1.1 该试验方法是一种非常严格的程序，用于确定新的和使用过的活性炭从空气和气流中去除放射性标记的甲基碘的能力。所述的单一试验方法适用于新碳和旧碳，其试验结果应与世界各地要求和执行的类似试验结果相当。所采用的条件是为了近似核反应堆的运行或事故条件，这将严重降低活性炭的性能。提高进行该试验的温度通常会通过增加化学和物理吸收以及同位素交换的速率来提高碳的去除效率，即增加放射性碘去除机制的动力学。 降低试验的相对湿度通常会提高活性炭去除甲基碘的效率。水蒸气与碘化甲酯竞争碳上的吸附位置，随着水蒸气量的减少，规定的相对湿度越低，碘化甲酯越容易被吸附。因此，由于规定的低温和高相对湿度，该试验方法是对核级活性炭进行的非常严格的试验。建议使用本试验方法对新碳进行鉴定，并量化旧碳的降解。 1.1.1 使用不同于本试验方法的条件测试新碳和旧碳的指南见 附录A1 . 1.2 以国际单位表示的数值视为标准值。本标准不包括其他计量单位。 1.3 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 本试验方法的结果给出了所有核电厂暖通空调系统中用于去除放射性碘的核级活性炭性能的保守估计。

1.1 This test method is a very stringent procedure for establishing the capability of new and used activated carbon to remove radio-labeled methyl iodide from air and gas streams. The single test method described is for application to both new and used carbons, and should give test results comparable to those obtained from similar tests required and performed throughout the world. The conditions employed were selected to approximate operating or accident conditions of a nuclear reactor which would severely reduce the performance of activated carbons. Increasing the temperature at which this test is performed generally increases the removal efficiency of the carbon by increasing the rate of chemical and physical absorption and isotopic exchange, that is, increasing the kinetics of the radioiodine removal mechanisms. Decreasing the relative humidity of the test generally increases the efficiency of methyl iodide removal by activated carbon. The water vapor competes with the methyl iodide for adsorption sites on the carbon, and as the amount of water vapor decreases with lower specified relative humidities, the easier it is for the methyl iodide to be adsorbed. Therefore, this test method is a very stringent test of nuclear-grade activated carbon because of the low temperature and high relative humidity specified. This test method is recommended for the qualification of new carbons and the quantification of the degradation of used carbons. 1.1.1 Guidance for testing new and used carbons using conditions different from this test method is offered in Annex A1 . 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 The results of this test method give a conservative estimate of the performance of nuclear-grade activated carbon used in all nuclear power plant HVAC systems for the removal of radioiodine.