Construction of a car-borne survey system for measurement of dose rates in air. KURAMA-II, and its application

Japan Atomic Energy Agency (JAEA) has been performing air dose rate mapping after the Fukushima Daiichi nuclear power plant accident using a car-borne survey system KURAMA-II, in response to a commission from the Ministry of Education, Culture, Sports, Science and Technology. The Kyoto University RAdiation MApping system (KURAMA) is a GPS-aided mobile radiation monitoring system that has been newly developed by the Kyoto University Research Reactor Institute (KURRI) in response to the nuclear disaster. The KURAMA system consists of an energy-compensated scintillation survey meter for measuring dose rates, an electric device for recording both the dose rates and the position data from a GPS module, a computer server for processing and analyzing data from KURAMA, and client PCs for providing end users with the data. The second generation of the KURAMA system, KURAMA-II, has been improved using smaller-packaging, increased durability, and automated data transmission. These improvements enable simultaneous monitoring using 100 KURAMA-II survey systems through collaboration between JAEA and local self-governing bodies such as Fukushima and surrounding prefectures. Consequently, dose rate mapping of a wide area in shorter period of time has become possible. This report describes the construction of KURAMA-II, its application and a suggested technique to manage a large number of KURAMA-II survey systems. (author)