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Modelling the Effect of Mechanical Remediation on Dose Rates Above Radiocesium Contaminated Land

  • Alex MalinsEmail author
  • Hiroshi Kurikami
  • Akihiro Kitamura
  • Masahiko Machida
Chapter

Abstract

Mechanical strategies for remediating radiocesium contaminated soils, e.g. at farms, schoolyards, gardens or parks, lower air dose rates in one of two characteristic ways. The first is to physically remove radiocesium from the environment, for example by stripping topsoil and sending it for disposal. The second is to redistribute the radiocesium deeper within the ground, e.g. by mixing the topsoil or switching the positions of different soil layers, in order that soil attenuates radiocesium gamma rays before they reach the surface. The amount that air dose rates reduce because of remediation can be calculated using radiation transport methods. This chapter summarizes modelling results for the effect of topsoil removal (with and without recovering with a clean soil layer), topsoil mixing, and soil layer interchange on dose rates. Using measurements of the depth profile of 134Cs and 137Cs activity in soil at un-remediated sites across North East Japan, the potential effectiveness of remediation work was estimated considering remediation to different soil depths and different time lags after the accident. The results show that remediation performance would have been essentially constant irrespective of the time at which it was undertaken in the initial five year period following the fallout.

Keywords

Radiocesium 134Cs 137Cs Mechanical Remediation Decontamination Soil Topsoil stripping Soil mixing Soil layer interchange Modelling 

Notes

Acknowledgements

We thank S. Nakama, K. Saito and K. Miyahara for their advice and assistance to this work.

