Supplemental information is presented in this appendix on the potential impacts to humans from the normal operational releases of radioactivity and hazardous chemicals from the Stockpile Stewardship and Management Program facilities. This information is intended to support assessments of normal operation for the management and stewardship facilities described in sections 4.2.3.9, 4.3.3.9, 4.4.3.9, 4.5.3.9, 4.6.3.9, 4.7.3.9, 4.8.3.9, and 4.9.3.9 of this programmatic environmental impact statement (PEIS). Section E.2 provides information on radiological impacts while section E.3 provides information on hazardous chemical impacts.
Section E.2 presents supporting information on the potential radiological impacts to humans during normal operation of the PEIS alternatives. This section provides the reader with background information on the nature of radiation (section E.2.1), the methodology used to calculate radiological impacts (section E.2.2), and radiological releases from stockpile management facilities (section E.2.3). Releases associated with the No Action alternative for each site can be found in the referenced site environmental reports.
What is Radiation? Humans are constantly exposed to radiation from the solar system and from the earth's rocks and soil. This radiation contributes to the natural background radiation that has always surrounded us. But there are also manmade sources of radiation, such as medical and dental x rays, household smoke detectors, and materials released from nuclear and coal-fired powerplants.
All matter in the universe is composed of atoms, and radiation comes from the activity of these tiny particles. Atoms are made up of even smaller particles (protons, neutrons, and electrons). The number and arrangement of these particles distinguishes one atom from another.
Atoms of different types are known as elements. There are over 100 natural and manmade elements. Some of these elements, such as uranium, radium, plutonium, and thorium, share a very important quality: they are unstable. As they change into more stable forms, invisible waves of energy or particles, known as ionizing radiation, are released. Radioactivity is the emitting of this radiation.
Ionizing radiation refers to the fact that this energy force can ionize, or electrically charge atoms by stripping off electrons. Ionizing radiation can cause a change in the chemical composition of many things, including living tissue (organs), which can affect the way they function.
The effects on people of radiation that is emitted during disintegration (decay) of a radioactive substance depends on the kind of radiation (alpha and beta particles and gamma and x rays) and the total amount of radiation energy absorbed by the body. Alpha particles are the heaviest of these direct types of ionizing radiation, and despite a speed of about 16,100 kilometers (km) per second(s) (kps) (10,000 miles [mi] per second [mps]), they can travel only a few inches in the air. Alpha particles lose their energy almost as soon as they collide with anything. They can easily be stopped by a sheet of paper or the skin's surface.
Beta particles are much lighter than alpha particles. They can travel as fast as 161,000 kps (100,000 mps) and can travel in the air for a distance of about 3 meters (m) (10 feet [ft]). Beta particles can pass through a sheet of paper but may be stopped by a thin sheet of aluminum foil or glass.
Gamma and x rays, unlike alpha or beta particles, are waves of pure energy. Gamma rays travel at the speed of light (300,000 kps [186,000 mps]). Gamma radiation is very penetrating and requires a thick wall of concrete, lead, or steel to stop it.
The neutron is another particle that contributes to radiation exposure, both directly and indirectly. Indirect exposure is associated with the gamma rays and alpha particles that are emitted following neutron capture in matter. A neutron has about one quarter the weight of an alpha particle and can travel at speeds of up to 38,600 kps (24,000 mps). Neutrons are more penetrating than beta particles, but less penetrating than gamma rays. They can effectively be shielded by water, graphite, paraffin, or concrete.
The radioactivity of a material decreases with time. The time it takes a material to lose half of its original radioactivity is its half-life. For example, a quantity of iodine-131, a material that has a half-life of 8 days, will lose half of its radioactivity in that amount of time. In 8 more days, half of the remaining radioactivity will be lost, and so on. Eventually, the radioactivity will essentially disappear. Each radioactive element has a characteristic half-life. The half-lives of various radioactive elements may vary from millionths of a second to millions of years.
As a radioactive element gives up its radioactivity, it often changes to an entirely different element, one that may or may not be radioactive. Eventually, a stable element is formed. This transformation may take place in several steps and is known as a decay chain. Radium, for example, is a naturally occurring radioactive element with a half-life of 1,622 years. It emits an alpha particle and becomes radon, a radioactive gas with a half-life of only 3.8 days. Radon decays to polonium and, through a series of steps, to bismuth and ultimately to lead.
Units of Radiation Measure. Scientists and engineers use a variety of units to measure radiation. These different units can be used to determine the amount, type, and intensity of radiation. Just as heat can be measured in terms of its intensity or its effects, using units of calories or degrees, amounts of radiation can be measured in curies, rads, or rems.
The curie, named after the French scientists Marie and Pierre Curie, describes the "intensity" of a sample of radioactive material. The rate of decay of 1 gram of radium is the basis of this unit of measure. It is equal to 3.7x10 10 disintegrations (decays) per second.
The total energy absorbed per unit quantity of tissue is referred to as absorbed dose. The rad is the unit of measurement for the physical absorption of radiation. Much like sunlight heats the pavement by giving up an amount of energy to it, radiation gives up rads of energy to objects in its path. One rad is equal to the amount of radiation that leads to the deposition of 0.01 joule of energy per kilogram (kg) of absorbing material.
