Abstract
To enhance reliability of population estimation by increasing the number of samples inspected, we examined the efficiency of nondestructive inspection methods. The nondestructive inspection system consists of detectors made from a combination of high-sensitivity scintillator crystals (Ce:Gd3(Al,Ga)5O12(Ce:GAGG)) and semiconductor devices. The radiation count rate (CPS) within the shiitake logs measured by the nondestructive inspection system was converted into Bq/kg. The moisture content of shiitake logs in the felling season was between 40 and 43%. The shiitake log density was between 1.0 and 1.1. This inspection resulted in differences in the slant of the regression line and sample weight. The differences were caused by the moisture content of the shiitake logs and standard sample. The standard sample was modified by processing fresh shiitake logs into a cylinder, wrapping it with radiocesium infiltrated paper and also by increasing its surface area with fiber-reinforced plastic (FRP). Based on examining the results of inspecting the modified shiitake mushroom logs, those covered with FRP most represented actual shiitake logs.
