PSI - Issue 22

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 ScienceDirect

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 22 (2019) 275–282

© 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers © 2019 The Authors. Published by Elsevier B.V.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers Abstract In this paper a probabilistic Leak-Before-Br ak alys s for WWER-1000 unit was performed based on the Failure Asse sment Diag a (FAD), reating strength and rack morphology parameters as stochastic values. In order to perf m probabilistic calcul tions Critical temperature of brittleness and Yield (Ultima e) Stress, wer fitted by normal distrib tion, and based on ex rimental data taken from the manufacture d cumentation found at the Ukrainian NPP. The statis ical b havior of the leak rate (LR) and Critical crack length was xamined. T e fai ure probability was calculated using Monte-Carlo simulation, for different types of cracks. It was proven, then crack morphology parameters highly affects the leak rate, among the mechanical characteristic a Fracture toughnes has mor influenc rather than Ultimate of Yield trength. © 2019 The Autho s. Publ shed by Elsev er B.V.This is an open access article u er th CC BY-NC-ND li ense (http://cr a ivecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organiz rs First International Symposium on Risk and Safety of Complex Structures and Components Application of Probabilistic Leak-Before-Break for WWER-1000 Unit Yaroslav Dubyk* IPP-Centre LLC, 8 Bolsunovska str, Kyiv, 01014, Ukraine Abstract In this paper a probabilistic Leak-Before-Break analysis for WWER-1000 unit was performed based on the Failure Assessment Diagram (FAD), treating strength and crack morphology parameters as stochastic values. In order to perform probabilistic calculations Critical temperature of brittleness and Yield (Ultimate) Stress, were fitted by normal distribution, and based on experimental data taken from the manufacture documentation found at the Ukrainian NPP. The statistical behavior of the leak rate (LR) and Critical crack length was examined. The failure probability was calculated using Monte-Carlo simulation, for different types of cracks. It was proven, then crack morphology parameters highly affects the leak rate, among the mechanical characteristic a Fracture toughness has more influence rather than Ultimate of Yield strength. First International Symposium on Risk and Safety of Complex Structures and Components Application of Probabilistic Leak-Before-Break for WWER-1000 Unit Yaroslav Dubyk* IPP-Centre LLC, 8 Bolsunovska str, Kyiv, 01014, Ukraine Keywords: Leak-Before-Break; Probabilistic analysis; Henry-Fauske flow model; crack morphology; WWER-1000 1. Introduction Leak-Before-Break (LBB) is a term that has been used for decades in reference to a methodology that means, that a leak will be discovered prior to a fracture occurring in service. For Ukranian's WWERs only deterministic LBB Keywords: Leak-Before-Break; Probabilistic analysis; Henry-Fauske flow model; crack morphology; WWER-1000 1. Introduction Leak-Before-Break (LBB) is a term that has been used for decades in reference to a methodology that means, that a leak will be discovered prior to a fracture occurring in service. For Ukranian's WWERs only deterministic LBB

* Corresponding author. Tel. fax: +380-44-502-4570. E-mail address: dubykir@gmail.com * Corresponding author. Tel. fax: +380-44-502-4570. E mail address: dubykir@gmail.com

2452-3216 © 2019 The Authors. Published by Elsevier B.V.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review statement: Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers 2452 3216 © 2019 The Authors. Published by Elsevier B.V.This is an open access rticle under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review statement: Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the First International Symposium on Risk and Safety of Complex Structures and Components organizers 10.1016/j.prostr.2020.01.035