Safety performance examination contents

Audit instruments can be evaluated on the basis of three different types of validity when linking the audit to safety performance. These are content-related, criterion-related, and construct-related procedures for accumulating evidence of validity (Anastasi 1988, 139). Content-related validity involves the examination of the audit content to determine whether it covers a representative sample of the behaviors to be measured. Criterion-related validity procedures indicate the effectiveness of an audit in predicting performance in specified activities. The performance on the audit is checked against a criterion that is considered a direct and independent measure of what the audit was intended to measure. The third type of validity, construct validity, is the extent to which the audit is said to be measuring a theoretical construct or trait. Construct validation requires accumulation of information from a variety of sources. 

Another study for the SG safety is aimed for the FBR design concept which eliminates the secondary sodium loop. To support this conceptual feasibility study, double-wall SG design is proposed and examined. Since a reliable leak detection system is essential for this design, detailed investigation of tube failure detectability is performed. A helium gas system in the g of double-wall tube is used for detection. In case of an inner tube failure, steam in the helium system is detected. On the contrary, helium gas contents in sodium is detected in case of an outer tube failure. Both experimental studies and code development are in progress to validate this detection system. 

ABSTRACT Since the standard EN ISO 13849-1 became effective in December 2012, manufacturers in the area of the machine tool industry have to assess the functional safety of the safety-related functions in a probabilistic quantitative way. Due to the specifications of the standard in combination with little experience and few existing quantitative data in the machine tool industry, manufacturers have huge problems by adapting the new requirements. The presented research project tries to develop an alternative and practicable procedure which shall allow the manufacturers to fulfil the normative requirements with a proven in use approach. Therefore, as shown in the ESREL-paper 2013, a first data analysis of real field data was performed to proof if the available field data in the machine tool industry is useful to develop a proven in use approach. Further the standard includes assumptions concerning the failure behaviour of the components, which were also checked with the first field data analysis. The first examination included the reliability of the analysed systems. To realise an approach for the Functional Safety of safety-related functions it is necessary to analyse these functions separately on the basis of field data. The aim and content of the presented paper is to extract the safety-relevant information out of the checked reliability field data. Afterwards, the safety-related field data has to be further analysed to identify those data that are responsible for one exemplified single safety-related function. Consequently, the received quantitative results can be compared with the requirements of the EN ISO 13849-1. 

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