Review of the LBDS Safety and Reliability Analysis in the Light of the Operational Experience during the Period 2010-2012

During the years 2010, 2011 and 2012 a large amount of LHC data was recorded, which also included failure events in the LHC Beam Dumping System (LBDS). We used these data for the validation of the safety and reliability analyses of the LBDS which were performed in 2003-2006. The results of the analysis confirm the agreement of the calculated statistics with the predicted estimates. The LBDS generated a number of about 10 false beam dumps per year, which is in agreement with the estimated 8 ± 2. A thorough investigation of the data set also confirms that the LBDS always preserved a sufficient residual margin of safety for all identified failure scenarios, and globally meets SIL3 at least. These results are accompanied by several recommendations, among which instructions for updating the reliability model to the actual operation scenarios, and suggestions for the improvement of safety and availability of the LBDS.