SUBMARINE GROUNDWATER DISCHARGE AS A SOURCE OF RADIOACTIVITY TO THE OCEAN FROM THE FUKUSHIMA NUCLEAR POWER PLANT
The tsunami-damaged Fukushima Nuclear Power Plant (FNPP) remains to this day a source radioactivity to the ocean. This is evidenced by time-series cesium (Cs)- 134 and -137 activities that have remained elevated over ~two years and exceed background values in the coastal ocean off Japan. Though most of the Fukushima atmospheric fallout was believed to be over the ocean, fallout over land led to Cs enrichment in river runoff and contamination of surficial aquifers. Furthermore, groundwater is infiltrating the NPP reactor buildings at several hundred tons/day and being transformed into highly contaminated radioactive wastewater. While some of this wastewater is being stored in tanks for further treatment, TEPCO has acknowledged ongoing direct radionuclide inputs to the local aquifer with the potential for transport to the coastal ocean via submarine groundwater discharge (SGD). We present results from a May 2013 survey of the coastal waters and surficial aquifer surrounding the FNPP where we measured naturally occurring radium isotopes in order to quantify SGD for this region. SGD fluxes for the key radionuclides of concern (Cs isotopes, 90-Sr) will be presented in the context of other known sources of FNPP discharge.
Charette, M. A., WHOI, USA, firstname.lastname@example.org
Breier, C., WHOI, USA
Kanda, J., Tokyo University of Marine Science and Technology, Japan
Nishikawa, J., University of Tokyo, Japan
Buesseler, K. O., WHOI, USA
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