An extended BEPU approach integrating probabilistic assumptions on the availability of safety systems in deterministic safety analyses. (November 2017)

• Record Type: Journal Article
• Authors: Martorell, S.; Sánchez-Sáez, F.; Villanueva, J.F.; Carlos, S.
• Is Part Of: Reliability engineering & system safety. Volume 167(2017)
• Page Start: 474
• Page End: 483
• Publication Date: 2017-11
• Subjects: BEPU, EBEPU -- Probabilistic and deterministic safety analysis -- Option 4 -- Realistic configurations -- Safety systems; AFWS Auxiliary Feed Water System -- ATWS Anticipated Transient Without Scram -- BE Best Estimate -- BEPU Best Estimate Plus Uncertainty methodology -- CD Core Damage -- CHF Critical heat flux -- DBA Design Basis Accidents -- DBC Design basis conditions -- DEC Design extension conditions -- DNBR Departure from Nucleate Boiling Rate -- DSA Deterministic safety analysis -- EBEPU Extended BEPU methodology -- FB Feed and Bleed -- FOM Figure of Merit -- FOS First order statistics -- IAEA International Atomic Energy Agency -- IE Initiating event -- IHI High pressure injection system – injection mode -- IHR High pressure injection system – recirculation mode -- LOFW Loss of Feed Water initiating event -- MCS Minimal Cut Set -- MFW Main feed water system -- MSIV Main steam isolation valve -- NPP Nuclear power plant -- OS Order Statistics -- PCT Peak cladding temperature -- PDF Probability Distribution Function -- PORV Pressure operated relief valve -- PRZ Pressurizer -- PSA Probabilistic Safety Analysis -- PWR Pressurized Water Reactor -- RCS Reactor coolant system -- RPS Reactor Protection System -- RV Relief valve -- SD Steam-dump valve -- SG Steam generator -- SSG Specific Safety Guide -- STL Standard Tolerance Level -- SSV Secondary side Safety Valve -- SV (Primary side) Safety Valve -- TCij Train/Component j of Safety Function i -- TH Thermal Hydraulic; Reliability (Engineering) -- Periodicals; System safety -- Periodicals; Industrial safety -- Periodicals; Fiabilité -- Périodiques; Sécurité des systèmes -- Périodiques; Sécurité du travail -- Périodiques; 620.00452
• DOI: 10.1016/j.ress.2017.06.020
• Languages: English
• ISSNs: 0951-8320

Abstract

Highlights: Option 4 Deterministic Safety Analysis. Best Estimate Plus Uncertainty (BEPU) methodology. Extended BEPU. Realistic safety systems configurations. PSA-based configurations. Abstract: The International Atomic Energy Agency (IAEA) produced guidance on the use of Deterministic Safety Analysis (DSA) for the design and licensing of Nuclear Power Plants (NPPs) in "DSA for NPP Specific Safety Guide, No. SSG-2", which proposes four options for the application of DSA. Option 3 involves the use of Best Estimate codes and data together with an evaluation of the uncertainties, the so called BEPU methodology. Several BEPU approaches have been developed in scopes that are accepted by the regulator authorities nowadays. They normally adopt conservative assumptions on the availability of safety systems. Option 4 goes beyond by pursuing the incorporation of realistic assumption on the availability of safety systems into the DSA. This paper proposes an Extended BEPU (EBEPU) approach that integrates insights from probabilistic Safety Analysis into a typical BEPU approach. There is an aim at combining the use of well-established BEPU methods and realistic ("probabilistic") assumptions on safety system availability. This paper presents the fundamentals of the EBEPU approach and the main results obtained for an example of application that focuses on an accident scenario corresponding to the initiating event "Loss of Feed Water (LOFW)" for a typical three-loops Pressurized Water Reactor (PWR) NPP.