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Fukushima Media Tip Sheet

The following are some of the key Fukushima-related presentations by Woods Hole Oceanographic Institution (WHOI) scientists and colleagues at the 2014 Ocean Sciences Meeting in Honolulu, Hawaii from February 23-28.

Fukushima and Radiation in the Ocean

Nearly three years ago on March 11, 2011, Japan’s earthquake, tsunami, and subsequent radiation releases from the Fukushima Dai-ichi nuclear power plant resulted in the largest accidental release of radiation to the ocean in history. Researchers will present their findings on the discharge of radioactive groundwater into the ocean, the circulation of the contaminants in the North Pacific Ocean, levels of radiation in the seafloor sediment, and the most up-to-date marine radiation levels.

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Groundwater Contamination

While most of the radioactive fallout was believed to be over the ocean, fallout over land has resulted in groundwater contamination as well. In addition, hundreds of tons of groundwater is infiltrating the nuclear power plant reactor buildings daily and becoming highly contaminated radioactive wastewater. While some of this wastewater is being stored in tanks for further treatment, the Tokyo Electric Power Company (TEPCO) has acknowledged that radiation continues to seep into the local aquifer. WHOI marine chemist Matt Charette presents his results from a survey of the aquifer and the coastal water surrounding the nuclear power plant to measure the contaminated discharge into the ocean, which remain at levels equal to 2012 but far less than at the time of the accident in 2011.

Presentation Title: Submarine Groundwater Discharge as a Source of Radioactivity to the Ocean from the Fukushima Nuclear Power Plant

Date: Monday, Feb. 24
Time: 10:45 a.m.

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Currents off Japan

The current off the coast of Fukushima is not well understood. To learn more about it, WHOI physical oceanography researcher Sachiko Yoshida traced radionuclides released from the nuclear power plant two years after the disaster. Water samples collected repeatedly from Climate Variability and Predictability (CLIVAR) transects hold clues about the current and how quickly the coastal water mixes with the open ocean. She was able to trace the leading edge of the Fukushima contaminant plume about 700 miles northeast of Hawaii last summer. She shares her findings from this investigation.

Presentation Title: Observational Evidence for Fukushima Radionuclide Signals in the North Pacific Two Years after the Release

Date: Monday, Feb. 24
11:00 a.m.
Location: 314

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Cesium in Sediments

Since the disaster at the Fukushima Dai-ichi nuclear power plant, there have been reports of bottom-dwelling fish with elevated cesium concentrations. WHOI-MIT Joint Program student Erin Black analyzed the radionuclides from Fukushima sediment cores and compared them to prior studies to re-evaluate the sediment inventories at 3,400-meter water depth. She found that Fukushima cesium in the seafloor off Japan is less than 1 percent of the amount released during the disaster. Calculations estimate that it takes from one to 20 years for cesium in the seafloor surface sediment to decrease by half because of downward sediment mixing.

Poster Title: Constraining Inventory Estimates and the Fate of Cesium in Ocean Sediments Off Fukushima Using Detailed Isotope Profiles and Mixing Rates

Date: Monday, Feb. 24
Time: 4:00-6:00 p.m.
Location: Exhibit Hall

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Radioisotopes in the Water Column

Big changes have been seen in the last three years in the relative amounts of cesium and strontium off Japan. With cesium-137 decreasing much faster than strontium-90, it raises concerns over continued strontium sources from the reactor site and storage tanks into the groundwater. Estimates of the total discharge of radioisotopes, cesium-137, cesium-134, strontium-90 have varied since the disaster at the Fukushima Dai-ichi Nuclear power plant. Additionally, contaminated water from trenches and tanks storing treated water has recently leaked.

In this poster, Pere Masqué with the Universitat Autònoma de Barcelona presents current data on radioisotope concentrations in the water column collected since 2011. The samples were collected in full transects from Japan to the West Coast of North America, as well as shallow areas off the coast of Japan to within 1 kilometer of Fukushima. This information provides a baseline for the total amount of radioisotopes released into the marine environment, which will help track their evolution as they move from the reactors further into the Pacific.

 Poster Title: Evolution of Cs-137, Cs-134 and Sr-90 in the Pacific Ocean Derived from the Fukushima Dai-ichi Nuclear Accident

Date: Monday, Feb. 24
Time: 4:00-6:00 p.m.
Location: Exhibit Hall

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Radioactivity from Fukushima

The Fukushima nuclear power plant is an unprecedented source of radionuclides to the ocean. Though orders of magnitude lower than what was released in 2011, today's levels in the seafloor and bottom dwelling fish remain elevated due to continued sources from the nuclear power plant.

The contaminant plume is expected to arrive off the West Coast of North America in 2014 at levels that are lower than human health concern, but no government agency is monitoring this plume. Hence, new crowd funding efforts are underway at Our Radioactive Ocean, www.ourradioactiveocean.org.

WHOI marine chemist Ken Buesseler has monitored the levels of radiation in the Pacific since the disaster and continues to sample and analyze seawater at various sites in the Pacific through this citizen science campaign. He will give an update on the current marine radiation levels and explain in relation to natural and previous radiation sources.

Presentation Title: Fukushima and Ocean Radioactivity

Date: Thursday, Feb. 27
Time: 2:30 p.m.
Location: 310 Theater

Last updated: February 21, 2014