R. Mitchell - S. M. Stoller Corporation
R Wilhelmsen and D. McBride - Bechtel/BWXT Idaho, LLC
M. Finnerty - Argonne National Laboratory-West
Contents:
To help assess the impact of contaminants released to the environment by operations at the Idaho National Engineering and Environmental Laboratory (INEEL), agricultural products (milk, lettuce, wheat, potatoes, and sheep); wildlife (waterfowl and large mammals); and soil were sampled and analyzed for radionuclides. In addition, direct radiation was measured on and off the INEEL in 2004.
Some human-made radionuclides were detected in agricultural products and soil samples. However, the results could not be directly linked to operations at the INEEL. Concentrations of radionuclides detected in agricultural products and soil samples were consistent with fallout levels from atmospheric weapons testing. The maximum levels for these radionuclides were all well below regulatory health-based limits for protection of human health and the environment. Some human-made radionuclides were also detected in samples of wildlife during 2004 but concentrations were similar to those found in samples taken off the INEEL.
Direct radiation measurements made at offsite, boundary, and onsite (except in the vicinity of some INEEL facilities) locations were consistent with background levels. The measured annual dose equivalent from external exposure was 122 mrem. Radiation measurements taken in the vicinity of waste storage and soil contamination areas near INEEL facilities were consistent with previous measurements. Direct radiation measurements using a radiometric scanner system at the Radioactive Waste Management Complex were greater than background levels but consistent with those made historically at that location.
This chapter provides a summary of the various environmental monitoring activities currently being conducted on and around the Idaho National Engineering and Environmental Laboratory (INEEL) (Table 7-1). These media are potential pathways for transport of INEEL contaminants to nearby populations.
The Management and Operating (M&O) contractor monitored soil, vegetation, and direct radiation on the INEEL to comply with applicable U.S. Department of Energy (DOE) orders and other requirements. The M&O contractor collected 418 soil, vegetation, and direct radiation samples for analysis in 2004.
Argonne National Laboratory-West (ANL-W) and the Naval Reactors Facility (NRF) also conduct monitoring of soil, vegetation, and direct radiation. These programs are to show compliance with DOE orders but are limited in scope to their specific facilities.
The Environmental Surveillance, Education and Research Program (ESER) contractor conducted offsite environmental surveillance and collected samples from an area of approximately 23,308 km2 (9,000 mi2) of southeastern Idaho at locations on, around, and distant to the INEEL. The ESER contractor collected approximately 225 agricultural products, wildlife, and direct radiation samples for analysis in 2004.
Section 7.2 presents the agricultural products and wildlife surveillance results sampled under the ESER Program. Section 7.3 presents the results of soil sampling by both the ESER contractor and the M&O contractor. The direct radiation surveillance results are presented in Section 7.4. Results of the waste management surveillance activities are discussed in Section 7.5.
The INEEL Oversight Program, conducted by the state of Idaho, collects split samples with the M&O and other INEEL contractors of some agricultural products and soil, and maintains collocated direct radiation monitors. Results of the Oversight Program’s monitoring are presented in annual reports prepared by that organization and are not reported here.
The analytical results reported in the following surveillance sections are those that are greater than three times the analytical uncertainty (see Appendix B for information on statistical methods). Analytical uncertainties reported in text and tables are plus or minus one standard deviation (± 1s) uncertainty for the radiological analysis.
Milk
During 2004, 152 milk samples were collected by the ESER Program. All of
the samples were analyzed for gamma-emitting radionuclides including iodine-131
(131I). During the second and fourth quarters, selected samples were
analyzed for strontium-90 (90Sr) and tritium.
