Exposure Limits Specifically for H-3

Exposure Limits for H-3

  1. Individuals involved in operations which utilize, at any one time, more than 100 millicuries of tritium in a non-contained form, other than metallic foil, shall have a bioassay performed within one week following a single operation, and at weekly intervals for continuing operations.
    1. Tritium shall not be used in such a manner as to cause any individual to receive a radiation exposure such that urinary excretion rates exceed 28 microcuries of tritium per liter when averaged over a calendar quarter.
    2. If the average concentration of tritium in urine for an individual during a calendar quarter is less than 10 microcuries per liter, urinalysis may be performed on that individual at monthly intervals for the following calendar quarter and may continue at monthly intervals so long as the average concentration in a calendar quarter remains below 10 microcuries per liter.
    3. The urine specimen should be collected on the same day of the week, whenever practical.
    4. Scheduling of routine bioassays is the responsibility of the individual radiation worker.
  2. Operations which utilize 100 millicuries or more of tritium in a non-contained form, other than metallic foil, shall be performed in either a closed system or in a certified working fume hood. Operations in biosafety cabinets or on benchtops are prohibited.
  3. Persons with more than 10% of the applicable limit for internal exposure of tritium will be counseled by a Radiation Safety staff member.
  4. The Principle Investigator and Radiation Safety will evaluate the probable causes of the exposure and changes in procedures, work habits, or equipment will be recommended as appropriate.
  5. A written summary of the investigation results, including potential corrective actions, should be provided to the Radiation Protection Committee.