銀ゼオライトを用いたFCVSの高度化

(15)チャギング防止ノズルとフィン付冷却管によるFCVSの高度化

抄録

The FCVS under development in this research consists of a scrubber nozzle, a scrubber pool, a metal fiber and a silver zeolite, three-stage filters, and can constitute an ultra-high-performance filter vent system. However, it is necessary to consider the decay heat of the adsorbed radioactive materials and the heat of chemical reaction of hydrogen and CO with oxygen. Therefore, we conducted a cooling evaluation test using a cooling pipe with fins to prevent overheating in the filter, and conducted a test to evaluate the cooling effect that can maintain the silver zeolite at 800°C or less. The FCVS assumes automatic start-up by a safety relief valve (SRV) when the critical pressure of 2Pd, which is twice the design pressure of the containment vessel, is reached.

When the FCVS starts up, the scrubber nozzle operates stably up to the saturation temperature, dissolving iodine and cesium iodide in water. For this reason, the decay heat of radioactive materials is removed by the water temperature rise in the scrubber pool and evaporation, so heat generation in metal fibers and silver zeolite filters is mainly due to chemical reactions of hydrogen and carbon monoxide with oxygen in the vent gas. As the test results, cooling with finned cooling pipes is effective and preventing overheating due to the hydrogen and CO with oxygen in the silver zeolite at the final stage.