ABSTRACT
This study aimed to establish a walking survey technique for rapidly determining the distribution of the ambient gamma dose rate. The measurement system consists of a scintillation spectrometer and a Global Positioning System receiver, which are controlled using a laptop. In addition to locality information, the ambient gamma dose rates were measured continuously and corrected based on shielding by the measurer body. The measurement interval was optimized at 12 s based on the locality resolution and fluctuations of the measured dose rates. A comparison was also made between the dose rate distribution maps depicted by the walking survey technique and spot measurements at fixed points. Based on the measurement data selected for the comparison, it was found that the values of 80% of the data obtained using the walking survey technique deviated within ±20% relative to those obtained by spot measurements. Compared to the spot measurements, the time taken to depict the map was reduced to one-fifth, and the localized contamination points could be depicted.
Acknowledgments
The authors would like to thank the faculty of the Radiation Disaster Medical Center in Fukushima Medical University for arranging the use of the survey meters. This work was partly supported by JSPS KAKENHI Grant Number JP20H04318.
Disclosure statement
No potential conflict of interest was reported by the author(s).