Vacuum pressure swing adsorption for continuous xenon removal and helium recovery in molten salt reactor off-gas treatment

초록

Xenon (Xe), a noble gas generated as a fission product in molten salt reactors (MSRs), poses operational and environmental challenges due to its radiological nature and its detrimental impact on neutron economy. To address these issues, we evaluated the feasibility of a vacuum pressure swing adsorption (VPSA) system employing microporous activated carbon for selective separation of Xe from simulated MSR off-gas streams. The physical and thermal properties of the adsorbent were systematically characterized, and both equilibrium and dynamic Xe adsorption behaviors were investigated under varying conditions. The effects of adsorption pressure, desorption pressure, and cycle duration on separation performance were analyzed in detail. Under optimized conditions, the VPSA process achieved Xe removal and helium (He) recovery efficiencies exceeding 99 % and 95 %, respectively. While previous studies have focused on recovering non-radioactive Xe from ambient air or industrial sources, its application to radiologically sensitive MSR off-gas systems remains insufficiently studied. The proposed process demonstrated effective He reuse and operational robustness, indicating its potential as a regenerable and energy-efficient gas purification method. These findings are expected to support the development of safe and sustainable off-gas management strategies for next-generation nuclear systems and offer valuable insights into selective noble gas separation for environmental and industrial applications.

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