Featured Research

from universities, journals, and other organizations

Marshall Islands research could lead to resettlement after nuclear tests

Date:
February 12, 2010
Source:
DOE/Lawrence Livermore National Laboratory
Summary:
Through Laboratory soil cleanup methods, residents of Bikini, Enjebi and Rongelap Islands -- where nuclear tests were conducted on the atolls and in the ocean surrounding them in the 1950s -- could have lower radioactive levels than the average background dose for residents in the United States and Europe.

Through Laboratory soil cleanup methods, residents of Bikini, Enjebi and Rongelap Islands -- where nuclear tests were conducted on the atolls and in the ocean surrounding them in the 1950s -- could have lower radioactive levels than the average background dose for residents in the United States and Europe.

Related Articles


The National Nuclear Security Administration's Lawrence Livermore National Laboratory scientists Bill Robison and Terry Hamilton calculated the radiation doses for people resettling Bikini, Enjebi, Rongelap and Utrok Islands. The two found that when it rains, a portion of the soluble cesium-137 (137Cs) -- an isotope of cesium -- is transported to the groundwater that lies about three meters below the soil surface. The groundwater eventually gets mixed with the ocean waters so the 137Cs is lost from the soil and is not available for uptake by growing vegetation on the island. The rate of this loss process is much faster than the loss by radiological decay.

In addition, treatment of food crops with potassium reduces the 137Cs concentration in edible fruits to about 5 percent of pretreatment concentrations. Potassium treatment and removal of the top 15 centimeters of soil around houses and community buildings prior to construction of new buildings to reduce external exposure where people spend most of their time -- referred to as the combined option -- could be used as a remediation strategy before resettlement, Robison said.

"If this approach is taken, the natural background dose plus the nuclear-test-related dose at Bikini, Enjebi and Rongelap would be less than the usual background dose in the United States and Europe," Hamilton said.

The United States conducted 24 nuclear tests at Bikini Atoll with a total yield of 76.8 megatons (MT). The Castle series of tests produced about 60 percent of this total yield and included the 15-megaton Bravo test that was the primary source of radioactive contamination of Bikini Island and Rongelap and Utrok Atolls. Pretest estimated yield for the Bravo test was about five megatons. The much larger yield resulted in vaporization of more coral reef and island than expected and the debris-cloud reached a much higher altitude than anticipated.

High-altitude winds were to the east at the time of detonation and carried the radioactive debris 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 Utr_k.

Today, scientists in Lawrence Livermore's Marshall Islands Dose Assessment and Radioecology Program work to minimize exposure through ingestion and other pathways for the Marshallese now living on or wishing to return to their islands. The program continues research begun nearly 30 years ago to characterize radiological conditions on affected islands and develop strategies to minimize radiological exposure to a people who want to resettle. The program also supports Marshallese efforts to implement radiation protection programs for residents wishing to track their exposure to radionuclides from fallout contamination that still lingers on the islands.

Previous assessments showed that 137Cs accounts for about 98 percent of the total dose for returning resident at the various atolls. About 85 percent to 90 percent of the dose (depending on the atoll) is from consumption of locally grown foods such as coconut meat and fluid, copra meat and milk, Pandanus fruit and breadfruit. About 10 percent of the dose is due to external gamma radiation from 137Cs in the soil. Isotopes of strontium, plutonium and americium account for less than 5 percent of the estimated dose.

The research appears as the cover article in the journal, Health Physics.


Story Source:

The above story is based on materials provided by DOE/Lawrence Livermore National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

DOE/Lawrence Livermore National Laboratory. "Marshall Islands research could lead to resettlement after nuclear tests." ScienceDaily. ScienceDaily, 12 February 2010. <www.sciencedaily.com/releases/2010/02/100211151651.htm>.
DOE/Lawrence Livermore National Laboratory. (2010, February 12). Marshall Islands research could lead to resettlement after nuclear tests. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2010/02/100211151651.htm
DOE/Lawrence Livermore National Laboratory. "Marshall Islands research could lead to resettlement after nuclear tests." ScienceDaily. www.sciencedaily.com/releases/2010/02/100211151651.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Newsy (Nov. 23, 2014) Microsoft has robotic security guards working at its Silicon Valley Campus. Video provided by Newsy
Powered by NewsLook.com
Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
Powered by NewsLook.com
Raw: Paralyzed Marine Walks With Robotic Braces

Raw: Paralyzed Marine Walks With Robotic Braces

AP (Nov. 21, 2014) Marine Corps officials say a special operations officer left paralyzed by a sniper's bullet in Afghanistan walked using robotic leg braces in a ceremony to award him a Bronze Star. (Nov. 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins