This report for the first quarter, 2004, 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, 2004. All sample types (media) and the sampling schedule followed during 2004 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, s, where “s” is an estimate of the population standard deviation (assuming a normal (Guassian) distribution. The following guidelines, based on Currie (1984), are used to interpret the analytical results.

• Results greater than 3s are reported as “detected”.
• Results less than 2s are reported as “undetected”.
• Results between 2-3s are reported as “questionable” (i.e., the radionuclide might have been detected but such detection may not be considered reliable.)

Gross alpha and gross beta measurements are used as general indicators of the presence of alpha-emitting and beta-emitting radionuclides in air. 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 also not statistically different for weekly comparisons. Gross beta concentrations measured at Boundary locations were greater than those measured at Distant locations during the weeks of February 2, 2004. This difference was attributed to a higher measurement made at Arco. However, the result was within historical measurements and can be attributed to natural variations in air concentrations.

During the first quarter iodine-131 was not detected in any batches of charcoal cartridges.

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). No human-made radionuclides greater than their related 3s values were measured in the first quarter of 2004.

Seven atmospheric moisture samples were obtained during the first quarter of 2004; two each from Blackfoot, Idaho Falls, and Atomic City and one from Rexburg. Both samples from Atomic City exceeded their respective 3s values. The maximum value of (4.4 ± 1.3) x 10^-13 mCi/mL_air (1.6 ± 0.5 x 10^-8 Bq/mL_air) 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 for particulate sampling. 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 particulate concentration was 47.6 µg/m³ on March 9, 2004, in Rexburg.

Sufficient precipitation occurred to allow collection of four monthly composite samples from Idaho Falls, three monthly composite samples 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 one sample from CFA at a concentration of 191.0 ± 55.7 pCi/L (7.1 ± 2.1 Bq/L). 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 not detected in any of the collected samples during the quarter. Cesium-137 was detected in the March sample from Blackfoot. The occasional detection of ¹³⁷Cs during initial counting is not unusual and is unsupported by recounting.

No game animals were available for sampling during the first quarter of 2004.

Quality assurance checks and samples submitted for analysis during the first quarter 2004 met most QA requirements. QA issues arose with method uncertainty and recount accuracy for ¹³¹I measurements in charcoal cartridges and milk and ²⁴¹Am and ⁹⁰Sr in quarterly composites as measured by criteria established in the ESER Quality Assurance Project Plan. These issues are being resolved with the laboratory to avoid future problems.

 

Table E-1       Summary of results for the first quarter of 2004.

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