Skip to main content Accessibility help

Variation of 14C in Japanese Tree Rings Related to the Fukushima Nuclear Accident

  • Tamás Varga (a1), László Palcsu (a1), Tomoko Ohta (a2) (a3), Yasunori Mahara (a4), A J Timothy Jull (a1) (a5) (a6) and Mihály Molnár (a1)...


Radiocarbon (14C) analysis was performed on Japanese cedar (Cryptomeria japonica) tree rings from Koriyama, Fukushima prefecture. Our primary aim was to detect any 14C release from the Fukushima Dai-ichi nuclear power plant accident on 11 March 2011. We also completed and assessed the 14C level in Japanese tree rings for the period of 1990–2014 because of the lack of environmental 14C results in the Japanese island that time. For this reason, we used a trajectory model to investigate the air mass forward and backward trajectories at the area of the power plant and sampling site. The modeling data show that the air masses mainly moved to the Pacific Ocean, both during March 2011 and during the growing season (March–September). During the period 1990–2014 there was no significant 14C excess in any of the samples, but there was a detectable Suess effect in almost every tree ring sample. The average fossil contribution was 0.83 ± 0.01% and the calculated anthropogenic component ratio, the 14C excess varied between +0.5 and –1.6%. The Δ14C value decreased from 150.0‰ to 9.5‰ from 1990–2014, which follows the decline of the 14C bomb peak, in addition to any detectable Suess effect.


Corresponding author

*Corresponding author. Email:


