S.M. Stoller Corporation
Environmental Surveillance, Education and Research Program
ISSN NUMBER 1089-5469
Idaho National Engineering and Environmental Laboratory Offsite Environmental
Surveillance Program Report:
First Quarter 2003
January 2003
Contributors:
Marilyn Case, Christopher Martin
Program conducted for the U.S. Department of Energy, Idaho Operations Office
Under Contract DE-AC07-00ID13658
By the S.M. Stoller Corporation,
Environmental Surveillance, Education and Research Program
Douglas K. Halford, Program Manager
1780 First Street, Idaho Falls, Idaho 83401
www.stoller-eser.com
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None of the radionuclides detected in any of the samples collected during the first quarter of 2003 could be directly linked with INEEL activities. Levels of detected radionuclides were no different than values measured at other locations across the United States and/or were consistent with levels measured historically at the INEEL. 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. (See Table E-1.) |
This report for the first quarter, 2003, 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, January 1 through March 31, 2003. All sample types (media) and the sampling schedule followed during 2003 are listed in Appendix A. Specifically, this report contains the results for the following:
Air sampling, including low-volume air sampling with air filters and charcoal cartridges, collection of atmospheric moisture, and sampling of particulate matter with an aerodynamic diameter less than or equal to 10 micrometers (PM10);
Water sampling, specifically collection of precipitation;
Agricultural product sampling, including collection of milk and large game animals.
Results are presented in this report with an analytical uncertainty term, 2s, where “s” is an estimate of the population standard deviation (s), assuming a normal (Guassian) distribution. The result plus or minus (±) the uncertainty term represents the 95 percent confidence interval of the analytical result. That is, there is 95 percent confidence that the real concentration in the sample lies somewhere between the measured concentration minus the uncertainty term and the measured concentration plus the uncertainty term. Results that are greater than 2s are considered “detected”.
Gross alpha and gross beta measurements are used as general indicators of the presence of alpha-emitting and beta-emitting radionuclides in air. Gross alpha and gross beta results were found to have no discernable statistical distribution during the first quarter of 2003. Because of this, these data were statistically analyzed using nonparametric methods, including the use of the median to represent central tendency. Neither quarterly nor monthly statistical analyses of gross alpha and gross beta concentrations during the first quarter showed any concentrations from Boundary locations to be statistically higher than corresponding data sets for Distant locations, as one would expect if the INEEL were a significant source of radionuclide contamination. Gross alpha concentrations were statistically different for the week ending April 2, 2003, with the Distant locations being higher than the Boundary locations. Gross beta concentrations measured at Boundary locations were greater than those measured at Distant locations during the weeks of January 8, and February 12, 2003. This difference was attributed to temperature inversion conditions, which act to trap gases and fine particulates, that existed at the Boundary locations during this week.
During the first quarter, analysis of two eight-cartridge batches detected 131I greater than the associated 2s values. Immediate reanalysis of each individual cartridge yielded results below both the 2s values. Because initial counting is done as a batch sample, it appears that the cumulative activity for these eight cartridge batches was above the 2s values but was not attributable to any single location (cartridge).
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). Selected samples collected from all air monitoring stations showed at least one human-made radionuclide greater than its related 2s value. Plutonium-239/240 and 241Am were detected in six samples. Strontium-90 was detected in ten samples. No 137Cs or 238Pu were detected in any sample. All values were within the range of those measured in the past and are likely due to fallout from past nuclear weapons testing. All results were far less than their respective DOE Derived Concentration Guide (DCG) values.
Ten atmospheric moisture samples were obtained during the first quarter of 2003; two and two duplicates from Blackfoot, two from Rexburg, and two and one duplicate from Idaho Falls, and one from Atomic City. All but three sample results, one from Rexburg in January and two (a sample and a duplicate from the Blackfoot CMS in February and March, respectively, exceeded their respective 2s values. The seven remaining samples are considered positive detections. The maximum value of 5.54 ± 3.15 x 10-13 mCi/mLair (2.05 ± 1.17 x 10-8 Bq/mL) is well below the DCG for tritium in air of 1 x 10-7 mCi/mL (3.7 x 10-3 Bq/mL).
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 37.4 µg/m3 on February 12, 2003, in Rexburg.
Sufficient precipitation occurred to allow collection of two monthly composite samples from Idaho Falls, three monthly composite samples from the Central Facilities Area (CFA) on the INEEL, and eight weekly samples (five samples and three duplicates) from the Experimental Field Station (EFS) on the INEEL. Tritium was detected in ten samples: all three from CFA and all but one from the EFS. There is no DCG for tritium in precipitation, but in drinking water it is 2.0 x 106 pCi/L (74,074 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 first quarter precipitation samples were well below the DCG value and the Safe Drinking Water Act Limit.
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. Iodine 131 (131I) was detected in one of the collected samples from Howe in March. An immediate recount of the sample yielded a result below the 2s value and could not support the first result as a true detection. No 137Cs concentrations were greater than their 2s uncertainty. The occasional detection of 131I during initial counting is not unusual and most of these are unsupported by recounting suggesting the initial count was a false positive.
One large game animal (a mule deer) was sampled during the first quarter of 2003. It was killed as a result of vehicular collisions. Every effort was made to collect thyroid, liver, and muscle tissue from each animal. However, certain tissues could not be collected from all animals due to their condition at the time of collection. Only the naturally occurring radionuclide potassium-40 was measured at concentrations greater than the associated 2s uncertainty values. The concentrations were well within historical measurements. No human-made radionuclides were detected.
Table E-1 Summary of results for the first quarter of 2003.
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Media |
Sample Type |
Analysis |
Results |
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Air |
Filters |
Gross alpha, Gross beta |
Statistical comparisons of all gross alpha and gross beta data collected during the first quarter indicate no differences between INEEL, Boundary, and Distant locations. Weekly statistical differences in gross alpha and gross beta results were observed twice between Boundary and Distant location groups. These differences can be attributed to natural variation in the data and to meteorological conditions (i.e.,temperature inversions). All gross alpha and gross beta results were within historical levels and were far less than applicable DOE DCGs. |
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Gamma emitting radionuclides (including 137Cs), select actinides (238Pu, 239,240Pu, & 241Am) and 90Sr |
Plutonium-239/240 was detected in one sample collected from Rexburg CMS. No 90Sr, 238Pu or 137Cs was detected in any quarterly composite sample. The result was well below the DOE DCG and within historical measurements. |
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Charcoal Cartridge |
Iodine-131 |
None of the cartridges had measurable 131I. |
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PM10 |
Particulate matter |
No regulatory limits were exceeded for atmospheric particulates. |
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Atmospheric Moisture |
Liquid |
Tritium |
Two of 10 atmospheric moisture samples had tritium detected in them. No sample result exceeded the DCG for tritium in air. |
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Precipitation |
Liquid |
Tritium |
Seven of 13 samples had measurable concentrations of tritium. All samples were well below regulatory limits for tritium in drinking water which is used for comparison only. |
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Milk |
Liquid |
Iodine-131, gamma emitting radionuclides (including 137Cs) |
Iodine-131 and 137Cs were not reported above the 3s level in any sample collected during the first quarter of 2003. |
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Game Animals |
Tissue |
Iodine-131, gamma emitting radionuclides (including 137Cs) |
Iodine-131 and 137Cs were not reported above the 3s level in any sample collected during the first quarter of 2003. |