Committed Effective Dose Equivalent Research Articles

A comprehensive dosimetry analysis of barakah nuclear power plant: Integrating gaseous and liquid radionuclide dispersion across multiple units

Monitoring radioactive releases during the normal operation of power plants is crucial to ensure compliance with safety limits set by regulatory bodies for environmental safety. In the case of the Barakah nuclear power plant in the UAE, comprehensive multiunit dispersion modelling and radiological safety analysis have been conducted. Utilizing the HotSpot Health Physics Code and GENII (Second-generation environmental dosimetry), assessments were made for both 37 gaseous and 51 liquid source terms generated by GALE. Release rates for source terms were determined using GALE based on APR 1400 specifications. HotSpot employed the Gaussian Plume model to simulate the dispersion of gaseous source terms up to 80 km surrounding the plant, calculating Total Effective Dose Equivalent (TEDE) and Committed Effective Dose Equivalent (CEDE) in rural and urban areas. Findings indicated that neither scenario exceeded the 1 mSv threshold for the general public nor the 20 mSv limit for operational workers. Notably, skin, thyroid, and surface bones exhibited the highest CEDE, primarily influenced by iodide radionuclides. GENII's Surface Water module modelled the effects of liquid source terms, accounting for various contamination and exposure pathways such as external exposure and ingestion across different age groups. The calculated doses remained well below FANR's annual limits, with negligible cancer incidences and fatalities predicted for one year of exposure.

Assessment of radiological consequences to a hypothetical accident of the 3-MW TRIGA Mark-II nuclear research reactor of Bangladesh

The radiological consequences to a hypothetical accident are assessed for the 3-MW TRIGA Mark-II Nuclear Research Reactor of Bangladesh for both wet and dry seasons. Accident simulations are crucial for assessing the potentialrisks in the event of a nuclear accident. ORIGEN code was used to carry out the facility's radionuclide inventory. In the event of a hypothetical accident, the Total Effective Dose Equivalent (TEDE) is assessed using HotSpots. The findings indicate that for stability class A during the rainy season, the selected radionuclides arrived at a downwind distance of 0.03 km with an arrival time of less than one minute, and the highest TEDE, respiratory time-integrated air concentration, and ground deposition activity, respectively, were marked at 2.8E-12 Sv, 9.4E-01 Bq-sec/m3, and 2.4E-05 kBq/m2. In the case of I-131 at 0.03 km from the source, the thyroid gland is the most sensitive human organ, followed by the lung, esophagus, thymus, surface bone, skin, and breast. The estimated Committed Effective Dose Equivalent (CEDE) from I-131 is 9.1E-11 Sv. In contrast, the adrenal was the most sensitive organ with a maximum CEDE of 1.3E-13 Sv in the case of Cs-137 at a downwind distance of 0.03 km. The highest TEDE values for the general public and the vicinity around the TRIGA Mark II reactor facility are lower than the annual dose limits.

Интеграция моделей oir мкрз в дозиметрическую систему idose 2

Introduction: The iDose 2 dosimetry system is a tool for assessing the doses of internal irradiation of workers under the current individual dosimetry control (IDC). In this system, according to a series of measurements of the activity of radionuclides in biological objects (including those not exceeding the detection limit of the measurement technique) and information on contact times and types of compounds, estimates of the committed effective dose equivalent (CEDE) of internal irradiation, as well as their uncertainties, are made based on the Bayesian approach. It is possible to integrate practically any biokinetic models of the behavior of radionuclides in the human body, presented in the form of a system of ordinary differential equations (ODEs) with constant transition coefficients between compartments, into the iDose 2 dosimetry system without changing the source code. Purpose: Integration of new combined biokinetic models for the list of radionuclides: H-3, Sr-90, Cs-137, Pu-238, Pu-239 and Am-241 from Publications 100, 130, 134, 137 and 141 of the ICRP (conventionally called the series Occupational Intakes of Radionuclides (OIR)), for ingestion and inhalation routes of intake with AMAD = 1 and 5 microns. Material and methods: For each variant of the biokinetic model, the functions of retention/removal of radionuclides were found through the eigenvectors and eigenvalues of the matrix describing the ODE system. Results: A total of 65 new biokinetic models and 180 functions of radionuclide retention/removal in the form of a sum of exponents were integrated and quality control was carried out.

