exposure units (roentgens). Although the original references often re- ferred to dose, there is no evidence that whole-body energy deposition was determined, nor that dose was indeed measured. In this report all measurements of exposure intensity (roentgen) given in whole units and decimal fractions. are This is not the common way these are reported in the source literature. The lower exposure intensi- ties were usually reported in milliroentgens (mR) and the higher exposure intensities in roentgens (R). Often the same measuring device could meas- ure both the lower and higher intensities but with different dial settings and thus differing accuracies. Personnel records show the same sort of differentiation. The lower individual exposures are usually recorded in millirem but the larger maxi- mums allowed or permitted are stated in whole rem. This use of different measuring units for different levels of radiation could cause some confusion to readers who are unfamiliar with the field; therefore, the wholeunit convention is used. Radsafe Standards In accordance with the safety criteria prescribed by the JTF 7 Operation Plan, two kinds of radsafe standards were established; Maximum Permissible Exposures. and Maximum Permissible Limits. Maximum Permissible Exposure, usually abbreviated MPE and sometimes referred to as the "rule dose,” set 3.9 rem (gamma) over a 13-week period as the maximum allowable accumulation of whole-body gamma radiation per individual during Operation CASTLE. This total would increase automatically by 0.3 rem (gamma) week for each week the operation extended beyond 13 weeks Annex.G). per (Reference 9, For recordkeeping purposes, the operation was assumed to begin 15 days before the first detonation. The MPE for CASTLE was identical to the federal standard approved by the National Committee on Radiation Protection (NCRP) for those in radiologically hazardous occupations. This standard permitted accumulation of radiation exposure at the rate of 0.3 rem per week to a total of no more than 15 rem in one 1l2-month period. 95