Adsorption data and isotherms of various fission products on graphite are needed for high-temperature gas-cooled reactor mechanistic source term estimations. Measurements of such data for NBG-17 graphite powders, preloaded with Ag, are described. The samples were desorbed in a Knudsen-effusion mass-spectrometer. Data was sorted into adsorption isosteres for surface loadings from 23.2 to 90.4 mmolAg (kgC)⁻¹. Straight-line fits to the Clausius-Clapeyron representation of isosteres gave the heats of adsorption as function of surface loading. Adsorption isosteres were further refined to determine adsorption isotherms from 1050 to 1175 K. Langmuir, IAEA-Freundlich, and IAEA isotherm models were fitted to the isotherm data. The IAEA and Langmuir isotherms provided a better fit than the IAEA Freundlich isotherm.

高温气冷反应堆机械源项估计需要石墨上各种裂变产物的吸附数据和等温线。描述了对预加载 Ag 的 NBG-17 石墨粉末的此类数据的测量。样品在 Knudsen-efusion 质谱仪中解吸。将数据分类为表面负载从 23.2 到 90.4 mmolAg (kgC) ^{-1 的}吸附等排体。等排体的 Clausius-Clapeyron 表示的直线拟合给出了作为表面负载函数的吸附热。吸附等排线进一步细化以确定从 1050 到 1175 K 的吸附等温线。 Langmuir、IAEA-Freundlich 和 IAEA 等温线模型拟合等温线数据。IAEA 和 Langmuir 等温线提供了比 IAEA Freundlich 等温线更好的拟合。