Historical doses to the public from routine and accidental releases of tritium - Lawrence Livermore National Laboratory, 1953-2005

Throughout fifty-three years of operations, an estimated 29,300 TBq of tritium have been released to the atmosphere at the Livermore site of Lawrence Livermore National Laboratory; about 75% of this was released accidentally as gaseous tritium in 1965 and 1970. Routine emissions contributed slightly more than 3,700 TBq gaseous tritium and about 2,800 TBq tritiated water vapor to the total. Mean annual doses (with 95% confidence intervals) to the most exposed member of the public were calculated for all years using the same model and the same assumptions. Because time-dependent tritium models require detailed meteorological data that were unavailable for the large releases, ingestion/inhalation dose ratios were derived from experience with UFOTRI. Even with assumptions to assure that doses would not be underestimated, all doses from routine and accidental releases were below the level (3.6 mSv) at which adverse health effects have been documented, and most were below the current regulatory limit of 100 μSv per year from releases to the atmosphere. (authors)