Gamma dose rate readings at four inches distanee from a plane surfaee two inokes in radius, is 1/40 that from ar equally contaminated infinite field. (See Appendix Dd.) Assume an object having atwo-ineh radius is eontaminated on all sides (but not necessarily wniformly) ac that the gemma dose rate is 1} times thet from an equally contaminated surface whose area is equivalent to the major cross-sectional plane of the objeet one mow becomes about 1/2’. The frastion given in paregrayph Further assume « 1901 ratio for beta surface dose rate to gamma dose rate at three feet above an infinite field. the beta surface dose rate to gamma dose sate at four inches will be 2700/1. DOK. NY yO CAFIED Then,