TRANSURANIC AND TRACER SIMULANT RESUSPENSION 25 7 



^^^Pu and ^^^Cs. The range for ^^^Pu was from less than radiochemical analytical limits 

 to 6.9 X 10^^ MCi/g of surface solids. The maximum reported ■^^^Pu concentrations for 

 surface solids were within the 200 Areas. The minimum ^'^^Pu concentrations on surface 

 solids reported (Corley, Robertson, and Brauer, 1976) in the literature occurred at 19 to 

 34 km from Hanford. Surface contamination levels were reported only out to 34 km. The 

 ^^^Cs concentrations ranged from 3 x 10~^ to 2.5 X 10^ ■^ i^Ci/g. These contamination 

 levels are used in Table 4. 



Although there are only limited data for comparing the ratio of airborne soil to that 

 of surface soils, these ratios were calculated from the available Hanford data summarized 

 in Table 4. Table 4 is a summary of Hanford airborne solids concentrations (Sehmel, 

 1977c) for ^^^Pu, ■^'*' Am, and '^^Cs. Plutonium and americium concentrations were 

 obtained from Figs. 14 and 19. Table 4 also shows ground-surface ratios of airborne 

 solids. From these, ratios of airborne solids were determined. The last column shows 

 maximum ratio ranges. Ratios vary from 1 X 10"^ to 1.5 x lO"', which indicates that 

 contamination levels on airborne solids can be either much less than or much greater than 

 contamination levels on contaminated surface solids. 



Caution should be used in interpreting these data. The ground-surface contamination 

 data are limited in quantity and were not necessarily obtained in the same areas where 

 resuspension experiments were performed. Airborne-particle and ground contamination 

 levels are shown for the BC-Crib Area in the central columns of Table 4. In this case the 

 BC-Crib Area was sampled (Mishima, 1973) in ten 1-m^ areas. Data from these 10 squares 

 indicated that surface contamination levels varied by about a factor of 100. Ratio ranges 



TABLE 4 Ratio of Airborne to Ground -Surface Radioactivity Concentrations 



per Gram of Solids at Hanford 



*Ratios from positive reported ground contamination values. 



tLAL, less than radiochemical analytical limit; NR, surface contamination levels not reported for 

 all areas. If available, data for each area are reported separately. 



