The scope of the work was to build up an overall data collection about the existing experience on the performances and management of the JET tritium system. Particularly: • Update the analysis performed in 2002 on data related to JET Active Gas Handling System (AGHS) failures, considering last information on failures occurred in the AGHS between September 2002 and September 2006. The information investigated on failures/malfunctions concern the identification of failed components, failure modes and, where possible, causes and consequences of the failures. To perform statistical analysis, the whole sets of components, which the failures/malfunctions are related to, have to be also identified. Components have been classified and counted in order to find out amount of components, related operating hours and, related demands to operate (for components operating in intermittent way). Main reliability parameters, (such as the failure rate and the corresponding standard errors and confidence intervals), associated to the components have been estimated. • Analyze in more detail the most significant failures considering the unavailability of components, the maintenance, the possible impact on doses to the workers, the possible environmental releases related to the maintenance activities. About 460 failures/malfunctions on a set of more than 6200 components, operating for about 215,000,000 hours, have been pointed out since 1995 up to September 2006 for the AGHS. Failure rates here evaluated are in very good agreement with the corresponding ones existing in literature for similar applications (e.g.: nuclear power plants). The data here reported could be very useful to evaluate reliability parameters in support of safety assessment and for availability/reliability analyses of fusion machines/plants. The investigation on significant maintenance operations highlights the very low consequences for workers in terms of worker doses and the negligible effects on environmental releases.
JET Operating Experience: Global analysis of tritium plant failure / T. Pinna; G. Cambi; S. Knipe. - STAMPA. - (2008).
JET Operating Experience: Global analysis of tritium plant failure
CAMBI, GILIO;
2008
Abstract
The scope of the work was to build up an overall data collection about the existing experience on the performances and management of the JET tritium system. Particularly: • Update the analysis performed in 2002 on data related to JET Active Gas Handling System (AGHS) failures, considering last information on failures occurred in the AGHS between September 2002 and September 2006. The information investigated on failures/malfunctions concern the identification of failed components, failure modes and, where possible, causes and consequences of the failures. To perform statistical analysis, the whole sets of components, which the failures/malfunctions are related to, have to be also identified. Components have been classified and counted in order to find out amount of components, related operating hours and, related demands to operate (for components operating in intermittent way). Main reliability parameters, (such as the failure rate and the corresponding standard errors and confidence intervals), associated to the components have been estimated. • Analyze in more detail the most significant failures considering the unavailability of components, the maintenance, the possible impact on doses to the workers, the possible environmental releases related to the maintenance activities. About 460 failures/malfunctions on a set of more than 6200 components, operating for about 215,000,000 hours, have been pointed out since 1995 up to September 2006 for the AGHS. Failure rates here evaluated are in very good agreement with the corresponding ones existing in literature for similar applications (e.g.: nuclear power plants). The data here reported could be very useful to evaluate reliability parameters in support of safety assessment and for availability/reliability analyses of fusion machines/plants. The investigation on significant maintenance operations highlights the very low consequences for workers in terms of worker doses and the negligible effects on environmental releases.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
