ISAAC, a framework for integrated safety analysis of functional, geometrical and human aspects

International audienceThis paper aims at presenting methods and tools that are developed in the ISAAC project (Improvement of Safety Activities on Aeronautical Complex Systems, www.isaac-fp6.org), a European Community funded project, to support the safety assessment of complex embedded systems. The ISAAC methodology proposes to base as much of the safety analyses as is feasibly possible on simulable and formally verifiable system models that include fault models and can be shared both by safety and design engineers. On one hand, tools were developed to support safety assessment of Simulink, SCADE, Statemate, NuSMV and AltaRica models. On the other hand, formal models are coupled with additional models to address the problems of common cause analysis and human error analysis

Safety Assessment of an Electrical System with AltaRica 3.0

International audienceThis article presents the high level, modeling language Al-taRica 3.0 through the safety assessment of an electrical system. It shows how, starting from a purely structural model, several variants can be derived .Two of them target a compilation into Fault Trees and two others target a compilation into Markov chains. Experimental results are reported to show that each of these variants has its own interest. It also advocates that this approach made of successive derivation of variants is a solid ground to build a modeling methodology onto

Natural organic matter (NOM)-clay association and impact on Callovo-Oxfordian clay stability inhigh alkaline solution: Spectromicroscopic evidence

International audienceThe understanding of chemical association between natural organic matter (NOM) and clay minerals is of paramount importance to predict the long term stability of host rock formations for deep geological nuclear waste repositories. Synchrotron-based soft X-ray spectromicroscopy demonstrates a strong association between K-rich clay phases (illite) and NOM in the Callovo-Oxfordian argillite (Meuse-Haute Marne, or MHM site, France) and a weaker association in the Opalinus clay (Benken, Switzerland). C(1s) spectra show no significant depth dependent variation in the MHM site (447-516m). Alteration experiments under oxidizing conditions and high pH of the Callovo-Oxfordian clay indicate a passivation of chemically reactive sites by NOM that is responsible for the kinetic hindered clay dissolution/transformation. These experiments lead to a significant release of humic/fulvic acid colloids in the alkaline solution with time dependent variation in size and functional group content

Clay minerals in the Meuse - Haute Marne underground laboratory (France): Possible influence of organic matter on clay mineral evolution. Clays and

A clay-rich Callovo-Oxfordian sedimentary formation was selected in the eastern Paris Basin (MHM site) to host an underground laboratory dedicated to the assessment of nuclear waste disposal feasibility in deep geological formations. As described initially, this formation shows a mineralogical transition from an illite-smectite (I-S) mixed-layered mineral (MLM), which is essentially smectitic and randomly interstratified (R=0) in the top part of the series to a more illitic, ordered (R≥1) I-S in its deeper part. This description has been challenged by using the multi-specimen method developed by Drits et al. (1997a) and Sakharov et al. (1999). It is shown that all samples contain a physical mixture of an unusually (?) illitic (~65 %I) randomly interstratified I-Exp (Illite-Expandable MLM) and of a discrete smectite, in addition to discrete illite, kaolinite and chlorite. Structural parameters of the different clay phases vary little throughout the series. According to the proposed model, the mineralogical transition corresponds to the disappearance of smectite with increasing burial depth. Comparison with clay minerals from formations of similar age (Oxfordian-Toarcian

A Model-Checking Approach to Analyse Temporal Failure Propagation with AltaRica

International audienceThe design of complex safety critical systems raises new technical challenges for the industry. As systems become more complex—and include more and more interacting functions—it becomes harder to evaluate the safety implications of local failures and their possible propagation through a whole system. That is all the more true when we add time to the problem, that is when we consider the impact of computation times and delays on the propagation of failures.We describe an approach that extends models developed for Safety Analysis with timing information and provide tools to reason on the correctness of temporal safety conditions. Our approach is based on an extension of the AltaRica language where we can associate timing constraints with events and relies on a translation into a realtime model-checking toolset. We illustrate our method with an example that is representative of safety architectures found in critical systems

ISAAC, a framework for integrated safety analysis of functional, geometrical and human aspects.

International audienceThis paper aims at presenting methods and tools that are developed in the ISAAC project (Improvement of Safety Activities on Aeronautical Complex Systems, www.isaac-fp6.org), a European Community funded project, to support the safety assessment of complex embedded systems. The ISAAC methodology proposes to base as much of the safety analyses as is feasibly possible on simulable and formally verifiable system models that include fault models and can be shared both by safety and design engineers. On one hand, tools were developed to support safety assessment of Simulink, SCADE, Statemate, NuSMV and AltaRica models. On the other hand, formal models are coupled with additional models to address the problems of common cause analysis and human error analysis

geometrical and

a framework for integrated safety analysis of functional