A rem is a measurement of the dose from radiation based on its biological effects. The rem is used to measure the effects of radiation on the body, much like degrees Celsius can be used to measure the effects of sunlight heating pavement. Thus, 1 rem of one type of radiation is presumed to have the same biological effects as 1 rem of any other type of radiation. This standard allows comparison of the biological effects of radionuclides that emit different types of radiation.
An individual may be exposed to ionizing radiation externally from a radioactive source outside the body and/or internally from ingesting radioactive material. An external dose is delivered only during the actual time of exposure to the external radiation source. An internal dose, however, continues to be delivered as long as the radioactive source is in the body, although both radioactive decay and elimination of the radionuclide by ordinary metabolic processes decrease the dose rate with the passage of time. The dose from internal exposure is calculated over 50 years following the initial exposure.
The three types of doses calculated in this PEIS include an external dose, an internal dose, and a combined external and internal dose. Each type of dose is discussed below.
External Dose. The external dose can arise from several different pathways. All these pathways are similar because the radiation causing the exposure is external to the body. In this PEIS, these pathways include being exposed to a cloud of radiation passing over the receptor, standing on ground that is contaminated with radioactivity, swimming in contaminated water, and boating in contaminated water. The appropriate measure of dose is called the effective dose equivalent. It should be noted that if the receptor departs from the source of radiation exposure, his dose rate will be reduced. It is assumed that external exposure occurs uniformly during the year.
Internal Dose. The internal dose arises from a radiation source entering the human body through ingestion of contaminated food and water or inhalation of contaminated air. In this PEIS, pathways for internal exposure include ingestion of crops contaminated by airborne radiation that has been deposited on the crops or by irrigation of crops using contaminated water sources, ingestion of animal products from animals that ingested contaminated food, ingestion of contaminated water, inhalation of contaminated air, and absorption of contaminated water through the skin during swimming. Unlike external exposures, once radioactive material enters the body, it remains there for various periods of time depending on decay and biological elimination rates. The unit of measure for internal doses is the committed dose equivalent. It is the internal dose that each body organ receives from 1 "year intake" (ingestion plus inhalation). Normally, a 50- or 70-year dose-commitment period is used (i.e., the 1-year intake period plus 49 or 69 years). The dose rate increases during the 1 year of intake. The dose rate, after the 1 year of intake, slowly declines as the radioactivity in the body continues to produce a dose. The integral of the dose rate over the 50 or 70 years gives the committed dose equivalent. In this PEIS, a 50-year dose-commitment period was used.
The various organs of the body have different susceptibilities to harm from radiation. The committed effective dose equivalent takes these different susceptibilities into account and provides a broad indicator of the risk to the health of an individual from radiation. It is obtained by multiplying the committed dose equivalent in each major organ or tissue by a weighting factor associated with the risk susceptibility of the tissue or organ, then summing the totals.
The committed dose equivalent to an organ is larger than the committed effective dose equivalent because the organ has a weighting factor of less than one. The concept of committed effective dose equivalent applies only to internal pathways.
Differences in radionuclide characteristics lead to different internal doses. For example, for the same amount of radioactivity, in curies, taken into the body, the dose from tritium is much less than from uranium or plutonium. Tritium emits a weak beta particle and is biologically eliminated from the body over several weeks. Uranium and plutonium emit relatively high-energy alpha particles and are retained in the body for periods of several months to many years.
Combined External and Internal Dose. For convenience, the sum of the committed effective dose equivalent from internal pathways and the effective dose equivalent from external pathways is also called the committed effective dose equivalent in this PEIS (note that in DOE Order 5400.5, Radiation Protection of the Public and the Environment, this quantity is called the effective dose equivalent).
The units used in this PEIS for committed dose equivalent, effective dose equivalent, and committed effective dose equivalent to an individual are the rem and millirem (mrem) (1/1000 of 1 rem). The corresponding unit for the collective dose to a population (the sum of the doses to members of the population, or the product of the number of exposed individuals and their average dose) is the person-rem.
Sources of Radiation. The average American receives a total of about 350 mrem per year from all sources of radiation, both natural and manmade. The sources of radiation can be divided into six different categories: cosmic radiation, terrestrial radiation, internal radiation, consumer products, medical diagnosis and therapy, and other sources. Each category is discussed below.
Cosmic radiation is ionizing radiation resulting from energetic charged particles from space continuously hitting the earth's atmosphere. These particles and the secondary particles and photons they create are cosmic radiation. Because the atmosphere provides some shielding against cosmic radiation, the intensity of this radiation increases with altitude above sea level. For the sites considered in this PEIS, the cosmic radiation ranged from about 30 to 50 mrem per year. The average annual dose to people in the United States is about 27 mrem.
External terrestrial radiation is the radiation emitted from the radioactive materials in the earth's rocks and soils. The average annual dose from external terrestrial radiation is about 28 mrem. The external terrestrial radiation for the sites in this PEIS ranged from about 30 to 75 mrem per year.
Internal radiation arises from the human body metabolizing natural radioactive material that has entered the body by inhalation or ingestion. Natural radionuclides in the body include isotopes of uranium, thorium, radium, radon, polonium, bismuth, potassium, rubidium, and carbon. The major contributors to the annual dose equivalent for internal radioactivity are the short-lived decay products of radon which contribute about 200 mrem per year. The average dose from other internal radionuclides is about 39 mrem per year.
Consumer products also contain sources of ionizing radiation. In some products, like smoke detectors and airport x-ray machines, the radiation source is essential to the products' operation. In other products, such as televisions and tobacco products, the radiation occurs incidentally to the product function. The average annual dose is about 10 mrem.
Radiation is an important diagnostic medical tool and cancer treatment. Diagnostic x rays result in an average annual exposure of 39 mrem. Nuclear medical procedures result in an average annual exposure of 14 mrem.
There are a few additional sources of radiation that contribute minor doses to individuals in the United States. The doses from nuclear fuel cycle facilities, such as uranium mines, mills, and fuel processing plants; nuclear power plants; and transportation routes has been estimated to be less than 1 mrem per year. Radioactive fallout from atmospheric atomic bomb tests, emissions of radioactive material from Department of Energy (DOE) facilities, emissions from certain mineral extraction facilities, and transportation of radioactive materials contributes less than 1 mrem per year to the average dose to an individual. Air travel contributes approximately 1 mrem per year to the average dose.
The collective (or population) dose to an exposed population is calculated by summing the estimated doses received by each member of the exposed population. This total dose received by the exposed population is measured in person-rem. For example, if 1,000 people each received a dose of 1 mrem (0.001 rem), the collective dose is 1,000 persons x 0.001 rem = 1.0 person-rem. Alternatively, the same collective dose (1.0 person-rem) results from 500 people, each of whom received a dose of 2 mrem (500 persons x 2 mrem = 1 person-rem).
Limits of Radiation Exposure. The amount of manmade radiation that the public may be exposed to is limited by Federal regulations. Although most scientists believe that radiation absorbed in small doses over several years is not harmful, U.S. Government regulations assume that the effects of all radiation exposures are cumulative.
The exposure to a member of the general public from DOE facility releases into the atmosphere is limited by the Environmental Protection Agency (EPA) to an annual dose of 10 mrem, in addition to the natural background and medical radiation normally received (40 Code of Federal Regulations [CFR] 61, Subpart H). DOE also limits to 10 mrem, the dose annually received from material released into the atmosphere (DOE Order 5400.5). EPA and DOE also limit the annual dose to the general public from radioactive releases to drinking water to 4 mrem (40 CFR 141; DOE Order 5400.5). The DOE annual limit of radiation dose to a member of the general public from all DOE facilities is 100 mrem total from all pathways (DOE Order 5400.5). For people working in an occupation that involves radiation, DOE and the Nuclear Regulatory Commission (NRC) limit doses to 5 rem (5,000 mrem) in any one year (10 CFR 20; 10 CFR 835).
Radiation exposure and its consequences are topics of interest to the general public. For this reason, this PEIS places much emphasis on the consequences of exposure to radiation, even though the effects of radiation exposure under most circumstances evaluated in this PEIS are small. This section explains the basic concepts used in the evaluation of radiation effects in order to provide the background for later discussion of impacts.
Radiation can cause a variety of ill-health effects in people. The most significant ill-health effects that result from environmental and occupational radiation exposure are cancer fatalities. These ill-health effects are referred to as "latent" cancer fatalities because the cancer may take many years to develop and for death to occur and may not actually be the cause of death. In the discussions that follow, it should be noted that all fatal cancers are latent; therefore, the term "latent" is not used.
Health impacts from radiation exposure, whether from sources external or internal to the body, generally are identified as "somatic" (affecting the individual exposed) or "genetic" (affecting descendants of the exposed individual). Radiation is more likely to produce somatic effects rather than genetic effects. Therefore, for this PEIS, only the somatic risks are presented. The somatic risks of most importance are the induction of cancers. Except for leukemia, which can have an induction period (time between exposure to carcinogen and cancer diagnosis) of as little as 2 to 7 years, most cancers have an induction period of more than 20 years.
For a uniform irradiation of the body, the incidence of cancer varies among organs and tissues. The thyroid and skin demonstrate a greater sensitivity than other organs; however, such cancers also produce relatively low mortality rates because they are relatively amenable to medical treatment. Because of the readily available data for cancer mortality rates and the relative scarcity of prospective epidemiologic studies, somatic effects leading to cancer fatalities rather than cancer incidence are presented in this PEIS. The numbers of cancer fatalities can be used to compare the risks among the various alternatives.
The fatal cancer risk estimators presented in this appendix for radiation technically apply only to low-Linear Energy Transfer radiation (gamma rays and beta particles). However, on a per rem rather than a per rad basis, the fatal risk estimators are higher for this type of radiation than for high-Linear Energy Transfer radiation (alpha particles). In this PEIS, the low-Linear Energy Transfer risk estimators are conservatively assumed to apply to all radiation exposures.
The National Research Council's Committee on the Biological Effects of Ionizing Radiations (BEIR) has prepared a series of reports to advise the U.S. Government on the health consequences of radiation exposure. The latest of these reports, Health Effects of Exposure to Low Levels of Ionizing Radiation BEIR V , published in 1990, provides the most current estimates for excess mortality from leukemia and cancers other than leukemia expected to result from exposure to ionizing radiation. The BEIR V Report updates the models and risk estimates provided in the earlier report of the BEIR III Committee, The Effects of Exposure of Populations to Low-Levels of Ionizing Radiation, published in 1980. BEIR V models were developed for application to the U.S. population.
BEIR V provides estimates that are consistently higher than those in BEIR III. This is attributed to several factors, including the use of a linear dose response model for cancers other than leukemia, revised dosimetry for the Japanese atomic bomb survivors, and additional followup studies of the atomic bomb survivors and other cohorts. BEIR III employs constant relative and absolute risk models, with separate coefficients for each sex and several age-at-exposure groups, while BEIR V develops models in which the excess relative risk is expressed as a function of age at exposure, time after exposure, and sex for each of several cancer categories. BEIR III models were based on the assumption that absolute risks are comparable between the atomic bomb survivors and the U.S. population, while BEIR V models were based on the assumption that the relative risks are comparable. For a disease such as lung cancer, where baseline risks in the United States are much larger than those in Japan, the BEIR V approach leads to larger risk estimates than the BEIR III approach.
The models and risk coefficients in BEIR V were derived through analyses of relevant epidemiologic data, including the Japanese atomic bomb survivors, ankylosis spondylitis patients, Canadian and Massachusetts fluoroscopy patients (breast cancer), New York postpartum mastitis patients (breast cancer), Israel tinea capitis patients (thyroid cancer), and Rochester thymus patients (thyroid cancer). Models for leukemia, respiratory cancer, digestive cancer, and other cancers used only the atomic bomb survivor data, although results of analyses of the ankylosis spondylitis patients were considered. Atomic bomb survivor analyses were based on revised dosimetry with an assumed Relative Biological Effectiveness of 20 for neutrons and were restricted to doses of less than 400 rads. Estimates of risks of fatal cancers other than leukemia were obtained by totaling the estimates for breast cancer, respiratory cancer, digestive cancer, and other cancers.
Risk Estimates for Doses Received During an Accident. BEIR V includes risk estimates for a single exposure of 10 rem to a population of 100,000 people (10 6 person-rem). In this case, fatality estimates for leukemia, breast cancer, respiratory cancer, digestive cancer, and other cancers are given for both sexes and nine age-at-exposure groups. These estimates, based on the linear model, are summarized in table E.2.1.2-1. The average risk estimate from all ages and both sexes is 885 excess cancer fatalities per million person-rem. This value has been conservatively rounded up to 1,000 excess cancer fatalities per million person-rem.
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Male | 220 | 660 | 880 |
Female | 160 | 730 | 890 |
Average | 190 | 695 | 885 2 |
Although values for other health effects are not presented in this PEIS, the risk estimators for nonfatal cancers and for genetic disorders in future generations are estimated to be approximately 200 and 260 per million person-rem, respectively. These values are based on information presented in the 1990 Recommendations of the International Commission on Radiological Protection (ICRP Publication 60) and are seen to be 20 and 26 percent, respectively, of the fatal cancer estimator (ICRP 1991a:22). Thus, if the number of excess fatal cancers is projected to be "Z", the number of excess genetic disorders would be 0.26xZ.
Risk Estimates for Doses Received During Normal Operation. For low doses and dose rates, a linear-quadratic model was found to provide a significantly better fit to the data for leukemia than a linear one, and leukemia risks were based on a linear-quadratic function. This reduces the effects by a factor of two over estimates that are obtained from the linear model. For other cancers, linear models were found to provide an adequate fit to the data, and were used for extrapolation to low doses. However, the BEIR V Committee recommended reducing these linear estimates by a factor between 2 and 10 for doses received at low dose rates. For this PEIS, a risk reduction factor of 2 was adopted for conservatism.
Based on the above discussion, the resulting dose-to-risk conversion factor would be equal to half the value observed for accident situations or approximately 500 excess fatal cancers per million person-rem (0.0005 excess fatal cancers per person-rem). This is the risk value used in this PEIS to calculate fatal cancers to the general public during normal operation. For workers, a dose-to-risk conversion factor of 400 excess fatal cancers per million person-rem (0.0004 excess fatal cancers per person-rem) is used in this PEIS. This lower value reflects the absence of children in the workforce. Again, based on information provided in ICRP Publication 60, the health risk estimators for nonfatal cancers and genetic disorders among the public are 20 percent and 26 percent, respectively, of the fatal cancer dose-to-risk conversion factor. For workers, the health risk estimators for nonfatal cancers and genetic disorders are both 20 percent of the fatal cancer dose-to-risk conversion factor. For this PEIS, only fatal cancers are presented.
The risk estimates may be applied to calculate the effects of exposing a population to radiation. For example, in a population of 100,000 people exposed only to natural background radiation (0.3 rem per year), 15 cancer fatalities per year would be inferred to be caused by the radiation (100,000 persons x 0.3 rem per year x 0.0005 cancer fatalities per person-rem = 15 cancer fatalities per year).
