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Dispersion Coefficients for Coastal Regions (!1vL- L/0;z7 /- NUREG/CR-3149 PNL-4627 Dispersion Coefficients for Coastal Regions Prepared by B. L. MacRae, R. J. Kaleel, D. L. Shearer/ TRC TRC Environmental Consultants, Inc. Pacific Northwest Laboratory Operated by Battelle Memorial Institute Prepared for U.S. Nuclear Regulatory Commission NOTICE This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, or any of their employees, makes any warranty, expressed or implied, or assumes any legal liability of re ­ sponsibility for any third party's use, or the results of such use, of any information, apparatus, product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights. Availability of Reference Materials Cited in NRC Publications Most documents cited in NRC publications will be available from one of the following sources: 1. The NRC Public Document Room, 1717 H Street, N.W. Washington, DC 20555 2 The NRC/GPO Sales Program, U.S. Nuclear Regulatory Commission, Washington, DC 20555 3. The National Technical Information Service, Springfield, VA 22161 Although the listing that follows represents the majority of documents cited in NRC publications, it is not intended to be exhaustive. Referenced documents available for inspection and copying for a fee from the NRC Public Docu­ ment Room include NRC correspondence and ir.ternal NRC memoranda; NRC Office of Inspection and Enforcement bulletins, circulars, information not1ces, inspection and investigation notices; licensee Event Reports; vendor reports and correspondence; Commission papers; and applicant and licensee documents and correspondence. The following documents in the NUREG series are available for purchase from the NRC/GPO Sales Program: formal NRC staff and contractor reports, NRC-sponsored conference proceedings, and NRC booklets and brochures. Also available are Regulatory Guides, NRC regulations in the Code of Federal Regulations. and Nuclear Regulatory Commission Issuances. Documents available from the National Technical Information Service include NUREG series reports and technical reports prepared by other federal agencies and reports prepared by the Atomic Energy Commission, forerunner agency to the Nuclear Regulatory Comm1ssion. Documents available from public and special technical libraries include all open literature items, such as books, journal and periodical articles, and transactions. Federal Register notices, federal and state legislation, and congressional reports can usually be obtained from these libraries. Documents such as theses. dissertations, fore1gn reports and translations, and non·N RC conference proceedings are available for purchase tram the organizatiOn sponsoring the publication cited. Single copies of NRC draft reports are available free upon written request to the Division of Tech· nical Information and Document Control, US. Nuclear Regulatory Commission, Washington, DC 20555. Cop1es of industry codes and standards used in a substantive manner in the NRC regulatory process are maintained at the NRC Library, 7920 Norfolk Avenue, Bethesda, Maryland. and are available there for reference use by the public. Codes and standards are usually copyrighted and may be purchased from the ongtnatlng organization or, if they are Amencan National Standards. from the American National Standards Institute. 1430 Broadway, New York, NY 10018. GPO Pnnted copy pnce $4 ::..• .:....:::.7 5 __ NUREG/CR-3149 PNL-4627 RB Dispersion Coefficients for Coastal Regions Manuscript Completed: February 1983 Date Published: March 1983 Prepared by B. L. MacRae, R. J . Kaleel, D. L. Shearer, TRC TRC Environmental Consultants, Inc. Englewood, CO 80111 Under Subcontract to Pacific Northwest Laboratory Richland, WA 99352 Prepared for Division of Health, Siting and Waste Management Office of Nuclear Regulatory Research U.S. Nuclear Regulatory Commission Washington, D.C. 20666 NRC FIN 82384 TABLE OF CONTENTS SECTION TITLE PAGE ACKNOWLEDGMENTS EXECUTIVE SUMMARY . vii 1.0 INTRODUCTION • . 1 2.0 DATA BASE . 3 2 .1 OVERVIEW • • • • • • • • • • • • • • • • 3 2.2 CRITERIA FOR SELECTION OF DATA SETS ••••• 3 2.3 DESCRIPTION OF SELECTED DATA SETS •••••• 4 3.0 METHODS • • • • • • • • • • • • • • • • • • • • • 11 3.1 EXTRACTED DISPERSION COEFFICIENTS • . 11 3.2 DERIVATION OF HORIZONTAL DISPERSION COEFFICIENTS 18 3.3 DERIVATION OF VERTICAL DISPERSION COEFFICIENTS . 23 4.0 RESULTS • • • • • • • • • • • • • • • • • • • • • 29 4.1 COMPLEX TERRAIN/CONTINUOUS SOURCE •••••• 31 4.2 FLAT TERRAIN/CONTINUOUS SOURCE •••• 33 4.3 FLAT TERRAIN/INSTANTANEOUS SOURCE • • ••• 33 4.4 ELEVATED SOURCE/PLUME DOWNWASH ••••••••• 33 4. 5 SUMMARY OF RESULTS • • • • • • • • • • • • • • • 33 5.0 CONCLUSIONS AND RECOMMENDATIONS . 