Filtered containment venting system (FCVS) is an emergency response system for severe accident. FCVS reduces the pressure in reactor vessel and removes radioactive iodine and cesium. Recently, silver doped zeolite (AgX) has been attracting attentions since it is believed to remove over 99.99% of CH_3I in the ventilation gas. However, the reliable data of AgX for CH_3I sorption under expected severe accident conditions are still limited. Therefore, the sorption behavior of CH_3I on AgX was investigated under several expected conditions. In this study, the CH_3I labeled by ~(125)I tracer was synthesized by isotope exchange reaction, and it was devoted for sorption experiment on AgX. Sorption experiment using stable CH_3I was also conducted by the same procedure. From results of the sorption experiment, over 99.9% of 2.28g of CH_3I were sorbed by 10g of AgX. After the sorption experiment, AgX samples were analyzed by powder X-ray diffraction (XRD) and SEM-EDX. These results indicated the distribution of Ag agreed with that of I in micro area of AgX. For the evaluation of apparent sorption capacity of AgX, breaking through experiment was carried out. The apparent sorption capacity of AgX for CH_3I was determined as 0.25g / g (AgX) at 24°C. The breaking through experiment was also carried out for the evaluation of CH_3I flux and humidity effects in the vent gas. The effect of temperature on the sorption capacity was also studied. When the flux of CH_3I supply was increased from 1.09 × 10~(-4) to 2.33 × 10~(-4)g/cm~2s, apparent sorption capacity was unchanged (=0.21g / g (AgX)). Besides, the apparent sorption capacity was unchanged in the humidity range of ～0 % H_2O to 0.01 % H_2O, while it decreased to 0.19 g / g (AgX) at 3% H_2O. When sorption temperature increased to 170°C, the apparent sorption capacity also increased to 0.69 g / g (AgX).
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机译：过滤式安全壳通风系统（FCVS）是严重事故的应急响应系统。 FCVS降低了反应堆容器中的压力，并去除了放射性碘和铯。最近，掺杂银的沸石（AgX）引起了人们的关注，因为据信它可以除去通气气体中99.99％以上的CH_3I。但是，在预期的严重事故情况下，AgX的CH_3I吸附的可靠数据仍然有限。因此，在几种预期条件下研究了CH_3I在AgX上的吸附行为。本研究通过同位素交换反应合成了〜（125）I示踪剂标记的CH_3I，专门用于AgX的吸附实验。使用稳定的CH_3I进行吸附实验也通过相同的程序进行。从吸附实验的结果来看，10g的AgX吸附了2.28g的CH_3I的99.9％以上。吸附实验后，通过粉末X射线衍射（XRD）和SEM-EDX分析AgX样品。这些结果表明在AgX的微小区域中Ag的分布与I的分布一致。为了评价AgX的表观吸附能力，进行了突破实验。在24°C下，AgX对CH_3I的表观吸附能力确定为0.25g / g（AgX）。还进行了突破性实验，以评估排放气体中的CH_3I通量和湿度影响。还研究了温度对吸附容量的影响。当CH_3I供给流量从1.09×10〜（-4）增加到2.33×10〜（-4）g / cm〜2s时，表观吸附容量不变（= 0.21g / g（AgX））。此外，在〜0％H_2O到0.01％H_2O的湿度范围内，表观吸附能力没有变化，而在3％H_2O时，表观吸附能力下降到0.19 g / g（AgX）。当吸附温度增加到170°C时，表观吸附容量也增加到0.69 g / g（AgX）。
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