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Title: Tobolar briefing: The resource potential of Copra collected from nuclear affected atolls in the northern Marshall Islands

Abstract

This presentation describes the results of some Toblar measurements, meant to detect 137Cs and radioactive contaminants in copra near the Northern Marshall Islands.

Authors:
 [1];  [1];  [1];  [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1389953
Report Number(s):
LLNL-TR-736983
DOE Contract Number:
AC52-07NA27344
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
99 GENERAL AND MISCELLANEOUS; 54 ENVIRONMENTAL SCIENCES; 61 RADIATION PROTECTION AND DOCIMETRY; 38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY

Citation Formats

Hamilton, T. F., Kehl, S. R., Berry, R. M., and Martinelli, R. M. Tobolar briefing: The resource potential of Copra collected from nuclear affected atolls in the northern Marshall Islands. United States: N. p., 2017. Web. doi:10.2172/1389953.
Hamilton, T. F., Kehl, S. R., Berry, R. M., & Martinelli, R. M. Tobolar briefing: The resource potential of Copra collected from nuclear affected atolls in the northern Marshall Islands. United States. doi:10.2172/1389953.
Hamilton, T. F., Kehl, S. R., Berry, R. M., and Martinelli, R. M. Sun . "Tobolar briefing: The resource potential of Copra collected from nuclear affected atolls in the northern Marshall Islands". United States. doi:10.2172/1389953. https://www.osti.gov/servlets/purl/1389953.
@article{osti_1389953,
title = {Tobolar briefing: The resource potential of Copra collected from nuclear affected atolls in the northern Marshall Islands},
author = {Hamilton, T. F. and Kehl, S. R. and Berry, R. M. and Martinelli, R. M.},
abstractNote = {This presentation describes the results of some Toblar measurements, meant to detect 137Cs and radioactive contaminants in copra near the Northern Marshall Islands.},
doi = {10.2172/1389953},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Aug 13 00:00:00 EDT 2017},
month = {Sun Aug 13 00:00:00 EDT 2017}
}

Technical Report:

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  • An aerial radiological survey was conducted over eleven atolls and two islands within the northern Marshall Islands between September and November 1978. This survey was part of a comprehensive radiological survey, which included extensive terrestrial and marine sampling, to determine possible residual contamination which might remain as a result of the United States nuclear testing program conducted at Bikini Enewetak Atolls between 1946 and 1958. A similar survey was conducted at Enewetak Atoll in 1972. The present survey covered those atolls known to have received direct fallout from the Bravo event, conducted in March 1954 at Bikini Atoll. These includedmore » Bikini, Rongelap, Rongerik, Ailinginae, Bikar, Taka, and Utirik Atolls. In addition, several atolls and islands which might have been at the fringes of the Bravo fallout were also surveyed, including Likiep and Ailuk Atolls, Jemo and Mejit Islands, and Wotho Atoll. Ujelang Atoll, which lies approximately 200 km southwest of Enewetak, was also surveyed. Island-averaged terrestrial exposure rates in the range of 30 to 50 ..mu..R/h were observed over parts of Bikini Atoll, including Bikini Island, and over the northern part of Rongelap Atoll. Levels over southern Rongelap and over Rongerik Atoll ranged from 4 to 7 ..mu..R/h. Levels were somewhat lower at Ailinginae Atoll (approximately 2 ..mu..R/h) and at Utirik Atoll (approximately 0.7 ..mu..R/h). The variations observed were consistent with what might be expected from the fallout pattern of the Bravo event. Levels at Ailuk, Likiep, Wotho and Ujelang Atolls and at Mejit and Jemo Islands were consistent with /sup 137/Cs activity, due to worldwide fallout, observed within the United States and at other locations in the central Pacific. These four atolls and the two islands, therefore, do not appear to have recieved any significant direct contamination from the Bravo event or the other tests conducted at Bikini and Enewetak Atolls.« less
  • This book explains the results of the 1978 radiation measurements for the following atolls: Rongelap, Utrik, Taka, Bikar, Rongrik, Ailinginae, Likiep, Ailuk, Jemo, Mejit, Wotho and Ujelang. It explains the meaning of radiation, and about the radioactive particles that came from the atomic bombs, and about their distribution in the soil of each of these atolls. The book also gives information about the amounts of radiation people might receive now and later from radioactivity remaining on the atolls. (ACR)
  • The Marshall Islands in the Equatorial Pacific, specifically Enewetak and Bikini Atolls, were the site of US nuclear testing from 1946 through 1958. In 1978, the Northern Marshall Islands Radiological Survey was conducted to evaluate the radiological conditions of two islands and ten atolls downwind of the proving grounds. The survey included aerial external gamma measurements and collection of soil, terrestrial, and marine samples for radionuclide analysis to determine the radiological dose from all exposure pathways. The methods and models used to estimate doses to a population in an environment where natural processes have acted on the source-term radionuclides formore » nearly 30 y, data bases developed for the models, and results of the radiological dose analyses are described.« less
  • The United States conducted 24 nuclear tests at Bikini Atoll with a total yield of 76.8 Megatons (MT). The Castle series produced about 60% of this total and included the Bravo test that was the primary source of contamination of Bikini Island and Rongelap and Utrok Atolls. One of three aerial drops missed the atoll and the second test of the Crossroads series, the Baker test, was an underwater detonation. Of the rest, 17 were on barges on water and 3 were on platforms on an island; they produced most of the contamination of islands at the atoll. There weremore » 42 tests conducted at Enewetak Atoll with a total yield of 31.7 MT (Simon and Robison, 1997; UNSCEAR, 2000). Of these tests, 18 were on a barge over wateror reef, 7 were surface shots, 2 aerial drops, 2 under water detonations, and 13 tower shots on either land or reef. All produced some contamination of various atoll islands. Rongelap Atoll received radioactive fallout as a result of the Bravo test on March 1, 1954 that was part of the Castle series of tests. This deposition was the result of the Bravo test producing a yield of 15 MT, about a factor of three to four greater than the predicted yield that resulted in vaporization of more coral reef and island than expected and in the debris-cloud reaching a much higher altitude than anticipated. High-altitude winds were to the east at the time of detonation and carried the debris-cloud toward Rongelap Atoll. Utrok Atoll also received fallout from the Bravo test but at much lower air and ground-level concentrations than at Rongelap atoll. Other atolls received Bravo fallout at levels below that of Utrok [other common spellings of this island and atoll (Simon, et al., 2009)]. To avoid confusion in reading other literature, this atoll and island are spelled in a variety of ways (Utrik, Utirik, Uterik or Utrok). Dose assessments for Bikini Island at Bikini Atoll (Robison et al., 1997), Enjebi Island at Enewetak Atoll (Robison et al., 1987), Rongelap Island at Rongelap Atoll (Robison et al., 1994; Simon et al., 1997), and Utrok Island at Utrok Atoll (Robison, et al., 1999) indicate that about 95-99% of the total estimated dose to people who may return to live at the atolls today (Utrok Island is populated) is the result of exposure to {sup 137}Cs. External gamma exposure from {sup 137}Cs in the soil accounts for about 10 to 15% of the total dose and {sup 137}Cs ingested during consumption of local food crops such as drinking coconut meat and fluid (Cocos nucifera L.), copra meat and milk, Pandanus fruit, and breadfruit accounts for about 85 to 90%. The other 1 to 2% of the estimated dose is from {sup 90}Sr, {sup 239+240}Pu, and {sup 241}Am. The {sup 90}Sr exposure is primarily through the food chain while the exposure to {sup 239+240}Pu, and {sup 241}Am is primarily via the inhalation pathway as a result of breathing re-suspended soil particles.« less