A LABORATORY APPARATUS FOR MEASURING THE AMOUNT OF TRITIUM ACTIVITY REMOVED FROM A CONTAMINATED SURFACE, BY DIRECT CONTACT WITH THE SURFACE
Abstract
The sampling component is a small glass roller wrapped with a strip of filter paper dampened with ethylene glycol. It is rolled over the contaminated surface to sample the activity. After a run, the contaminated roller is dropped immediately after contact with the surface into a counting vial containing a scintillant solution, and the activity is assayed. The apparatus is small enough to be operated in a conventional glove box. The precision of the measurements is influenced by the texture of the surface sampled. Precision measured on a smooth optical quartz surface using a nonvolatile tracer, promethium(143), as a contaminant, was determined to be = 2%. The precision for tirtium sampling from a relatively coarser, nonuniform metal surface was approximately = 25%. The apparatus can be used to study the rate of tritium desorbed from the surface, which allows estimation of the cumulative hazard effect of multiple contacts with the surface during the desorption period. Representative samples of metal surfaces exposed to tritium show that after exposure, desorption is exponential, decreasing to an 'equilibrium' amount within a few hours. Multiple contracts with these desorbing surfaces did not seem to significantly alter the desorption process.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1965
- Accession Number
- AD0624202
Entities
People
- Don A. Kubose
- William R. Balkwell
Organizations
- Naval Radiological Defense Laboratory