Executive Summary

None of the radionuclides detected in any of the samples collected during the third quarter of 2002 could be directly linked with INEEL activities. Levels of detected radionuclides were no different than values measured at other locations across the United States 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 ES-1.)

This report for the third quarter, 2002, 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, July 1 through September 30, 2002. All sample types (media) and the sampling schedule followed during 2002 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) (Section 3);
Water sampling, specifically collection of precipitation (Section 4);
Agricultural product sampling, including milk, lettuce, wheat, and large game animals (Section 5); and
· Soils (Section 6).

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 third quarter of 2002. 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 third quarter were gross alpha or gross beta concentrations from Boundary locations statistically higher than corresponding data sets for Distant locations, as one would expect if the INEEL were a significant source of radionuclide contamination. There were no statistical differences between gross alpha or gross beta results when grouped by location on a quarterly basis. Statistical analysis by month also showed no statistical difference between locations for gross alpha or gross beta.

Weekly comparisons of gross alpha and gross beta concentrations at Distant and Boundary locations showed statistical differences for two weeks each. Gross alpha had a statistical difference between Boundary locations and Distant locations for the weeks of September 4 and September 18, 2002. For both weeks the Distant locations were higher than the Boundary locations, suggesting natural variations, probably due to atmospheric conditions (i.e., an inversion or resuspended particulates from harvesting/plowing). Gross beta statistical analysis had significant deviations for the weeks of July 10, and August 28, 2002. Analysis of stations within each group showed no statistical difference. As with the gross alpha result, gross beta concentrations at the Distant locations were higher than the Boundary locations, again suggesting natural variations.

During the third quarter, analysis of one six-cartridge batch detected iodine-131 (¹³¹I) greater than the associated 2s value. Immediate reanalysis of each individual cartridge yielded results below the 2s values. Because initial counting is done as a batch sample, it appears that the cumulative activity for these six cartridges was above the 2s value 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). Nine samples collected from air monitoring stations located at Craters of the Moon, the Blackfoot and Rexburg Community Monitoring Stations (CMS), the Experimental Field Station (EFS), FAA Tower, both the Howe and the Howe QA (Q/A-2) samplers, Idaho Falls, and Monteview showed at least one human-made radionuclide (²⁴¹Am, ^239,240Pu or cesium-137 [¹³⁷Cs]) greater than their related 2s values. These values are within the range of those measured in the past and are likely due to resuspension of particulates associated with fallout from past nuclear weapons testing. All results were far less than their respective DOE Derived Concentration Guide (DCG) values.

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 79.0 µg/m³on July 12, 2002, from Blackfoot.

Twenty-one atmospheric moisture samples were obtained during the third quarter of 2002: two from Rexburg, four from Blackfoot, six from Atomic City, and nine from Idaho Falls. A total of eleven samples (one from Rexburg, two from Blackfoot, three from Atomic City, and five from Idaho Falls) exceeded their respective 2s values. Of these detections, five samples are questionable due to small sample size (less than 9 mL). All sample results were well below the DOE DCG for tritium in air of 1 x 10^-7mCi/mL (3.7 x 10^-3 Bq/mL). The maximum value was 6.6 x 10^-12 mCi/mL of air (2.6 x 10^-7 Bq/mL of air).

Sufficient precipitation occurred to allow collection of 14 samples (11 samples and two splits) – three and two splits from Idaho Falls, three from CFA, and six and five from the EFS. Tritium was detected above the samples' 2s values in all the CFA and EFS samples, and three of the Idaho Falls samples. While there is no regulatory limit for tritium in precipitation, the DOE DCG and maximum contaminant level set by EPA for tritium in drinking water can be used as screening values. The highest tritium concentration was many times lower than the DCG value (2 x 10⁶ pCi/L) and the Safe Drinking Water Act limit (20,000 pCi/L) for tritium in drinking water.

Milk samples were collected weekly in Idaho Falls and monthly at nine other locations around the INEEL. All samples were analyzed for gamma emitting radionuclides. No ¹³¹I or ¹³⁷Cs was measured in any of the samples collected during the quarter. Four samples had ⁹⁰Sr concentrations greater than their 2s values. There are no established limits for ⁹⁰Sr in milk but, for comparison, the EPA has set the limit for ⁹⁰Sr in drinking water at 8 pCi/L (0.3 Bq/L). 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 ⁹⁰Sr concentration measured in milk during the third quarter, 2002 was many times lower than the 8-pCi/L limit.

