DECONTAMINATION OF SHIPS' SURFACES. II. DESIGN AND CONSTRUCTION OF EXPERIMENTAL FACILITIES

A laboratory study of the fallout from a seawater nuclear detonation and its contamination of ships surfaces requires special equipment to make the radioactive simulant, to generate and disperse the simulant on painted surfaces, and to decontaminate these surfaces by liquid methods. The simulant is produced by evaporating 30 gal of seawater containing approximately 2 curies of a selected gamma-emitting radionuclide to a final volume of 3 gal. The concentrated solution is fed to a spinning disc generator which produces 200- micron diameter drops at flow rates from 0.06 mlsec to 2.5 mlsec. The drops are generated at the top of a polyethylene-lined chamber 36 ft high, and, as they settle at terminal velocity, they are distributed by a rotating cluster of fans to uniformly deposit on plates 8.5 in. sq. The plates are painted with navy paints, and cover a floor area of 1256 ft2. The contaminated plates are counted, washed, and recounted at the rate of 50hr in a machine which simulates firehosing and steam cleaning. The effects of solution temperature, spray pressure, spray time and chemical additives in the liquid decontamination methods may thus be evaluated.