Abstract The paper discusses the results of numerical assessment of LWR fuel bundle degradation phenomena during heating up in a flowing steam and top flooding with water under severe accident conditions that were investigated in the PARAMETER-SF1 test. The simulation was performed with the code SOCRAT that is widely used in Russia for safety assessment of VVER-type NPP under severe accident conditions. A set of interacting processes, including heat transfer, fuel liquefaction, oxidation of fuel rods claddings, melt relocation and oxidation, hydrogen generation is discussed. PARAMETER-SF1 was the first test in the PARAMETER program that comprised several tests with different configurations of the VVER bundle flooding (top, bottom, and combined). Investigation of the phenomenology during flooding of an overheated core at the early phase of severe accident when core keeps a mainly rod-like geometry is extremely important for understanding the possibilities and conditions for implementing the measures of severe accident management at LWR NPPs.

中文翻译：

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PARAMETER-SF1ЗФ试验对顶驱条件下轻水堆燃料组件氧化熔化的数值评价

摘要 本文讨论了在 PARAMETER-SF1 试验中研究的严重事故工况下流动蒸汽加热和顶部注水过程中 LWR 燃料束退化现象的数值评估结果。模拟使用代码 SOCRAT 进行，该代码在俄罗斯广泛用于严重事故工况下 VVER 型核电厂的安全评估。讨论了一系列相互作用的过程，包括传热、燃料液化、燃料棒包壳的氧化、熔体重新定位和氧化、氢气生成。PARAMETER-SF1 是 PARAMETER 程序中的第一个测试，该程序包括使用不同配置的 VVER 束流淹没（顶部、底部和组合）的多个测试。