Comparison of U.S. NRC'S Rascal Emergency Response Code with Noaa's Hyrad Dispersion Model and Tracer Experimental Data.

The U.S. National Oceanic and Atmospheric Administration's Field Research Division uses the HYRad-HYSPLIT dispersion model to assess hypothetical accidental releases of airborne radioactive materials at the Idaho National Laboratory in southeastern Idaho.

Radioactive cesium isotope ratios as a tool for determining dispersal and re-dispersal mechanisms downwind from the Nevada Nuclear Security Site.

Fractionation of the two longer-lived radioactive cesium isotopes ((135)Cs and (137)Cs) produced by above ground nuclear tests have been measured and used to clarify the dispersal mechanisms of cesium deposited in the area between the Nevada Nuclear Security Site and Lake Mead in the southwestern United States. Fractionation of these isotopes is due to the 135-decay chain requiring several days to completely decay to (135)Cs, and the 137-decay chain less than one hour decay to (137)Cs. Since the Cs precursors are gases, iodine and xenon, the (135)Cs plume was deposited farther downwind than the (137)Cs plume.