The initial size distribution and morphological parameters of sodium aerosols are critical in evaluating the accidental suspended aerosol behaviour in Sodium-cooled Fast Reactor (SFR) containment. Mass-based measurements were more familiar in characterizing the sodium aerosols. Real-time number size distribution measurements are carried out in this study. The sensitivity analysis of sodium aerosol effective density () in deriving the actual number size distributions from the measured Aerodynamic Particle Size Distributions (APSD) and predicting suspended aerosol dynamics is presented. Tests are conducted in a 1 m chamber at 47 ± 3% RH for different initial mass concentrations () of 0.1, 1, and 2.9 g/m. The initial APSDs measured just after the generation completions are observed to be polydisperse with the count median aerodynamic diameter (CMAD) < 1 μm. The literature reported values of sodium aerosols, 2.27, 1.362, and 0.61 g/cm are used to derive mobility equivalent PSDs from APSD in each test. The real-time number concentration decay and size growth for four different PSDs are measured and compared with the estimate using nodal method-based code to ascertain the actual parameters. The validated parameters CMD = 0.66 μm, σ = 1.96, = 1 g/cm and χ = 1 are used for improved estimation of sodium aerosol dynamics in Indian SFR containment with = 4 g/m for severe accident scenarios.

中文翻译：

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测试室中钠燃烧气溶胶动力学的实时测量和建模，以改进 SFR 遏制气溶胶行为的评估

钠气溶胶的初始尺寸分布和形态参数对于评估钠冷快堆（SFR）安全壳中的意外悬浮气溶胶行为至关重要。基于质量的测量在表征钠气溶胶方面更为常见。本研究进行了实时数量大小分布测量。提出了钠气溶胶有效密度 () 的敏感性分析，用于从测量的空气动力学颗粒尺寸分布 (APSD) 推导出实际数量尺寸分布并预测悬浮气溶胶动力学。测试在 1 m 室内、相对湿度 47 ± 3% 下进行，初始质量浓度 () 分别为 0.1、1 和 2.9 g/m。生成完成后测量的初始 APSD 观察到是多分散的，计数中值空气动力学直径 (CMAD) < 1 μm。文献报告的钠气溶胶值 2.27、1.362 和 0.61 g/cm 被用于在每次测试中从 APSD 导出等效迁移率 PSD。测量四种不同 PSD 的实时数浓度衰减和尺寸增长，并与使用基于节点方法的代码的估计值进行比较，以确定实际参数。经验证的参数 CMD = 0.66 μm、σ = 1.96、= 1 g/cm 和 χ = 1 用于改进对印度 SFR 安全壳中钠气溶胶动力学的估计，严重事故情况下 = 4 g/m。