TRANSURANIUM ELEMENTS AROUND THE ROCKY FLATS PLANT . NX page 2 to prevent spread of the plutonium bearing soil and four water sample wells for confirmation that no downwaxrd migration was occuring were completed in November 1969. After a fire on May 11, 1969 at Rocky Flats, studies were conducted by the Colorado Committee on Environmental Information (CCEI) and by the Health and Safety Laboratory (HASL) of the USAEC, concerning the possible release of plutonium from the fire. These investigations detected measurable quantities of plutonium in the soil around the Rocky Flats Plant. Concentrations of plutonium in soil at Rocky Flats have also been estimated by the Colorado Department of Health (CDH), Rockwell International, ° Jefferson County Health Department, and private housing developers. In general, measurements made by the different groups have shown similar surface plutonium levels. (but not identical) results for The HASL data indicate that releases from past operations have amounted to about 11 curies of plutonium, approx- imately 99% of which was leakage from drums in the storage area. The epicenter of the isopleth map shows that the contamination can not be attributed to the May 1969 fire but is due to resuspension and redistribution of contaminated soil from the oil drum storage area. During the removal of the corroded drums and the sub- sequent covering operations, some radioactive material was resuspended and distributed by wind action to the east of the storage area. The HASL estimate of the total amount of plutonium dispersed by the oil leaks (11 Ci) is higher than the estimate of the total amount of plu- tonium available to be dispersed. The potential amount was estimated by Rocky Flats on the basis that the 5000 gallons of oil that leaked from the drums contained 86 grams (5.3 Ci) of plutonium. estimates, accurate. To reduce conflicting the HASL data is considered to be the most The HASL data suggest that of the 11 Ci released, 8.6 Ci are on site. Of the amount off site, the HASL data indicate that about 1.5 Ci are included in the area above 0.003 mCi/m2 (3mCi/km2) which extends to about 5 miles ‘