Asset Management Evaluation: The Key Role of Expert Elicitation

Abstract

The life management of a nuclear power plant raises several major issues amongst which ranks the aging management of the key components of the plant, both from a technical and an economic point of view. Decision-makers are thus faced with the need to define the best strategy in order to achieve the best possible performance which requires both a very precise modeling of the plant and a detailed analysis of all risks potentially incurred.In this paper, we wish to provide the reader with an overview of how advanced expert elicitation techniques can help identify, structure, quantify and feed sensitive data into a risk-based information system which can then be used for risk-based asset management evaluation.First we focus on the way knowledge management techniques allow EDF to structure and collect life-cycle management data into knowledge-based information systems. The elicitation of component experts is key, particularly in order to get technical information on the future behavior of the component ("anticipation" of whatever events may occur on the plant).We then detail how expert elicitations allow to quantify the probabilities of occurrence of the events: whether there is feedback data, models or not, expert opinion has to be taken into account and mixed, for instance with Bayesian procedures, to this information.Lastly we describe how the information elicited from experts can help top level decision makers get a transverse, long term view on how life management investment strategy translates into plant availability, avoided costs and improved component durability. INTRODUCTIONThe management of a production asset, especially with a long-term goal to achieving an optimum lifetime, raises several major issues, among which rank the technical management of the plant, its economics and the fleet level perspective one has to adopt.Decision-makers are therefore faced with the need to define long-term policies (until the end of the life of the asset), which take into account multiple criteria including safety (which is paramount) and performance.In this paper, we first remind the reader of the EDF three-level methodology for nuclear asset management, as introduced in PVP 2003 [1] and PVP 2004 [2]. The knowledge management techniques used to support the expert elicitation process (in order to anticipate whatever could occur to the plant) and which facilitate the structuring and the processing of the acquired knowledge are then presented. Emphasis is given to the methodology developed for the quantification of the events (i.e. their probabilities of occurrence, their consequences in terms of availability) and of the mitigation actions (i.e. their cost, duration and impacts on events' occurrences). Lastly, we describe how the methodology, the information elicited from experts and their implementation in a software tool can be used in order to process technical and economic indicators obtained at the plant level as well as the conclusions top level decision makers can draw from them in order to evaluate and analyz...

Gestion des connaissances et systèmes d'organisation de connaissances. Premier modèle et retours d'expérience industriels

“…Dans le projet Durabilité (Bauby et al, 2006), le besoin métier est d'identifier, en connaissance de cause, les stratégies à mettre en oeuvre pour optimiser la gestion de différents composants d'une usine de production d'électricité tout au long de l'exploitation. Cette optimisation suppose d'anticiper les événements futurs pouvant influer fortement sur le fonctionnement des matériels, de faire, en particulier d'un point de vue technico-économique, les bons choix de maintenance et de prévoir et anticiper les actions à entreprendre.…”