sail-world.com
 
 
News Home Cruising Photo Gallery Video Gallery

 

Sail-World.com : Researchers assess radioactivity released from Fukushima Dai-Ichi

Researchers assess radioactivity released from Fukushima Dai-Ichi

'Marine chemist Ken Buesseler (left) and University of Hawaii technician Paul Balch make a final inspection of a water sampling rosette prior to deploying it in the Pacific in June 2011.'    Ken Kostel / WHOI

In light of news this week regarding additional radioactive leaks from the Fukushima nuclear power plants, the impact on the ocean of releases of radioactivity from the plants continues to be unclear. But a new study by U.S. and Japanese researchers analyzes the levels of radioactivity discharged from the facility in the first four months after the accident and draws some basic conclusions about the history of contaminant releases to the ocean.

The study, conducted by Woods Hole Oceanographic Institution chemist Ken Buesseler and two Japanese colleagues, Michio Aoyama of the Meteorological Research Institute and Masao Fukasawa of the Japan Agency for Marine-Earth Science and Technology, reports that discharges from the Fukushima Dai-Ichi nuclear power plants peaked one month after the March 11 earthquake and tsunami that precipitated the nuclear accident, and continue through at least July. Their study finds the levels of radioactivity, while quite elevated, are not a direct exposure threat to humans or marine life, but cautions that the impact of accumulated radionuclides in marine sediments is poorly known.

The release of radioactivity from Fukushima—both as atmospheric fallout and direct discharges to the ocean—represent the largest accidental release of radiation to the ocean in history. Concentrations of cesium-137, an isotope with a 30-year half life, at the plants's discharge point to the ocean, peaked at over 50 million times normal/previous levels, and concentrations 18 miles off shore were much higher than those measured in the ocean after the Chernobyl accident 25 years ago. This is largely due to the fact that the Fukushima nuclear power plants are located along the coast, whereas Chernobyl was several hundred miles from the nearest salt water basins, the Baltic and Black Seas. However, due to ocean mixing processes, the levels are rapidly diluted off the Northwest coast of Japan.

The study used publically available data on the concentrations of cesium-137, cesium-134, and iodine-131 as a basis to compare the levels of radionuclides released into the ocean with known levels in the sea surrounding Japan prior to the accident. Impacts of the Fukushima Nuclear Power Plants on Marine Radioactivity is published in the latest issue of Environmental Science & Technology and is available on the journal's website. Buesseler received funding support for this work from the Gordon and Betty Moore Foundation and the National Science Foundation’s Chemical Oceanography program.

The investigators compiled and analyzed data on concentrations of cesium and iodine in ocean water near the plants’s discharge point made public by TEPCO, the electric utility that owns the plants, and the Japanese Ministry of Culture, Sports, Science and Technology (MEXT). The team found that releases to the ocean peaked in April, a fact they attribute to “the complicated pattern of discharge of seawater and fresh water used to cool the reactors and spent fuel rods, interactions with groundwater, and intentional and unintentional releases of mixed radioactive material from the reactor facility.” They also found that the releases decreased in May by a factor of 1000, “a consequence of ocean mixing and a primary radionuclide source that has dramatically abated,” they report.

While concentrations of some radionuclides continued to decrease, by July they were still 10,000 times higher than levels measured in 2010 off the coast of Japan. This indicates the plants “remain a significant source of contamination to the coastal waters off Japan,” they report. “There is currently no data that allow us to distinguish between several possible sources of continued releases, but these most likely include some combination of direct releases from the reactors or storage tanks, or indirect releases from groundwater beneath the reactors or coastal sediments, both of which are likely contaminated from the period of maximum releases.”

Buesseler says that at levels indicated by these data the releases are not likely to be a direct threat to humans or marine biota in the surrounding ocean waters, but says there could be concern if the source remains high and radiation accumulates in marine sediments.  “We don’t know how this might impact benthic marine life, and with a half-life of 30 years, any cesium-137 accumulating in sediments or groundwater could be a concern for decades to come,” he said.

