Islands from the first shot of Operation CASTLE are considered. Data were summarized from field Radiological Safety surveys, fall-out radiochemical studies, and fall-out gamma spectral measurements. The influence of these and other factors on an evaluation of survey meter response and total dose estimates was considered. Estimates of fall-out duration times and energy distribution of the dose from a plane source were made and the effect of diffuse source-geometry on the depth-dose to air-dose relationship was considered. Superficial doses from soft gamma and beta radiation were also considered. Since the fall-out incident created an initial emergency during which data collection was of secondary importance, attempts to reconstruct the event have been uncertain. However, a fairly consistcnt estimate of external gamma dosage was possible, although the question of beta exposure remains mostly unanswered. It was assumed that no siginificant neutron or alpha particle exposure occurred. Internal doses from inhaled or ingested material and the biomedical aspects of the incident have been discussed in other CASTLE reports. lt was concluded that the AN/PDR39A requires a correction factor 0; about plus 20% in doserate readings made under the conditions described; decay of the radioactivity of the fall-out is believed expressible by the factor of T/sup -0.83/; the external gamma dose was delivered priroarily by radiation energies of 100, 700, and 1500 kev; the beta dose was delivered by beta radiation of maximum energies of 0.3 and 1.8 Mev, mostly from fallout deposited on the skiin itself; exposures occurred between 4 and 78 hours after the detonation, the the fall-outs were probably of 12-hours duration; diffuse source geometry increased the-midline dose by abcut 50% compared to the midline dose which would have resulted from a bilateral narrow beam exposure of the same air-dose; error in the estimates is believed to be less than 50%; and total air gamma doses were estimated as follows: Rongerik, 56 r; Rongelap, 182 r; Ailinginae, 81 r; and Utirik, 13 r. (auth) Descriptors: AIR; BETA DECAY; DECAY; DISTRIBUTION; DOSEMETERS; ENERGY; ERRORS; FALLOUT; ISLANDS; MAN; MARSHALL ISLANDS; NEUTRONS; NUCLEAR EXPLOSIONS; PACIFIC OCEAN; POPULATIONS; PROJECT CASTLE; RADIATION DOSES; RADIATION SOURCES; RADIOACTIVITY; RADIOCHEMISTRY; SAFETY; SKIN; SPECTROMETERS; THERMONUCLEAR EXPLOSIONS i10000000000000000000000 Subject Codes (NSA): BIOLOGY AND MEDICINE 10/5/206 116506 (Item 206 from file: NSA-14-000028 109) THE ARTIFICIAL RADIOACTIVITY IN RAIN WATER OBSERVED AUGUST 1954 IN JAPAN FROM MAY TO Miyake, Y. Meteorological Research Inst., Tokyo Papers Meteorol. and Geophys. (Tokyo) v 5. Publication Date: (1954) Sept. 173-7 p. Journal Announcement: NSA14 Document Type: Journal Article Language: English Data are summarized on levels of radioactivity in samples of ait-borne dust and rain water collected in Japan following the thermonuclear weapons tests at Bikini atoll from March to May 1954. (C.H.) Descriptors: AIR; BIKINI; DUSTS; JAPAN; NUCLEAR EXPLOSIONS; QUANTITY RATIO; RADIOACTIVITY; RAIN; SAMPLING; TESTING; THERMONUCLEAR EXPLOSIONS Subject Codes (NSA): BIOLOGY AND MEDICINE 10/5/207 (Item 207 from file: 115568 NSA-13-022235 109) INTERPRETATION OF SURVEY-METER DATA. ANNEX 6.5 OF SCIENTIFIC DIRECTOR’S REPORT OF ATOMIC WEAPON TESTS AT ENIWETOK, 1951. OPERATION GREENHOUSE Tochilin, E.; Howland, P. Naval Radiological Defense Lab., San Francisco Publication Date: Aug. 1951 134 p. Primary Report No.: WT-26 Note: Decl. Mar. 6, 1957 Journal Announcement: NSA1 Availability: NTIS 3 0 0 3 J 4 | Document Type: Report