Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Terada, Hiroaki; Chino, Masamichi
Proceedings of 2nd International Conference on Radioactivity in the Environment, p.15 - 18, 2005/10
The previous version of Worldwide version of System for Prediction of Environmental Emergency Dose Information (WSPEEDI) has been composed of mass-consistent wind field model WSYNOP and particle dispersion model GEARN. Because WSYNOP has no capability to predict meteorological fields, its accuracy and resolution depends on meteorological input data, and it is impossible to treat physical processes realistically. To improve these problems, an atmospheric dynamic model MM5 is introduced and applied to the Chernobyl accident for the verification. Two calculation cases are conducted, CASE-1 a calculation for European region Domain-1, and CASE-2 a domain nesting calculation for Domain-1 and the region around Chernobyl Domain-2. The air concentration and surface deposition of 
Cs calculated by CASE-1 agree well with the measurements by statistical analysis and comparison for the horizontal distribution. In the result of CASE-2, the detailed distribution of surface Cs deposition around Chernobyl which was impossible to calculate in CASE-1 is predicted with high accuracy.
Cs deposition due to the Chernobyl nuclear accidentTerada, Hiroaki; Chino, Masamichi
Journal of Nuclear Science and Technology, 42(7), p.651 - 660, 2005/07
Times Cited Count：18 Percentile：74.82(Nuclear Science & Technology)The prediction performance of WSPEEDI (Worldwide version of System for Prediction of Environmental Emergency Dose Information), which consists of the atmospheric dynamic model MM5 and the Lagrangian particle dispersion model GEARN-new, is evaluated by measurements of precipitation and surface deposition of Cs over Europe during the Chernobyl accident. It is concluded that MM5/GEARN-new can predict Cs deposition distribution with good accuracy when accurate precipitation is predicted by using a explicit scheme on cloud microphysics with ice phase processes. High-resolutional calculation is also conducted for the area surrounding Chernobyl by a nesting method. MM5/GEARN-new can predict quite a realistic distribution of Cs deposition around Chernobyl which was not calculated by the previous version.
Terada, Hiroaki; Furuno, Akiko; Chino, Masamichi
Journal of Nuclear Science and Technology, 41(5), p.632 - 640, 2004/05
Times Cited Count：22 Percentile：79.05(Nuclear Science & Technology)The new version of WSPEEDI (Worldwide version of System for Prediction of Environmental Emergency Dose Information) is developed by introducing the combination of models, the atmospheric dynamic model MM5 and the Lagrangian particle dispersion model GEARN-new to improve the prediction capability. One of the improvements by the new system is that Environmental contaminations in multi domains are predicted simultaneously, and the other is that more precise physical processes are considered by using predicted meteorological conditions with high resolution in time and space. The performance of the system is evaluated for the test calculations of hypothetical nuclear accident in the East Asia region and the Chernobyl accident. The results of test calculation in East Asia seem to be reasonable and the calculated surface air concentrations of Cs from Chernobyl show good agreement with measurements.
Terada, Hiroaki; Furuno, Akiko; Chino, Masamichi
Proceedings from the International Conference on Radioactivity in the Environment (CD-ROM), 4 Pages, 2002/09
The present study aims to expanding the capability of WSPEEDI, so that it can be applied to atmospheric releases of radionuclides in the world for terrorist attack as well as nuclear accident. A terrorist attack would be possible in any time, any place and any scale. Altough WSPEEDI has already had a function to acquire global meteorological forecasts to generate a geographical map at arbitrary region in the world, it had no capability for simultaneous multi-scale predictions. Thus, the combination of models, non-hydrostatic meteorological model MM5 and atmospheric dispersion model GEARN, is introduced to WSPEEDI. MM5 can forecast local and regional meteorological condition simultaneously by domain nesting calculations. By the input of meteorological condition generated by MM5, GEARN can forecast multi-scale environmental contaminations considering detailed boundary layer and precipitation processes. Using this improved WSPEEDI, we made test calculations assuming a nuclear accident or terrorist attack in Asia.
Nagai, Haruyasu; Chino, Masamichi; Yamazawa, Hiromi
Nihon Genshiryoku Gakkai-Shi, 41(7), p.777 - 785, 1999/07
Times Cited Count：13 Percentile：68.49(Nuclear Science & Technology)no abstracts in English
