Emergency monitoring of environmental radiation and atmospheric radionuclides at Nuclear Science Research Institute, JAEA following the accident of Fukushima Daiichi Nuclear Power Plant

Okura, Takehisa; Oishi, Tetsuya; Taki, Mitsumasa; Shibanuma, Yukio; Kikuchi, Masamitsu; Akino, Hitoshi; Kikuta, Yasuaki; Kawasaki, Masatsugu; Saegusa, Jun; Tsutsumi, Masahiro; et al.

JAEA-Data/Code 2012-010, 37 Pages, 2012/05

JAEA-Data-Code-2012-010.pdf:2.28MB

Due to the accident at Fukushima Daiichi Nuclear Power Plant caused by the 2011 off the Pacific coast of Tohoku Earthquake occurred at 11th March 2011, the emergency environmental radiation monitoring was conducted at Nuclear Science Research Institute, Japan Atomic Energy Agency (JAEA). This report provides the monitoring results of ambient -ray dose rate and atmospheric radioactivity concentration until the beginning of June 2011. Some anthropogenic radionuclides such as Cs-134, Cs-137, I-131, I-132, Te-132, Xe-133 and others were detected from air samples. The atmospheric radioactivity concentrations varied with some peaks corresponded with that of ambient -ray dose rate after 15th March 2011. Composition of each peak showed various characteristic. Internal exposure caused by inhalation was estimated from the observed atmospheric radioactivity.

CREPT-MCNP; Code system for efficiency calibration of -ray spectrometer based on the representative point method

Saegusa, Jun; Ogose, Hitoshi; Takamura, Atsushi*; Sugita, Takeshi*

no journal, , 

The representative point method is an efficiency calibration method for a -ray spectrometer. A calculation code system, CREPT-MCNP, for implementing the method has been newly developed. CREPT-MCNP can be operated under the Windows PC environment as a GUI based application. The code system estimates the position of the representative point which is intrinsic to each shape of volume sample, and also gives the self-absorption factors to make correction on the efficiencies measured at the representative point with a standard point source. It can deal with photons between 20 keV and 2 MeV with p- or n-type germanium semiconductor detectors.