Gamma dose rate readings at four inches distance from a plane surface two inches in radius, is 1/40 that from an equally contaminated infinite field. (See Appendix D.) Assume an object having a two-inch radius is contaminated on all sides (but not necessarily uniformly) so thet the ganna dose rate is lt tines that from an equally contaninated surface whose area is equivalent to the major cross-sectional plane of the object. one nov becomes shout 1/27, The fraction given in paragraph Farther assume d 100/1 ratie for beta surface dose rate to gamma dose rate at three feet above an infinite field. Then, the beta surface dose rate to gamma dose rate at four inches will be 2700/1. ow pea woo _-a o_o