MEASUREMENT OF TRITIUM ON SURFACES

The quantitative significance of surface-contamination levels determin ed by different methods was assessed by carrying out measurements usin g the wipe-assay method and a commercial surface-contamination monitor (Whitlock Vacuum Scintillation Counter(VSC)). The results were compar ed to the total tritium desorbed from the sample. Simple correlations between these measurements were not found. Laser-assisted desorption m ethods are currently being investigated to measure total tritium on su rfaces. Preliminary results obtained with a Nd:YAG laser (532 nm) are reported. Only water vapor and CO2 were found in the gas released unde r laser irradiation by mass spectroscopy. Approximately 65-95% of the surface tritium could be desorbed from all metal samples investigated.