A Multi-State Physics Modeling approach for the reliability assessment of Nuclear Power Plants piping systems

Francesco Di Maio (1) , Davide Colli (1) , Enrico Zio (2, 1) , Liu Tao (3) , Jiejuan Tong (4)

1 Dipartimento di Energia [Milano]
2 SSEC - Chaire Sciences des Systèmes et Défis Energétiques EDF/ECP/Supélec
3 Institute of Nuclear and New Energy Technology
4 Department of Computing and the Digital Environment, Faculty of Engineering and Computing

A Multi-State Physics Modeling (MSPM) approach is here proposed for degradation modeling and failure probability quantification of Nuclear Power Plants (NPPs) piping systems. This approach integrates multi-state modeling to describe the degradation process by transitions among discrete states (e.g., no damage, micro-crack, flaw, rupture, etc.), with physics modeling by (physic) equations to describe the continuous degradation process within the states. We propose a Monte Carlo (MC) simulation method for the evaluation of the time-dependent transition rates between the states of the MSPM. Accountancy is given for the uncertainty in the parameters and external factors influencing the degradation process. The proposed modeling approach is applied to a benchmark problem of a piping system of a Pressurized Water Reactor (PWR) undergoing thermal fatigue. The results are compared with those obtained by a continuous-time homogeneous Markov Chain Model.

Mots clés: time-dependant transition rates; Markov Chain Model; Monte Carlo; Piping reliability; Multi-State Physics Modeling; Degradation process; Nuclear Power Plant

Domaines: Energie électrique; Physique des Hautes Energies - Expérience [hep-ex]

Francesco Di Maio, Davide Colli, Enrico Zio, Liu Tao, Jiejuan Tong. A Multi-State Physics Modeling approach for the reliability assessment of Nuclear Power Plants piping systems. Annals of Nuclear Energy, 2015, 80, pp.151-165. ⟨10.1016/j.anucene.2015.02.007⟩. ⟨hal-01177012⟩