mes. aap <8, OO ateats ore on eeoe Te mw aited Set ope foe Te ~~: as , ~ ere - see Le . ye vary . oh je Re 4 re Sataeh thane Nate TT mer ABSTRACT. No No fallout could be located following — ~Zuni, 2 land-surface.shot, contaminated 13, 400 nautmi?ofoc ocean withpercent ofits fission- iN 4 ts \ A Paes productyield. distributions. Data on depth of mixing was obtained from samples of sea water collected by the U.S. Naval Radiological Defense Laboratory and the Scripps Institute of Oceanography. Repeated aerial surveys Provided information on the stability of the contaminated volumé. ? — epee t “e« 7“ the sea, the depth of mixing of the fallout in the water volume must be determined before the survey results may be converted to equivalent land-fallout contours and contamination-density ~ gh ee a Tee ge Gite COMER eGo) eeoksee cee! + Helicopters and P2V-5 aircraft were used to gather data for air-absorption measurements. The aerial-survey technique may be used directly for radiological surveys over land. Over > 4i ‘ tte Tewa, a reefshot,contaminated 43,500 naut mi? of ocean with 28 percentof the fissionproduct_yield. y P-\ - 1 surface shots was concentrated primarily in the more remote areas, and a relatively small amount fell close to ground zero. day ®Rua eet‘ we + in" . 4 ry f Navajo, a water-surface shot, contaminated 10,500 naut mj* with 50 percent of the fissionproduct yield. After Flathead, another water-surface shot, the outer boundary could not be determined because of contamination of project aircraft on D + 1 day by airborne radioactive material that resultedin a high background. However, extrapolated values indicate 29 percent of its fission-product yield was present as fallout in the local area. The fallout from the water- ‘ 4 Shot Cherokee and only on atoll islandsafter Shot Mohawk. wy Tea the total yield that produced fission products. Gamma-isodose plots were prepared from data obtained during Shots Zuni, Flathead, Navajo, and Tewa. OU oe" RadiationmountedP25aircraft that surveyed the ocean areas of expected fallout_after-Shots Cherokee, -Zunil,-Fiathead, Navajo, Mohawk, and Tewa. A contro! center coordinated all alr and surface radiation-survey activities to insure complete coverage of the fallout area. The contamination densities in the delineated areas were related to the percentage of 0. 4, . “T ments 60 thaf the data might be related to the gose rates at 3 feet above the sea. 0 et renetntmenetlvanin tape 2 Ue Mb one oo Ao The objectives were to: (1) survey the gamma radiation from fallout-contaminated ocean areas by meansof aerial detectors and (2) from the aerial detectors make air-absorption measure-