Iodine-131 was not detected in any sample in 2004. Strontium-90 was detected in three out of nine samples ranging from 0.6 ± 0.2 pCi/L at Idaho Falls to 1.2 ± 0.2 pCi/L in a sample from Roberts. All levels of 90Sr in milk were consistent with those data previously reported by the U.S. Environmental Protection Agency (EPA) as resulting from worldwide fallout deposited on soil and taken up by ingestion of grass by cows (EPA 1995). The maximum value is lower than the DOE derived concentration guide (DCG) for 90Sr in water of 1,000 pCi/L.
Tritium was detected in four of nine samples with a maximum concentration of 107 ± 27 pCi/L at Blackfoot. This value is well below the DOE DCG of 20,000 pCi/L for water.
Lettuce
ESER Program personnel collect lettuce samples every year from the areas
adjacent to the INEEL. The collection of lettuce from home gardens around the
INEEL typically depends on availability. To make this sampling more reliable,
ESER added two prototype lettuce planters in conjunction with other sampling
locations at Atomic City and the Experimental Field Station (EFS) on the INEEL.
These locations are relatively remote and have no access to water, requiring
that a self-watering system be developed. This method allows for the placement
and collection of lettuce at areas previously unavailable to the public (i.e.,
on the INEEL). The boxes are set out in the spring with the lettuce grown from
seed. This new method also allows for the accumulation of deposited
radionuclides on the plant surface throughout the growth cycle.
Figure 7-1 shows the seven locations where lettuce was collected in 2004.
Seven lettuce samples, including one duplicate, were collected from regional private gardens and two were collected from the portable lettuce gardens placed at Atomic City and EFS. No anthropogenic radionuclides were detected above the 3s level in 2004 (Table 7-2). Strontium-90 and Cesium-137 (137Cs) in lettuce results from plant uptake of these isotopes in soil as well as deposition from airborne dust containing 90Sr and 137Cs. Strontium-90 and 137Cs are present in soil as a residual of fallout from aboveground nuclear weapons testing, which took place between 1945 and 1980. The quantities detected historically were most likely from weapons testing fallout.
Wheat
None of the 13 wheat samples (including one duplicate) collected during 2004
contained a measurable concentration of 90Sr above the 3s uncertainty level. No
other anthropogenic radionuclides were detected (Table 7-3).
Potatoes
Eleven potato samples, including one duplicate, were collected during
2004: five samples from distant locations, four samples and one duplicate from
boundary locations, and one sample from an out-of-state location (Colorado) (Figure 7-1).
The nine Idaho samples were collected from Arco, Blackfoot, Fort Hall, Howe,
Idaho Falls, Monteview, Rupert, Terreton, and Taber. Strontium-90 was detected
in two of the Idaho samples at levels of (2.4 ± 0.8) × 10-1 pCi/g at
Monteview and (2.7 ± 0.8) × 10-1 pCi/g at Fort Hall. Strontium-90 is
present in soil as a result of fallout from aboveground nuclear weapons testing,
and these detections were most likely from that fallout. No other anthropogenic
radionuclides were detected in potatoes.
Sheep
Certain areas of the INEEL are open to grazing under lease agreements
managed by the U.S. Bureau of Land Management. Every year, during the second
quarter, ESER personnel collect samples from sheep grazed in these areas, either
just before or shortly after they leave the INEEL. Muscle, liver, and thyroid
samples were collected from each animal. For the calendar year 2004, six sheep
were sampled. Four were from INEEL land, and two were from Dubois to serve as
control samples. Cesium-137 was detected above 3s in the muscle tissue of one
onsite sample at a level of (4.0 ± 1.3) x 10 -3 pCi/g but was not
detected in offsite muscle samples. Cesium-137 was also detected in the liver
tissue sample from two onsite animals at levels of
(4.3 ± 1.3) x 10 -3 pCi/g and (4.8 ± 1.2) x 10 -3 pCi/g.
Cesium-137 was not measured above the 3s uncertainty in any control sheep in
2004. However, all 137Cs concentrations measured in 2004 were similar
to those found in both onsite and offsite sheep samples in previous years and
are within historical values. Cesium-137 concentrations in both sheep liver and
muscle have been essentially the same (error bars overlap) since 1998 (DOE-ID
2004) (Figure 7-2). Iodine-131 did not exceed the 3s uncertainty in any sample.
Game Animals
Muscle, liver, and thyroid samples were collected from six mule deer,
five pronghorn, and two elk, which were accidentally killed on INEEL roads or
died from natural causes. There was detectable 137Cs radioactivity
above 3s in the muscle of two different pronghorn, and in the liver of one
pronghorn taken on or near the INEEL. No tissue samples contained detectable
131I above 3s (Table 7-4).
In 1998 and 1999, four pronghorn, five elk, and eight mule deer muscle samples were collected as background samples from hunters across the Western United States: three from central Idaho; three from Wyoming; three from Montana; four from Utah; and one each from New Mexico, Colorado, Nevada, and Oregon. Each background sample had small, but detectable, 137Cs concentrations in its muscle ranging from (5.1 ± 1.5) x 10-3 to (15 ± 0.2) x 10-3 pCi/g.
Muscle results from animals sampled in 2004 were within this range, from (4.0 ± 1.1) x 10-3 to (5.8 ± 1.5) x 10-3 pCi/g. The 2004 values were also within the range of historical values. Cesium-137 was also found in the liver of one pronghorn at (8.1 ± 1.6) x 10-3 pCi/g. These values can be attributed to the ingestion of radionuclides in plants from worldwide fallout associated with aboveground nuclear weapons testing. No 131I was detected in any of the thyroid gland samples.
Marmots are hunted and consumed by the Shoshone-Bannock Tribes. No marmots were collected during 2004. During 1998, 2000, 2002, and 2003, a total of 15 marmots were collected from the Radioactive Waste Management Complex (RWMC) and 11 from control areas. During 1998 and 2000, marmots were collected at random locations near the RWMC. During 2002 and 2003, marmots were collected at known contaminated areas at RWMC (primarily near the Subsurface Disposal Area [SDA] and Pit 9), which biased the results toward higher concentrations. Muscle, viscera, and fur/bone samples were collected from each, sent to a commercial radiochemistry laboratory, and analyzed for Americium-241 (241Am), Plutonium-238 (238Pu), Plutonium-239/240 (239/240Pu), 90Sr, and gamma-emitting radionuclides.
Analyses indicated that analytes were generally below detectable levels in all tissues from control animals. One animal collected from RWMC contained low levels of 137Cs in all three tissue types. The 137Cs concentrations detected in 2002 and 2003 were approximately one order of magnitude higher than those detected in marmots collected around the RWMC in 1998 (DOE-ID 2004). However, the 137Cs concentrations observed in the 2002/2003 animals were below those observed in other wildlife species collected previously at the SDA as well as in control animals collected for an older study (Arthur and Janke 1986).
Strontium-90 levels followed a similar pattern to 137Cs (both are also worldwide fallout products) in external tissues. However, muscle tissue collected in 2002 and 2003 showed a decrease from the 1998 concentrations. The animals sampled in 2002 and 2003 were collected from the Pit 9 area which contains higher concentrations. Again, these concentrations were well below 90Sr levels detected in animals in previous studies at the subsurface disposal area (SDA) (Arthur and Janke 1986).
Six waterfowl were collected during 2004: four control samples from Market Lake and two from the Test Reactor Area (TRA) Radioactive Disposal Ponds. Samples of the viscera, edible portions, and the remainder (18 samples total plus one duplicate) of all these waterfowl were analyzed for gamma-emitting radionuclides, 90Sr, 241Am, 238Pu, and 239/240Pu. Six radionuclides had at least one detectable value above 3s. Total radionuclide concentrations for those samples are summarized in Table 7-5. The potential dose from consuming these ducks is discussed in Chapter 8.
Mourning doves were not collected in 2004.
