7__ surfaces and configurations for each ship will be averaged and used to determine on average cffectivoness for various types of ships structures and configurctions, (See Tab A-14 for details and rosults), No over-all average is contemplated because it vould be meaningful only for these specific test ships, 3.3.2 Washdorm Effectiveness in Reducing the Gamma Radiation Field on the Ships Weather Surfaces The results of Tab A-6 will be used to caleulete tho relative difforence in gamma dose rate attributable to surface con- taminent on the two ships at any given time and locations. This reletive difference vill be used as tho second definition of washdorm effectiveness ond will be plotted as a function of time, (Sec Tab A-1 for Weshdown System, Tab A-3 for location, and Tab A-13 for results), In addition to dotermination of cffectiveness cat each station, an average effectivoness for various types of ships structures cand con= figurations will be detormined in a manner similar to that employed in paragreph 3.3.1. 3.3.3 (Sce Tab A-14 for details and results), Uniformity of Weshdowm Effoctiveness It is desired to estimate the uniformity of the washdovn effectiveness in reducing the surfece contaminent in relation ‘to the weshdotm nozzle locetions, Since a deteiled survey vith directional gamme radiation detectors is impractical,it is necessary to use the less reliable Beta radietion surfaco survey data of Tab A-7, Because of uncertaintics in beta decay and absorption, and boceuse there twill be a significant time interval betiiecn the surveys on tho two ships, absolute values of effectiveness vill not be considored,. Hovever, on any one ship the measurement time differonces will be negligible, thorefore a common unknown decay factor could bo applicd to bring ell readings to a common base time, If the retio of values, from Tab A-7, for Transit ABLE with respect to Transit BAKER for each locetion are comparcd to the highest ratio found, then this retio of ratios will have climineted the unknowm decey factor but will still include the uncertainty due to ebsorption, Assuming the absorption error to be minor, we heve the relative values of fractions of betaemitting contaminsnt remaining, These relrtive values will be plotted on sketches of test areas shoving nozzle locations, (See Tab A-15 for results). ST. LOUIS FRC 3.3.4 upon Limitrtions Imposed the Exporimental Dat Results of Tab A-9, A-10, A-1l and other information on ships course ond atmosphcric conditions will be used to dctermine 0 ane, YO