ll. Discussion turned to sampling increment to be utilized. Increments discussed included the averaged 10 centimeter depth used for most of the available data; averaged 20 centimeter depth, based-on a nominal 6-inch cut capability for a dozer; and 20 centimeter increments with a specific The operations plan specifies 5 centimeter sample from each increment. Five 5 cm sample depth because of past experience at Nevada Test Site. centimeter depth samples will be the basis for certification of the condiDiscussion included tion of the islands upon completion of cleanup. the advantages and disadvantages of horizontal averagingversus vertical averaging for sampling. Discussion Consensus favored vertical averaging. also included the capability of the laboratory to analyze the samples Maximum capability would be about 150 samples per day for gamma produced. scan and gross alpha count plus about five percent radiochemical analysis. Other operations This level would not permit support of other operations. It was agreed could be supported at levels of 50 samples per day input. that gamma scan of samples at the laboratory could be used to select Other Only the "hot" samples would be analyzed. samples for analysis. samples would be held for future use depending on the outcome of the "hot" samples analysis. This technique was favored over using gamma scan on This sample site sidewalls and only sampling "hot" areas (see encl 9). concluded the first day's discussion. 12. Discussion resumed on 5 October. The chair outlined the two incremental sampling techniques discussed and proposed adoption of 29 cm sampling increments with a discrete 5 cm sample to be taken from each 20 cm increment. This technique should suffice for characterization and may also meet some certification requirements. The proposal was accepted. 13. The chair requested the group consider depth to which sampling should extend. Consensus indicated that a depth of 120 cm generally will suffice but that the option to go deeper should be left to field personnel. [It may be particularly desirable to go to greater sampling depths in areas of ground zeros, in burm or mound areas, and in ejecta areas near Cactus crater. The backhoe may not suffice for some of these depths (greater than 10 feet) and other equipment may be required. 14. tion. Discussion reverted to the sampling grid to be used for characterizaMr. Church proposed, for consideration, a 10 meter grid for the “hot'' areas (Fig/Quince and Cactus crater areas), and a wider spaced grid for the “cool'" area in between. Several members indicated their support for the half distance technique for initial exploration with grid size to be decided later based on data obtained from initial efforts. This lead to extensive discussion of desire for data versus reasonable expenditure of resources and purpose and extent of characterization. The chair maintained that characterization should be limited to determining the extent of known subterranean pockets and the extent of surface contamination areas. : CARRE sa. ee as 2 7 Pees “Pe. The effort should not extend to exploration to locate other RT rt . ITytes A eon . ABtet PEE . tee. . “ ~aNwT ee nee greeee rad " & .teres Bee4wees “7 Se ryt " ae wremane : arene es a we ‘ vs ORI . . . ; fal ~ a1 . m * av 4 . .