UNCLASSIBetas T. L. Shipman, M.D. —2— 1 DATE: 16 June 1953 During January, 1949, a survey was made by Brig. Gen. James P, Cooney, USAMC, DMA of ABC; Dr. Harry O. Whipple and Mr. Gordon Pettengill, H-Div. LASL; Dr. K. Z. Morgan, ORNL; and Dr. Carl C. Gamertsfelder, Hanford Works. This survey was preliminary to a conference at Holmes & Narver offices in Los Angeles on ways and means for decontaminating the Shot Islands. Following this conference, it was decided that decontamination should be done by (1) First, removing and dumping into the sea all of the radioactive scrap, (e.g. radioactive steel debris) that could be located. wralta Ke note Tey &o- ) = om “De pel. (2) Second, wetting the soil to allay dust, and bulldozing the top layer to bury the generally dispersed radioactive contamination, Note Since it might appear that burying the contamination would not entirely solve the problem in an area where subsequent excavation work would be necessary, a digression is made here to set forth the reasoning upon which this method of disposal was based. On account of the great penetrating power of gamma rays in air, much of the radiation exposure of a man standing in a contaminated area is due to distant radioactive material. For the kind of gamma radiation existing on the Shot Islands, 80 or 90% of the exposure is due to radiation coming from distances greater than 10 feet. Suppose then that all of the radioactive material is adequately covered, and that subsequently a 20 foot diameter hole is dug. Suppose that the hole is dug in such a way as to expose the previously covered radioactivity without removing any of it (which is a practical impossibility). Then the man could at most receive 10 to 20% of the radiation exposure which he would have received if the decontaminatio by burial had not been done, % | RM 255 SOM 6-52 canine UNCLASSIFIED LLL ZC“