In June, Buesseler led the first international, multidisciplinary assessment of the levels and dispersion of radioactive substances in the Pacific Ocean off the Fukushima Dai-Ichi nuclear power plants—a major research effort also funded by the Gordon and Betty Moore Foundation. During the research expedition, a group of 17 researchers and technicians spent two weeks aboard the University of Hawaii research vessel R/V Kaimikai-O-Kanaloa examining many of the physical, chemical, and biological characteristics of the ocean that determine the fate of radioactivity in the water and potential impact on marine biota.  The results of their initial assessments will be presented in Salt Lake City in February 2012 at the Ocean Sciences Meeting, an international gathering of more than 4,000 researchers sponsored by The Oceanography Society, the American Society of Limnology and Oceanography, and the American Geophysical Union.

While international collaborations for comprehensive field measurements to determine the full range of isotopes released are underway, it will take some time before results are available to fully evaluate the impacts of this accident on the ocean.

The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment.

 


http://www.whoi.edu/




by WHOI

  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=91799

9:47 PM Mon 12 Dec 2011 GMT






Click here for printer friendly version
Click here to send us feedback or comments about this story.


News - USA and the World



















The first annual WetaFresh is a big success by Tim Wieringa, Muskegon, MI


















Techno 293 Worlds - France and Italy claim titles by International Windsurfing Association,














420 World Championship - Singapore and Spain out front by 420 International Class Association,
















Round Britain and Ireland Race 2014 - Tactics, endurance, achievement
Alpari World Match Racing Tour moves on to Poland + Video
2014 ISAF Sailing World Cup final qualification system published
Chicago Yacht Club Race to Mackinac - Karma Sailing Group wins
Red Bull 49erFX: Easing into the Olympic scene at Rio
Kempe thrilled to invite himself to Gold Cup party
2014 420 World Championships - Singapore wins Day 2 race
Lightning strikes cut short CFJ Nationals
Etchells Invitational Cup - Girls on top in Cowes
National Sailing Hall of Fame reveals inductees
J/111 North American Championship - Wind Czar victorious
Sevenstar Round Britain and Ireland Race sets off August 10th
PWA Fuerteventura Grand Slam - Antoine Albeau victorious on day 5
Snipe Western Hemisphere and Orient Championship headed for San Diego
WPA Championships - Kids race divisions offered
New Clever Pig launched by US Sailing
America's Cup: Group agrees to co-operate in London Meeting
Copa del Rey Mapfre - Build-up reveals some remarkable enthusiasm
Marblehead NOOD Regatta - Images by Leighton O'Connor
America's Cup: Two AC72 skippers discuss Foiling Moths and the Cup
RS Feva World Championship - Brilliant sailing on day 2   
America's Cup: Alameda makes overtures on Venue hosting for San Fran *Feature   
Cape Panwa Hotel Phuket Race Week 2014 - Relishing a challenge   
Edgartown Race Weekend - BBBR and Round-the-Island Race winners named   
Etchells Invitational Cup - Aussies take early lead in Cowes   
PWA Fuerteventura Grand Slam - Antoine Albeau strikes back on day 4   
Aquece Rio – International Sailing Regatta - All set for test event   
ISAF World Sailing Rankings for 28 July 2014   
29er World Championship - All set in Kingston   
ORC World Championship - Third Course area opens for huge fleet   
Day one of the Allen RS Feva World Championships   
Anna Tunnicliffe: Final two days of the 2014 Reebok CrossFit Games   
Joachim Aschenbrenner takes gold at ISAF Youth Match Race Worlds 2014   
Maxi Soh scores double wins in CMRC Summer Doubleheader   
29er World Championship opening ceremonies in Confederation Park   
PWA Fuerteventura Grand Slam - Action resumes on day 3   
Vic-Maui Yacht Race - Polishing the silverware   
Land Rover Sydney Gold Coast Yacht Race Start 2014 VIDEO   
Laser Radial Men’s World Championship 2014- Final day   
2014 Pacific Cup - Scarlet Runner wins   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL WAS US
LocalAds   DE  ES  FR  IT