ote RRs. as Pa. DEPART } le Te Ni OF DEFENSE . 2. MILITARY LIAISON COMMITTEE P.O. BOX 1814 WASHINGTON 25, 0.¢. A IN REPLY REFER TO1 410453 9045: APR 11 1957 Dear Mr. ye CANCELLED CLASSIFICATION vv ~ & a.” $ 46 Wi2/Fs 7 Filimed JY Gipsy The U. S. Air Force is faced with the problem that both Convair and Boeing Aircraft Companies have stated that certain U. S, Air Force aircraft sent to these companies for modification are too contaminated to permit company personnel to work on them. These include aircraft which have not participated in atomic test operations. The aircraft companies are using tolerance levels based on 12,000 dpm per square foot for surface contamination. Use of such extremely conservative standards has necessitated extensive and expensive decontamination procedures which have, in some instances, unduly delayed returning B-36 and B-52 aircraft to combat configurations. The U. S. Air Force has been evaluating this contamination hazard for the last two years. This evaluation has resulted in the publication of U. S. Air Force Technical Order QO-110A-1, “Identification and Handling of Radioactive and Contaminated Aircraft and Material,'' dated 25 May 1956 and Armed Forces Special Weapons Center \ sy . yr % & Uh hye eS 9 L } Technical Note 56-2, "Safe Levels of Contamination from Fission Products." Both of these documents were given to the Atomic Energy “Commission Division of Biology and Medicine on 21 February 1957. A revision of the AFSWC Technical Note containing additional informa- 4 x 5 3 ou, 5 Strauss: tion will be forwarded to the AEC about 15 April 1957. : These documents provide tolerances believed to be realistic and conserva- ™ tive and procedures based on established AEC criteria of permissible as concentrations of fission products in air, water, and various < ES surfaces. acl \ The aircraft companies have doubted the validity of the U. S. Air Force tolerances. As a result of the last two atomic test operations at the Eniwetok Proving Grounds, sufficient fission products have been deposited throughout the continental U. S. to be readily detectable by radiation monitoring instriments available ta U. S. Air Force contractors. For example, Atomic Energy Commission Research and Development Report, NYO 4645, ‘Worldwide Fallout from Operation CASTLE," by Robert J. List, dated 17 May 1955 indicates maximum depositions of radioactivity in certain areas of approximately 40,000 dpm per square foot one hundred days after the conclusion Bec ved US LOe ARCEIVES tte GO ae TN on -- cet do ee ms Colleoticn DRnt- FILES Tex A Tel JobFF7L2A7 op MLM ES NO ? was Sia GS bE

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