CHAPTIR 6 PRIMARY FALLOUT PATTERNS The extent of fallout documentation ucder the two orperctional phases of Project 2.5a was different for the various snots. Data were obtained under tne land and lagoon phase for Snots 1,3,4, and 6. The lugoon and islends were not contaminated efter Shot 2 and no data were taken for Shot 5. Although there was some stem fallout vest of tae snot roint as indicated by th- trajectory analysis presented in Section 5.5, the free-floating sea stations fe~ Shot 1 were liid just beyond tne westward linit of the gamma field. Concesently tue buoys showed that inappreciable amounts of muterizl from Snot 1 fell in the area sannled. For Shot 2, free-floating stations documented fallout to a distarce of 50 nautical niles. A complete analysic of the fallout patterns to a distance of 300 nautical miles is presentcd for Snot 1. Because of the linited experimental data available for tuis Snot it was not possivle to reconstruct the contours on tois basis alone. ‘he samma field data were surplemented by developing an exnerinental model of tne fallout mechanisn whica defined the axis of symmetry of tne pactern. Tnis addition enabled one to construct a conplete contour pattern, Fallout patterns for Shots 5 and 6 were derived from weter sam- pling data and are considered in Project 2.7.4/ 6.1 FALLOUT NEAR GROU'D ZEPO FOR SOLS 1,3,4, AND 6 To obtain the infinite field ga-ma levels witnin the atolls, taree basic collecting devices were pleced on the islands and on the rafts within tae lagoon as follows: (a) Totel collector - a 7-in, diameter polyetnylene funnel (b) Gummed paper collector ~ 1 sc ft of “um-Kleen ecetate-backed (c) Project 2.1 filn badges placed toth vertically and horizon- fitted to a legal polyethylene bottle. paper stapled te a cardboard backing supported in ea metal tray. tally. By comparing the laboratcry mesured levels of gamma activity obtained from sanples that were collected on islends with the actual in-~ finite field gamma survey readings, a relationship was developed and 7h