Return to top

Return to top

Return to top

Approximately 8,500 people work at the Idaho National Laboratory (INL) Site, making it the largest employer in eastern Idaho and the third largest employers in the State. The INL Site has a tremendous economic impact on eastern Idaho. Boise State University’s College of Business and Economics studied the effects of INL operations on the Idaho economy and found that the INL Site accounts for more than 2.5 percent of personal income and 3 percent of all tax revenues in Idaho. Moreover, the impacts of employees’ charitable contributions, educational outreach and volunteer activities are significant to the region and state.

The prime contractors at the INL Site are: Battelle Energy Alliance (BEA), the management and operations (M&O) contractor for the INL and CH2M-WG Idaho, LLC (CWI) which manages ongoing cleanup operations under the Idaho Cleanup Project or ICP. Other contractors include Bechtel BWXT Idaho, LLC, which operates the Advanced Mixed Waste Treatment Project (AMWTP), and Bechtel Bettis, Inc., which manages the Naval Reactors Facility.
This Annual Site Environmental Report (ASER) summarizes environmental data, information, and regulations, and highlights major environmental programs and efforts during calendar year 2006 at the INL Site. The report is published annually for the U.S. Department of Energy - Idaho Operations Office (DOE-ID) in compliance with DOE Order 231.1A, Environment, Safety and Health Reporting (DOE 2004).

Environmental Program Information

Many environmental programs help implement the environmental compliance policy for the INL Site, as discussed in Chapter 3. Most of the regulatory compliance activity is performed through environmental monitoring programs, the Environmental Restoration Program, the Waste Management Program, and other risk reduction activities.

The major objectives of the environmental monitoring programs conducted at the INL Site are to identify the key contaminants released to the environment, to evaluate different pathways through which contaminants move in the environment, and to determine the potential effects of these contaminants on the public and the environment. This is accomplished through sampling and analysis of air; surface, subsurface, and drinking water; soil; wildlife; and vegetation, as well as measurement of direct radiation. During 2006, BEA and CWI had primary responsibility for environmental monitoring at the INL Site. The Environmental Surveillance, Education and Research Program (ESER) contractor, which was a team led by the S. M. Stoller Corporation, was responsible for offsite environmental monitoring.

Ambient air, drinking water, surface water, groundwater, soils, vegetation, agricultural products, wildlife, and direct radiation were sampled by the monitoring programs. Samples were analyzed for a variety of contaminants including, but not limited to, pH, inorganics, volatile organics, gases, gross and beta activity, and specific radionuclides, such as tritium, strontium-90 (⁹⁰Sr), and plutonium isotopes.

The ICP continued progress during 2006 toward final cleanup of contaminated sites at the INL Sites. Examples of significant accomplishments during 2006 are:

• Reinitiated exhumation and processing of targeted waste from the Accelerated Retrieval Project;

• Completed removal of sludge and water from the CPP-603 spent nuclear fuel basins and grouted basins;

• High-level waste tank closure activities began at the Idaho Nuclear Technology and Engineering Center (INTEC);

• Over 4,135 m² (44,507 ft²) of buildings and structures were demolished;

• A total of 6,655 m³ (234,842 ft³) of transuranic waste was shipped to the Waste Isolation Pilot Plant in Carlsbad, New Mexico.

Environmental Monitoring Programs

The INL Site environmental surveillance programs, conducted by the INL and ICP contractors and the ESER contractor, emphasize measurement of airborne radionuclides because air transport is considered the major potential pathway from INL Site releases to receptors. The INL Site contractor monitors airborne effluents at individual INL facilities and ambient air outside the facilities to comply with appropriate regulations and DOE orders. The ICP contractor focuses on environmental surveillance of waste management facilities. The ESER contractor samples ambient air at locations within, around, and distant from the INL Site. Chapter 4 presents results of airborne monitoring.
An estimated total of 6,340 Ci of radioactivity, primarily in the form of short-lived noble gas isotopes, was released as airborne effluents in 2006. Samples of airborne particulates, atmospheric moisture, and precipitation were analyzed for gross alpha and gross beta activity, as well as for specific radionuclides, primarily tritium, ⁹⁰Sr, iodine-131 (¹³¹I), cesium-137 (¹³⁷Cs), plutonium-239/240 (^239/240Pu), and americium-241 (²⁴¹Am). All concentrations were well below regulatory standards and were within historical measurements.

Nonradiological pollutants, including particulates, were monitored at select locations around the INL Site. All results were well below regulatory standards.

One potential pathway for exposure (primarily to workers) to the contaminants released from the INL Site is through surface, drinking, and groundwater. INL Site contractors monitored liquid effluents, drinking water, groundwater, and storm water runoff at the INL Site to comply with applicable laws and regulations, DOE orders, and other requirements (e.g., Wastewater Land Application Permit [WLAP] requirements). The ESER contractor monitored drinking water and surface water at offsite locations. Chapter 5 presents results of monitoring drinking water, effluent and WLAP site performance.

During 2006, liquid effluent and groundwater monitoring were conducted in support of WLAP requirements for INL Site facilities that generate liquid waste streams covered under WLAP rules. The WLAPs generally require compliance with the Idaho groundwater quality primary and secondary constituent standards in specified groundwater monitoring wells. The permits specify annual discharge volume and application rates and effluent quality limits. As required, an annual report was prepared and submitted to the Idaho Department of Environmental Quality (DEQ). Additional parameters were also monitored in the effluent in support of surveillance activities.

Most wastewater and groundwater regulatory and surveillance results were below applicable limits in 2006. However, several elevated concentrations of metals and other constituents were detected in some samples taken from wells at INTEC and at the Test Area North (TAN). An investigation of these exceedances will be conducted during 2007.

A maximum effective dose equivalent of 0.3 mrem/year (3 µSv/year), less than the 4 mrem/year (40 µSv/year) U.S. Environmental Protection Agency (EPA) standard for public drinking water systems, was calculated for workers at the Central Facilities Area on the INL Site in 2006.

The DOE no longer conducts compliance activities associated with storm water as it was determined by EPA that no project has a reasonable potential to discharge to U.S. waters.

Chapter 6 presents the results of environmental monitoring of the Eastern Snake River Plain Aquifer and surface water. Results from a number of special studies conducted by the USGS of the properties of the aquifer were published during 2006. Two monitoring wells downgradient of Reactor Technology Complex (RTC) and INTEC show the highest tritium concentrations in the aquifer and are thus representative of maximum tritium concentration trends in the rest of the aquifer. Tritium concentrations in these two wells demonstrate a decreasing trend over time. Several purgeable organic compounds continue to be found in monitoring wells, including drinking water wells at the INL Site. Concentrations of organic compounds were below the state of Idaho groundwater primary and secondary constituent standards as well as EPA maximum contaminant levels (MCLs) for these compounds.

Groundwater surveillance monitoring continued for the WAG on the INL Site in 2006. At TAN, results of groundwater monitoring indicated that in situ bioremediation of the plume of Trichloroethene has been effective. Chromium was above the MCL in one well at the the RTC. However this concentration has been decreasing over time. Monitoring at Central Facilities Area landfills detected nitrate and thallium levels above their respective MCLs. At the INTEC, four constituents exceeded their MCLs, but concentrations of most radionuclides are decreasing over time. Concentrations of carbon tetrachloride and trichloroethylene consistently exceeded the MCLs in two wells located north of the Subsurface Disposal Area (SDA). While concentrations of these two constituents are increasing at locations north of the SDA, they are decreasing in wells south of the SDA.

Thirty semiannual drinking water samples were collected from 14 locations off the INL Site and around the Snake River Plain in 2006. Two samples had measurable tritium, three samples had measurable gross alpha activity, and 26 samples had measurable gross beta activity. None of the sample results exceeded the EPA MCL for these constituents and were considered to be within background levels.

Thirteen offsite surface water samples were collected from six offsite locations, including the Big Lost River. Two samples had measurable gross alpha activity. All samples had measurable gross beta activity, while only two samples had measurable tritium. None of these constituents were above regulatory limits and are consistent with background levels.

To help assess the impact of contaminants released to the environment by operations at the INL Site, agricultural products (milk, lettuce, wheat, potatoes, and sheep), wildlife, and soil were sampled and analyzed for radionuclides (see Chapter 7). In addition, direct radiation was measured on and off the INL Site in 2006. Some human-made radionuclides were detected in agricultural product, wildlife, and soil samples. Direct radiation measurements made at offsite, boundary, and onsite locations (except RWMC) were consistent with background levels.

Dose to the Public and Biota

Chapter 8 provides an analysis of the potential radiation dose to members of the public and to biota. Potential radiological doses to the public from INL Site operations were evaluated to determine compliance with pertinent regulations and limits. Two different computer programs were used to estimate doses: the Clean Air Act Assessment Package, 1988 (CAP-88) computer code and the mesoscale diffusion (MDIFF) air dispersion model. CAP-88 is required by the EPA to demonstrate compliance with the Clean Air Act. The NOAA Air Resources Laboratory-Field Research Division developed MDIFF to evaluate dispersion of pollutants in arid environments such as those found at the INL Site.
The maximum calculated dose to an individual by either of the methods was well below the applicable radiation protection standard of 10 mrem/year. The dose to the maximally exposed individual, as determined by the CAP-88 program, was 0.04 mrem (0.4 µSv). The dose calculated using the MDIFF dispersion guide was 0.05 mrem (0.5 µSv). The dose from natural background radiation was estimated to be 357 mrem (3.6 mSv). The maximum potential population dose to the approximately 290,819 people residing within an 80-km (50-mi) radius of any INL facility was calculated as 0.61 person-rem (6.1 x 10^-3 person-Sv), well below that expected from exposure to background radiation (103,822 person-rem or 1,038 person-Sv).

The maximum potential individual doses from consuming waterfowl and big game animals at the INL, based on the highest concentrations of radionuclides measured in samples of these animals, were estimated to be 0.01 mrem (.13 µSv), and 0.007 mrem (0.07 µSv), respectively. These estimates are conservatively high.

Doses were also evaluated using a graded approach for nonhuman biota at the INL Site. Based on this approach, there is no evidence that INL Site-related radioactivity in soil or water is harming populations of plants or animals.

Ecological Research at the Idaho National Environmental Research Park

Chapter 9 describes the ecological research activities that took place on the INL Site. The INL Site was designated as a National Environmental Research Park (NERP) in 1975. The NERP program was established in the 1970s in response to recommendations from citizens, scientists, and members of Congress to set aside land for ecosystem preservation and study. In many cases, these protected lands became the last remaining refuges of what were once extensive natural ecosystems. The NERPs provide rich environments to train researchers and introduce the public to ecological science. They have been used to educate grade school and high school students and the general public about ecosystem interactions at DOE sites; to train graduate and undergraduate students in research related to site-specific, regional, national, and global issues; and promote collaboration and coordination among local, regional, and national public organizations, schools, universities, and federal and state agencies.

Ecological research at the INL Site began in 1950 with the establishment of the long-term vegetation transect. This is perhaps DOE’s oldest ecological data set and one of the oldest vegetation data sets in the West. Ecological research on the NERPs is leading to planning for better land use, identifying sensitive areas on DOE sites so that restoration and other activities are compatible with ecosystem protection and management, and increasing contributions to ecological science in general.

The following ecological research projects took place at the Idaho NERP during 2006:

• Monitoring amphibian and reptile populations on the INL Site as indicators of environmental health and change;

• Annotated checklist of the ants on the INL Site;

• Ecology and conservation of rattlesnakes in sagebrush steppe ecosystems;

• Seasonal and landscape variation of snake mortality on the Upper Snake River Plain;

• The Protective Cap/Biobarrier Experiment;

• Developing a conservation management plan for the INL Site;

• Cesium in soils and plants in the sagebrush steppe ecosystems;

• Monitoring risk of Cheatgrass invasion and dominance at the INL Site;

• Sagebrush demography on the INL Site; and

• Long-term vegetation trends on the INL Site.

