Fusion Science and Technology / Volume 48 / Number 1 / July 2005 / Pages 775-778
Technical Paper / Tritium Science and Technology - Biology, Health, and Radiation
Heavy water (D2O) vapor release experiments were carried out in a greenhouse using deuterium as a substitute for tritium and uptake and loss kinetics of D2O in leaf of a tangerine tree and formation, translocation and retention of organically bound deuterium (OBD) in tangerine exposed to D2O under different growth stage were investigated. Rate constants of D2O uptake in leaves of tangerine were 0.2-1.11 hr-1 in the daytime release and 0.03-0.12 hr-1 in the nighttime release. Rate constants of D2O loss in leaf after daytime release were almost the same as those after the nighttime release. No significant differences in the half time of D2O loss were observed between daytime and nighttime releases, but those in winter experiments were about 6 times higher than those in summer ones. The retention of OBD of the edible part of tangerine at harvest was very low and OBD was 0.08% or 0.07% on average of D2O in air moisture in daytime or nighttime releases.