Fourth Quarter 2006
INL Quarterly Site Environmental Report
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S.M. Stoller Corporation
Environmental Surveillance, Education and Research Program
ISSN NUMBER 1089-5469
Stoller-ESER-104
Idaho National Laboratory Offsite Environmental
Surveillance Program Report:
Fourth Quarter 2006
June 2007
Contributors:
Marilyn Case, Russ Mitchell
Program conducted for the U.S. Department of Energy, Idaho Operations Office
Under Contract DE-AC07-06ID14680
By the S.M. Stoller Corporation,
Environmental Surveillance, Education and Research Program
Douglas K. Halford, Program Manager
120 Technology Drive, Idaho Falls, Idaho 83402
www.stoller-eser.com
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Most of the radionuclides detected in any of the samples collected during the fourth quarter of 2006 could not be directly linked with INL Site activities. One probably exception was waterfowl taken directly from wastewater ponds located on the INL Site. Levels of other detected radionuclides were no different than values measured at other locations across the United States or were consistent with levels measured historically at the INL Site. All detected radionuclide concentrations were well below guidelines set by the U.S. Department of Energy (DOE) and regulatory standards established by the U.S. Environmental Protection Agency (EPA) for protection of the public. |
This report for the fourth quarter of 2006 contains results from the Environmental Surveillance, Education and Research (ESER) Program’s monitoring of the Department of Energy’s Idaho National Laboratory (INL) Site’s offsite environment, October 1 through December 31, 2006. All sample types (media) and the sampling schedule followed during 2006 are listed in Appendix A. Specifically, this report contains the results for the following:
Air sampling, including air filters and charcoal cartridges, atmospheric moisture, and 10 micron particulate matter (PM10)
Precipitation sampling
Surface water sampling
Drinking water sampling
Milk sampling
Large game animal sampling
Waterfowl sampling
Gross alpha and gross beta measurements are used as general indicators of the presence of radionuclides. Gross alpha and gross beta results were found to have no discernable statistical distribution during the fourth quarter of 2006. Because of this, these data were statistically analyzed using nonparametric methods, including the use of the median to represent central tendency. At no time during the fourth quarter were monthly or quarterly gross alpha or gross beta concentrations in air collected at Boundary locations statistically greater than corresponding data for Distant locations, as one would expect if the INL Site were a significant source of radionuclide contamination. Weekly comparisons of gross alpha concentrations at Distant and Boundary locations showed a statistical difference during the week of November 29. In this case, the Distant locations were statistically greater than the Boundary locations.
There were no statistical differences between gross beta results when grouped by location on quarterly, monthly and weekly bases. There were statistical differences found during the weeks of November 8 and November 29. In the first instance, the Boundary locations were statistically greater than the Distant locations; in the second case, the Distant locations were statistically greater. These differences appear to be due to random variability in the data.
Iodine-131 (131I) was not detected in any batch of charcoal cartridges during the fourth quarter.
Selected quarterly composite filter samples were analyzed for gamma emitting radionuclides, strontium-90 (90Sr), plutonium-238 (238Pu), plutonium-239/240 (239/240Pu) and americium-241 (241Am). Cesium-137 was detected at Arco within the range of historical measurements and well below the DOE Derived Concentration Guide (DCG). No other manmade radionuclides were found.
Fourteen atmospheric moisture samples were obtained during the fourth quarter of 2006 and analyzed for tritium. Two from sampling location exceeded their respective 3s levels. The maximum value was well below the DOE DCG for tritium in air.
The ESER Program operates three PM10 samplers for particulate sampling, one each at Rexburg, Blackfoot, and Atomic City. Sampling of PM10 is primarily informational as no analyses are conducted for contaminants. The maximum 24-hour particulate concentration was 30.9 µg/m3 on October 13, 2006, at Rexburg. This is well below the EPA Air Quality Standard of 150 µg/m3.
Storm events in the fourth quarter of 2006 produced sufficient precipitation to yield 12 samples –three from Idaho Falls and CFA, and six weekly samples from the EFS. Three of the samples contained a detectable concentration of tritium, within the range reported by the EPA across the western United States.
