r0005">We assumed that tritium migrates from biomass hybrid fusion system to fuel cell vehicles.
r0010">We developed a seven-compartment model to describe the water flow and tritium in an urban area Osaka.
r0015">Tritium concentration of surface soil water run by 4 Bq/L level after 60 years later.
r0020">The tritium does not deserve health hazard but easily detectable in the environment.