Soils are sampled to determine if long-term deposition of airborne materials released from the INEEL have resulted in a buildup of radionuclides in the environment and to support the Wastewater Land Application Permit (WLAP) for the Central Facilities Area (CFA) Sewage Treatment Plant. Samples are analyzed for gamma-emitting radionuclides, 90Sr, and certain actinides. Above-ground nuclear weapons testing has resulted in many radionuclides being distributed throughout the world. Of these, 137Cs, 90Sr, 238Pu, 239/240Pu, and 241Am, all of which potentially could be released from INEEL operations, are of particular interest because of their abundance from nuclear fission events (e.g., 137Cs and 90Sr) or from their persistence in the environment because of long half-lives (e.g., 239/240Pu with a half-life of 24,390 years). All of these radionuclides were detected in one or more soil samples collected during 2004. However, if INEEL inputs had contributed significantly to these concentrations, it would be expected that boundary concentrations would be higher than distant locations. There were no differences (using independent sample t-tests and a = 0.05) between boundary and distant group concentrations for any of these radionuclides.
The ESER contractor collects offsite soil samples every two years (in even years, except for 1975); thus, soil sampling was conducted in 2004. Results from 1975 to 2004 are presented in Figure 7-3. The geometric means were used because the data were log-normally skewed. The shorter-lived radionuclides (90Sr and 137Cs) show overall decreases through time.
Radionuclide levels in soils at 109 site surveillance locations near major INEEL facilities were measured by the M&O contractor in 2004 using in situ gamma spectrometry with 13 additional grab samples collected from 0 to 5 cm (0 to 2 in.) at selected locations. Table 7-6 summarizes the in situ gamma results, and Table 7-7 summarizes the analytical laboratory gamma and radiochemistry results.
Wastewater Land Application Permit Soil Sampling at CFA
The WLAP for the CFA Sewage Treatment Plant allows for nonradioactive
wastewater to be pumped from the treatment lagoons to the ground surface by
sprinkler irrigation (DOE-ID 1999, IDEQ 2000). Soils are sampled from the CFA
land application area following each application season. Subsamples are taken
from 0 to 30 cm (0 to 12 in.) and 30 to 61 cm (12 to 24 in.) at each location
and composited, yielding two composite samples, one from each depth. These
samples are analyzed for pH, electrical conductivity, sodium absorption ratio,
percent organic matter, extractable phosphorus, and nitrogen, in accordance with
the WLAP, to determine whether wastewater application is resulting in
detrimental changes in soil quality. These results are presented in Table 7-8.
Preapplication data collected by Cascade Earth Sciences, Ltd. in 1993 are
presented for comparison purposes in Table 7-8.
Soil pH has remained fairly constant during the application period (Table 7-8). Percent organic matter has varied around preapplication concentrations; however, it is expected to take several years for decomposed vegetation to be incorporated into the soil profile.
The soil salinity averages are within acceptable ranges based on electrical conductivity results. Soil salinity levels between 0 to 2 mmhos/cm are generally accepted to have negligible effects on plant growth (Bohn et al. 1985). During 2004, the electrical conductivity in both the 0 to 30 cm (0 to 12 in.) and the 30 to 61 cm (12 to 24 in.) intervals were above historical levels but remained well below the recommended 2 mmhos/cm maximum. Soils with sodium adsorption ratios (SARs) below 15 are generally classified as not having sodium or salinity problems (Bohn et al. 1985). During 2004, SARs were elevated at the upper depth relative to preapplication SARs, but both depths remain well below the ratio generally indicating a sodium problem in soil.
Nitrogen data suggest negligible nitrogen accumulation from wastewater application. The low soil-available nitrogen (ammonium-nitrogen and nitrate-nitrogen) concentrations suggest that the native sagebrush and grass vegetation use all of the plant-available nitrogen and that the total nitrogen application is low. Increased nutrients and water from wastewater application may be stimulating plant growth, which in turn rapidly utilizes plant available nitrogen. The ammonium and nitrate nitrogen concentrations are comparable to those of unfertilized, background agricultural soils.
