Xenon International is a fully automated, unattended system designed to collect, separate, enrich, quantify, and perform nuclear counting on radioxenon isotopes, as well as transmit data using two way communications. Xenon International is designed to stringent requirements* that make it an improved-performance next-generation-system for use in nuclear explosion monitoring networks such as the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT).