Executive SummaryThis report for the fourth quarter, 2001, contains results from the Environmental Surveillance, Education, and Research (ESER) Program’s monitoring of the Department of Energy’s Idaho National Engineering and Environmental Laboratory’s (INEEL) offsite environment, October 1 through December 31, 2001. All sample types (media) and the sampling schedule followed during 2001 are listed in Appendix A. Specifically, this report contains the results for the following:
Air Sampling
Eleven
atmospheric moisture samples were obtained during the fourth quarter of
2001; one from Blackfoot, two from Rexburg, and four each from Idaho
Falls and Atomic City. All
sample results but one, collected from Rexburg in October, exceeded
their respective 2s values. All were well below the DCG value of 1 x 10-7 µCi/mL
(3.7 x 10-3 Bq/mL) for tritium in air. Details of atmospheric moisture sampling appear in section
3.2. The
ESER Program operates three PM10 samplers, one each at
Rexburg, Blackfoot, and Atomic City.
Sampling of PM10 is informational as no analyses are
conducted for contaminants. PM10
concentrations were well below all health standard levels for all
samples. The maximum
24-hour concentration was 77.8 µg/m3 on November 11, 2001,
in Blackfoot. Details of PM10
sampling appear in section 3.3. Precipitation Sampling Sufficient
precipitation occurred to allow collection of three monthly composite
samples each from Idaho Falls and from the Central Facilities Area (CFA)
on the INEEL, and six weekly samples from the Experimental Field Station
(EFS) on the INEEL. Tritium
was detected in nine samples: two from Idaho Falls, three from CFA, and
four from EFS. There is no DCG for tritium in precipitation, but in drinking
water it is 80,000 pCi/L (2,960 Bq/L).
The Safe Drinking Water Act sets a limit of 20,000 pCi/L (740 Bq/L)
for tritium. The levels of
tritium measured in fourth quarter precipitation samples were well below
the DCG value and the Safe Drinking Water Act Limit.
Details of precipitation sampling appear in section
4.1. Drinking Water Sampling
Surface Water Sampling Surface water samples were collected from five locations along the Snake River in the area where the Snake River Plain Aquifer discharges and from one upstream location in Idaho Falls. Samples were analyzed for the same constituents as drinking water. No sample had detectable concentrations of gross alpha activity. All samples had detectable levels of gross beta activity, which did not exceed the DCG and SDWA limit and were well within the range of past measurements. One sample, collected at Hagerman, had a detectable concentration of tritium, well within results measured in the past. The tritium result was far less than the DCG and SDWA limit for tritium in drinking water. Details of surface water sampling appear in section 4.3. Milk Sampling Milk
samples were collected weekly in Idaho Falls and monthly at eight other
locations around the INEEL. All
samples were analyzed for gamma emitting radionuclides with samples from
four locations (Arco, Dietrich, Howe, and Roberts) being analyzed for 90Sr.
Iodine-131 was detected in two samples, one from Roberts and one
from Idaho Falls. However,
reanalysis of these samples indicated no detectable levels of 131I.
Three samples had 137Cs concentrations greater than their 2s
uncertainty. Of the four
samples analyzed for 90Sr only the Arco sample did not yield
concentrations greater than their associated 2s value.
There are no established limits for 137Cs or 90Sr
in milk but, for comparison, the EPA has set the limit for 137Cs
in drinking water at 12 pCi/L and at 8pCi/L for 90Sr.
The Safe Drinking Water limit is based on a 4 mrem per year
maximum allowable dose and the assumption that two liters per day are
consumed. The maximum 137Cs
concentration measured in milk during the fourth quarter, 2001 was many
times lower than the 12 pCi/L limit and the
maximum 90Sr concentration was below the 8 pCi/L limit.
Details of milk sampling appear in section
5.1. Game Animal Sampling Three
large game animals were sampled during the fourth quarter of 2001.
All were killed as a result of vehicular collisions.
These accidents all involved mule deer (Odocoileus hemionus).
Thyroid, liver, and muscle tissue were collected from each
animal. None of the samples
contained measurable radionuclides above the 2s uncertainty or the MDC.
Details of large game animal sampling appear in section
5.2. Potato Sampling Potatoes
were collected from various growers in southeast Idaho as well as from
locations around the United States.
All samples were analyzed for gamma emitting radionuclides and 90Sr. No sample collected during the fourth quarter contained
levels of 90Sr or 137Cs above the 2s level.
Details of potato sampling appear in section
5.3. Waterfowl Sampling Fourteen
waterfowl were collected during 2001: three each from the Idaho Nuclear
Technology and Engineering Center (INTEC) percolation ponds and Market
Lake and four each from the Argonne National Laboratory-West (ANL-W) and
Test Reactor Area (TRA) ponds. All
were analyzed for gamma emitting radionuclides with a subset analyzed
for 90Sr, plutonium-238 (238Pu),
plutonium‑239/240 (239/240Pu), and americium-241 (241Am).
Seven ducks had
detectable levels of at least one radionuclide in edible tissue.
The highest concentrations were in the TRA samples. Duck hunting is not allowed on the
INEEL but a maximum potential exposure scenario to humans would be
someone collecting a duck directly from the TRA radioactive waste ponds
and immediately consuming all muscle, liver, heart, and gizzard tissue.
The estimated dose, 0.08 mrem, is far less than the dose limit of
100 mrem. Details of duck
sampling appear in section 5.4.
The ESER and its predecessors have placed an array of thermoluminescent dosimeters (TLDs) throughout the Eastern Snake River Plain to measure the amount of radiation in the environment. The results of the November sampling (the period of measurement being May 2001 through November 2001) show the average exposure rate for locations in the Boundary group to range from a low of 0.32 mR/day at Birch Creek to a high of 0.40 mR/day at Mud Lake. The overall average was 0.35 mR/day. The Distant set had a high of 0.43 mR/day at Rexburg and a low of 0.33 mR/day at the new station in Jackson Wyoming. The overall average Distant value was 0.36 mR/day. There was no statistical difference between Boundary and Distant locations. Details of environmental radiation measurements appear in section 6. Conclusions Overall,
the only radionuclides measured that could be attributed to the INEEL
were 60Co and 137Cs in some of the ducks and doves
collected directly from contaminated waste ponds on the INEEL.
No radionuclides in any other samples taken during the fourth
quarter, 2001, could be directly linked with INEEL activities.
Levels of detected radionuclides were below regulatory limits and
not different from values measured at other locations across the United
States. Concentrations of 60Co
and 137Cs in ducks from TRA were higher than in samples taken
from offsite locations, still, all concentrations were much lower than
regulatory dose limits. Concentrations
in all of the samples collected and analyzed during the fourth quarter,
2001 were below guidelines set by both the DOE and the U.S.
Environmental Protection Agency (EPA) for protection of the public. |
At
no time during the fourth quarter were weekly average gross alpha or
gross beta concentrations from Boundary locations statistically higher
than corresponding averages for Distant locations, as one would expect
if the INEEL was a significant source of radionuclide contamination.
Drinking water samples
were collected from tap water from 14 locations throughout southeast
Idaho.
Direct
Radiation