Ex-reactor determination of thermal gap and contact conductance between uranium dioxide: zircaloy-4 interfaces. Stage I: low gas pressure. [PWR; BWR]

Abstract

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Extension and Demonstration of NEAMS Multiphysics Tools to Lead-Cooled, Sodium-Cooled, and Molten Salt Fast Reactor Applications

“…The expression [Eq 2.9.1] predicts a 4-fold improvement in gap conductance while the experimental data obtains 40-fold gap conductance improvement compared to the no-JOG case. This trend is consistent with the conclusion from the experimental research [Garnier 1979] that the expression usually underestimate the actual gap conductance. First, the JOG fully filling the gap is an ideal situation, so the deviation between the expression and the experimental data usually is much smaller since the JOG formation does not cover the entire gap.…”

“…The second database is from an experimental study of thermal gap and contact conductance between depleted uranium dioxide (UO2) and Zircaloy-4 (Zr4) [Garnier 1979]. The experimental data shows that analytical expressions for ideal gap conductance (such as Eq.…”

“…2.9.1 and 2.9.2. The "Gap conductance improvement_experiment" series is from the experimental reference [Garnier 1979].…”

FRAPCON-3: Modifications to fuel rod material properties and performance models for high-burnup application

“…noted that considerable scatter existed in contact conductance data available at that time, with the available data taken under widely varying surface and ambient conditions. Therefore, NRC initiated a program to make ex-reactor controlled measurements of gap conductance, including contact conductance; Garnier and Begej (1979) reported their findings from this program.…”

Review of thermal conductance models for joints incorporating enhancement materials

“…Song et al 5 present a review of various gap-conductancemodels, as summarized in Table 1 where b t is given in terms of the centerline average surface roughness (CLA) (see Refs. [6][7][8][9][10][11][12][13]. Note that only the Yovanovich integral gap-conductance(YIGC) model (see Ref.…”