Abstract: The use of He-3 loop for power transient test of LWR fuel element raises tritium safety issues due to occupational exposure. This paper proposed some protection programs of tritium and the tritium decontamination in He-3 loop, and analysed the tritium source term and the hazard of the tritiated water vapor. Then, the normal and accidental release rates of tritium from He-3 loop into the glove-box and working area are discussed. The released tritium can be treated safely. Finally, the intake doses for internal exposure of tritium are calculated through each pathway based on the failures of He-3 system safety measures. The results show the maximum individual doses to the operator are 1.27 μSv/d in normal operation and less than 10 mSv if not all the protective precautions fail or loss simultaneously in an extreme accident case.

Key words: He-3 loop, tritium safety, internal exposure, dose assessment