the past, at least one previous abnormality indication facility that indicates signs of abnormality in the nuclear power plant, correlated with one or more among the plurality of the previous abnormality events,
• previous parameter transitions related to one or more among the plurality of the previous abnormality events of the nuclear power plant based on an operation history of the nuclear power plant and in the past, and
• the previous parameter contributions related to one or more among the plurality of the previous abnormality events of the nuclear power plant based on the operation history,
• wherein the abnormality diagnosis control unit is configured to specify, when determining the parameter transitions match with the previous parameter transitions and the parameter contributions match with the previous parameter contributions, an abnormality event and an abnormality indication facility correlated with the matched previous parameter transitions and the matched previous parameter contributions.