TREATMENTS FOR FARMLAND CONTAMINATED WITH RADIOACTIVE MATERIAL 9 



tamination quickly or prevent its spreading to come primarily from external gamma radiation, 

 other areas. Fallout on sparsely populated farmland would 

 In case of widespread contamination after a contribute relatively little external gamma radi- 

 nuclear attack, decontamination effort should be ation to the whole population. It would con- 

 concentrated in densely populated areas. For tribute more radiation internally through the 

 the population as a whole, this would give the entry of strontium-90 and other fission prod- 

 greatest reduction in radiation dose, which would nets into the food chain. Thus, the probable pur- 



Table 3. — .4 compiirixon of methods for remoring soil surface contamination in cold weather 



Effort required — Effect on 



Condition of Implement Removal of For For soil 



surface radioactivity ' removal ' disposal ' productivity ' 



Loose snow 2 to 7" deep Motor grader Poor to good Fair Fair Good. 



Do. Carryall scraper Fair Fair Good Good. 



Do. Bulldozer Fair Fair Fair Good. 



Do. Rotary snow blower Fair Poor Fair Good. 



Loose snow 7 to 12" deep Snow plow Good Good Poor Good. 



Do. Motor grader Good Fair Poor Good. 



Do. Carryall scraper Fair Fair Fair Good. 



Do. Rotary snow blower Poor to good Poor Poor Good. 



Packed snow Motor grader Fair Fair to poor Fair Good. 



Do. Rotary -broom sweeper Fair Fair to poor Good Good. 



Do. Vacuumized sweeper Poor to fair Poor Good Good. 



Loose snow on Motor grader Poor to fair Poor Fair Good. 



packed snow. 



Frozen loose snow Snow plow Poor Good Fair Good. 



on packed snow. 

 Frozen ground Jlotor grader Poor Poor Fair Good. 



Do. Rotary-broom sweeper Fair to good Poor to fair Good Good. 



Do. Vacuumized sweeper Poor to fair Poor to fair Good Good. 



Thawing ground Motor grader Good Poor Poor Good to 



fair. 



Do. Carryall sweeper Good Poor Fair Good to 



fair. 



Do. Bulldozer Good Poor Poor Good to 



fair. 



Do. Rotary -broom sweeper Poor Fair Good Good. 



' Rating of removal of radioactivity : Good — > 95 percent removal. 



Fair — 7.5 to 95 percent removal. 

 Poor — <; 75 percent removal. 

 "Rating of removal effort; Good — > 5 acres per hour. 



Fair — 1 to 5 acres per hour. 

 Poor — < 1 acre per hour. 

 " Rating of disposal effort : Good — additional loading and hauling effort minimal. 



Fair — considerable effort in loading and hauling. 

 Poor — very great loading and hauling effort. 

 ' Rating of effect on soil productivity : Good — Increases or does not change productivity. 



Fair — Reduces productivity < 20 percent. 

 Poor — Reduces productivity > 20 percent. 



