ABSTRACT A new gap conductance model is proposed in this study as a combination of Toptan’s model and the Ross-Stoute model. A variance-based sensitivity analysis is performed to understand how simulation results depend on all input parameters of the proposed model. Additionally, new modeling options (e.g. fill gas thermal conductivity, temperature jump distance, thermal accommodation coefficient, etc.) are added into the nuclear fuel performance code, BISON. The need for further investigation of the gap heat transfer between fuel and cladding in BISON motivated this study to evaluate its impact on the code’s predictions. New gap conductance modeling is proposed. A series of integral-effects validation tests is performed: (1) to demonstrate the impact of the proposed model on the code’s fuel temperature predictions at the beginning of life and through the reactor’s life; (2) to ensure that the proposed model is capable of accurately modeling gap heat transfer characteristics in real-world problems; and (3) to investigate the impact of the estimation of fission gas release on the fuel temperature predictions with the proposed model. The results indicate that the proposed gap conductance model improves BISON’s predictions.

中文翻译：

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应用于 BISON 规范的 LWR 燃料棒间隙电导建模

摘要 本研究中提出了一种新的间隙电导模型，作为 Toptan 模型和 Ross-Stoute 模型的组合。执行基于方差的敏感性分析以了解模拟结果如何取决于所提出模型的所有输入参数。此外，新的建模选项（例如填充气体热导率、温度跳跃距离、热调节系数等）被添加到核燃料性能代码 BISON 中。需要进一步研究 BISON 中燃料和包壳之间的间隙传热，促使本研究评估其对规范预测的影响。提出了新的间隙电导建模。执行了一系列积分效应验证测试：(1) 证明提议的模型对反应堆寿命开始和整个寿命期间规范燃料温度预测的影响；(2) 确保所提出的模型能够准确地模拟现实世界问题中的间隙传热特性；(3) 用所提出的模型研究裂变气体释放的估计对燃料温度预测的影响。结果表明，所提出的间隙电导模型改进了 BISON 的预测。