Production scale separation of tritium from other hydrogen isotopes at the Savannah River Site (SRS) in Aiken, SC, USA, has been accomplished by several methods. These methods include thermal diffusion (1957–1986), fractional absorption (1964–1968), and cryogenic distillation (1967–present). Most recently, the Thermal Cycling Absorption Process (TCAP), a metal hydride based hydrogen isotope separation system, began production in the Replacement Tritium Facility (RTF) on April 9, 1994. TCAP has been in development at the Savannah River Technology Center since 1980. The production startup of this semi-continuous gas chromatographic separation process is a significant accomplishment for the Savannah River Site and was achieved after years of design, development, and testing.