Reliability assessment of passive isolation condenser system of AHWR using APSRA methodology

A review: passive system reliability analysis – accomplishments and unresolved issues

“…The top event for the fault tree is considered as passive system functional failures (for example, passive system unable to maintain the clad temperature below certain threshold) and the basic events are malfunctioning or failed component states. To reduce the uncertainty in code predictions, APSRA methodology suggests relying on experimental data from integral test facilities as well as from separate effect tests (Nayak et al, 2009). Figure 2 illustrates the steps followed in APSRA methodology.…”

Finite mixture models for sensitivity analysis of thermal hydraulic codes for passive safety systems analysis

“…Passive systems seem to offer several advantages in terms of safety and reliability [Nayak et al 2009] [ . For this reason, they are considered in the design of innovative and advanced nuclear reactor concepts.…”

How to effectively compute the reliability of a thermal–hydraulic nuclear passive system

“…Passive systems are expected to contribute significantly to nuclear safety by combining peculiar characteristics of simplicity, reduction of human interaction and reduction or avoidance of external electrical power and signals input [Nayak et al, 2008a and b;Nayak et al, 2009]. On the other hand, the assessment of the effectiveness of passive systems must include considerations on their reliability; these have to be drawn in the face of lack of data on some underlying phenomena, scarce or null operating experience of these systems over the wide range of conditions encountered during operation and less guaranteed performance as compared to active safety systems [Pagani et al, 2005;Burgazzi, 2007a].…”

“…Reactor (HWR) [Nayak et al, 2008a and b;Nayak et al, 2009]. 1 Notice that in the following, the discussion will focus on Type B passive systems, i.e., those involving moving working fluids and referred to as T-H passive systems; thus, the locution "passive system" will implicitly mean "T-H passive system" in the remainder of the paper.…”