GLOSSARY
E-Z
effective probe area: The physical probe area corrected for the amount of the probe area covered by a protective screen.
elevated area: See area of elevated activity.
elevated measurement: A measurement that exceeds a specified value DCGL EMC.
Elevated Measurement Comparison (EMC): This comparison is used in conjunction with the Wilcoxon test to determine if there are any measurements that exceed a specified value DCGL EMC.
exposure pathway: The route by which radioactivity travels through the environment to eventually cause radiation exposure to a person or group.
exposure rate: The amount of ionization produced per unit time in air by X-rays or gamma rays. The unit of exposure rate is Roentgens/hour (R/h); for decommissioning activities the typical units are microRoentgens per hour (µR/h), i.e., 10-6 R/h.
external radiation: Radiation from a source outside the body.
false negative decision error: The error that occurs when the null hypothesis (H0) is not rejected when it is false. For example, the false negative decision error occurs when the decision maker concludes that the waste is hazardous when it truly is not hazardous. A statistician usually refers to a false negative error as a Type II decision error. The measure of the size of this error is called beta, and is also known as the complement of the power of a hypothesis test.
false positive decision error: A false positive decision error occurs when the null hypothesis (H0) is rejected when it is true. Consider an example where the decision maker presumes that a certain waste is hazardous (i.e., the null hypothesis or baseline condition is "the waste is hazardous"). If the decision maker concludes that there is insufficient evidence to classify the waste as hazardous when it truly is hazardous, the decision maker would make a false positive decision error. A statistician usually refers to the false positive error as a Type I decision error. The measure of the size of this error is called alpha, the level of significance, or the size of the critical region.
Field Sampling Plan: As defined for Superfund in the Code of Federal Regulations 40 CFR 300.430, a document which describes the number, type, and location of samples and the type of analyses to be performed. It is part of the Sampling and Analysis Plan.
final status survey: Measurements and sampling to describe the radiological conditions of a site, following completion of decontamination activities (if any) in preparation for release.
fluence rate: A fundamental parameter for assessing the level of radiation at a measurement site. In the case of in situ spectrometric measurements, a calibrated detector provides a measure of the fluence rate of primary photons at specific energies that are characteristic of a particular radionuclide.
gamma (g) radiation: Penetrating high-energy, short-wavelength electromagnetic radiation (similar to X-rays) emitted during radioactive decay. Gamma rays are very penetrating and require dense materials (such as lead or steel) for shielding.
graded approach: The process of basing the level of application of managerial controls applied to an item or work according to the intended use of the results and the degree of confidence needed in the quality of the results. See data quality objectives process.
gray region: A range of values of the parameter of interest for a survey unit where the consequences of making a decision error are relatively minor. The upper bound of the gray region in MARSSIM is set equal to the DCGLW, and the lower bound of the gray region (LBGR) is a site-specific variable.
grid: A network of parallel horizontal and vertical lines forming squares on a map that may be overlaid on a property parcel for the purpose of identification of exact locations. See reference coordinate system.
grid block: A square defined by two adjacent vertical and two adjacent horizontal reference grid lines.
half-life (t½): The time required for one-half of the atoms of a particular radionuclide present to disintegrate.
Historical Site Assessment (HSA): A detailed investigation to collect existing information, primarily historical, on a site and its surroundings.
hot measurement: See elevated measurement.
hot spot: See area of elevated activity.
hypothesis: An assumption about a property or characteristic of a set of data under study. The goal of statistical inference is to decide which of two complementary hypotheses is likely to be true. The null hypothesis (H0) describes what is assumed to be the true state of nature and the alternative hypothesis (Ha) describes the opposite situation.
impacted area: Any area that is not classified as non-impacted. Areas with a possibility of containing residual radioactivity in excess of natural background or fallout levels.
independent assessment: An assessment performed by a qualified individual, group, or organization that is not part of the organization directly performing and accountable for the work being assessed.
indistinguishable from background: The term indistinguishable from background means that the detectable concentration distribution of a radionuclide is not statistically different from the background concentration distribution of that radionuclide in the vicinity of the site or, in the case of structures, in similar materials using adequate measurement technology, survey, and statistical techniques.
