planning for tactical or emergency situations. cnreneee A higher dose, based on prompt health effects, was incorporated into The tactical dose concept gave broad guidelines to assist command decisions, i.e., an exposure of 100 R would result in no acute effects, an exposure of 450 R would be lethal to half those exposed, etc. (The tactical dose rationale assumes the dose would be received as a single lifetime exception to the potential occupational dose.) Planning documents warned the task groups that previous exposure records should be checked to assure that individuals with prior exposure did not exceed the MPE. This warning was probably directed to the scientific projects of TG 7.1, whose personnel might have been exposed in the labora- tory, since the previous field test (UPSHOT~KNOTHOLE) at the Nevada Proving Ground (later named Nevada Test Site) had been completed about 9 months before CASTLE. The crewmembers of TG 7.4 sampling aircraft were authorized an MPE of 20 R for the entire period of Operation CASTLE. Anyone exposed to the 20 R maximum was to be removed from further work with radioactive materials until sufficient time elapsed to bring his average exposure down to 0.3 R per week. It was planned to expose the sampling crews to a maximum of only 10 R in order to reserve the remainder as a contingency against accident (Reference 16, p. 26). In addition _to the overall exposure limit, specific Maximum Permis- sible Limits (MPLs) related to radioactive contamination on parts of the body, clothing and personal effects, food, water, air, vehicles and equipment, and materials. These MPLs specified either the level of decontami- nation required or the upper limit for restriction of activity. Table 8 lists the CASTLE MPLs. Radiation Exposure Waivers Absolute adherence to the radiological standards prescribed for routine laboratory or industrial use was recognized as unrealistic for the (Reference 9). Provision was made for 96 o™ Special conditions of a field test