only locations 1A and 1D exceeded 160 pCi/g TRU, and the others were lower, only locations 2A, 2B, 2F, 2G and 2H were sampled in the second iteration. If, of these, only 2H showed activity greater than 160 pCi/g, then only 3K and 3L would need to be sampled in the next iteration. This was modified in practice to speed the process. If the general direction of the contamination pattern was evident, but not the extent, two iterations of samples would be taken at the same time in an attempt to "second-guess" the boundary's location. This modification was fairly successful in reducing the number of sampling missions. The sampling distances were designed such that any four adjacent points in the same iteration together represent 1/16 hectare. Adjacent points in different iterations are also easily combined to form sample sets representing 1/16 hectare. From these combinations, it can be determined whether any 1/16 hectare has average TRU exceeding 160 pCi/g. This design also helps to determine the smallest area which, when excised, would reduce all 1/16 hectare average TRU activities below 160 pCi/g. This smaller area would be recommended to JTG for excision. () Wi ©) A 3A FISSION PRODUCTS SAMPLING LOCATION FIRST ITERATION SAMPLES SECOND ITERATION SAMPLES THIRD ITERATION SAMPLES 3B A 2A 3L 3K 3 1c a O 3H A A 2E oO 3I 12.5 m 3F a 2F O A 2D O i 2G 3E a 1D A © 1B | 2H O A 2C Oo 1A A 3D A 2B O A 3C A A 3G A FIGURE 8-18-1. SUBSURFACE ITERATIVE SAMPLING DESIGN B-18-2