B LEGAL NOTICE This report was prepared by Battelle as an account of sponsored research activities. Neither Sponsor nor Battelle nor any person acting on behalf of either: MAKES ANY WARRANTY OR REPRESENTATION, EXPRESSOR IMPLIED, with respect to the accuracy, completeness, or usefulnessof the information contained in this report, or that the use of any information, apparatus, process, or composition disclosed in this report may not infringe privately owned f:onts; or Assumes any liabilities with respect to the use'of, or damages resulting from the use of, any information, apparatus, process, or composition disclosed in this report. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply endorsement, recommendation, or favoring by Sponsor or Battelle.

No abstract

MASTEB under Contract 200-92-0503(CDC)/18620(BNW) DISTRIBUTION OF THIS DOCUMENT IS UNI.J_ Battelle _ ' Pacific NorthwestLaboratories Richland,Washington 99352 DISCLAIMER his report was pr,_paredas an account of work sponsored by an agency of the United States _overnment. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or _1 process disclosed, or represents that its use would not infrmge prwateiy°wned rights" Ref©r" ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Governmentor any agency thereof. I rN Station was moved: 3/61 Measurement height: 6.1 meters (20 feet). Wind roses: High-speed westerly or northwesterly winds up the Columbia gorge are most common here. Low speed winds are remarkablyuniform in their distribution. Figure 3.1 illustratesthe wind roses for this station.

Approximately 2.6 x 10(4) TBq (700,000 Ci) of 131I were released to the air from reactor fuel processing plants on the Hanford Site in southcentral Washington State from December 1944 through December 1949. The Hanford Environmental Dose Reconstruction Project developed a suite of codes to estimate the doses that might have resulted from these releases. The Regional Atmospheric Transport Code for Hanford Emission Tracking (RATCHET) computer code is part of this suite. The RATCHET code implements a Lagrangian-trajectory, Gaussian-puff dispersion model that uses hourly meteorological and release rate data to estimate daily time-integrated air concentrations and surface contamination for use in dose estimates. In this model, iodine is treated as a mixture of three species (inorganic gases, organic gases, and particles). Model deposition parameters are functions of the mixture and meteorological conditions. A resistance model is used to calculate dry deposition velocities. Equilibrium between concentrations in the precipitation and the air near the ground is assumed in calculating wet deposition of gases, and irreversible washout of the particles is assumed. RATCHET explicitly treats the uncertainties in model parameters and meteorological conditions. Uncertainties in 131I release rates and partitioning among the nominal species are treated by varying model input. The results of 100 model runs for December 1944 through December 1949 indicate that monthly average air concentrations and deposition have uncertainties ranging from a factor of two near the center of the time-integrated plume to more than an order of magnitude near the edge. These results indicate that approximately 10% of the 131I released to the atmosphere decayed during transit in the study area, approximately 56% was deposited within the study area, and the remaining 34% was transported out of the study area while still in the air.

Codes histogram A graphical representation of a distributionfunction using rectangles where the heights represent the number of observations occurring in each interval HMS Hartford, Washington, Meteorological Station isohyet A line drawn through geographic points recording equal amounts of precipitation for a specified period of time