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Radiation Monitoring and Dose Estimation of the Fukushima Nuclear Accident
2014, pp 59-66, Open Access
Date: 06 Dec 2013
Radiation Survey Along Two Trails in Mt. Fuji to Investigate the Radioactive Contamination Caused by TEPCO?s Fukushima Daiichi Nuclear Plant Accident
[h=2]Abstract[/h] Mt. Fuji is located approximately 300 km southwest of TEPCO?s Fukushima Daiichi Nuclear Power Plant. We performed the radiation survey along two main Mt. Fuji?s trails from 04:30 to 18:30 on July 9, 2011. We climbed Yoshida trail from Fuji-Subaru Line fifth station (2,300 m in altitude) to Yoshida-Subashiri top (3,720 m in altitude) and descended Subashiri trail from the Yoshida-Subashiri top to Subashiri new fifth station (2,000 m in altitude) on foot while measuring gamma rays. The dose rate 1 m above ground as measured using a NaI(Tl) scintillation survey meter was within the range from 0.03 to 0.05 μSv/h throughout our measuring trip. We used a NaI(Tl) scintillation spectrometer for gamma-ray pulse height spectra measurement. The gamma-ray pulse height spectra obtained at least 2,500 m in altitude on both Yoshida and Subashiri trails showed the peaks of two radioactive cesium isotopes ([SUP]134[/SUP]Cs and [SUP]137[/SUP]Cs) and natural radioactive nuclides. It was confirmed that a radioactive plume released from the Fukushima Daiichi Nuclear Power Plant had arrived at least 2,500 m above sea level of Mt. Fuji.