Quality Assurance

Chapter 10 describes programs used at the INL Site to ensure environmental data quality. Quality assurance and quality control programs are maintained by contractors conducting environmental monitoring and by laboratories performing environmental analyses to ensure precise, accurate, representative, and reliable results and maximize data completeness. Data reported in this document were obtained from several commercial, university, government, and government contractor laboratories. To assure quality results, these laboratories participate in a number of laboratory quality check programs.
Quality issues that arose with laboratories used by the INL, ICP and ESER contractors were addressed with the laboratories and resolved.

Return to top

Scientific notation is used to express numbers that are very small or very large. A very small number is expressed with a negative exponent, for example, 1.3 x 10^-6. To convert this number to the decimal form, the decimal point must be moved left by the number of places equal to the exponent (six, in this case). The number, thus, becomes 0.0000013.

For large numbers, those with a positive exponent, the decimal point is moved to the right by the number of places equal to the exponent. The number 1,000,000 can be written as 1.0 x 10⁶.

Units for very small and very large numbers are often expressed with a prefix. One common example is the prefix kilo (abbreviated k), which means 1000 of a given unit. One kilometer is, therefore, equal to 1000 meters. Table HI-1 shows fractions and multiples of units.

The basic unit of radioactivity used in this report is the curie (abbreviated Ci). The curie is historically based on the number of disintegrations that occur in 1 gram of the radionuclide radium-226, which is 37 billion nuclear disintegrations per second. For any other radionuclide, 1 Ci is the amount of the radionuclide that decays at this same rate.

Radiation exposure is expressed in terms of the roentgen (R), the amount of ionization produced by gamma radiation in air. Dose is given in units of roentgen equivalent man (or rem), which takes into account the effect of radiation on tissues. For the types of environmental radiation generally encountered, the unit of roentgen is approximately numerically equal to the unit of rem. A person-rem is the sum of the doses received by all individuals in a population.

The concentration of radioactivity in air samples is expressed in units of microcuries per milliliter (µCi/mL) of air. For liquid samples, such as water and milk, the units are in picocuries per liter
(pCi/L). Radioactivity in agricultural products is expressed in picocuries per gram (pCi/g) dry weight. Annual human radiation exposure, measured by environmental dosimeters, is expressed in units of milliroentgens (mR). This is sometimes expressed in terms of dose as millirem (mrem), after being multiplied by an appropriate dose equivalent conversion factor.

The Système International is also used to express units of radioactivity and radiation dose. The basic unit of radioactivity is the Becquerel (Bq), which is equivalent to one nuclear disintegration per second. The number of curies must be multiplied by 3.7 x 10¹⁰ to obtain the equivalent number of Becquerels. Radiation dose may also be expressed using the Système International unit sievert (Sv), where 1 Sv equals 100 rem.

There is always an uncertainty associated with the measurement of environmental contaminants. For radioactivity, a major source of uncertainty is the inherent statistical nature of radioactive decay events, particularly at the low activity levels encountered in environmental samples. The uncertainty of a measurement is denoted by following each result with plus or minus (±) uncertainty term. Individual analytical results are presented in this report with plus or minus one analytical deviation (± 1s). Generally the result is considered "detected" if the measurement is greater than three times its estimated analytical uncertainty (3s) unless noted otherwise, for consistency with other INL Site environmental monitoring reports.

Negative values occur in radiation measurements when the measured result is less than a pre-established average background level for the particular counting system and procedure used. These values are reported as negative, rather than as "not detected" or "zero," to better enable statistical analyses and observe trends or bias in the data.

Radionuclides are frequently expressed with the one- or two-letter chemical symbol for the element. Radionuclides may have many different isotopes, which are shown by a superscript to the left of the symbol. This number is the atomic weight of the isotope (the number of protons and neutrons in the nucleus of the atom). Most commonly used radionuclide symbols used in this report are shown in Table HI-2.

Return to top