In 2004, available phosphorus concentrations remained below preapplication concentrations and less than that considered adequate for range and pasture crop growth (EPA 1981).
Based on these results, the application of wastewater at the CFA does not appear to adversely affect soil chemistry. However, sampling and analysis will continue, as required by the WLAP, to evaluate potential long-term effects.
Argonne National Laboratory-West
ANL-W collects four soil samples annually, two from the predominant wind
direction and two from the crosswind directions. Sufficient material to fill a
500 mL (16 oz) wide mouth jar is collected from 0-5 cm (0-2 in.) depth within an
approximately 1 m2 (approximately 10 ft2) area. Samples
are analyzed for low-level gamma-emitting radionuclides, and uranium, plutonium,
and thorium isotopes. Table 7-9 presents the results of the 2004 sampling
effort.
Naval Reactors Facility
Naval Reactors Facility personnel also sample soil and vegetation
annually for programmatic radionuclides. For detailed information see Bechtel
Bettis 2005.
Thermoluminescent dosimeters (TLDs) measure cumulative exposures to ambient ionizing radiation. The TLDs detect changes in ambient exposures attributed to handling, processing, transporting, or disposing of radioactive materials. The TLDs are sensitive to beta energies greater than 200 kilo-electron volts (keV) and to gamma energies greater than 10 keV. The TLD packets contain four lithium fluoride chips and are placed about 1 m (approximately 3 ft) above the ground at specified locations. The four chips provide replicate measurements at each location. The TLD packets are replaced in May and November of each year. The sampling periods for 2004 were from November 2003 through April 2004 (spring) and from May 2004 through October 2004 (fall).
The measured cumulative environmental radiation exposure for offsite locations from November 2003 through October 2004 is shown in Table 7-10 for two adjacent sets of dosimeters maintained by the ESER and M&O contractors. For purposes of comparison, annual exposures from 2000-2003 are also included for each location.
The mean annual exposures from distant locations in 2004 were 118 ± 3 milliroentgens (mR) as measured by both the ESER and M&O contractor dosimeters (Table 7-10). For boundary locations, the mean annual exposures were 120 ± 3 mR as measured by ESER contractor dosimeters and 119 ± 4 mR as measured by M&O contractor dosimeters. Using both ESER and M&O data, the average dose equivalent of the distant group was 122 millirem (mrem), when a dose equivalent conversion factor of 1.03 was used to convert from milliroentgens to millirem in tissue (NRC 1997). The average dose equivalent for the boundary group was 123 mrem.
In addition to TLDs, the M&O contractor uses a global positioning radiometric scanner system to conduct gamma radiation surveys. The global positioning radiometric scanner is mounted on a four-wheel drive vehicle. The two plastic scintillation detectors of the radiometric scanner measure gross gamma in counts per second with no coincidence corrections or energy compensation. Elevated count rates suggest possible areas of contamination or elevated background areas. Both global positioning system and radiometric data are continuously recorded. The vehicle is driven at approximately 8 km/hr (5 mph) to collect survey data (see Section 7.5, Waste Management Surveillance Sampling).
Onsite TLDs maintained by the M&O contractor representing the same exposure
period as the offsite dosimeters are shown in
Appendix D, Figures D-1 through
D-10. The results are expressed in mR ± 1 standard deviation. Onsite dosimeters
were placed on facility perimeters, concentrated in areas likely to show the
highest gamma radiation readings. Other onsite dosimeters are located in the
vicinity of radioactive materials storage areas. At some facilities, elevated
exposures result from areas of soil contamination around the perimeter of these
facilities.
The maximum exposure onsite recorded during 2004 was 333 ± 23 mR at location
RWMC 41. This dosimeter is located near active waste storage and management
areas. The 2004 exposure is similar to that of previous years.