Hide All
Buzinny, M. 2006. Radioactive graphite dispersion in the environment in the vicinity of the Chernobyl Nuclear Power Plant. Radiocarbon 48(3):451458.
Buzinny, MG, Los, IP, Talerko, N, Tsigankov, N. 1998. Radiocarbon analysis of annual tree rings from the vicinity of the Chernobyl NPP. Radiocarbon 40(1):373380.
Chen, B, Xu, S, Cook, G-T, Freeman, SPHT Hou, X, Naysmith, P, Yamaguchi, K. 2017. Local variance of atmospheric 14C concentrations around Fukushima Dai-ichi Nuclear Power Plant from 2010 to 2012. Journal of Radioanalytical and Nuclear Chemistry 314:10011007.
Chudy, M, Povinec, P. 1982. Radiocarbon production in a CO2 coolant of nuclear reactor. Acta Univ Comen Physica 22:127134.
Davis, W. 1979. Carbon-14 production in reactor. In: Carter, MW, Moghissi, AA, Khan, B, editors. Management of low-level radioactive waste 1. Oxford: Pergamon Press. p. 151191.
Draxler, RR, Hess, GD. 1998. An overview of the HYSPLIT_4 modeling system of trajectories, dispersion, and deposition. Australian Meteorological Magazine 47:295308.
Graven, HD. 2015. Impact of fossil fuel emissions on atmospheric radiocarbon and various applications of radiocarbon over this century. Proceedings of the National Academy of Sciences of the United States of America 112(31):95429545.
Hammer, S, Levin, I. 2017. Monthly mean atmospheric D14CO2 at Jungfraujoch and Schauinsland from 1986 to 2016, heiDATA, V2; JFJ_SIL_C14_MM_2017_Mar.xlsx.
IAEA. 2001. Generic methods for use in assessing the impact of discharges of radioactive substances to the environment. Safety Report Series 19. Vienna.
Janovics, R, Futó, I, Molnár, M. 2018. Sealed tube combustion method with MnO2 for AMS 14C measurement. Radiocarbon 60(5):13471355.
Janovics, R, Kern, Z, Güttler, D, Wacker, L, Barnabás, I, Molnár, M. 2013. Radiocarbon impact on a nearby tree of a light-water VVER-type nuclear power plant, Paks, Hungary. Radiocarbon 55(2–3):826832.
Ješkovsky, M, Povinec, PP, Steier, P, Šivo, A, Richtarikova, M, Golser, R. 2015. Retrospective study of 14C concentration in the vicinity of NPP Jaslovské Bohunice using tree rings and the AMS technique. Nuclear Instruments and Methods in Physics Research B 361:129132.
Levin, I, Kromer, B, Schoch–Fischer, H, Bruns, M, Münnich, M, Berdau, D, Vogel, JC, Münnich, K. 1985. 25 years of tropospheric 14C observations in central Europe. Radiocarbon 27(1):119.
Levin, I, Kromer, B. 2004. The tropospheric 14CO2 level in mid-latitudes of the Northern Hemisphere (1959–2003). Radiocarbon 46(3):12611272.
Major, I, Haszpra, L, Rinyu, L, Futó, I, Bihari, Á, Hammer, S, Molnár, M. 2018. Temporal variation of atmospheric fossil and modern CO2 excess at a Central European rural tower station between 2008 and 2014. Radiocarbon 60(5):12851299.
Molnár, M, Bujtás, T, Svingor, É, Futó, I, Svetlík, I. 2007. Monitoring of atmospheric excess 14C around Paks Nuclear Power Plant, Hungary. Radiocarbon 49(2):10311043.
Molnár, M, Janovics, R, Major, I, Orsovszki, J, Gönczi, R, Veres, M, Leonard, AG, Castle, SM, Lange, TE, Wacker, L, Hajdas, I, Jull, AJ. 2013a. Status report of the new AMS 14C sample preparation lab of the Hertelendi Laboratory of Environmental Studies (Debrecen, Hungary). Radiocarbon 55(2–3):665676.
Molnár, M, Rinyu, L, Veres, M, Seiler, M, Wacker, L, Synal, H-A. 2013b. EnvironMICADAS: A Mini 14C AMS with enhanced gas ion source interface in the Hertelendi Laboratory of Environmental Studies (HEKAL), Hungary. Radiocarbon 55(2–3):338344.
Nemec, M, Wacker, L, Hajdas, I, Gäggeler, H. 2010. Alternative methods for cellulose preparation for AMS measurement. Radiocarbon 52(2–3):13581370.
Pirouzmand, A, Kowsar, Z, Dehghani, P. 2018. Atmospheric dispersion assessment of radioactive materials during severe accident conditions for Bushehr nuclear power plant using HYSPLIT code. Progress in Nuclear Energy 108:169178.
Povinec, P, Chudy, M, Sivo, A. 1986. Anthropogenic radiocarbon: past, present, and future. Radiocarbon 28(2A):668672.
Povinec, P, Kwong, LLW, Kaizer, J, Molnár, M, Nies, H, Palcsu, L, Papp, L, Pham, MK, Jean-Baptise, P. 2017. Impact of the Fukushima accident on tritium, radiocarbon, and radiocesium levels in seawater of the western North Pacific Ocean: a comparison with pre-Fukushima situation. Journal of Environmental Radioactivity 166:5666.
Rinyu, L, Molnár, M, Major, I, Nagy, T, Veres, M, Kimák, Á, Wacker, L, Synal, H-A. 2013. Optimization of sealed tube graphitization method for environmental 14C studies using MICADAS. Nuclear Instruments and Methods in Physics Research B 294:270275.
Stein, AF, Draxler, RR, Rolph, GD, Stunder, BJB, Cohen MD Ngan, F. 2015. NOAA’s HYSPLIT atmospheric transport and dispersion modeling system. Bulletin of the American Meteorological Society 96:20592077.
Stenström, KE, Skog, G, Georgiadou, E, Grenberg, J, Johansson, A. 2011. A guide to radiocarbon units and calculations. Lund University (Sweden), Department of Physics, Division of Nuclear Physics Internal Report LUNFD6(NFFR–3111)/1–17/ (2011).
Su, L, Yuan, Z, Fung, JCH, Lau, AKH. 2015. A comparison of HYSPLIT backward trajectories generated from two GDAS datasets. Science of the Total Environment 506–507:527537.
Suess, HE. 1955. Radiocarbon concentration in modern wood. Science 122:415417.
Theodórsson, P. 1991. Gas proportional versus liquid scintillation counting, radiometric versus AMS dating. Radiocarbon 33(1):913.
U.S. Energy Information Administration. 2017. Country analysis brief: Japan, independent statistics & analysis. Update: 2 February 2017.
Veres, M, Hertelendi, E, Uchrin, G, Csaba, E, Barnabás, I, Ormai, P, Volent, G, Futó, I. 1995. Concentration of radiocarbon and its chemical forms in gaseous effluents, environmental air, nuclear waste and primary water of a pressurized water reactor power plant in Hungary. Radiocarbon 37(2):497504.
Xu, S, Cook, GT, Cresswell, AJ, Dunbar, E, Freeman, SPHT, Hastie, H, Hou, X, Jacobsson, P, Naysmith, P, Sanderson, DCW. 2015. Radiocarbon concentration in modern tree rings from Fukushima, Japan. Journal of Environmental Radioactivity 146:6772.
Xu, S, Cook, GT, Cresswell, AJ, Dunbar, E, Freeman, SPHT, Hou, X, Jacobsson, P, Knich, HR, Naysmith, P, Sanderson, DCW, Tripney, BG. 2016b. Radiocarbon releases from the 2011 Fukushima nuclear accident. Scientific Reports 6:36947. doi 10.1038/srep36947(2016).
Xu, S, Cook, GT, Cresswell, AJ, Dunbar, E, Freeman, SPHT, Hastie, H, Hou, X, Jacobsson, P, Naysmith, P, Sanderson, DCW, Tripney, BG, Yamaguchi, K. 2016a. 14C levels in the vicinity of the Fukushima Dai-ichi Nuclear Power Plant prior the 2011 accident. Journal of Environmental Radioactivity 157:9096.
Yim, MS, Caron, F. 2006. Life cycle and management of carbon-14 from nuclear power generation. Progress in Nuclear Energy 48:236.



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed