TRANSURANIUM ELEMENTS AROUND THE ROCKY FLATS PLANT
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from the Plant boundary.
About 1.9 Ci are spread at
distances far from the Plant at levels equal to or
below fallout of 0.0015 mCi/m2 (1.5 mCi/km2).
Of the
total 8.6 Ci included on-site, the HASL data indicate
that about 1.7 Ci are included in the area that was
covered with asphalt.
Analyses for plutonium and americium in 175 soil samples
collected on private and municipal lands around the
Rocky Flats Plant have not revealed concentrations
greater than the EPA Proposed Screening Level.
Evaluation of analyses of 27 soil samples, collected for
purposes of certain land litigation indicates that soil
on private land east of the Plant contains levels less
than 50% of the screening level.
One sample from 14
collected on City of Broomfield land west of Great
Western Reservoir contains 118 mCi/km2 plutonium, which
is 59% of the screening level, but adjacent samples
indicate less than 50 mCi/km2.
The HASL data indicate plutonium levels in the range
between 50 and 500 mCi/km2 for the soil in the area
near the Plant's eastern boundary.
Access to this area
is not open to the general public and is controlled by
a barbed wire fence and locked gates.
Analyses of soil
samples by Rockwell at 7 sites in this area confirm the
HASL measurements which indicate the presence of plu-
tonium greater than the EPA screening level.
The plutonium concentrations in the soil from one 10 acre site
are in the range from 80 to 252 mCi/km2 with a median
of 108 mCi/km2.
The median values for the other sites
fall within the range from 3 to 34 mCi/km2.
On the basis of the EPA Guidance Technical Assessment,
the above-mentioned evaluation of additional soil data
and airborne plutonium concentration data, there will be
no impact on current operations at Rocky Flats if the
Proposed Guidance is finalized.
There is no need (based
on EPA criteria) for decontamination of onsite lands
other than those actions currently planned for other
reasons.
If the EPA guidance were ever to apply to
onsite property then the cost could be substantial if
removal were required.