road leaves 66% of the activity which would be a contribution of 0.66 X% 3.58 pCi/g and equal to a radiation field of 2.37 pCi/g. When combined with the 17.02 pCi/g the IMP should measure 19.39 pCi/g. It actually saw 18.9 pCi/g or within 2.6% of the 19.39 pCi/g value. The effect of the IMP moving back and forth over the road 10 times was small; therefore, the movement of the IMP along the road to make a measurement is very small. The use of a bulldozer to clear a road of brush by scraping a blade along the surface of the soil does not effect the IMP measurements appreciably. Only when the road has been bladed deeply would there be a significant change in the radiation field. Finally, in some of the debris removal stations, such as 1-N-1 and 2-8-1 where the brush was cleared away by the dozer, one can expect a decrease in the radiation from the movement back and forth of the dozer tracks. In the experiment, dozer tracks were made in the north and south direction and then in the east and west direction. The result was a decrease in the radiation field of 16.4%, but at station 1-N-1 and 2-S-1 the brush was removed, thereby increasing the radiation field because of the previous brush attenuation of 14.7%. This result offset the decrease and leaves us with the knowledge that the metal debris removal was responsible for the reduction in the 24l4m, The final item one can see in this soil disturbance experiment was the very large effect when the dozer made circles. Keeping one track slow and the other rapid causes a vigorous deep churning motion of the soil. TABLE B-4-1. RESULTS OF DEBRIS CLEARING ON PEARL With Without (pCi/g) (pCi/g) Debris Change 32.2 21.5 17.8 62.3 22.7 11.6 14.8 19.1 -30 -46 -17 -69 23.8 14,2 19.3 91.7 21.2 11.1 17.7 34.9 -11 -22 ~8 62 241 4m 155py 41.3 23.7 25.9 15.1 -37 -36 60Co 37.3 1-N-1 241 4m 155 Ey 137 Cs 80Co Debris (%) 9-S-1 241 am 159py 13%Cs 60Co 5-S-3 13%Cs 36.3 27.4 28.8 B-4-2 -25 -23