An integral response scaling method for reduced-height test facilities and its validation using RELAP5 for loss of RHR during midloop operation

Abstract

An integral response scaling method for reduced-height test facilities is described and validated for the local and the integral phenomena using the RELAP5 thermal-hydraulic code. In the present schematic scaling methodology, the scaling laws are generated from four scaling analyses: three-dimensional differential equation-based scaling analysis, one-dimensional differential equation-based scaling analysis, component-based scaling analysis, and overall integral scaling analysis. Through use of integral response function, scaling parameters related to four types of requirements are identified: time scaling, initial-condition scaling, transient scaling, and bifurcation-phenomena scaling requirements. In the present scaling method, flow velocities in the vertical channel and at break locations of the scaled-down model can be preserved setting up the scaling as tau (R) = l(R). The significance of the velocity preservation in the reduced-height facility is demonstrated by the RELAP5 code.