infiltration rate: The rate at which a quantity of a hazardous substance moves from one environmental medium to another - e.g., the rate at which a quantity of a radionuclide moves from a source into and through a volume of soil or solution.
inspection: An activity such as measuring, examining, testing, or gauging one or more characteristics of an entity and comparing the results with specified requirements in order to establish whether conformance is achieved for each characteristic.
inventory: Total residual quantity of formerly licensed radioactive material at a site.
investigation level: A derived media-specific, radionuclide-specific concentration or activity level of radioactivity that: 1) is based on the release criterion, and 2) triggers a response, such as further investigation or cleanup, if exceeded. See action level.
isopleth: A line drawn through points on a graph or plot at which a given quantity has the same numerical value or occurs with the same frequency.
judgment measurement: Measurements performed at locations selected using professional judgment based on unusual appearance, location relative to known contaminated areas, high potential for residual radioactivity, general supplemental information, etc. Judgment measurements are not included in the statistical evaluation of the survey unit data because they violate the assumption of randomly selected, independent measurements. Instead, judgment measurements are individually compared to the DCGL W.
karst terrain: A kind of terrain with characteristics of relief and drainage arising from a high degree of rock solubility. The majority of karst conditions occur in limestone areas, but karst may also occur in areas of dolomite, gypsum, or salt deposits. Features associated with karst terrain may include irregular topography, abrupt ridges, sink holes, caverns, abundant springs, and disappearing streams. Well developed or well integrated drainage systems of streams and tributaries are generally not present.
klystron: An electron tube used in television, etc., for converting a stream of electrons into ultra high-frequency waves that are transmitted as a pencil-like radio beam.
less-than data: Measurements that are less than the minimum detectable concentration.
license: A license issued under the regulations in parts 30 through 35, 39, 40, 60, 61, 70 or part 72 of 10 CFR Chapter I.
licensee: The holder of a license.
license termination: Discontinuation of a license, the eventual conclusion to decommissioning.
lower bound of the gray region (LBGR): The minimum value of the gray region. The width of the gray region (DCGL-LBGR) is also referred to as the shift, ).
lower limit of detection (LD): The smallest amount of radiation or radioactivity that statistically yields a net result above the method background. The critical detection level, LC, is the lower bound of the 95% detection interval defined for LD and is the level at which there is a 5% chance of calling a background value "greater than background." This value should be used when actually counting samples or making direct radiation measurements. Any response above this level should be considered as above background; i.e., a net positive result. This will ensure 95% detection capability for LD. A 95% confidence interval should be calculated for all responses greater than LC.
m: The number of measurements from the reference area used to conduct a statistical test.
magnetron: A vacuum tube in which the flow of ions from the heated cathode to the anode is controlled by a magnetic field externally applied and perpendicular to the electric field by which they are propelled. Magnetrons are used to produce very short radio waves.
measurement: For the purpose of MARSSIM, it is used interchangeably to mean: 1) the act of using a detector to determine the level or quantity of radioactivity on a surface or in a sample of material removed from a media being evaluated, or 2) the quantity obtained by the act of measuring.
micrometeorology: The study of weather conditions in a local or very small area, such as immediately around a tree or building, that can affect meteorological conditions.
minimum detectable concentration (MDC): The minimum detectable concentration (MDC) is the a priori activity level that a specific instrument and technique can be expected to detect 95% of the time. When stating the detection capability of an instrument, this value should be used. The MDC is the detection limit, LD , multiplied by an appropriate conversion factor to give units of activity.
minimum detectable count rate (MDCR): The minimum detectable count rate (MDCR) is the a priori count rate that a specific instrument and technique can be expected to detect.
missing or unusable data: Data (measurements) that are mislabeled, lost, or do not meet quality control standards. Less-than data are not considered to be missing or unusable data. See R.
munitions: Military supplies, especially weapons and ammunition.
N: N = m + n, is the total number of measurements required from the reference area and a survey unit. See m and n.
n: Number of measurements from a survey unit used to conduct a statistical test.
nf: The number of samples that should be collected in an area to assure that the required number of measurements from that area for conducting statistical tests is obtained. nf = n/(1-R).
NARM: Naturally occurring or accelerator-produced radioactive material, such as radium, and not classified as source material.
naturally occurring radionuclides: Radionuclides and their associated progeny produced during the formation of the earth or by interactions of terrestrial matter with cosmic rays.
non-blind measurement: Non-blind measurements are measurements that have a concentration and origin that are known to the individual performing the measurement. See single-blind measurement and double-blind measurement.
nonconformance: A deficiency in characteristic, documentation, or procedure that renders the quality of an item or activity unacceptable or indeterminate; nonfulfillment of a specified requirements.
non-impacted area: Areas where there is no reasonable possibility (extremely low probability) of residual contamination. Non-impacted areas are typically located off-site and may be used as background reference areas.
nonparametric test: A test based on relatively few assumptions about the exact form of the underlying probability distributions of the measurements. As a consequence, nonparametric tests are generally valid for a fairly broad class of distributions. The Wilcoxon Rank Sum test and the Sign test are examples of nonparametric tests.
normal (gaussian) distribution: A family of bell shaped distributions described by the mean and variance.
organization: a company, corporation, firm, government unit, enterprise, facility, or institution, or part thereof, whether incorporated or not, public or private, that has its own functions and administration.
outlier: Measurements that are unusually large or small relative to the rest and therefore are suspected of misrepresenting the population from which they were collected.
p: The probability that a random measurement from the survey unit is less than ).
p': The probability that the sum of two independent random measurements from the survey unit is less than 2).
Pr: The probability that a measurement performed at a random location in the survey unit is greater than a measurement performed at a random location in the reference area.
peer review: A documented critical review of work generally beyond the state of the art or characterized by the existence of potential uncertainty. The peer review is conducted by qualified individuals (or organization) who are independent of those who performed the work, but are collectively equivalent in technical expertise (i.e., peers) to those who performed the original work. The peer review is conducted to ensure that activities are technically adequate, competently performed, properly documented, and satisfy established technical and quality requirements. The peer review is an in-depth assessment of the assumptions, calculations, extrapolations, alternate interpretations,
methodology, acceptance criteria, and conclusions pertaining to specific work and of the documentation that supports them. Peer reviews provide an evaluation of a subject where quantitative methods of analysis or measures of success are unavailable or undefined, such as in research and development.
performance evaluation: A type of audit in which the quantitative data generated in a measurement system are obtained independently and compared with routinely obtained data to evaluate the proficiency of an analyst or laboratory.
physical probe area: The physical surface area assessed by a detector. The physical probe area is used to make probe area corrections in the activity calculations.
Pitman efficiency: A measure of performance for statistical tests. It is equal to the reciprocal of the ratio of the sample sizes required by each of two tests to achieve the same power, as these sample sizes become large.
power (1-$): The probability of rejecting the null hypothesis when it is false. The power is equal to one minus the Type II error rate, i.e. (1-$).
precision: A measure of mutual agreement among individual measurements of the same property, usually under prescribed similar conditions, expressed generally in terms of the standard deviation.
process: A combination of people, machine and equipment, methods, and the environment in which they operate to produce a given product or service.
professional judgement: An expression of opinion, based on technical knowledge and professional experience, assumptions, algorithms, and definitions, as stated by an expert in response to technical problems.
qualified data: Any data that have been modified or adjusted as part of statistical or mathematical evaluation, data validation, or data verification operations.
quality: The totality of features and characteristics of a product or service that bear on its ability to meet the stated or implied needs and expectations of the user.
quality assurance (QA): An integrated system of management activities involving planning, implementation, assessment, reporting, and quality improvement to ensure that a process, item, or service is of the type and quality needed and expected by the customer.
Quality Assurance Project Plan (QAPP): A formal document describing in comprehensive detail the necessary QA, QC, and other technical activities that must be implemented to ensure that the results of the work performed will satisfy the stated performance criteria. As defined for Superfund in the Code of Federal Regulations 40 CFR 300.430, the Quality Assurance Project Plan describes policy, organization, and functional activities and the Data Quality Objectives and measures necessary to achieve adequate data for use in selecting the appropriate remedy.
QAPP is a plan that provides a process for obtaining data of sufficient quality and quantity to
satisfy data needs. It is a part of the Sampling and Analysis Plan.
quality control (QC): The overall system of technical activities that measure the attributes and performance of a process, item, or service against defined standards to verify that they meet the stated requirements established by the customer, operational techniques and activities that are used to fulfill requirements for quality.
quality indicators: Measurable attributes of the attainment of the necessary quality for a particular environmental decision. Indicators of quality include precision, bias, completeness, representativeness, reproducibility, comparability, and statistical confidence.
Quality Management Plan (QMP): A formal document that describes the quality system in terms of the organizational structure, functional responsibilities of management and staff, lines of authority, and required interfaces for those planning, implementing, and assessing all activities conducted.
quality system: A structured and documented management system describing the policies, objectives, principles, organizational authority, responsibilities, accountability, and implementation plan of an organization for ensuring quality in its work processes, products (items), and services. The quality system provides the framework for planning, implementing, and assessing work performed by the organization and for carrying out required QA and QC.
R: The rate of missing or unusable measurements expected to occur for samples collected in reference areas or survey units. See missing or unusable data. See nf. (Not to be confused with the symbol for the radiation exposure unit Roentgen.)
RA: The acceptable level of risk associated with not detecting an area of elevated activity of area Amin.
radiation survey: Measurements of radiation levels associated with a site together with appropriate documentation and data evaluation.
radioactive decay: The spontaneous transformation of an unstable atom into one or more different nuclides accompanied by either the emission of energy and/or particles from the nucleus, nuclear capture or ejection of orbital electrons, or fission. Unstable atoms decay into a more stable state, eventually reaching a form that does not decay further or has a very long half-life.
radioactivity: The mean number of nuclear transformations occurring in a given quantity of radioactive material per unit time. The International System (SI) unit of radioactivity is the Becquerel (Bq). The customary unit is the Curie (Ci).
radiological survey: Measurements of radiation levels and radioactivity associated with a site together with appropriate documentation and data evaluation.
radioluminescence: Light produced by the absorption of energy from ionizing radiation.
radionuclide: An unstable nuclide that undergoes radioactive decay.
random error: The deviation of an observed value from the true value is called the error of observation. If the error of observation behaves like a random variable (i.e., its value occurs as though chosen at random from a probability distribution of such errors) it is called a random error. See systematic error.
readily removable: A qualitative statement of the extent to which a radionuclide can be removed from a surface or medium using non-destructive, common, housekeeping techniques (e.g., washing with moderate amounts of detergent and water) that do not generate large volumes of radioactive waste requiring subsequent disposal or produce chemical wastes that are expected to adversely affect public health or the environment.
reference area: Geographical area from which representative reference measurements are performed for comparison with measurements performed in specific survey units at remediation site. A site radiological reference area (background area) is defined as an area that has similar physical, chemical, radiological, and biological characteristics as the site area being remediated, but which has not been contaminated by site activities. The distribution and concentration of background radiation in the reference area should be the same as that which would be expected on the site if that site had never been contaminated. More than one reference area may be necessary for valid comparisons if a site exhibits considerable physical, chemical, radiological, or biological variability.
reference coordinate system: A grid of intersecting lines referenced to a fixed site location or benchmark. Typically the lines are arranged in a perpendicular pattern dividing the survey location into squares or blocks of equal areas. Other patterns include three-dimensional and polar coordinate systems.
reference region: The geographical region from which reference areas will be selected for comparison with survey units.
regulation: A rule, law, order, or direction from federal or state governments regulating action or conduct. Regulations concerning radioisotopes in the environment in the United States are shared by the Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), the U.S. Department of Energy (DOE), and many State governments. Federal regulations and certain directives issued by the U.S. Department of Defense(DOD) are enforced within the DOD.
relative shift ()/s): ) divided by s, the standard deviation of the measurements. See delta.
relative standard deviation: See coefficient of variation.
release criterion: A regulatory limit expressed in terms of dose or risk.
rem (radiation equivalent man): The conventional unit of dose equivalent. The corresponding International System (SI) unit is the Sievert (Sv): 1 Sv = 100 rem.
remedial action: Those actions that are consistent with a permanent remedy taken instead of, or in addition to, removal action in the event of a release or threatened release of a hazardous substance into the environment, to prevent or minimize the release of hazardous substances so that they do not migrate to cause substantial danger to present or future public health or welfare or the environment. See remedy.
remediation: Cleanup or other methods used to remove or contain a toxic spill or hazardous materials from a Superfund site.
remediation control survey: A type of survey that includes monitoring the progress of remedial action by real time measurement of areas being decontaminated to determine whether or not efforts are effective and to guide further decontamination activities.
remedy: See remedial action.
removable activity: Surface activity that is readily removable by wiping the surface with moderate pressure and can be assessed with standard radiation detectors. It is usually expressed in units of dpm/100 cm2.
removal: The cleanup or removal of released hazardous substances, or pollutants or contaminants which may present an imminent and substantial danger; such actions as may be necessary taken in the event of the threat of release of hazardous substances into the environment; such actions as may be necessary to monitor, assess, and evaluate the threat of release of hazardous substances; the removal and disposal of material, or the taking of other such actions as may be necessary to prevent, minimize or mitigate damage to the public health or welfare or the environment.
replicate: A repeated analysis of the same sample or repeated measurement at the same location.
representative measurement: A measurement that is selected using a procedure in such a way that it, in combination with other representative measurements, will give an accurate representation of the phenomenon being studied.
representativeness: A measure of the degree to which data accurately and precisely represent a characteristic of a population, parameter variations at a sampling point, a process condition, or an environmental condition.
reproducibility: The precision, usually expressed as a standard deviation, that measures the variability among the results of measurement of the same sample at different laboratories.
residual radioactivity: Radioactivity in structures, materials, soils, groundwater, and other media at a site resulting from activities under the cognizant organization's control. This includes radioactivity from all sources used by the cognizant organization, but excludes background radioactivity as specified by the applicable regulation or standard. It also includes radioactive materials remaining at the site as a result of routine or accidental releases of radioactive material at the site and previous burials at the site, even if those burials were made in accordance with the provisions of 10 CFR Part 20.
restoration: Actions to return a remediated area to a usable state following decontamination.
restricted use: A designation following remediation requiring radiological controls.
robust: A statistical test or method that is approximately valid under a wide range of conditions.
run chart: A chart used to visually represent data. Run charts are used to monitor a process to see whether or not the long range average is changing. Run charts are points plotted on a graph in the order in which they become available, such as parameters plotted versus time.
s: The arithmetic standard deviation of the mean.
S+: The test statistic used for the Sign test.
sample: (As used in MARSSIM) A part or selection from a medium located in a survey unit or reference area that represents the quality or quantity of a given parameter or nature of the whole area or unit; a portion serving as a specimen.
sample: (As used in statistics) A set of individual samples or measurements drawn from a population whose properties are studied to gain information about the entire population.
Sampling and Analysis Plan (SAP): As defined for Superfund in the Code of Federal Regulations 40 CFR 300.430, a plan that provide a process for obtaining data of sufficient quality and quantity to satisfy data needs. The sampling and analysis plans consists of two parts: 1) the Field Sampling Plan, which describes the number, type, and location of samples and the type of analyses; and 2) the Quality Assurance Project Plan, which describes policy, organization, functional activities, the Data Quality Objectives, and measures necessary to achieve adequate data for use in selecting the appropriate remedy.
scanning: An evaluation technique performed by moving a detection device over a surface at a specified speed and distance above the surface to detect radiation.
scoping survey: A type of survey that is conducted to identify: 1) radionuclide contaminants, 2) relative radionuclide ratios, and 3) general levels and extent of contamination.
self-assessment: Assessments of work conducted by individuals, groups, or organizations directly responsible for overseeing and/or performing the work.
shape parameter (S): For an elliptical area of elevated activity, the ratio of the semi-minor axis length to the semi-major axis length. For a circle, the shape parameter is one. A small shape parameter corresponds to a flat ellipse.
shift: See delta (D).