38 REFERENCES • • • • • • • • • • • . 40 iii ACKNOWLEDGMENTS The work reported herein was supported by Pacific Northwest Laboratory, operated by Battelle Memorial Institute, under subcontract B-C3061-A-H. The programmatic direction and technical guidance of Dr. Ronald K. Hadlock, Manager, Applied Meteorology & Emission Assessment, Geosciences and Engineering Department, PNL, contributed significantly to the preparation of this report. The Earth Sciences Branch, Division of Health, Siting, and Waste Management, Office of Nuclear Regulatory Research, U.S. NRC, funds PNL under FIN B2384 to conduct a program entitled "Atmospheric Dispersion Data Assessment," of which this report is a part. The useful and relevant perspective of Dr. Robert F. Abbey, Jr., the NRC technical contract monitor, served to focus the effort on NRC's particular needs in the area of atmospheric transport and diffusion in shoreline environments. The contributions of Drs. Hadlock and Abbey are gratefully acknowledged. v EXECUTIVE SUMMARY The study being reported here was sponsored by the U.S. Nuclear Regulatory Commission (NRC). It has been directed toward obtaining and presenting atmospheric dispersion coefficients representative of coastal regions from previously conducted field measurement programs. This was done in an attempt to minimize the need to generate new data, as well as to improve the measurement programs that may still be required. In total, some 495 individual tracer experiments obtained from nine field measurement programs, comprised the data base. Coefficient curves presented here have been compiled from these data to comprise a compendium of dispersion coefficients representative of coastal regions within the limits of currently available historical field measurements. The following conclusions are made from the results of this analysis: • good agreement is evident between the Pasquill-Gifford coefficient values and those derived in this study from tests performed using continuous emission sources located in flat terrain; • results obtained from tests in complex terrain indicate a greater degree of turbulence than those from flat terrain as the coefficient values are greater in magnitude for each stability class and downwind distance; • instantaneous (puff) releases experience a different spectrum of turbulent eddy sizes than do continuous (plume) emission releases, as evidenced by the lower dispersion coefficients derived from experiments using instantaneous releases; • a decrease in plume growth rates with increasing downwind distance is indicated by the leveling off of many of the dispersion coefficient curves at downwind distances greater than one kilometer; • a smaller range of coefficient values, between the most stable cases and the most unstable, is indicated by these results as compared to the Pasquill-Gifford curves. Dispersion conditions for daylight hours and continuous emissions in a variety of terrain conditions are well represented by the existing data set. However, there are coastal dispersion conditions likely to be vii of critical interest to the NRC that are poorly represented. Based on this; the following recommendations are made for future work on coastal dispersion: • detailed measurements of vertical dispersion in coastal regimes should be performed; • detailed measurements of instantaneous point source emissions, in a variety of terrain conditions, should be performed; • more information is needed regarding dispersion in stable atmospheres in coastal regions; • better information on dispersion during nonsteady-state conditions, and especially conditions which are uniquely coastal in nature (such as the diurnal sea/land breeze cycle, and the turbulent internal boundary layer), should be obtained; • measurements of dispersion at very short (less than one kilometer) or very long (greater than five kilometers) downwind distances should be performed; • a standardized method of stability measurement and classifications should be employed to insure that the results from future measurment programs are easily intercomparable. viii 1.0 INTRODUCTION The Nuclear Regulatory Commission (NRC) has undertaken an extensive atmospheric dispersion research and measurement program from which it is intended will emerge improved predictive techniques for employment in licensing decisions and for emergency planning and response. Through this program the NRC has conducted field measurement programs over a wide range of geographic and topographic locations, and are using the acquired tracer and meteorological measurements to evaluate existing dispersion models and prediction techniques, and to develop new techniques when necessary. The NRC has recognized however, that extensive
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