Sometimes, calculations of the number of excess cancer fatalities associated with radiation exposure do not yield whole numbers and, especially in environmental applications, may yield numbers less than 1.0. For example, if a population of 100,000 were exposed as above, but to a total dose of only 0.001 rem, the collective dose would be 100 person-rem, and the corresponding estimated number of cancer fatalities would be 0.05 (100,000 persons x 0.001 rem x 0.0005 cancer fatalities/person-rem = 0.05 fatal cancers).
How should one interpret a nonintegral number of cancer fatalities such as 0.05? The answer is to interpret the result as a statistical estimate. That is, 0.05 is the average number of deaths that would result if the same exposure situation were applied to many different groups of 100,000 people. In most groups, no person (0 people) would incur a cancer fatality from the 0.001 rem dose each member would have received. In a small fraction of the groups, one fatal cancer would result; in exceptionally few groups, two or more fatal cancers would occur. The average number of deaths over all the groups would be 0.05 fatal cancers (just as the average of 0, 0, 0, and 1 is 1/4, or 0.25). The most likely outcome is 0 cancer fatalities.
These same concepts apply to estimating the effects of radiation exposure on a single individual. Consider the effects, for example, of exposure to background radiation over a lifetime. The "number of cancer fatalities" corresponding to a single individual's exposure over a (presumed) 72-year lifetime to 0.3 rem per year is the following:
1 person x 0.3 rem/year x 72 years x 0.0005 cancer fatalities/person-rem = 0.011 cancer fatalities.
Again, this should be interpreted in a statistical sense; that is, the estimated effect of background radiation exposure on the exposed individual would produce a 1.1-percent chance that the individual might incur a fatal cancer caused by the exposure. Presented another way, this method estimates that approximately 1.1 percent of the population might die of cancers induced by the background radiation.
The radiological impacts of normal operation of alternatives were calculated using Version 1.485 of the GENII computer code. Site-specific and technology-specific input data were used, including location, meteorology, population, food production and consumption, and source terms. The GENII code was used for analysis of normal operations and design basis accidents. Section E.2.2.1 briefly describes GENII and outlines the approach used for normal operations.
The GENII computer model, developed by Pacific Northwest Laboratory for DOE, is an integrated system of various computer modules that analyze environmental contamination resulting from acute or chronic releases to, or initial contamination in, air, water, or soil. The model calculates radiation doses to individuals and populations. The GENII computer model is well documented for assumptions, technical approach, methodology, and quality assurance issues ( GENII -- The Hanford Environmental Radiation Dosimetry Software System [December 1988]). The GENII computer model has gone through extensive quality assurance and quality control steps. These include the comparison of results from model computations against those from hand calculations, and the performance of internal and external peer reviews. Recommendations given in these reports were incorporated into the final GENII computer model, as deemed appropriate.
For this PEIS only the ENVIN, ENV, and DOSE computer modules were used. The codes are connected through data transfer files. The output of one code is stored in a file that can be used by the next code in the system. In addition, a computer code called CREGENII was prepared to aid the user with the preparation of input files into GENII.
CREGENII. The CREGENII code helps the user, through a series of interactive menus and questions, prepare a text input file for the environmental dosimetry programs. In addition, CREGENII prepares a batch processing file to manage the file handling needed to control the operations of subsequent codes and to prepare an output report.
ENVIN. The ENVIN module of the GENII code controls the reading of the input files prepared by CREGENII and organizes the input for optimal use in the environmental transport and exposure module, ENV. The ENVIN code interprets the basic input, reads the basic GENII data libraries and other optional input files, and organizes the input into sequential segments on the basis of radionuclide decay chains.
A standardized file that contains scenario, control, and inventory parameters is used as input to ENVIN. Radionuclide inventories can be entered as functions of releases to air or water, concentrations in basic environmental media (air, soil, or water), or concentrations in foods. If certain atmospheric dispersion options have been selected, this module can generate tables of atmospheric dispersion parameters that will be used in later calculations. If the finite plume air submersion option is requested in addition to the atmospheric dispersion calculations, preliminary energy-dependent finite plume dose factors also are prepared. The ENVIN module prepares the data transfer files that are used as input by the ENV module; ENVIN generates the first portion of the calculation documentation--the run input parameters report.
ENV. The ENV module calculates the environmental transfer, uptake, and human exposure to radionuclides that result from the chosen scenario for the user-specified source term. The code reads the input files from ENVIN and then, for each radionuclide chain, sequentially performs the precalculations to establish the conditions at the start of the exposure scenario. Environmental concentrations of radionuclides are established at the beginning of the scenario by assuming decay of preexisting sources, considering biotic transport of existing subsurface contamination, and defining soil contamination from continuing atmospheric or irrigation depositions. Then, for each year of postulated exposure, the code estimates air, surface soil, deep soil, groundwater, and surface water concentrations of each radionuclide in the chain. Human exposures and intakes of each radionuclide are calculated for pathways of external exposure from finite atmospheric plumes, inhalation, external exposure from contaminated soil, sediments, and water, external exposure from special geometries, and internal exposures from consumption of terrestrial foods, aquatic foods, drinking water, animal products, and inadvertent intake of soil. The intermediate information on annual media concentrations and intake rates are written to data transfer files. Although these may be accessed directly, they are usually used as input to the DOSE module of GENII.
GENII is a general purpose computer code used to model dispersion, transport, and long-term exposure effects of specific radionuclides and pathways. Sophisticated codes such as UFOTRI and ETMOD (Environmental Tritium Model) are used exclusively for modeling tritium transport and dosimetry. The UFOTRI and ETMOD codes were not chosen for use in this PEIS because of the lack of information on detailed facility design and on the breakdown of tritium into elemental and tritiated water forms, and because these codes cannot be used for modeling the exposure effects of radionuclides other than tritium. GENII was chosen because it can model both air and surface transport pathways and is not restricted to any radionuclides.
DOSE. The DOSE module reads the annual intake and exposure rates defined by the ENV module and converts the data to radiation dose. External dose is calculated with precalculated factors from the EXTDF module or from a data file prepared outside of GENII. Internal dose is calculated with precalculated factors from the INTDF module.
EXTDF. The EXTDF module calculates the external dose-rate factors for submersion in an infinite cloud of radioactive materials, immersion in contaminated water, and direct exposure to plane or slab sources of radionuclides. EXTDF was not used. Instead, the dose rate factors listed in External Dose Rate Factors for Calculation of Dose to the Public (DOE/EH-0070) were used for this PEIS.
INTDF. Using the Limits for Intakes of Radionuclides by Workers (ICRP Publication 30) model, the INTDF module calculates the internal (inhalation and ingestion) dose conversion factors of radionuclides for specific organs. The factors generated by INTDF were used for the calculations presented in this PEIS.
In order to perform the dose assessments for this PEIS, different types of data must be collected and/or generated. In addition, calculational assumptions have to be made. This section discusses the data collected and/or generated for use in the dose assessment and assumptions made for this PEIS.
Meteorological Data. The meteorological data used for all applicable DOE sites were in the form of joint frequency data files. A joint frequency data file is a table listing the fractions of time the wind blows in a certain direction, at a certain speed, and within a certain stability class. The joint frequency data files were based on measurements over a 1-year period at various locations and at different heights at the sites. Average meteorological conditions (averaged over the 1-year period) were used for normal operation. For use in design basis accidents, the 50 percentile option was used.
Population Data. Population distributions were based on 1990 Census of Population and Housing data. Projections were determined for the year 2030 for areas within 80 km (50 mi) of the proposed facilities at each candidate site. This year of analysis was selected as conservatively representative of the population over the operational period evaluated, and was used in the impact assessments. The population was spatially distributed on a circular grid with 16 directions and 10 radial distances up to 80 km (50 mi). The grid was centered on the facility from which the radionuclides were assumed to be released.
Source Term Data. The source terms (quantities of radionuclides released into the environment over a given period) were estimated on the basis of latest conceptual designs of facilities and experience with similar facilities. The source terms used to generate the estimated impacts of normal operation are provided in section E.2.3.
Food Production and Consumption Data. Data from the 1987 Census of Agriculture were used to generate site-specific data for food production. Food production was spatially distributed on the same circular grid as was used for the population distributions. The consumption rates were those used in GENII for the maximum individual and average individual. People living within the 80 km (50 mi) assessment area were assumed to consume only food grown in that area.
Calculational Assumptions. Dose assessments were performed for members of the general public and workers. Dose assessments for members of the public were performed for two different types of receptors considered in this PEIS: a maximally exposed offsite individual and the general population living within 80 km (50 mi) of the facility. It was assumed that the maximally exposed individual was located at a position on the site boundary that would yield the highest impacts during normal operation of a given alternative. If more than one facility was assumed to be operating at a site, the dose to the individual from each facility was calculated. The doses were then summed to give the total dose to the individual. A 80 km (50 mi) population dose was calculated for each operating facility at a site. These doses were then added to give the total population dose at that site.
To estimate the radiological impacts from normal operation of Stockpile Stewardship and Management alternatives, additional assumptions and factors were considered in using GENII:
Resuspension of particulates was not considered because prior calculations of dust loading in the atmosphere showed that this pathway was negligible compared with others. The exposure, uptake, and usage parameters used in the GENII model are provided in tables E.2.2.2-1 through E.2.2.2-4.
Annual average doses to workers for No Action at all DOE sites were based on measured values received by radiation workers during the 1992 time period. The average No Action dose received by a worker at these sites in future years was assumed to remain the same as the annual average during the 1992 period. The total workforce dose in future years was calculated by multiplying the average worker dose by a projected number of future workers.
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6,136 | 6,136 | 6,136 | 270 |
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Leafy vegetables | 90.0 | 1.5 | 1.0 | 30.0 | 90.0 | 1.5 | 14.0 | 15.0 |
Root vegetables |
90.0 | 4.0 | 5.0 | 220.0 | 90.0 | 4.0 | 14.0 | 140.0 |
Fruit |
90.0 | 2.0 | 5.0 | 333 | 90.0 | 2.0 | 14.0 | 64.0 |
Grains/cereals |
90.0 | 0.8 | 180.0 | 80.0 | 90.0 | 0.8 | 180.0 | 72.0 |
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Beef | 80.0 | 15.0 | 0.25 | 90.0 | 0.80 | 180.0 | 0.75 | 45.0 | 2.00 | 100.0 | ||
Poultry |
18.0 | 1.0 | 1.00 | 90.0 | 0.80 | 180.0 | ||||||
Milk |
270.0 | 1.0 | 0.25 | 45.0 | 2.00 | 100.0 | 0.75 | 30.0 | 1.50 | 0.0 | ||
Eggs |
30.0 | 1.0 | 1.00 | 90.0 | 0.80 | 180.0 | ||||||
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General Population | |||||||||||
Beef | 70.0 | 34.0 | 0.25 | 90.0 | 0.80 | 180.0 | 0.75 | 45.0 | 2.00 | 100.0 | ||
Poultry |
8.5 | 34.0 | 1.00 | 90.0 | 0.80 | 180.0 | ||||||
Milk |
230.0 | 4.0 | 0.25 | 45.0 | 2.00 | 100.0 | 0.75 | 30.0 | 1.50 | 0.0 | ||
Eggs |
20.0 | 18.0 | 1.00 | 90.0 | 0.80 | 180.0 | ||||||
HNUS 1995a. | ||||||||||||
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to Usage Point |
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to Usage Point |
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Drinking water | 0.0 | 0.0 | 730 L |
| 0.0 | 0.0 | Site dependent |
Swimming | 0.0 | 0.0 | 100 hours |
| 0.0 | 0.0 | Site dependent |
Boating | 0.0 | 0.0 | 100 hours |
| 0.0 | 0.0 | Site dependent |
Shoreline | 0.0 | 0.0 | 500 hours |
| 0.0 | 0.0 | Site dependent |
Ingestion of fish | 0.0 | 0.0 | 40 kg |
| 0.0 | 0.0 | Site dependent |
Ingestion of mollus | 0.0 | 0.0 | 6.9 kg |
| 0.0 | 0.0 | Site dependent |
Ingestion of crusta | 0.0 | 0.0 | 6.9 kg |
| 0.0 | 0.0 | Site dependent |
Ingestion of plants | 0.0 | 0.0 | 6.9 kg |
| 0.0 | 0.0 | Site dependent |
HNUS 1995a. | |||||||
Doses to workers directly associated with stewardship and management facilities were taken either from data reports prepared by the DOE Complex sites or from occupational dose histories for similar operations. To obtain the total workforce dose at a site with particular stewardship and/or management facilities in operation, the site dose from No Action was added to that from the facilities being evaluated. The average dose to a site worker was then calculated by dividing this dose by the total number of workers at the site. All doses to workers include a component associated with the intake of radioactivity into the body and another component resulting from external exposure to direct radiation.
Doses calculated by GENII were used to estimate health effects using the risk estimators presented in section E.2.1.2. The incremental cancer fatalities in the general population and groups of workers due to radiation exposure were therefore estimated by multiplying the collective combined effective dose equivalent by 0.0005 and 0.0004 fatal cancers/person-rem, respectively. In this PEIS, the collective combined effective dose equivalent is the sum of the collective committed effective dose equivalent (internal dose) and the collective effective dose equivalent (external dose), section E.2.1.1.
Although health risk factors are statistical factors and therefore not strictly applicable to individuals, they have been used in the past to estimate the incremental risk to an individual from exposure to radiation. Therefore, the factors of 0.0005 and 0.0004 per rem of individual committed effective dose equivalent for a member of the public and for a worker, respectively, have also been used in this PEIS to calculate the individual's incremental fatal cancer risk from exposure to radiation.
For the public, the health effects expressed in this PEIS are the risk of fatal cancers for the maximally exposed individual and the number of fatal cancers in the 80 km (50 mi) population from exposure to radioactivity released from any site over the 25-year operational period. For workers, the health effects expressed are the risk to the average worker at a site and the number of fatal cancers to all workers at the site from 25 years of site operation.
This section presents source terms (i.e., radiological releases) to the environment from the normal operation of stockpile management alternatives at each of the applicable proposed sites (Oak Ridge Reservation [ORR], table E.2.3-1; Savannah River Site [SRS], table E.2.3-2; Pantex Plant [Pantex], table E.2.3-3; Los Alamos National Laboratory [LANL], tables E.2.3-4 and E.2.3-5; Lawrence Livermore National Laboratory [LLNL], table E.2.3-6; and Nevada Test Site [NTS], table E.2.3-7). These source terms were used in the GENII dose model calculations, which were ultimately used in estimating the most conservative radiological impacts at each site from each of the applicable management alternatives presented in this PEIS. These resultant incremental doses (and associated cancer risks) can be found in sections 4.2.3.9, 4.3.3.9, 4.5.3.9, 4.6.3.9, 4.7.3.9, and 4.9.3.9, respectively, by subtracting the applicable site's No Action impacts from each management alternative's impact total. Only atmospheric releases have been presented because liquid radiological discharges are not expected from any of the alternatives at any of the sites.
