a the body is totally unshielded, while it may take 900 r to be lethal with 30% protection. But, with 30% protection of the abdomen alone, the.Jethal dose may be raised to about 800 r. reduction of effective 62 1b of lead in trunk should be supplemented standard clothing, and The conclusion was reached that 40% radiation intensity is attainable by the use of armor, or 31 1b in abdomen armor, This protection by combat boots, steel helmet, two layers of leather gloves. The final report of this work appeared as CRLR 2Zll. CRLR - 104 - CONTAMINATION-DECONTAMINATION STUDIES ALOFT (WT-27). (Operiztion GREENHOUSE) Simon'R. Sinnreich, Malcolm G. Gordon, and Glenn E. Fulmer, 2 January 1953. SECRET we This study was designed to provide information concerning the ifferences in radioactive contamination of materials having various surface characteristics, and in the decontamination of their surfaces by various agents. Test panels incorporating 54 possible surface variations were attached to aircraft flown through atomic clouds and thus exposed to contamination. The variations inéluded three degrees (low, medium, and high) each of roughness, porosity, and contact angle, and two conditions of dye retentivity (fast and nonretentive). Twelve decontaminating agents, fundamental components of commercial detergents, were tested on each contaminated panel surface, The data resulting from this work indicate that roughness, ani to a lesser extent, dye retentivity, are characteristics requiring careful consideration in the selection of surfaces for military use. Contact angles and porosity may be regarded as unimportant factors in the selecticn of such surfaces. Sequestrants and anionic detergents are the most efficient agents for the radiological decontamination of all +t yoes of surfaces. CRLR - 105 - CLOUD SAMPLING TECHNIQUES USING SNAP SAMPLERS. (Operation IVY) Michael J. Schumchyk, 16 February 1953. SECRET~RESTRICTED DATA Lennard Snap samplers were installed in several jet aircraft flown throug: nuclear clouds at Operation IVY (November 1952). This aerosol-sampling device consisted of a probe with an orifice designed to give approximately isokinetic sampling, projecting from the nose of the aircraft, and comnected via a quick-opening valve to a collapsed, plastic bag. The pilot opened the gate valve electrically when cockpit instruments indicsted that the plane had entered an area of at least 1 r/br activity. RES 4 — Le BEST AVAILA BLE COPY gree Air filled