Publication Date:
2022-05-26
Description:
Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 114 (2017): 11092-11096, doi:10.1073/pnas.1708659114.
Description:
There are 440 operational nuclear reactors in the world, with approximately half situated
along the coastline. This includes the Fukushima Dai-ichi Nuclear Power Plant (FDNPP),
which experienced multiple reactor meltdowns in March 2011 followed by the release of
radioactivity to the marine environment. While surface inputs to the ocean via atmospheric
deposition and rivers are usually well monitored after a nuclear accident, no study has
focused on subterranean pathways. During our study period, we found the highest cesium-137 (137Cs) levels (up to 23,000 Bq m-3) outside of the FDNPP site not in the ocean, rivers or
potable groundwater, but in groundwater beneath sand beaches over tens of kilometers
away from the FDNPP. Here, we present evidence of a previously unknown, ongoing source
of Fukushima-derived 137Cs to the coastal ocean. We postulate that these beach sands were
contaminated in 2011 through wave and tide driven exchange and sorption of highly
radioactive Cs from seawater. Subsequent desorption of 137Cs and fluid exchange from the
beach sands was quantified using naturally occurring radium isotopes. This estimated
ocean 137Cs source (0.6 TBq y-1) is of similar magnitude as the ongoing releases of 137Cs
from the FDNPP site for 2013-2016, as well as the input of Fukushima-derived dissolved
137Cs via rivers. Though this ongoing source is not at present a public health issue for
Japan, the release of Cs of this type and scale needs to be considered in NPP monitoring
and scenarios involving future accidents.
Description:
V. Sanial was supported by a Postdoctoral Scholarship from the Center
for Marine and Environmental Radioactivity (CMER). Funding for this work was provided by
the Gordon and Betty Moore Foundation, the Deerbrook Charitable Trust, as well as the EC
7th Framework project COMET-FRAME (COordination and iMplementation of a pan-Europe
instrumenT for radioecology) and KAKENHI (24110008).
Keywords:
Fukushima Dai-ichi Nuclear Power Plant accident
;
Cesium
;
Submarine groundwater discharge
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
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