Sievert (Sv): The special name for the International System (SI) unit of dose equivalent.
1 Sv = 100 rem = 1 Joule per kilogram.
Sign test: A nonparametric statistical test used to demonstrate compliance with the release criterion when the radionuclide of interest is not present in background and the distribution of data is not symmetric. See also Wilcoxon Rank Sum test.
single-blind measurement: A measurement that can be distinguished from routine measurements but are of unknown concentration. See non-blind measurement and double-blind measurement.
site: Any installation, facility, or discrete, physically separate parcel of land, or any building or structure or portion thereof, that is being considered for survey and investigation.
site reconnaissance: A visit to the site to gather sufficient information to support a site decision regarding the need for further action, or to verify existing site data. Site reconnaissance is not a study of the full extent of contamination at a facility or site, or a risk assessment.
size (of a test): See alpha.
soil: The top layer of the earth's surface, consisting of rock and mineral particles mixed with organic matter. A particular kind of earth or ground - e.g., sandy soil.
soil activity (soil concentration): The level of radioactivity present in soil and expressed in units of activity per soil mass (typically Bq/kg or pCi/g).
source material: Uranium and/or Thorium other than that classified as special nuclear material.
source term: All residual radioactivity remaining at the site, including material released during normal operations, inadvertent releases, or accidents, and that which may have been buried at the site in accordance with 10 CFR Part 20.
special nuclear material: Plutonium, 233U, and Uranium enriched in 235U; material capable of undergoing a fission reaction.
split: A sample that has been homogenized and divided into two or more aliquots for subsequent analysis.
standard normal distribution: A normal (Gaussian) distribution with mean zero and variance one.
standard operating procedure (SOP): A written document that details the method for an operation, analysis, or action with thoroughly prescribed techniques and steps, and that is officially approved as the method for performing certain routine or repetitive tasks.
statistical control: The condition describing a process from which all special causes have been removed, evidenced on control chart by the absence of points beyond the control limits and by the absence of non-random patterns or trends within the control limits. A special cause is a source of variation that is intermittent, unpredictable, or unstable.
stratification: The act or result of separating an area into two or more sub-areas so as each sub-area has relatively homogeneous characteristics such as contamination level, topology, surface soil type, vegetation cover, etc.
subsurface soil sample: A soil sample that reflects the modeling assumptions used to develop the DCGL for subsurface soil activity. An example would be soil taken deeper than 15 cm below the soil surface to support surveys performed to demonstrate compliance with 40 CFR 192.
surface contamination: Residual radioactivity found on building or equipment surfaces and expressed in units of activity per surface area (Bq/m2 or dpm/100 cm2).
surface soil sample: A soil sample that reflects the modeling assumptions used to develop the DCGL for surface soil activity. An example would be soil taken from the first 15 cm of surface soil to support surveys performed to demonstrate compliance with 40 CFR 192.
surveillance (quality): Continual or frequent monitoring and verification of the status of an entity and the analysis of records to ensure that specified requirements are being fulfilled.
survey: A systematic evaluation and documentation of radiological measurements with a correctly calibrated instrument or instruments that meet the sensitivity required by the objective of the evaluation.
survey plan: A plan for determining the radiological characteristics of a site.
survey unit: A geographical area consisting of structures or land areas of specified size and shape at a remediated site for which a separate decision will be made whether the unit attains the site-specific reference-based cleanup standard for the designated pollution parameter. Survey units are generally formed by grouping contiguous site areas with a similar use history and the same classification of contamination potential. Survey units are established to facilitate the survey process and the statistical analysis of survey data.
systematic error: An error of observation based on system faults which are biased in one or more ways, e.g., tending to be on one side of the true value more than the other.