Radiological Safety Analysis for a Hypothetical Accident of a Generic VVER-1000 Nuclear Power Plant

Atmospheric dispersion modelling and radiological safety analysis have been performed for a postulated accident scenario of a generic VVER-1000 nuclear power plant using the HotSpot Health Physics code. The total effective dose equivalent (TEDE), the respiratory time-integrated air concentration, and the ground deposition concentration are calculated considering site-specific meteorological conditions. The results show that the maximum TEDE and ground deposition concentration values of 3.69E – 01 Sv and 3.80E + 06 kBq/m2 occurred at downwind distance of 0.18 km from the release point. This maximum TEDE value is recorded within a distance where public occupation is restricted. The TEDE values at distances of 5.0 km and beyond where public occupation is likely to be found are far below the annual regulatory limits of 1 mSv from public exposure in a year even in the event of worse accident scenario as set in IAEA Safety Standard No. GSR Part 3; no action related specifically to the public exposure is required. The released radionuclides might be transported to long distances but will not have any harmful effect on the public. The direction of the radionuclide emission from the release point is towards the north east. It is observed that the organ with the highest value of committed effective dose equivalent (CEDE) appears to be the thyroid. It was followed by the bone surface, lung, red marrow, and lower large intestine wall in order of decreasing CEDE value. Radionuclides including I-131, I-133, Sr-89, Cs-134, Ba-140, Xe-133, and Xe-135 were found to be the main contributors to the CEDE.

Dose assessment of radionuclides dispersion from Bushehr nuclear power plant stack under normal operation and accident conditions

Assessment of individual and collective doses around the unit-1 of Bushehr nuclear power plant (BNPP-1) site during normal nuclear reactor operation and under reactor accident conditions which are essential for safety and environmental analyses is presented in this paper. Release of radioactive materials to the environment following a design basic accident (DBA) (e.g. LBLOCA) is evaluated using HOTSPOT health physics computer code. In the normal operation conditions, atmospheric dispersion of radioactive material is calculated using CAP88-PC code. These codes utilize a Gaussian dispersion air transport plume model to simulate the atmospheric dispersion of radionuclides in different atmospheric stability classes and various wind speeds and directions. To calculate the doses under normal operation using CAP88 code, the surrounding area of the BNPP-1 within a radius of 30 km is gridded into 12 concentric rings and 16 sectors and the distribution of population and data of agricultural products are calculated for each grid. The meteorological data on atmospheric stability conditions, wind speed and the frequency distribution of wind direction based on data collected near the reactor site are also analyzed and applied. The results illustrate that the maximum total effective dose equivalent (TEDE) and committed effective dose equivalent (CEDE) values for personnel and public around the BNPP-1 site are lower than the annual effective dose limits for workers and public in normal operation and under accident conditions. Also, the results of the radiological impacts of the BNPP-1 in normal and accidental radioactive materials releases are compared with the dose values given in the Final Safety Analysis Report (FSAR) of the BNPP-1.

Plutonium determination in bioassay samples using radiochemical thermal ionization mass spectrometry

A new high-sensitivity plutonium bioassay program employing thermal ionization mass spectrometry (TIMS) has been developed to monitor Savannah River Site employees for intakes of PuO2. The U.S. Department of Energy requires bioassay laboratories which have the ability to detect a 100 mRem, 50-year committed effective dose equivalent (CEDE) intake of radioactive material. For PuO2, traditional alpha-spectrometry methods are not sensitive enough to meet this specification. To comply with this requirement, a radiochemical TIMS method was developed to determine Pu in urine bioassay samples. Four radiochemical separation steps were used to purify Pu from urine to ensure samples were free from matrix effects that interfere with TIMS analysis. These included precipitation, ion-extraction chromatography, electrodeposition, and ion-exchange chromatography. A batch of reagent blanks determined the detection limit for this method was 0.59 fg 239Pu/l (1.3 µBq 239Pu/l). The 239Pu concentration was also measured in 20 urine blank samples to determine the minimum 239Pu concentration that would indicate an occupational intake. A Probit plot was constructed for the results and the 99 th percentile of the urine blanks showed that the minimum 239Pu concentration that would indicate an uptake was 2.4 fg/l (5.5 µBq/l).

Radionuclides in pinon pine (Pinus edulis) nuts from los alamos national laboratory lands and the dose from consumption

One of the dominant tree species growing within and around the eastern portion of Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis). Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food—the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of 3H, 137Cs, 90Sr, totU, 238Pu, 239, 240Pu, and241 Am in soils (0‐ to 12‐in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (3) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of 3H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 μSv); this is far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem (1000 μSv). Soil‐to‐nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.

Radionuclides in deer and elk from Los Alamos national laboratory and the doses to humans from the ingestion of muscle and bone

This paper summarizes radionuclide concentrations (3H, 90Sr, 137Cs, 238Pu, 239,240Pu, 241Am, and totU) in muscle and bone tissue of mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus) collected from Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, lands from 1991 through 1998. Also, the committed effective dose equivalent (CEDE) and the risk of excess cancer fatalities (RECF) to people who ingest muscle and bone from deer and elk collected from LANL lands were estimated. Most radionuclide concentrations in muscle and bone from individual deer (n = 11) and elk (n = 22) collected from LANL lands were either at less than detectable quantities (where the analytical result was smaller than two counting uncertainties) and/or within upper (95%) level background (BG) concentrations. As a group, most radionuclides in muscle and bone of deer and elk from LANL lands were not significantly higher (p<0.10) than in similar tissues from deer (n = 3) and elk (n = 7) collected from BG locations. Also, elk that had been radio collared and tracked for two years and spent an average time of 50% on LANL lands were not significantly different in most radionuclides from road kill elk that have been collected as part of the environmental surveillance program. Overall, the upper (95%) level net CEDEs (the CEDE plus two sigma for each radioisotope minus background) at the most conservative ingestion rate (50 lbs of muscle and 13 lbs of bone) were as follows: deer muscle = 0.22 mrem y‐1 (2.2 μSv y‐1), deer bone = 3.8 mrem y‐1 (38 μSv y‐1), elk muscle = 0.12 mrem y‐1 (1.2 μSv y‐1), and elk bone = 1.7 mrem y‐1 (17 μSv y‐1). All CEDEs were far below the International Commission on Radiological Protection guideline of 100 mrem y‐1 (1000 μSv y‐1), and the highest muscle plus bone net CEDE corresponded to a RECF of 2E‐06, which is far below the Environmental Protection Agency upper level guideline of 1E‐04.

The uptake of radionuclides by beans, squash, and corn growing in contaminated alluvial soils at Los Alamos national laboratory

Pinto beans (Phaselous vulgaris), sweet corn (Zea mays), and zucchini squash (Cucurbita pepo) were grown in a field pot study using alluvial floodplain soils contaminated with various radionuclides within Los Alamos Canyon (LAC) at Los Alamos National Laboratory, New Mexico. Soils as well as washed edible (fruit) and nonedible (stems and leaves) crop tissues were analyzed for tritium (3H), cesium (137Cs), strontium (90Sr), plutonium (238Pu and 239,240Pu), americium (241Am), and total uranium (totU). Most radionuclides, with the exception of 3H and totU, in soil and crop tissues from LAC were detected in significantly higher concentrations (p <0.05) than in soil or crop tissues collected from regional background locations. Significant differences in radionuclide concentrations among crop species (squash were generally higher than beans or corn) and plant parts (nonedible tissue were generally higher than edible tissue) were observed. Most soil‐to‐plant concentration ratios for radionuclides in edible and nonedible crop tissues grown in soils from LAC were within default values in the literature commonly used in dose and risk assessment models. Overall, the maximum net positive committed effective dose equivalent (CEDE)—the CEDE plus two sigma for each radioisotope minus background and then all positive doses summed—to a hypothetical 50‐year resident that ingested 352 lb ([160 kg]; the maxiumum ingestion rate per person per year) of beans, corn, and squash in equal proportions was 74 mrem y‐1 (740 μS y‐1). This upper bound dose was below the International Commission on Radiological Protection permissible dose limit of 100 mrem y‐1 (1000 (μS y‐1) from all pathways and corresponds to a risk of an excess cancer fatality of 3.7 x 10s (37 in a million), which is also below the U.S. Environmental Protection Agency's guideline of 10‐4.

