The tritium metering, assay, recovery and storage (TriMARS) facility of KEPCO Research Institute has been installed to develop expertise in the tritium handling technology and to support the tritium control system in Korea. The major systems and equipment of the facility consisted of a tritium assaying and dispensing system, a tritium recovery system, a purge gas recombiner system, a tritium calorimeter, a gas chromatograph, tritium monitors, a high integrity glove box and air purged enclosures. The annual tritium usage is restricted below 11.5 PBq of tritium. The tritium dispensing and loading would be carried out by batch transfers. Tritium metering is based on accurate pressure-volume-temperature measurements and GC analysis. Three metering tanks were provided to measure 0.37 TBq to 185 TBq of T2 gas at sub-atmospheric pressure. Three uranium beds were installed to store tritium from outside and to recover the tritium residual of process equipment in the facility. Tritium recovery systems, secondary enclosures and tritium monitors were provided to protect workers from tritium exposure. For tritium accountancy for all shipments in and out at the facility, a dedicated twin cell tritium calorimeter was installed and demonstrated.