254 TRANSURANIC ELEMENTS IN THE ENVIRONMENT 



10" 



10" 





< 



o 

 z 

 o 

 o 



10" 



o 



^ 10"^ 



a. 



IXI 



z 



QC 

 O 

 CD 



10"«:r 



M I I I I I I I M I I M M I I M ! M M I M I I I I M M I I M 



^^^Pu at 6.1-m height 



239 



238 



Pu 



Pu 



■♦■ U-Pond area 



I 



622 R 



near HMS tower 



10" 



Q I *l I I I I I I I I 1 I I I I I I I M I I I I I I I I I I I M I I I I I I I 



I I I I I 



A J |J A J O |J A J |J A J 

 1972 1973 1974 1975 



DATE 



Fig. 14 Range of plutonium concentration on airborne solids at on-site Hanford 

 resuspension sites. 



for a 5-cm sampling depth are summarized in Table 1 for sampling sites near sites A, AB, 

 and B. Ground-surface ^^^Pu/^'^^Pu ratios are also shown. 



Ground and airborne plutonium soil-sample results are compared in Table 2 for both 

 ^^^Pu and ^^^Pu. Comparisons are for plutonium in ground-surface samples 5 cm deep 

 vs. airborne nonrespirable particle concentrations in particle diameter ranges. Airborne 

 concentrations were taken from Figs. 11 and 12 data limits. From these data activity 

 ratios of airborne to surface concentrations (microcuries per gram) were calculated. Only 

 the maximum ranges are reported. Maximum ranges of the ratio of airborne/ground- 

 surface soil concentrations are shown in the last two columns. These ratios range from 

 1 X 10"^'* up to 2. Thus in hazard evaluations (Johnson, Tiball, and Severson, 1976) one 

 might consider maximum plutonium concentrations on airborne soil to be comparable to 

 plutonium concentrations on ground-surface soils. This is indicated by the ratio 2. 

 However, in most cases plutonium concentrations on airborne soil were significantly less 

 than those on ground-surface soils. 