T+: The test statistic for the Wilcoxon Signed Rank test.
tandem testing: Two or more statistical tests conducted using the same data set.
technical review: A documented critical review of work that has been performed within the state of the art. The review is accomplished by one or more qualified reviewers who are independent of those who performed the work, but are collectively equivalent in technical expertise to those who performed the original work. The review is an in-depth analysis and evaluation of documents, activities, material, data, or items that require technical verification or validation for applicability, correctness, adequacy, completeness, and assurance that established requirements are satisfied.
technical systems audit (TSA): A thorough, systematic, on-site, qualitative audit of facilities, equipment, personnel, training, procedures, recordkeeping, data validation, data management, and reporting aspects of a system.
TEDE (total effective dose equivalent): The sum of the effective dose equivalent (for external exposure) and the committed effective dose equivalent (for internal exposure). TEDE is expressed in units of Sv or rem. See CEDE.
test statistic: A function of the measurements (or their ranks) that has a known distribution if the null hypothesis is true. This is compared to the critical level to determine if the null hypothesis should be accepted or rejected. See S+, T+, and Wr.
tied measurements: Two or more measurements that have the same value.
traceability: The ability to trace the history, application, or location of an entity by means of recorded identifications. In a calibration sense, traceability relates measuring equipment to national or international standards, primary standards, basic physical constants or properties, or reference materials. In a data collection sense, it relates calculations and data generated throughput the project back to the requirements for quality for the project.
triangular sampling grid: A grid of sampling locations that is arranged in a triangular pattern.
See grid.
two-sample t test: A parametric statistical test used in place of the Wilcoxon Rank Sum (WRS) test if the reference area and survey unit measurements are known to be normally (Gaussian) distributed and there are no less-than measurements in either data set.
Type I decision error: A decision error that occurs when the null hypothesis is rejected when it is true. The probability of making a Type I decision error is called alpha (a).
Type II decision error: A decision error that occurs when the null hypothesis is accepted when it is false. The probability of making a Type II decision error is called beta (b).
unity rule (mixture rule): A rule applied when more than one radionuclide is present at a concentration that is distinguishable from background and where a single concentration comparison does not apply. In this case, the mixture of radionuclides is compared against default concentrations by applying the unity rule. This is accomplished by determining: 1) the ratio between the concentration of each radionuclide in the mixture, and 2) the concentration for that radionuclide in an appropriate listing of default values. The sum of the ratios for all radionuclides in the mixture should not exceed 1.
unrestricted area: Any area where access is not controlled by a licensee for purposes of protection of individuals from exposure to radiation and radioactive materials - including areas used for residential purposes.
unrestricted release: Release of a site from regulatory control without requirements for future radiological restrictions. Also known as unrestricted use.
validation: Confirmation by examination and provision of objective evidence that the particular requirements for a specific intended use are fulfilled. In design and development, validation concerns the process of examining a product or result to determine conformance to user needs.
verification: Confirmation by examination and provision of objective evidence that the specified requirements have been fulfilled. In design and development, verification concerns the process of examining a result of given activity to determine conformance to the stated requirements for that activity.
W r: The sum of the ranks of the adjusted measurements from the reference area, used as the test statistic for the Wilcoxon Rank Sum test.
Ws : The sum of the ranks of the measurements from the survey unit, used with the Wilcoxon Rank Sum test.
weighting factor (Wt): The fraction of the overall health risk, resulting from uniform, whole-body radiation, attributable to specific tissue. The dose equivalent to tissue is multiplied by the appropriate weighting factor to obtain the effective dose equivalent to the tissue.
Wilcoxon Rank Sum (WRS) test: A nonparametric statistical test used to determine compliance with the release criterion when the radionuclide of concern is present in background. See also Sign test.
working level: A special unit of radon exposure defined as any combination of short-lived radon daughters in 1 liter of air that will result in the ultimate emission of 1.3x105 MeV of potential alpha energy. This value is approximately equal to the alpha energy released from the decay of progeny in equilibrium with 100 pCi of 222Ra.
Z1-N : The value from the standard normal distribution that cuts off 100 N % of the upper tail of the standard normal distribution. See standard normal distribution.
|
