Abstract
After the Fukushima Dai-ichi nuclear accident, Filtered Containment Venting Systems (FCVSs) were developed and installed at nuclear power plants in Japan. Using silver zeolite, a design of an additional filter had been developed for FCVSs to capture radioactive organic iodine, which cannot be captured by conventional aerosol filters. For expanding the design flexibility of the FCVS with the organic iodine filter, additional laboratory tests were conducted in this study. To secure the absorption performance, silver zeolite must be kept dry during the operation of the FCVS. The additional tests were conducted to evaluate the absorption performance of silver zeolite under the conditions of relatively low degrees of superheat. And the test results demonstrated that the decontamination factor of the silver zeolite was over 50 even under the condition that the difference between gas temperature and dew point was 2.1 K and contact time was 0.129 s. In addition, absorption performance tests simulating FCVS start-up conditions were conducted. Although similar tests had been conducted in previous studies, the tests in this study demonstrated the performance under relatively short contact time conditions.
