Distribution and retention of Cs radioisotopes in soil affected by Fukushima nuclear plant accident

Mishra, Saurabh; Arae, Hideki; Hosoda, Masahiro; Tokonami, Shinji; Ishikawa, Tetsuo; Sahoo, Sarata Kumar

doi:10.1007/s11368-014-0985-2

Cited by 33 publications

(13 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Owing to the strong and irreversible bond to fine soil particles, the majority of FDNPP derived radiocesium currently remains stored within the top 5 cm of the soil profile in undisturbed soils Matsuda et al, 2015;Matsunaga et al, 2013;Mishra et al, 2015;Takahashi et al, 2015). Anthropogenic activities increase the depth of migration of radiocesium in the soil profile (Lepage et al, 2015;Matsunaga et al, 2013).…”

Section: Figmentioning

confidence: 99%

“…Sakai et al (2014) and Tanaka et al (2013b) both indicated that radiocesium from the FDNPP accident was measureable at 15 cm depth in rice paddy fields. Mishra et al (2015) reported that the vertical migration down the soil profile was slower in forest soils than in grassland soils. In a study of 85 soil sampling sites, Matsuda et al (2015) found that the depth penetration of radiocesium was higher than the standard range (0.2e1.0 kg m À2 y À1 ) depicted by He and Walling (1997).…”

Section: Figmentioning

confidence: 99%

See 1 more Smart Citation

Radiocesium transfer from hillslopes to the Pacific Ocean after the Fukushima Nuclear Power Plant accident: A review

Evrard

Laceby

Lepage

et al. 2015

Journal of Environmental Radioactivity

154

View full text Add to dashboard Cite

The devastating tsunami triggered by the Great East Japan Earthquake on March 11, 2011 inundated the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) resulting in a loss of cooling and a series of explosions releasing the largest quantity of radioactive material into the atmosphere since the Chernobyl nuclear accident. Although 80% of the radionuclides from this accidental release were transported over the Pacific Ocean, 20% were deposited over Japanese coastal catchments that are subject to frequent typhoons. Among the radioisotopes released during the FDNPP accident, radiocesium ((134)Cs and (137)Cs) is considered the most serious current and future health risk for the local population. The goal of this review is to synthesize research relevant to the transfer of FDNPP derived radiocesium from hillslopes to the Pacific Ocean. After radiocesium fallout deposition on vegetation and soils, the contamination may remain stored in forest canopies, in vegetative litter on the ground, or in the soil. Once radiocesium contacts soil, it is quickly and almost irreversibly bound to fine soil particles. The kinetic energy of raindrops instigates the displacement of soil particles, and their bound radiocesium, which may be mobilized and transported with overland flow. Soil erosion is one of the main processes transferring particle-bound radiocesium from hillslopes through rivers and streams, and ultimately to the Pacific Ocean. Accordingly this review will summarize results regarding the fundamental processes and dynamics that govern radiocesium transfer from hillslopes to the Pacific Ocean published in the literature within the first four years after the FDNPP accident. The majority of radiocesium is reported to be transported in the particulate fraction, attached to fine particles. The contribution of the dissolved fraction to radiocesium migration is only relevant in base flows and is hypothesized to decline over time. Owing to the hydro-meteorological context of the Fukushima region, the most significant transfer of particulate-bound radiocesium occurs during major rainfall and runoff events (e.g. typhoons and spring snowmelt). There may be radiocesium storage within catchments in forests, floodplains and even within hillslopes that may be remobilized and contaminate downstream areas, even areas that did not receive fallout or may have been decontaminated. Overall this review demonstrates that characterizing the different mechanisms and factors driving radiocesium transfer is important. In particular, the review determined that quantifying the remaining catchment radiocesium inventory allows for a relative comparison of radiocesium transfer research from hillslope to catchment scales. Further, owing to the variety of mechanisms and factors, a transdisciplinary approach is required involving geomorphologists, hydrologists, soil and forestry scientists, and mathematical modellers to comprehensively quantify radiocesium transfers and dynamics. Characterizing radiocesium transfers from hillslopes to the Pacific Ocean is necess...

show abstract

Section: Figmentioning

confidence: 99%

Section: Figmentioning

confidence: 99%

Radiocesium transfer from hillslopes to the Pacific Ocean after the Fukushima Nuclear Power Plant accident: A review

Evrard

Laceby

Lepage

et al. 2015

Journal of Environmental Radioactivity

154

View full text Add to dashboard Cite

show abstract

“…Radioactive Cs supplied by the FDNPP in wet deposition was immediately adsorbed onto soil particles and fixed in the top ~5 cm of surface soil where it remains (Fujiwara et al, 2012;Teramage et al, 2014;Mishra et al, 2015;Takahashi et al, 2015). Soluble Cs ion, regardless of the isotope, bonds strongly to the sheet-structure of alumino-silicates, such as weathered mica, illite, and vermiculite due to the presence of frayed-edge negatively charged sites (FES) (Sawhney, 1970;Cremers et al, 1988;Kogure et al, 2012); thus, it is difficult to desorb the strongly-bound Cs from the clays by chemical treatment.…”

Section: Introductionmentioning

confidence: 99%

Radioactive Cs in the estuary sediments near Fukushima Daiichi Nuclear Power Plant