Seven lettuce samples were collected from area gardens around the INEEL. No man-made gamma-emitting radionuclides were measured. Five samples detectable ⁹⁰Sr concentrations above the 2s values. The maximum concentration is consistent with concentrations seen in the recent past.

Wheat samples were obtained from 15 area grain elevators. The man-made radionuclides ¹³⁷Cs and ⁹⁰Sr were measured in one sample each. Again these concentrations were consistent with those measured in the recent past and are attributable to plant uptake of fallout derived radionuclides.

Four large game animals were sampled during the third quarter of 2002. All were killed as a result of vehicular collisions. These accidents involved three mule deer (Odocoileus hemionus) and one pronghorn antelope (Antilocapra americana). 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 a single mule deer had results greater than their 2s value for any radionuclide. Cesium-137 appeared in all tissues (muscle, liver and thyroid) above the 2s value.

Soil samples were collected from four distant and eight boundary locations. Soil samples are composites of five 5-cm by 5-cm cores collected within a 10-m square grid. Americium-241, ^239/240Pu, and ¹³⁷Cs were detected in all samples above their respective 2s values. Plutonium-238 and ⁹⁰Sr were also detected above their respective 2s values in ten and three samples, respectively. All values were within the range of historical measurements.

Table E-1 Summary of results for the third quarter of 2002.

Media	Sample Type	Analysis	Results
Air	Filters	Gross alpha, gross beta, ¹³¹I	Independent statistical comparisons of gross alpha and gross beta data indicate no differences between INEEL, Boundary, and Distant locations. Statistical differences in both gross alpha and gross beta results were observed in two separate weeks for each constituent. However, these differences can be attributed to natural variation in the data. All gross alpha and gross beta results were within historical levels and were far less than applicable DOE DCGs.
		Gamma emitting radionuclides, select actinides, ⁹⁰Sr	Quarterly composite samples had levels of ²⁴¹Am, and/or ^239/240Pu greater than 2s in samples collected from Craters of the Moon, EFS, FAA Tower, Howe and Howe Q/A-2, Idaho Falls, Monetview, and Rexburg. Cesium-137 was measured above the 2s value at Blackfoot. The results were well below DOE DCGs and within historical measurements.
	Charcoal Cartridge	Iodine-131	One 6-cartridge batch, collected on July 24, had an initial detection of ¹³¹I. Immediate recounts of individual cartridges resulted in no measurable ¹³¹I.
	PM₁₀	Particulate matter	No regulatory limits were exceeded for atmospheric particulates.
Atmospheric Moisture	Liquid	Tritium	Eleven of 21 atmospheric moisture samples had tritium measured in them above their respective 2s values. Five of these results are questionable due to small sample size. No sample result exceeded the DCG for tritium in air.
Precipitation	Liquid	Tritium	Twelve of 14 samples had detectable concentrations of tritium. All samples were well below regulatory limits for tritium in drinking water.
Milk	Liquid	Iodine-131, gamma emitting radionuclides	No ¹³¹I or ¹³⁷Cs was measured in any sample. Four of five samples had concentrations of ⁹⁰Sr greater than their 2s values. The detected concentrations were below the regulatory limit for ⁹⁰Sr in drinking water.
Lettuce	Solid	Gamma emitting radionuclides (including ¹³⁷Cs), and ⁹⁰Sr	No gamma emitting radionuclides were measured in any of the seven samples collected. Strontium-90 was detected in five samples above the 2s value. All values were within the range of historical concentrations.
Wheat	Solid	Gamma emitting radionuclides (including ¹³⁷Cs), and ⁹⁰Sr	Cesium-137 was detected in one sample above the 2s value. Strontium-90 was measured in another single sample also above the 2s value. All values were within the range of historical concentrations.
Game Animals	Tissue	Iodine-131, gamma emitting radionuclides (including ^137Cs)	Cesium-137 was reported above the 2s value in all tissues (muscle, liver, thyroid) taken from a single mule deer. No man-made radionuclides were measured in any of the other three animals sampled. All concentrations were within the range of historical values for game animals.
Marmots	Tissue	Gamma emitting radionuclides (including ¹³⁷Cs), select actinides (²³⁸Pu, ^239,240Pu, &²⁴¹Am) and ⁹⁰Sr
Soil	Solid	Gamma emitting radionuclides (including ¹³⁷Cs), select actinides (²³⁸Pu, ^239,240Pu, &²⁴¹Am) and ⁹⁰Sr	All samples contained detectable concentrations of at least one of the analyzed radionuclides. All concentrations were consistent with those expected from background worldwide fallout and were within the range of past measurements.

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