Absorbed Dose Rate in Air at the Bunkyo-cho Campus of Hirosaki University

Abstract

Measurement of absorbed dose rate in air was carried out at the main campus (Bunkyo-cho Campus) of Hirosaki University about two years after the March 2011 accident at TEPCO’s Fukushima Daiichi Nuclear Power Plant. Three pocket survey meters and one 3-inch × 3-inch NaI(Tl) scintillation spectrometer were used for the measurement of absorbed dose rate and gamma-ray pulse height distribution, respectively. The arithmetic mean ± standard deviation based on 95 measurement locations at the main campus was 24 ± 3 nGy/h. Neither ¹³⁴Cs nor 137 _{Cs was observed throughout the whole survey time. This result suggested that their amounts} were comparable to the natural background radiation level found at Hirosaki University.