Yamasaki

Imoto

Furuki

et al. 2016

Science of The Total Environment

View full text Add to dashboard Cite

The migration and dispersion of radioactive Cs (mainly (134)Cs and (137)Cs) are of critical concern in the area surrounding the Fukushima Daiichi Nuclear Power Plant (FDNPP). Considerable uncertainty remains in understanding the properties and dynamics of radioactive Cs transport by surface water, particularly during rainfall-induced flood events to the ocean. Physical and chemical properties of unique estuary sediments, collected from the Kuma River, 4.0km south of the FDNPP, were quantified in this study. These were deposited after storm events and now occur as dried platy sediments on beach sand. The platy sediments exhibit median particle sizes ranging from 28 to 32μm. There is increasing radioactivity towards the bottom of the layers deposited; approximately 28 and 38Bqg(-1) in the upper and lower layers, respectively. The difference in the radioactivity is attributed to a larger number of particles associated with radioactive Cs in the lower part of the section, suggesting that radioactive Cs in the suspended soils transported by surface water has decreased over time. Sequential chemical extractions showed that ~90% of (137)Cs was strongly bound to the residual fraction in the estuary samples, whereas 60~80% of (137)Cs was bound to clays in the six paddy soils. This high concentration in the residual fraction facilitates ease of transport of clay and silt size particles through the river system. Estuary sediments consist of particles <100μm. Radioactive Cs desorption experiments using the estuary samples in artificial seawater revealed that 3.4±0.6% of (137)Cs was desorbed within 8h. More than 96% of (137)Cs remained strongly bound to clays. Hence, particle size is a key factor that determines the travel time and distance during the dispersion of (137)Cs in the ocean.

show abstract

“…the top 5 cm) in undisturbed soils (Lepage et al, 2014;Matsuda et al, 2013Matsuda et al, , 2015Takahashi et al, 2015;Mishra et al, 2015). Mishra et al (2015) reported that for these undisturbed soils, the vertical migration of radiocesium down the soil profile was slower in forest soils compared to grassland soils. In disturbed soils, anthropogenic activities may increase the depth migration of radiocesium down the soil profile Matsunaga et al, 2013).…”

Section: Radiocesium Distribution With Depth In the Soilmentioning

confidence: 99%

“…In general, owing to the strong and nearly irreversible bond of radiocesium to fine soil particles, the majority of FDNPPderived 137 Cs is stored within the topsoil (i.e. the top 5 cm) in undisturbed soils (Lepage et al, 2014;Matsuda et al, 2013Matsuda et al, , 2015Takahashi et al, 2015;Mishra et al, 2015). Mishra et al (2015) reported that for these undisturbed soils, the vertical migration of radiocesium down the soil profile was slower in forest soils compared to grassland soils.…”

Section: Radiocesium Distribution With Depth In the Soilmentioning

confidence: 99%

Effectiveness of landscape decontamination following the Fukushima nuclear accident: a review

Evrard

Laceby

Nakao

2019

SOIL

View full text Add to dashboard Cite

The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011 resulted in the contamination of Japanese landscapes with radioactive fallout. Accordingly, the Japanese authorities decided to conduct extensive remediation activities in the impacted region to allow for the relatively rapid return of the local population. The objective of this review is to provide an overview of the decontamination strategies and their potential effectiveness in Japan, focussing on particle-bound radiocesium. In the Fukushima Prefecture, the decision was taken to decontaminate the fallout-impacted landscapes in November 2011 for the 11 municipalities evacuated after the accident (Special Decontamination Zone -SDZ -1117 km 2 ) and for the 40 non-evacuated municipalities affected by lower, although still significant, levels of radioactivity (Intensive Contamination Survey Areas, 7836 km 2 ). Decontamination activities predominantly targeted agricultural landscapes and residential areas. No decontamination activities are currently planned for the majority of forested areas, which cover ∼ 75 % of the main fallout-impacted region. Research investigating the effectiveness of decontamination activities underlined the need to undertake concerted actions at the catchment scale to avoid renewed contamination from the catchment headwaters after the completion of remediation activities. Although the impact of decontamination on the radioactive dose rates for the local population remains a subject of debate in the literature and in the local communities, outdoor workers in the SDZ represent a group of the local population that may exceed the long-term dosimetric target of 1 mSv yr −1 . Decontamination activities generated ∼ 20 million m 3 of soil waste by early 2019. The volume of waste generated by decontamination may be decreased through incineration of combustible material and recycling of the less contaminated soil for civil engineering structures. However, most of this material will have to be stored for ∼ 30 years at interim facilities opened in 2017 in the vicinity of the FDNPP before being potentially transported to final disposal sites outside of the Fukushima Prefecture. Further research is required to investigate the perennial contribution of radiocesium from forest sources. In addition, the re-cultivation of farmland after decontamination raises additional questions associated with the fertility of remediated soils and the potential transfer of residual radiocesium to the plants. Overall, we believe it is important to synthesise the remediation lessons learnt following the FDNPP nuclear accident, which could be fundamental if a similar catastrophe occurs somewhere on Earth in the future.

show abstract

Distribution and retention of Cs radioisotopes in soil affected by Fukushima nuclear plant accident

Cited by 33 publications

References 19 publications

Radiocesium transfer from hillslopes to the Pacific Ocean after the Fukushima Nuclear Power Plant accident: A review

Radiocesium transfer from hillslopes to the Pacific Ocean after the Fukushima Nuclear Power Plant accident: A review

Radioactive Cs in the estuary sediments near Fukushima Daiichi Nuclear Power Plant

Effectiveness of landscape decontamination following the Fukushima nuclear accident: a review

Contact Info

Product

Resources

About