TRANSURANIC AND TRACER SIMULANT RESUSPENSION 261 



TABLE 5 Plutonium Concentration on Airborne Soil Collected 

 During Continuous Air Sampling at Rocky Flats 



*Respirable samples were collected for wind-speed increments rather than continuous sampling, 

 2 3 8 py ^2s less than radiochemical analytical detection limits, 1 (d/min) g" ' - 0.45 pCi/g. 



TABLE 6 Average Plutonium Flux Entering Cowl-Impactor 

 System During Continuous Air Sampling at Rocky Flats 



*Respirable is all material collected within a particle cascade impactor. 

 tLAL, less than radiochemical analytical limit. 



Average airborne plutonium fluxes entering cowl inlets at Rocky Flats were 

 calculated from airborne soil fluxes and plutonium concentrations on airborne soil. As 

 shown in Table 6, plutonium fluxes on both respirable and nonrespirable particles were 

 calculated. The calculation was based on collected plutonium, the sampling time, and the 

 cross-sectional area of the cowl inlet. The cowl-inlet diameter was 15.2 cm. The 

 maximum ^^^Pu flux was 1 x lO^^juCi m"^ day"\ and the minimum flux was 

 3 X 10^^ /iCi m~^ day"^^. On the basis of these limited data, these calculated fluxes 

 might be used to estimate the total plutonium fluxes over larger integrated areas. 

 However, such estimates should be made with caution since the flux variability at other 

 sites and evaluations is unknown. 



Average plutonium fluxes entering the cowl impactor system are used to estimate the 

 respirable fraction of airborne plutonium. Estimates given (Sehmel, 1976a) in Table 7 are 

 based on an isokinetic sampling assumption. Respirable fractions ranged from 3 to 98% of 

 total airborne plutonium. However, one should use these numbers with caution. Plu- 

 tonium collected v^thin particle cascade impactors contained particles of 7-, 3.3-, 2.0-, 



