APPENDIX C PROTOCOL FOR 241an VARIABILITY-WITH-DISTANCE STUDY Prepared by R. O. Gilbert and E. H. Essington August 10, 1976 INTRODUCTION The objective of this study is to obtain data that will be useful in determining the correlation structure between Pu concentrations collected at various distances. This information is necessary in order to determine whether Universal Kriging will be a useful technique for estimating Pu contours in soil. Two series of surface (0-5 cm) soil samples are to be collected along two straight lines in Area 13, Project 57 using the standard NAEG 5-in.-diamete1r ring. Sixty samples are to be collected on each line for a total of 120 samples. Two aliquots from each sample are to be analyzed for 241 am using the Ge(Li) system at REECo for a total of 240 analyses. FIDLER readings are to be taken along the line as indicated below. PROCEDURE 1. The spacing and location of surface (0-5 cm) is as follows: soil samples along Line 1 Collect 15 groups of 4 adjacent samples along a line beginning at Nevada Grid Coordinate N935900, E721100 and proceeding due east along the line N935900. Separate the first sample in each group of 4 by 20 ft. That is, collect the first sample in the first group at location N935900, E721100, the first sample in the second group 20 ft due east at location N935900, E721120,..., the first sample in the last (15th) group at location N935900, E721380. 2. The spacing and location of surface (0-5 cm) soil samples along Line 2 is as follows: Collect 15 groups of 4 adjacent samples along a line beginning at location N939700, E718600 and proceeding due east along the 445