title: The aftermath of the Fukushima nuclear accident: Measures to contain groundwater contamination.
abstract: Several measures are being implemented to control groundwater contamination at the Fukushima Daiichi Nuclear Plant. This paper presents an overview of work undertaken to contain the spread of radionuclides, and to mitigate releases to the ocean via hydrological pathways. As a first response, contaminated water is being held in tanks while awaiting treatment. Limited storage capacity and the risk of leakage make the measure unsustainable in the long term. Thus, an impervious barrier has been combined with a drain system to minimize the discharge of groundwater offshore. Caesium in seawater at the plant port has largely dropped, although some elevated concentrations are occasionally recorded. Moreover, a dissimilar decline of the radioactivity in fish could indicate additional sources of radionuclides intake. An underground frozen shield is also being constructed around the reactors. This structure would reduce inflows to the reactors and limit the interaction between fresh and contaminated waters. Additional strategies include groundwater abstraction and paving of surfaces to lower water levels and further restrict the mobilisation of radionuclides. Technical difficulties and public distrust pose an unprecedented challenge to the site remediation. Nevertheless, the knowledge acquired during the initial work offers opportunities for better planning and more rigorous decisions in the future.
authors.affiliation: CONICET (Argentina National Scientific and Technical Research Council), San Luis National University, FCFMyN, Department of Geology, San Luis 5700, Argentina. Electronic address: adgallardo@geowater.com.au.
authors.forename: Adrian H
authors.initials: AH
authors.lastname: Gallardo
authors.affiliation: AIST Geological Survey of Japan, Geo-Resources and Environment Institute, Groundwater Research Group, Ibaraki-ken, Tsukuba 305-8567, Japan.
authors.forename: Atsunao
authors.initials: A
authors.lastname: Marui
mesh_terms: D062406:Fukushima Nuclear Accident; D060587:Groundwater / Q000737:chemistry*; D011834:Radiation Monitoring; D012623:Seawater; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D014875:Water Pollutants, Radioactive
keywords: Control measures; Fukushima; Groundwater contamination; Radioactivity; Remediation