CAST SUBJECT: Report on Soil and "ater Sampling Mission collected at approximtoly 1200 M, 6 March 1954. Instrument readings with the MX-5 showed a maximum of 3 mr/hr, however this was not considered reliable, since ao - higher scale showed a lower reading. ce AILUK ATOLL. The ship reachod this atoll at approximtcly 1600 M, 6... farch 1954, and slowly moved to an anchorage off Ailuk Island, the most heavily populated. The lagoon has not been swept, and numerous coral heads and pinnacles provided considerable hazard to ship movement. The landing party moved ashore by whaleboat without difficulty, and agzin obtained water samples from the most promir: ent cistern and soil samples from random unshcltcred spots, showed approximtely 3 mr/hr (off the 2 mr scale), Readings with the MX-) An AN/PDR-27E showed a high reading of 7 mrfhr, however, on a diffcrent scale a reading of 12 or 15 ar/hr was obtained. The MX-5 rcading is probably nearest correct. No significant variatio ¢ were detceted on bare feet or clothing of individuals. taken at approximtely 1700 M, 6 March 1954. a d. MEJIT Island, . Samples and readings worc This single coral island is also surrounded by a recf, ~s is JEMO, but landing was possible with a whaleboat, duc to an arca protected fri: the surf, The island was found to be heavily populated in view of its size, the Sotal number of people being 327, according to the island magistrate, Soil and water samples were taken as in the proviously described mannor, at approximtoaly 1300 M, 7 March 1954. Roadings with the MX-5 showed maximum of approximtely 3 mr/hr (off the 2 scale, but approximately 1.5 on the 20 scale); the maximum readin; with a PDR 27 E was 10 m/hr, LYuO¢ The truc figure was probably somowhere botween the 2. CONCLUSIONS. Low lovel (less than 10 mr/nr) radiation measuromert s with ficld instrummts of the type used are highly unsatisfactory. One MX~5 and three AS/PDR 27 E instrumonts all showed widely variant readings on different scales, and varicd among cach other when cxposed to tho same radiation. An AN/PDR T1-B proved completely useless not holding to zero even after an hours warm-up, and also showing widely variant readings on diffcrent scales, 3. RECOMMENDATIONS, Landing partics in islands such as JEMO and MEJIT shoulc be provided with a rubber 6-man or 8—-man pneumatic boat, to provide greater safcty to personnel and equipment, This will permit landing directly on Uve coral reefs with less danger of the boat being stove in. Ships assigned to such missions should draw such cquipment prior to departure. 4. The successful accomplishment of the mission was greatly facilitated by the interest and enthusiasm of tho Commanding Officer of the USS RENSHAW, CDR L, H.- ‘lford, USN, and his officers and men, Their matcrial contributions were noccssary to the mission, however, the many valuable suggestios and assistance in solutions of problems proved invaluable. PIED/D ae oe /s/ Re D. Crea R. D. CREA MAS, USA rs es aces _——