Estimated Inventory of 239- 240py for Vegetation in Activity Strata of Aged Fallout Areas ar NTS (Romney et al. 1976). Higher numbered activity strata are nearer ground zero. Table 1. ~ ~ - ny a Olen woman Ssss|s am old moo elS zine ole easels “ * Sess Ssa|s esses Ssssge _ = Ee +i ti aif +1 o4t 4il 44 +1 4b +1 tif at +hoet aL al ot a WA Ol ° oscoals % > and Lloyd (1974, 1975} in the Rocky Flat area gave resuspension factors ~ a ana . 5 S which are occasionally very strong and gusty. Environmental surviellance data strongly indicate that the movement of contaminated soil particles by wind was a major force causing the original dispersion of plutonium 5 The initial source of most of the outlying contamination at Rocky Flats was from leakage of cutting oil containing plutonium. Subsequent Ta te 5 > ele soa m A}-a oe mayen we o/s on ° io ed aa $6a/6 gx see > 4 e a 2 & d o a al oss uo 3 S 3 + a3 AN ddale into several ecosystem compartments within study plots. a some 96 to 98 percent of Data indicate the plutontum fn the ecosystem is associated OBR x ot unit mass in the grasses (Whicker 1973; Little 1976). rt tte ee a Se —_——— -—- “e soo 3 i 2 Healy (1974) completed a noble task of synthesizing into a Stgnitican ipnifi t eas CLSR ooo . +OocOo Oo -t cA O38 3 8 OFA OOAR oe +141 41 ae Hi tl tt 4 ~ | a ~ a) NAOD 7 ON o~ aa pa ry Pa a4 a a at 73 om] ee < z 3 * f€nvironmental studies at Rocky Flats by the group at Colorado State University have shown some movement of plutonium ° " “ a ® NnNoo ass a Hh +l th 4 nn a ve at and larger sot] grains. + & Tf a c “ v oe can sow ttt dH 269g a] + het source to suspendable material led to the concept that the resuspendable "hot" particles are agglomerates of small plutonium-containing particles 3 ge 5 studies by Nathans and Holland (1971) of the transformation from this toy OD aN +1 ti 41 41 coef Pe na e5 es mi = aot n S S8 | ~ . The Rocky Flats area 1s subject to winds from a barrel storage area (Krey and Hardy 1970; Whicker etal. 1973). 5 es nea Results from Additional measurements by Sehmel and Orgiil (1973) and Sehmel ranging from 10-9 to 1075 m-l. @ a iM —— +vO +H +1 a fa ze ! PS 8 a z wWoetm [Mm (Volchok 1971, 4 Om ~r nee aes 1972), 5 pm. - 3 NORA|S mean diameter of about 10 um es —_ =" po * . Sonen ST roy Size distribution stu cyclone and elutricator samples indicated median diameters of about & o fine soil particles from the soil surface. of all suspended particles containing plutonium indicated a geometric eseage|s ~ “soy "Teale ) cm x vee Waist aren + th +h 6 wanes HAN MO asarse Am Ol-s FSIS 4 ta aa ot Sars vas 1S sooty RS SR ope ~~ AatlR on 5 stots —— soy + aesa|s eesss a2aqce Am 3/3 & td 0 8 Sin 14 . 2 —_ * 4} aL 2 0 9 SIs ooolo ° ee & coe assis esooe 3 ls HH a AIS a r Studies of airborne particulates around a contaminated area at the | Rocky Flats Plant yielded an average resuspension factor of orn during an 8-month sampling period. This factor was near 1079 m for particulate material collected upon sticky paper exposed to suspenea e °. * n tx 23 wos ~ Op Esr aa “ed ~ ~ # + aA 5 species, Data APS, are piven and literature cited which show resuspension factors ranging from 10-10 to 10-4 ml for arid or semiarid environments, The higher values represent more unstable, cutdoor conditions, Langham (1969) used a value of 10-6 m-! in assessing limits for a weapons accident of the type simulated by the safety tests in which plutonfum was dispersed at NTS. A continuing study of resuspension at NTS test * Bases Bag e ye — § “| * 4 onanenal 4 aaee) Ss 4 eee 6 9 mo RP ~ p a 4 q 5 aT an os % ea ‘ name & mass aman a Sl asea u oa % w “. Hw w oe WD ae = nw w o Oo & o o eB oe 2 Be 2 ela .o 290 the greater surface area per treatise some of the early air sampling data obtained during the safety es Sd mn *nN a oe £ again probably as the result of shots at NTS, where plutonium was dispersed by chemical explosives. ~ S5,. 5) exa % da = Eat vegetation and small mammals are generally less than 1 percent. Findings indicate that most of the plutonium present in vegetation samples is superficial contamination resulting from the attachment of particles to biological surfaces. There is also some indication that grass species have higher concentration of plutonium than other 2 = woo About 1 to 3 percent appears to be assoctfated with root and Litter samples, while the amounts in standing tt og m 3 E with the 0-3 em depth of soil. a ee a “Tt 440 41 41 mal m oo BE fsi a2 | areas {s underway by elements of the Nevada Applied Ecology Group (Anspaugh et_al. 1974, 1974a, 1974b, 1974c, 1975). Resuspension ' factor values calculated from recent experiments now fa ll within the range of 10-11 to 1079 m-l compared to values of 10-10 to 10-6 m-l measured about 20 years apo at some NTS T. sites. Most oa f the total mass of suspendable material is found between diameters of 0.7 ym and 1S um (Bretthauer et al. 1974; Shinn and Anspaugh 1975}. Sttrdies by Tamura (1974, 1975, 1976), have shown that from 50 to 75 percent of the plutonium in soil samples collected from an aged fallout area at NTS is predominantly . 291