Locations TRA 2, 3, and 4 are adjacent to the former radioactive disposal ponds, which have been drained and covered with clean soil and large rocks. The levels at TRA 2 and 3 have been reduced to less than one third of the values in 2002 (DOE-ID 2004).
The Idaho Nuclear Technology and Engineering Center (INTEC) 20 TLD is located near a radioactive material storage area with an exposure of 280 ± 19 mR. Exposures at INTEC 20 and the INTEC Tree Farm for 2004 were all comparable to historical exposures.
Table 7-11 summarizes the calculated effective dose equivalent an individual receives on the Snake River Plain from various background radiation sources.
The terrestrial portion of natural background radiation exposure
is based on concentrations of naturally occurring radionuclides found in soil
samples collected in 1976 (the last time a comprehensive background study was
completed). Concentrations of naturally occurring radionuclides in soil are not
expected to change significantly over this relatively short time period. Data
indicated the average concentrations of uranium-238 (238U),
thorium-232 (232Th), and potassium-40 (40K) were 1.5, 1.3,
and 19 pCi/g, respectively. The calculated external dose equivalent received by
a member of the public from 238U plus decay products, 232Th
plus decay products, and 40K based on the above average area soil
concentrations were 21, 28, and
27 mrem/yr, respectively, for a total of 76 mrem/yr (Table 7-11).
Because snow cover can reduce the effective dose equivalent Idaho residents receive from the soil, a correction factor must be made each year to the above estimate of 76 mrem/yr. For 2004, this resulted in a corrected dose of 70 mrem/yr because of snow cover, which ranged from 2.54 to 25.4 cm (1 to 10 in.) in depth with an average of 17.7 cm (6.99 in.) over 78 days with recorded snow cover.
The cosmic component varies primarily with altitude increasing from about 26 mrem at sea level to about 48 mrem at the elevation of the INEEL at approximately 1,500 m (4,900 ft) (NCRP 1987). Cosmic radiation may vary slightly because of solar cycle fluctuations and other factors.
The estimated sum of the terrestrial and cosmic components of dose to a person residing on the Snake River Plain in 2004 was 118 mrem (Table 7-11). This is slightly below the 122 mrem measured at distant locations by ESER and M&O TLDs after conversion from mR to mrem in tissue. Measured values are very close and within normal variability, of the calculated background doses (Table 7-10 and Table 7-11). Therefore, it is unlikely that INEEL operations contribute to background radiation levels at distant locations.
The component of background dose that varies the most is inhaled radionuclides. According to the National Council on Radiation Protection and Measurements, the major contributor of external dose equivalent received by a member of the public from 238U plus decay products are short-lived decay products of radon (NCRP 1987). The amount of radon in buildings and groundwater depends, in part, upon the natural radionuclide content of the soil and rock of the area. This also varies between buildings of a given geographic area depending upon the materials each contains, the amount of ventilation and air movement, and other factors. The United States average of 200 mrem was used in Table 7-11 for this component of the total background dose because no specific estimate for southeastern Idaho has been made and few specific measurements have been made of radon in homes in this area. Therefore, the effective dose equivalent from natural background radiation for residents in the INEEL vicinity may actually be higher or lower than the total estimated background dose of about 358 mrem shown in Table 7-11 and will vary from one location to another.
Naval Reactors Facility
The NRF also has TLDs placed around the perimeter fence of the facility
and at distant locations to measure cumulative exposure. For detailed
information see Bechtel Bettis 2005.
Vegetation, soil, and direct radiation sampling are performed at RWMC and direct radiation sampling is performed at the Waste Experimental Reduction Facility in compliance with DOE Order 435.1, "Radioactive Waste Management" (DOE 2001).
