Measuring and modeling the transport and dispersion of kRYPTON-85 1500km from a point source

Abstract

The 1974 long-range dispersion experiment in which Kr-85 was released from the Idaho National Engineering Laboratory and sampled twice-daily at 13 locations in the midwestern U.S. was considered inconclusive because very few distinct plumes were observed during the two month experimental period. These data have been reanalyzed and compared with model-calculated concentrations after filtering undesired noise by using the coherence of the measured and calculated air concentration time series as a weighting function. The dispersion model, which is responsive to the effects of wind shear, performed exceptionally well at the more southern samplers in Oklahoma and Kansas. At the northern sites the Kr-85 from Idaho was masked by fluctuations in background concentration as well as small local sources, both of which produced concentration fluctuations of similar magnitude to the Idaho source. Further, the transport of Kr-85 from Idaho to the northern samplers involved more complicated meteorological regimes than could be accounted for by a simple Lagrangian transport model.