Development of KURAMA-II and its operation in Fukushima

Abstract

Carborne surveyAir dose rate Fukushima Daiichi nuclear power plant a b s t r a c t A carborne survey system, named as KURAMA (Kyoto University RAdiation MApping system), was developed as a response to the nuclear accident at TEPCO Fukushima Daiichi Nuclear Power Plant in 2011. Now the system has evolved into KURAMA-II, characterized by its compactness, autonomous operation, and acquisition of pulse-height spectrum data. A two-year field test of radiation monitoring by KURAMA-II on local buses, performed by Kyoto University, has successfully proceeded to the phase of official operation by the Fukushima prefectural government, supported by Kyoto University and JAEA (Japan Atomic Energy Agency). An outline and the current status of KURAMA-II, including some results of the continuous monitoring by KURAMA-II on local buses in Fukushima, are introduced.

Spectrum–dose conversion operator of NaI(Tl) and CsI(Tl) scintillation detectors for air dose rate measurement in contaminated environments

“…The CsI(Tl) crystals were rectangular parallelepipeds with 13 Â 13 Â 20 mm for C12137e00 and 38 Â 38 Â 25 mm for C12137e01. The C12137 series of detectors were used in a car-borne survey system known as the Kyoto University RAdiation MApping system (KURAMA) developed by the Kyoto University Research Reactor Institute (Tanigaki et al, 2013(Tanigaki et al, , 2015. In the mapping projects, KURAMA systems were exploited in car-borne surveys (Andoh et al, 2015) and man-borne surveys.…”

“…The pulse height distributions were measured on December 28, 2011 around the Fukushima Dai-ichi Nuclear Power Plant using C12137e00 and C12137e01. The car-borne survey using the C12137s was conducted by setting the detectors next to the rear window of a sedan-type taxi (Tanigaki et al, 2015). Although TCS Please cite this article in press as: Tsuda, S., Saito, K., Spectrumedose conversion operator of NaI(Tl) and CsI(Tl) scintillation detectors for air dose rate measurement in contaminated environments, Journal of Environmental Radioactivity (2016), http://dx.doi.org/10.1016/ j.jenvrad.2016.02.008 was also loaded on the car as a survey meter for KURAMA (Tanigaki et al, 2013), the information of the pulse height distribution of TCS could not be obtained because TCS outputs the dose rates only.…”

Temporal Change in Radiological Environments on Land after the Fukushima Daiichi Nuclear Power Plant Accident

“…Although the regional coverage of car-borne surveys is much larger than those of other methods mentioned above, the area that one car can cover in a short time is limited. After the Fukushima accident, about 100 car-borne survey systems were used at the same time, and air dose rates over eastern Japan were measured in a short time [12] by applying the recently invented Kyoto University radiation-mapping (KURAMA-II) system, which can collect data from a number of cars automatically through a mobile-phone network [13]. The G(E) function for compensating the energy response of Fig.…”

Development and Operation of a Carborne Survey System, KURAMA

“…Such monitoring can be realized if moving vehicles in residential areas such as buses, delivery vans, or bikes for mail delivery have KURAMA onboard. KURAMA-II [11] is designed for such purpose. KURAMA-II stands on the architecture of KURAMA, but the in-vehicle part is totally redesigned.…”