TRANSURANIUM ELEMENTS AROUND THE
ROCKY
FLATS
PLANT
page 2
to prevent spread of the plutonium bearing soil and
four water sample wells for confirmation that no downward 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 subsequent 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 plutonium 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)
estimates,
accurate.
the
of plutonium.
HASL data
is
To reduce conflicting
considered
The HASL data suggest that of the
are on
dicate
be
the most
11 Ci released,
site.
Of the amount off site,
that about 1.5 Ci are included
0.003 mCi/m2
to
8.6 Ci
the HASL data inin the area above
(3mCi/km2) which extends to about 5 miles