Fourteen drinking water samples and one duplicate were collected from selected taps throughout southeast Idaho during the fourth quarter of 2006. Samples were analyzed for gross alpha, gross beta, and tritium (3H). Two of the samples exceeded its 3s value for gross alpha and two samples contained tritium above the detection limit, but within historical measurements. The maximum value was below the EPA limits established under the Safe Drinking Water Act and DOE DCGs. All but one sample exceeded the 3s value for gross beta. The maximum gross beta concentration measured, (7.89 ± 0.63) pCi/L, was from Fort Hall and was below the EPA Safe Water Drinking Water Act (SDWA) screening limit of 50 pCi/L and the DOE DCG of 100 pCi/L. Levels of gross beta activity observed are not unusual given the basaltic terrain.
Milk samples were collected weekly in Ucon and monthly at nine other locations around the INL Site. All samples were analyzed for manmade gamma-emitting radionuclides. Iodine-131 was not detected in any sample. Cesium-137 was detected in two samples at background level. Low levels of 90Sr were found in most samples. Tritium was measured in two of four samples analyzed.
Cesium-137 was detected in two potato samples, including one collected from out of the state. The detected concentrations were similar to those found in recent years.
Waterfowl were collected from wastewater ponds at two facilities
located on the INL and one Distant location (American Falls, ID). Several
manmade radionuclides above background, including americium-241, cesium-137,
chromium-51, cobalt-60, strontium-90, zinc-65 and plutonium-238 and 239/240 were
found in tissues from birds collected at the Reactor Technology Complex. Only
americiium-241 and strontium-90 were found in the control samples.
Concentrations of radionuclides were lower in 2006 than the previous year, and
lower than in an earlier study. The potential dose to a person eating the entire
edible mass of the duck with the highest concentration of radionuclides measured
was calculated to be 0.013 mrem.
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Media |
Sample Type |
Analysis |
Results |
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Air |
Filters |
Gross alpha, gross beta |
There were no statistical differences noted for monthly or quarterly gross alpha or gross beta concentrations measured at INL Site, Boundary and Distant locations. Some weekly differences were noted but these appear to be normal variability in the data. No result exceeded the DCG for gross alpha or gross beta activity in air. |
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Gamma-emitting radionuclides, select actinides (241Am, 238Pu, and 239,240 Pu), 90Sr |
Cesium-137 was found in one sample. The reported detection was within the range of historical measurements. No other manmade radionuclides were found. |
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Charcoal Cartridge |
Iodine-131 |
No detections of 131I were made during the fourth quarter. |
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PM10 |
Particulate matter |
Forty-eight valid samples were collected from three locations. No regulatory limits were exceeded. |
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Atmospheric Moisture |
Liquid |
Tritium |
A total of 14 samples were collected. Eight of these samples had tritium result s greater than the 3s uncertainty. Concentrations were consistent with those reported across the region and with previous results. |
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Precipitation |
Liquid |
Tritium |
Twelve samples were collected. Three of the results were greater than the 3s uncertainty. No sample result exceeded the DCG for tritium in air. |
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Drinking Water |
Liquid |
Gross alpha, gross beta, tritium |
Gross alpha activity was detected in two samples. Gross beta activity was measured in 14 of 15 samples collected (including duplicate). The maximum was well below the EPA Safe Drinking Water Act limits. Tritium was detected in two samples. |
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Surface Water |
Liquid |
Gross alpha, gross beta, tritium |
Six samples were collected. The 3s value was exceeded for gross alpha in one sample, tritium in two samples and gross beta in all samples. All concentrations were below EPA and DOE limits, and were within historical measurements. |
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Milk |
Liquid |
Iodine-131, gamma-emitting radionuclides, and 90Sr & tritium (select samples only) |
Cesium-137 was detected in two samples analyzed for gamma-emitting radionuclides.. Iodine-131 was not found in any sample. Strontium-90 was detected at low levels in four of five samples analyzed for 90Sr. Tritium was detected on two of four samples. Results were within historical measurements. |
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Potatoes |
Vegetation |
Gamma emitting radionuclides, 90Sr |
Cesium-137 was detected in one sample from the state of Idaho and an out-of-state sample from Colorado. No 90Sr was detected. |
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Waterfowl |
Tissue |
Gamma emitting radionuclides, select actinides (241Am, 238Pu, and 239,240 Pu), 90Sr |
Eight radionuclides were found in tissues from ducks collected at the Reactor Technology Complex, including four radionuclides found in edible tissue. Concentrations were generally lower than those found in the previous year. The estimated dose from eating the entire edible mass of the duck with the highest concentrations was estimated at 0.013 mrem. |
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Environmental Radiation |
TLD |
Ambient ionizing radiation |
Values were consistent with expected exposures given the altitude and location of the TLD's. There were no statistical differences between Boundary and Distant location results. |