Development of ESRAD program for estimation of spatial radioactivity distribution based on Kriging; User's manual

Ishigami, Tsutomu; Mukai, Masayuki ; Sukegawa, Takenori; Matsubara, Takeshi*

Verification for site release is one of procedures to confirm termination of decommissioning of nuclear installations. The verification procedure would need to confirm that the radioactive concentration at the site is lower than the criterion value by measurement. Then to efficiently perform the measurement and verification it is one of important issues how to efficiently estimate and evaluate overall spatial radioactivity distribution using a sampling method. For the efficient estimation and evaluation we have applied a Kriging technique which in the geostatistics, and have developed a computer program ESRAD (Estimation of Spatial RadioActivity Distribution). The ESRAD program is designed to support sample selection, calculate a variogram, and estimate a radioactivity distribution for the area concerned. This report describes the Kriging technique, structure and functions of ESRAD, input file format, output examples, execution procedure of ERSAR, and sample run with ESRAD.