wae: rv. NQQMD cHEMICAL AND RADIOLOGICAL LABORATORIES INTERIM REPORTS. {CRLIR) CRLIR - 24 5 - GROSS DECONTAMINATION STUDY OF A MACADAM ROADWAY CONTAMINATED BY FALLOUT OF RA. Joseph C. Maloney, William H. Carr, Jr., Ralph E. Rexroad, and Frank S. Badger, 31 August 1951. . SECRET-RESTRICTED DATA of Purpose of this study was the determination under field conditions the feasibility of decontaminating macadam roadway contaminated by fallout of RA, a candidate radiological warfare agent. f v “¥ To conduct these tests, an srea of rmacadam surface 10 ft by 10 ft, was marked off into 100 one-foot squares. An agent of 0.96 Mev gamma energy, having a half life of 2.7 days, wes dispersed over this area within a tent inclosure. Air-suspended contaminant was precipitated onto the test surface by water sprays, the water also hastening hydrolysis of agent on the roadway. Decontamination sed procedures were conducted, and activity readings made from a movable bridge strezdling the contaminated area and one foot above it. It was concluded that scruhbing with detergent solution is an effective method of decontamination, with efficiencies approaching 95%. Fosing, effective to a certain extent against all degrees of contamination, is especially effective in areas of high concentration. Existing Engineer Corps and Chemical Corps equipment may be used to achieve decontamination sufficient to prevent spread of radioactivity by the passage of troops srowgp see “°° BEST AVAILABLE COPY CRLIR - 25 - REPORT OF THE PROTECTION AFFORDED BY FIELD FORTIFICATIONS AGAINST GAMMA RADIATION FROM AN AIR-BURST ATOMIC BOMB. (Operation RANGER) Paul R. Cerar, 14 June 1951. SECRET~RESTRICTED DATA Study was made of the degree of protection afforded by one-man, two-man, and prone foxholes against gamma radiation emitted at the time of detoraticn of an air-burst atomic bomb. The foxholes were oriented Perpendicular, parallel, and at a 45°angle to the foxhole-burst line, and av distances up to 2,000 yd from ground zero. In addition to determination o> gamma ray dosages; determinations were made of gamma exposure as a - function of slant distance from the bomb burst, gamma attenuation by dirt, half-thickness for dirt, and gamma radiation at the foxhole positions due to atmcspheric scattering.