The overall objective of this task of JET Fusion Technology Task Force is to develop a fusion specific data collection (i.e. component failure database) with data coming out from operating experiences gained in the Joint European Torus (JET). The activity is related to JET Ion Cyclotron Resonance Heating (ICRH) system and it is the extension of the previous activities, which interested firstly Vacuum and Active Gas Handling systems, then the Coil and NBI Power Supply system. Alarms/Failures and malfunctions occurred in the years of operations from March 1996 to November 2005, including information on failure modes and, where possible, causes of the failures, have been identified. Moreover, also data related to crowbar events have been collected. About 3400 events classified as alarms or failures related to specific components or sub-systems were identified by analysing the 25 hand-written logbooks made available by the ICRH operating staff. Information about the JET pulses in which the ICRH system was operated have been extracted from 20 hand written tick sheets covering the period from March 1996 to middle May 2003 and electronic tick sheets covering the period from May 2003 to November 2005. It results that the ICRH was operated during about 12000 plasma pulses. Main statistical values, such as rates of alarms/failures and corresponding standard errors and confidence intervals, have been estimated. Failure rates of systems and components have been evaluated both with regard to the ICRH operation pulses and operating days (days in which at least one ICRH module was requested to operate). Failure probabilities on demand have been evaluated with regard to number of pulses operated. The Report is issued with Four Appendixes (A, B, C and D). The Appendix A is dedicated to general data collection, classification and summary statistical analysis at ICRH system and ICRH module level; the Appendix B is dedicated to details on failure data (based on data collected from ICRH logbooks); the Appendix C is dedicated to detailed statistical and Reliability analysis from both at ICRH system level, down and at ICRH component/part level; the Appendix D gives the full list of data collected from the ICRH logbooks and tick sheets. The Appendixes A, B and C are distributed together with the Report, while the Appendix D will be distributed in a restricted form to people directly involved in JET operations. People interested in Appendix D can ask authors or EFDA CSU at JET.
G. Cambi, T. Pinna (2006). JET data collection on component malfunctions and failures of Ion Cyclotron Resonant Heating ICRH system. FRASCATI (ROMA) : ENEA.
JET data collection on component malfunctions and failures of Ion Cyclotron Resonant Heating ICRH system
CAMBI, GILIO;
2006
Abstract
The overall objective of this task of JET Fusion Technology Task Force is to develop a fusion specific data collection (i.e. component failure database) with data coming out from operating experiences gained in the Joint European Torus (JET). The activity is related to JET Ion Cyclotron Resonance Heating (ICRH) system and it is the extension of the previous activities, which interested firstly Vacuum and Active Gas Handling systems, then the Coil and NBI Power Supply system. Alarms/Failures and malfunctions occurred in the years of operations from March 1996 to November 2005, including information on failure modes and, where possible, causes of the failures, have been identified. Moreover, also data related to crowbar events have been collected. About 3400 events classified as alarms or failures related to specific components or sub-systems were identified by analysing the 25 hand-written logbooks made available by the ICRH operating staff. Information about the JET pulses in which the ICRH system was operated have been extracted from 20 hand written tick sheets covering the period from March 1996 to middle May 2003 and electronic tick sheets covering the period from May 2003 to November 2005. It results that the ICRH was operated during about 12000 plasma pulses. Main statistical values, such as rates of alarms/failures and corresponding standard errors and confidence intervals, have been estimated. Failure rates of systems and components have been evaluated both with regard to the ICRH operation pulses and operating days (days in which at least one ICRH module was requested to operate). Failure probabilities on demand have been evaluated with regard to number of pulses operated. The Report is issued with Four Appendixes (A, B, C and D). The Appendix A is dedicated to general data collection, classification and summary statistical analysis at ICRH system and ICRH module level; the Appendix B is dedicated to details on failure data (based on data collected from ICRH logbooks); the Appendix C is dedicated to detailed statistical and Reliability analysis from both at ICRH system level, down and at ICRH component/part level; the Appendix D gives the full list of data collected from the ICRH logbooks and tick sheets. The Appendixes A, B and C are distributed together with the Report, while the Appendix D will be distributed in a restricted form to people directly involved in JET operations. People interested in Appendix D can ask authors or EFDA CSU at JET.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
