Scalings Laws for Simulating the CANDU Heat Transport System

Abstract

The RD-14 test facility at Whiteshell Nuclear Research Establishment is a full-elevation model of a typical CANDU primary heat transport loop. It consists of two full-scale, full-power electrically heated channels, full-scale feeders and two full-height steam generators. The loop is designed so that fluid mass flux, transit times, and pressure and enthalpy distributions in the primary system are the same as in a typical power reactor in both forced and natural circulation. To study the interaction between parallel channels in thermosiphoning and blowdown/emergency coolant injection transients, it is proposed to modify RD-14 to a multiple-channel configuration. A scaling rationale has been developed from a consideration of the one-dimensional, homogeneous, two-phase-flow conservation equations. The scaling laws show that to represent the CANDU system correctly, particularly under thermosiphoning conditions, the model loop must possess the full linear dimensions and elevation changes of the reactor. The paper will describe the development of the scaling laws and their application in defining the sizes of the major loop components of the proposed multiple-channel RD-14 loop.