Therefore the interior intensity at any time t after the detonation is given by: T(t) = F,st/ E - exp} “= D,(t) | . (7) Since detailed radiological data for the waters of Bikini Lagoon are not available for Operation CASTLE, Several assumptions are made in order to apply the CROSSROADS ship contamination model to the ships at CASTLE. It is documented that the anchorage areas in the lagoon became contaminated to varying degrees following Shots BRAVO, UNION and YANKEE. The assumption is made that ships entering the lagoon after each of these shots would reach the saturation level of contamination if they remained in the lagoon. The rate and level at which hulls become saturated is dependent on the intensity of the water surrounding the ship. was found that ships remaining in saturation within one or two days. radioactive lagoon At CROSSROADS, it water generally reached Based on these observations, this analysis assumes that the ships' hulls approached saturation linearly over a one-day period, i.e., any ship remaining in the lagoon for 24 hours became saturated. This assumption allows (highsided) exposure estimates to be calculated without detailed knowledge of the water environment, leading to: I(t) = FSt -1.3 . (8) It is further assumed that, upon departing the contaminated lagoon water, hull and piping intensities were reduced hy one-half, and that subsequent decay while out -1.3 of the lagoon followed the t decay rate. With these assumptions, the nodel developed for CROSSROADS ships is used to estimate the personnel exposure at Operation CASTLE due to contaminated lagoon water. Values of S and F(from Reference 6) for pertinent ship types are given below. Ship Type CVE TAP, LSD, AV AGC LST ATF, ARSD DDE S (mR-day 93) F, 1570 1570 1570 1570 1570 1300 0.10 0.15 0.20 0.33 0.39 0.39 30 FS 160 240 310 520 610 700