3H
(Hydrogen-3;
Tritium)
Physical
Characteristics
Half Life:
Physical 12.3 years
Biological 12 days
Effective 12 days
Radiation Emitted: ß-
Energy of Radiation (keV): 18.6 (max) 5.7 (mean)
Air 5 mm
Water 0.006 mm
Radiation Biology
Critical Organ: Whole Body
Toxicity: Low
ALI: Ingestion (Water) Inhalation
8 X 10+4 µCi 8 X 10+4 µCi
Bioassay: Urinalyses required within 10 working days after working with 100 mCi or more of tritiated water or sodium borohydride.
Health Physics
DAC (µCi/ml): 2 X 10-5
Survey Technique:
Wipes, counted by LSC
Shielding Required: None
Special
Considerations:
Tritium cannot be monitored directly because of the low beta energy. Special care is needed to control contamination. Regular monitoring by wipe testing is advisable. External contamination does not cause a radiation dose itself but can lead to potentially hazardous internal contamination and can interfere with experimental results.