An integrated structure and scaling methodology for severe accident technical issue resolution: Development of methodology

Assessment of CFD Codes Used in Nuclear Reactor Safety Simulations

“…A "structured" scaling methodology, referred to as hierarchical two-tiered scaling (H2TS), as proposed by Zuber [91], addresses the scaling issues from two fronts: a top-down (inductive) system approach, followed by a bottom-up (process-and-phenomena) approach. This strategy is proposed because the traditional local and component-level scaling strategies cannot reproduce the scaling criteria for component interaction.…”

A Procedure to Identify and Rank Rainfall/Runoff Phenomena for the Evaluation of Urban Stormwater Models

“…At the system, subsystem, module, or component level, the governing transport equations can be derived for the representative control volume using the above three parameters. For a constituent k, a balance equation for the conserved property M (mass, momentum or energy) can be expressed as (Zuber et al, 1998):…”

“…An approach to perform such assessments is given in Figure 1 and is based on methods presented in Boyak et al (1990), Zuber et al (1998), and Wilson and Boyak (1998). These methods were developed to assess the capabilities of computer models to predict the response of a nuclear reactor to postulated accident events.…”

IRIS Final Technical Progress Report

“…The IRIS Scaling Analysis Document, Part I has been provided to NRC and gives a detailed overview of the first two stages, Stage 1 -System Decomposition and Stage 2 -Scale Identification of the Hierarchical, Two-Tired Scaling Analysis. [36] A physically based decomposition (Stage 1) establishes a hierarchical architecture for the system. The system is subdivided into subsystem components and further into modules.…”