PIFSC honors staff with over 200 years of Federal service

These six folks are retiring from PIFSC with over 200 years of Federal service. This is an incredible fount of knowledge, skills, and capacity walking out the door. We will miss them and wish them well.

From left, Paul Shiota, David Hamm, Francine Fiust, Donald Tieman, Jan Pappas, and Pierre Kleiber.

Oceanic dispersion of radioactive cesium around Japan and western North Pacific after the Fukushima Dai-ichi Nuclear Power Plant accident

http://www.pices.int/publications/presentations/PICES-2012/Award-2012/Best_2012_abstracts.aspx

Hideki Kaeriyama¹, Daisuke Ambe¹, Masachika Masujima¹, Kou Nishiuchi², Ken Fujimoto¹, Tsuneo Ono¹ and
Tomowo Watanabe¹

The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident after the Great East Japan Earthquake and tsunami on 11 March 2011 resulted in the elevation of the level of anthropogenic radioactivity in the marine environment in the western North Pacific from atmospheric fallout and direct discharges of highly radioactive waters. Intensive monitoring of iodine-131, cesium-134 (Cs-134) and cesium-137 (Cs-137) in seawater near offshore FDNPP, and in marine organisms in the broader area around Japan, was conducted during the time when information of radioactive contamination in the seawater around western part of Japan and western North Pacific was quite limited. In this study, we report the concentrations of Cs-134 and Cs-137 in seawater collected from the western North Pacific, Japan Sea and East China Sea during 2011. Although high concentrations of Cs-134 and Cs-137 were detected off the coast of eastern Japan, an almost background level of Cs-137 was detected from the samples collected off the coast of western Japan, Japan Sea and East China Sea. In the western North Pacific, both Cs-134 and Cs-137 were detected from the sample collected along 155˚E, but Cs-134 was not detected at almost all stations along 175˚E in June and July 2011. The Kuroshio extension seemed to prevent the southward dispersion of radioactive cesium. The vertical distributions of radioactive cesium off the coast of northern Japan around FDNPP revealed complex patterns mainly due to the water mass interaction between Oyashio water and Kuroshio water.

Ocean still suffering from Fukushima fallout

• Geoff Brumfiel

http://www.nature.com/news/ocean-still-suffering-from-fukushima-fallout-1.11823

In fact, a fresh analysis by oceanographer Jota Kanda at the Tokyo University of Marine Science and Technology suggests that not one source, but three, are responsible. First, radioactivity from the land is being washed by rainfall into rivers, which carry it to the sea. Second, the plant itself is leaking around 0.3 terabecquerels (10¹² becquerels) per month, he estimates.

But Kanda thinks that the third source, marine sediment, is the main cause of the contamination. Around 95 terabecquerels of radioactive caesium has found its way to the sandy ocean floor near the plant. How it got there, Kanda says, no one is sure. It may have been absorbed directly by the sand itself, or it may be that tiny marine organisms such as plankton consumed the radioactive caesium and then deposited it on the sea floor through their excretions. Organic detritus from rivers could also be a source of the contamination, he says. Regardless of how it got there, “there must be some loaded organic material somewhere in the sediment”, Kanda says.