| |
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(Ci) |
|---|---|
| Uranium-235 | 4.2x10 -4 |
| Uranium-238 | 1.5x10 -3 |
OR MMES 1996j. | |
| |
|
(Ci) |
|---|---|
Plutonium-238 | 1.9x10 -8 |
Plutonium-239 | 1.3x10 -7 |
Plutonium-240 | 3.0x10 -8 |
Plutonium-241 | 9.0x10 -7 |
Americium-241 | 2.8x10 -8 |
Total | 1.1x10 -6 |
Representative of unclassified isotopic distribution associated with weapons-grade plutonium.LANL1995g. | |
|
(Ci) |
|---|---|
| Hydrogen-3 | 0.45 |
PX MH 1995a.
| |
|
(Ci) |
|---|---|
Plutonium-238 | 1.9x10 -8 |
Plutonium-239 | 1.3x10 -7 |
Plutonium-240 | 3.0x10 -8 |
Plutonium-241 | 9.0x10 -7 |
Americium-241 | 2.8x10 -8 |
Total | 1.1x10 -6 |
Representative of unclassified complete isotopic distribution associated with weapons-grade plutonium.LANL 1995g. | |
|
(Ci) |
|---|---|
Uranium-235 | 4.9x10 -4 |
Uranium-238 | 1.8x10 -3 |
LANL 1995e. | |
|
(Ci) |
|---|---|
| Uranium-235 | 1.4x10 -4 |
| Uranium-238 | 4.8x10 -4 |
LLNL 1995c. |
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(Ci) |
|---|---|
| Hydrogen-3 | 0.45 |
PX MH 1995a. |
Two general types of adverse human health effects are assessed for hazardous chemical exposure in this PEIS. These are carcinogenic and noncarcinogenic effects. A Chemical Health Effects Technical Reference (TTI 1996b) was developed to assist the risk assessor in the evaluation process. Part I of the Technical Reference contains a table of chemical toxicity profiles which characterizes each chemical in terms of physical properties, potential exposure routes, and the effects on target tissues/organs that might be expected. It is to be used qualitatively by the risk assessor to determine how exposure might occur (exposure route), what tissue or organ system might be impacted (e.g., central nervous system dysfunction, or liver cancer), and whether the chemical might possess other properties affecting its bioavailability in a given matrix (e.g., air, water, or soil). Part II of the Technical Reference contains a table of exposure limits which provides the risk assessor with the necessary information to calculate risk or expected adverse effects should an individual be exposed to a hazardous chemical for a long time at low levels (chronic exposure) or to higher concentrations for a short-term (acute) exposure. Where a dose effect calculation is required (milligram [mg]/kg/day), the reference dose is applicable, and where an inhalation concentration effect is required, the reference concentration (i.e., RfC in mg/m3) is applicable for chronic exposures. The permissible exposure limit values, which regulate worker exposures over 8-hour periods, determine the concentration allowed for occupational exposures that would be without adverse acute effects. Other values, such as the threshold limit value (TLV), are presented because they are prepared by the American Conference of Governmental Industrial Hygienists for guidance on exposures of 8-hour periods, and can be used to augment permissible exposure limits or serve as exposure levels in the absence of a permissible exposure limit. All currently regulated chemicals associated with each site and every hazardous chemical are presented in the Chemical Health Effects Technical Reference.
Part I of the Chemical Health Effects Technical Reference provides the pertinent facts about each chemical that is included in the risk assessment of this PEIS. This reference includes the chemical abstracts service number, which aids in a search for information available on any specific chemical and ensures a positive identity regardless of which name or synonym is used. It also contains physical information (i.e., solubility, vapor pressure, and flammability), as well as incompatibility data that is useful in determining whether a hazard might exist and the nature of the hazard. The route of exposure, target organs/tissues, and carcinogenicity provide an abbreviated summary on how individuals may get exposed, what body functions could be affected, and whether chronic exposure could lead to increased cancer incidence in an exposed population.
Hazardous chemicals are regulated by various agencies in order to provide protection to the public (EPA regulated) and to workers ( Occupational Safety and Health Administration [OSHA]), while others (National Institute for Occupational Safety and Health and the American Conference of Governmental Industrial Hygienists) provide guidelines. The reference doses and reference concentrations set by EPA represent exposure limits for long-term (chronic) exposure at low doses and concentrations, respectively, that can be considered safe from adverse noncancer effects. The permissible exposure limit represents concentration levels set by OSHA that are safe for 8-hour exposures without causing noncancer adverse effects. The slope factor or the unit risk is used to convert the daily uptake of a carcinogenic chemical averaged over a lifetime to the incremental risk of an individual developing cancer. Part II of the Chemical Health Effects Technical Reference presents the information on exposure limits used to develop HQs for each of the hazardous chemicals and the HIs derived from their summation and the slope factors used to calculate cancer risk for each chemical at the exposure concentrations identified at the various sites or associated with a proposed alternative action.
1
These are the linear estimates and are double the linear-quadratic
estimates provided in BEIR V for leukemia at low doses and dose-rates.