Representative Atmospheric Plume Development for Elevated Releases

doi:10.2172/1122312

GSTDTAP > 地球科学

DOI	10.2172/1122312
报告编号	PNNL-23176
来源ID	OSTI ID: 1122312
	Representative Atmospheric Plume Development for Elevated Releases
	Eslinger, Paul W.; Lowrey, Justin D.; McIntyre, Justin I.; Miley, Harry S.; Prichard, Andrew W.
	2014-02-01
出版年	2014
页数	21
语种	英语
国家	美国
领域	地球科学
英文摘要	An atmospheric explosion of a low-yield nuclear device will produce a large number of radioactive isotopes, some of which can be measured with airborne detection systems. However, properly equipped aircraft may not arrive in the region where an explosion occurred for a number of hours after the event. Atmospheric conditions will have caused the radioactive plume to move and diffuse before the aircraft arrives. The science behind predicting atmospheric plume movement has advanced enough that the location of the maximum concentrations in the plume can be determined reasonably accurately in real time, or near real time. Given the assumption that an aircraft can follow a plume, this study addresses the amount of atmospheric dilution expected to occur in a representative plume as a function of time past the release event. The approach models atmospheric transport of hypothetical releases from a single location for every day in a year using the publically available HYSPLIT code. The effective dilution factors for the point of maximum concentration in an elevated plume based on a release of a non-decaying, non-depositing tracer can vary by orders of magnitude depending on the day of the release, even for the same number of hours after the release event. However, the median of the dilution factors based on releases for 365 consecutive days at one site follows a power law relationship in time, as shown in Figure S-1. The relationship is good enough to provide a general rule of thumb for estimating typical future dilution factors in a plume starting at the same point. However, the coefficients of the power law function may vary for different release point locations. Radioactive decay causes the effective dilution factors to decrease more quickly with the time past the release event than the dilution factors based on a non-decaying tracer. An analytical expression for the dilution factors of isotopes with different half-lives can be developed given the power law expression for the non-decaying tracer. If the power-law equation for the median dilution factor, Df, based on a non-decaying tracer has the general form Df=a(Ăt)^(-b) for time t after the release event, then the equation has the form Df=e^(-Îťt)ĂaĂt^(-b) for a radioactive isotope, where Îť is the decay constant for the isotope.
英文关键词	Atmospheric dispersion radiation transport modeling HYSPLIT
URL	查看原文
来源平台	US Department of Energy (DOE)
引用统计
文献类型	科技报告
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/6687
专题	地球科学
推荐引用方式 GB/T 7714	Eslinger, Paul W.,Lowrey, Justin D.,McIntyre, Justin I.,et al. Representative Atmospheric Plume Development for Elevated Releases,2014.