Vegetation Sampling
At the RWMC, vegetation is collected from the four major areas shown in
Figure 7-4. Russian Thistle is collected in even-numbered years. Control samples
were collected near Frenchman's cabin (Figure 7-5). Because of recontouring and
construction activities at the RWMC, Russian Thistle was available for sampling
only on Pad A in 2004. The vegetation samples were analyzed for gamma-emitting
radionuclides. No gamma-emitting radionuclides were detected. Americium-241, and
90Sr results are shown in Table 7-12. The concentrations were all within the
background range for the INEEL and surrounding areas and are attributable to
past fallout.
Soil Sampling
Soil samples are collected every three years at the RWMC. Soil samples were
collected during 2003; thus, no RWMC soil samples were collected in 2004.
Direct Radiation
The radiometric scanner system was used to conduct soil surface radiation (gross
gamma) surveys at the SDA to complement soil sampling. The global positioning
radiometric scanner is mounted on a four-wheel drive vehicle. The system
includes two plastic scintillators that measure gross gamma in counts per second
with no coincidence corrections or energy compensation (elevated count rates
indicate possible areas of contamination or elevated background). Both the
global positioning system and radiometric data are continuously recorded.
Figure 7-6 shows the radiation readings from the 2004 RWMC annual survey. The survey around the active low-level waste pit was comparable to, or lower than, historical measurements for that area. No new elevated readings were identified during the survey. The maximum activity was 25,600 counts per second and was located at the west end of Trench 58. Although readings varied slightly from year to year, the results are comparable to previous years' measurements taken at the same locations.
Pad A cannot be surveyed via the global positioning radiometric scanner because of driving restrictions.
ANL-W measures direct background radiation through the use of four continuously running high pressure ion chambers (HPICs). In addition, it surveys the facility area annually with a portable radiation survey meter.
ANL-W also collects random vegetation samples from predominant wind directions and other areas of concern. Vegetation is sampled at the same locations as soil samples. Approximately 1 kg (2.2 lb) of mixed vegetation is collected and dried. The dried material is then powdered and analyzed for various radionuclides. Table 7-13 presents the 2004 vegetation results for ANL-W.
Arthur, W.J. and Janke, D.H., 1986, "Radionuclide Concentrations in Wildlife Occurring at the Solid Radioactive Waste Disposal Area," Northwest Science, 60 (3): 154-159.
Bechtel Bettis, 2005, 2004 Environmental Monitoring Report for the Naval Reactors Facility, NRFRC-EE-012.
Bohn, H.L., McNeal, B.L., and O'Connor, G.A., 1985, Soil Chemistry, 2nd edition, New York: Wiley and Sons, Inc.
EG&G, 1986, Development of Criteria for Release of Idaho National Engineering Laboratory Sites Following Decontamination and Decommissioning, EGG 2400, August.
EPA, 1995, Environmental Radiation Data Reports 79 82, July 1994-June 1995.
EPA, 1981, Process Design Manual for Land Treatment of Municipal Wastewater, EPA 625/1-81-013, Table 4-26.
IDEQ, 2000, Letter to J. Graham, "INEEL Central Facilities Area (CFA)," September 18.
NCRP, 1987, Exposure of the Population in the United States and Canada from Natural Background Radiation, NCRP Report No. 94, December 30.
NRC, 1997, Calculation of Annual Doses to Man From Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix I, Regulatory Guide 1.109, Revision 1, October.
U.S. Department of Energy (DOE), 2001, "Radioactive Waste Management," DOE Order 435.1, August 28.
U.S. Department of Energy-Idaho Operations Office (DOE-ID), 2004, Idaho National Engineering and Environmental Laboratory Site Environmental Report for Calendar-Year 2003, DOE/ID-12082 (03).
U.S. Department of Energy-Idaho Operations
Office (DOE-ID), 1999, Letter to Idaho Division of Environmental Quality,
"Wastewater Land Application Permit #LA-000141 Renewal Application and Report
for the Central Facilities Area Sewage Treatment Plant," U.S. Department of
Energy, Idaho Operations Office, February 9.