Calibration of a liquid scintillation counter to assess tritium levels in various samples

An LKB-Wallac 1217 Liquid Scintillation Counter (LSC) was calibrated with a newly adopted cocktail. The LSC was then used to measure tritium levels in various samples to assess the compliance of tritium levels with the recommended international levels, The counter was calibrated to measure both biological and operational samples for personnel and for an accelerator facility at KFUPM. The biological samples include the bioassay (urine), saliva, and nasal tests. The operational samples of the light ion linear accelerator include target cooling water, organic oil, fomblin oil, and smear samples. Sets of standards, which simulate various samples, were fabricated using traceable certified tritium standards. The efficiency of the counter was obtained for each sample. The typical range of the efficiencies varied from 33% for smear samples down to 1.5% far organic oil samples. A quenching curve for each sample is presented. The minimum detectable activity for each sample was established. Typical tritium levels in biological and operational values are presented. All measured values are far below the recommended international limits. (C) 1999 Elsevier Science B.V. All rights reserved.