The first generation of a hydrogen isotope separation process called the thermal cycling absorption process (TCAP) has been in service for tritium separation at the Savannah River Site since 1994. To prepare for replacement, a next-generation TCAP process has been developed. This new process simplifies the column design and reduces the equipment requirements of the thermal cycling system. An experimental 12-m column was fabricated and installed in the laboratory to demonstrate its performance. This new design and its initial test results were presented at the Eighth International Conference on Tritium Science and Technology and are published in the proceedings, Fusion Sci. Technol., Vol. 54, No. 2, p. 399 (2008). We have since completed the start-up and demonstrated the separation of protium and deuterium in the experimental unit. The unit has been operated for more than 200 cycles. A feed of 25% deuterium in protium was separated into two streams, each with better than 99.7% purity.