References

  1. Akleyev AV, Kisselyov MF (2002) Medical-biological and ecological impacts of radioactive contamination of the Techa River. Fregat, ChelyabinskGoogle Scholar
  2. Antonopoulos-Domis M, Clouvas A, Hiladakis A, Kadi S (1995) Radiocesium distribution in undisturbed soil: measurements and diffusion-advection model. Health Phys 69:949–953CrossRefGoogle Scholar
  3. Fuller AJ, Shaw S, Ward MB, Haigh SJ, Mosselmans JFW, Peacock CL, Stackhouse S, Dent AJ, Trivedi D, Burke IT (2015) Caesium incorporation and retention in illite interlayers. Appl Clay Sci 108:128–134CrossRefGoogle Scholar
  4. Government of Japan (2011) Act on special measures concerning the handling of environment pollution by radioactive materials discharged by the NPS accident associated with the Tohoku District-Off the Pacific Ocean Earthquake That Occurred on March 11, 2011Google Scholar
  5. IAEA (2006) STI/PUB/1239: environmental consequences of the Chernobyl accident and their remediation: 20 years of experience. Report of the Chernobyl Forum Expert Group ‘Environment’. http://www-pub.iaea.org/MTCD/publications/PDF/Pub1239_web.pdf
  6. ICRU (1994) ICRU 53: Gamma-Ray spectrometry in the environmentGoogle Scholar
  7. JAEA (2015a) Database for radioactive substance monitoring data-depth distribution in soil. http://emdb.jaea.go.jp/emdb/en/
  8. JAEA (2015b) JAEA-Review 2014-051: remediation of contaminated areas in the aftermath of the accident at the Fukushima Daiichi Nuclear Power Station: overview, analysis and lessons learned Part 1: a report on the ‘Decontamination Pilot Project’. Technical report, March, Japan Atomic Energy Agency. https://doi.org/10.11484/jaea-review-2014-051
  9. Kurikami H, Malins A, Takeishi M, Saito K, Iijima K (2017) Coupling the advection-dispersion equation with fully kinetic reversible/irreversible sorption terms to model radiocesium soil profiles in Fukushima prefecture. J Environ Radioact 171:99–109CrossRefGoogle Scholar
  10. Likhtarev IA, Kovgan LN, Jacob P, Anspaugh LR (2002) Chernobyl accident: retrospective and prospective estimates of external dose of the population of Ukraine. Health Phys 82:290–303CrossRefGoogle Scholar
  11. Malins A, Okumura M, Machida M, Takemiya H, Saito K (2015) Fields of view for environmental radioactivity. In: Proceedings of the international symposium on radiological issues for Fukushima’s revitalized future, pp 28–34Google Scholar
  12. Malins A, Kurikami H, Kitamura A, Machida M (2016a) Effect of remediation parameters on in-air ambient dose equivalent rates when remediating open sites with radiocesium-contaminated soil. Health Phys 111:357–366CrossRefGoogle Scholar
  13. Malins A, Kurikami H, Nakama S, Saito T, Okumura M, Machida M, Kitamura A (2016b) Evaluation of ambient dose equivalent rates influenced by vertical and horizontal distribution of radioactive cesium in soil in Fukushima Prefecture. J Environ Radioact 151:38–49CrossRefGoogle Scholar
  14. Matsuda N, Mikami S, Shimoura S, Takahashi J, Nakano M, Shimada K, Uno K, Hagiwara S, Saito K (2015) Depth profiles of radioactive cesium in soil using a scraper plate over a wide area surrounding the Fukushima Dai-ichi Nuclear Power Plant, Japan. J Environ Radioact 139:427–434CrossRefGoogle Scholar
  15. Mikami S, Maeyama T, Hoshide Y, Sakamoto R, Sato S, Okuda N, Sato T, Takemiya H, Saito K (2015) The air dose rate around the Fukushima Daiichi nuclear power plant: its spatial characteristics and temporal changes until December 2012. J Environ Radioact 139:250–259CrossRefGoogle Scholar
  16. Ministry of the Environment (2013) Decontamination guidelines. Technical report. http://josen.env.go.jp/en/framework/pdf/decontaminationguidelines 2nd.pdf
  17. Ministry of the Environment (2015) FY2014 decontamination report. Technical report. http://josen.env.go.jp/en/cooperation/pdf/decontaminationreport1503 01.pdf
  18. Ministry of the Environment (2017) Progress on off-site cleanup and interim storage in Japan (August 2017). Technical reportGoogle Scholar
  19. Miyazaki M, Hayano R (2017) Individual external dose monitoring of all citizens of Date City by passive dosimeter 5 to 51 months after the Fukushima NPP accident (series): II. Prediction of lifetime additional effective dose and evaluating the effect of decontamination on individual dose. J Radiol Prot 37:623–634CrossRefGoogle Scholar
  20. Mukai H, Hatta T, Kitazawa H, Yamada H, Yaita T, Kogure T (2014) Speciation of radioactive soil particles in the Fukushima contaminated area by IP autoradiography and microanalyses. Environ Sci Technol 48:13053–13059CrossRefGoogle Scholar
  21. Okumura M, Nakamura H, Machida M (2013) Mechanism of strong affinity of clay minerals to radioactive cesium: first-principles calculation study for adsorption of cesium at frayed edge sites in muscovite. J Phys Soc Jpn 82:033802CrossRefGoogle Scholar
  22. Oughton DH (2013) Social and ethical issues in environmental remediation projects. J Environ Radioact 119:21–25CrossRefGoogle Scholar
  23. Takahashi J, Tamura K, Suda T, Matsumura R, Onda Y (2015) Vertical distribution and temporal changes of 137Cs in soil profiles under various land uses after the Fukushima Dai-ichi Nuclear Power Plant accident. J Environ Radioact 139:351–361CrossRefGoogle Scholar
  24. Yasutaka T, Naito W (2016) Assessing cost and effectiveness of radiation decontamination in Fukushima Prefecture, Japan. J Environ Radioact 151:512–520CrossRefGoogle Scholar
  25. Yasutaka T, Naito W, Nakanishi J (2013) Cost and effectiveness of decontamination strategies in radiation contaminated areas in Fukushima in regard to external radiation dose. PLoS One 8(9):e75308CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2019

Authors and Affiliations

  • Alex Malins
    • 1
    Email author
  • Hiroshi Kurikami
    • 1
    • 2
  • Akihiro Kitamura
    • 1
    • 2
  • Masahiko Machida
    • 1
  1. 1.Center for Computational Science and e-SystemsJapan Atomic Energy AgencyKashiwaJapan
  2. 2.Fukushima Environmental Safety CenterJapan Atomic Energy AgencyTamura-gunJapan

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