Radionuclides in bees and honey within and around los alamos national laboratory

Honeybees are effective monitors of environmental pollution. Los Alamos National Laboratory (LANL), in fact, has maintained a network of honeybee colonies within and around LANL for 17 years (1979 through 1995); the objectives for maintaining this honeybee network were to (1) determine the bioavailability of certain radionuclides in the environment with respect to LANL operations (3H, 57Co, 60Co, 1S2Eu, 40K, 7Be, 22Na, 54Mn, 83Rb, 137Cs, 238Pu, 239Pu, 90Sr, 241Am, and totU) and (2) estimate the committed effective dose equivalent (CEDE) and the corresponding risk of excess cancer fatalities (RECF) to people who may consume honey from hives located around the perimeter of the Laboratory (Los Alamos [LA] and White Rock/Pajarito Acres [WR/PA], New Mexico). Based on the 17‐year average, bees from nine out of eleven hives and honey from six out of eleven hives on LANL lands contained 3H that was significantly higher (p <0.05) than background. The highest average concentration of 3H in bees (434 pCi mL−1) collected over the years was from LANL's Technical Area (TA) 54—a low‐level radioactive waste disposal site. Similarity, the highest average concentration of 3H in honey (709 pCi mL−1) was collected from a hive located near three 3H storage ponds at LANL TA‐53. The average concentrations of 3H in bees and honey from background hives was 1.1 pCi mL−1 and 1.6 pCi mL−1, respectively. Although the concentration of 3H in bees and honey from most LANL and perimeter (WR/PA) hives were significantly higher than background, most areas, with the exception of TA‐53 and TA‐54, generally exhibited decreasing 3H concentrations over time. Also, all other radionuclides in honey collected from perimeter hives around LANL were not significantly different from background. Overall, the maximum total net positive CEDE—based on the average concentration plus two std dev of all the radionuclides measured over the years after the subtraction of background‐from consuming 11 Ib of honey collected from LA and WR/PA, was 0.031 mrem y−1 and 0.006 mrem y−1, respectively. The highest CEDE was <0.04% of the International Commission on Radiological Protection permissible dose limit of 100 mrem y−1 from all pathways and corresponds to a RECF of 1.6 × 10−8 (0.016 in a million)—far below the Environmental Protection Agency's guideline of 1 × 10−6 (one in a million).

Radionuclides in fishes and mussels from the Farallon Islands Nuclear Waste Dump Site, California.

The Farallon Islands Nuclear Waste Dump Site (FINWDS), approximately 30 miles west of San Francisco, California, received at least 500 TBq encapsulated in more than 47,500 containers from approximately 1945 to 1970. During several seasons in 1986/87 deep-sea bottom feeding fishes (Dover sole = Microstomus pacificus; sablefish = Anoplopoma fimbria; thornyheads = Sebastolobus spp.) and intertidal mussels (Mytilus californianus) were collected from the vicinity of the FINWDS and from comparable depths at a reference site near Point Arena, CA. Tissues were analyzed for several radionuclides (137Cs, 238Pu, 239+240Pu, and 241Am). Radionuclide concentrations for fish mussel tissue ranged from non-detectable to 4,340 mBq kg(-1) wet weight, with the following means for Farallon fishes: 137Cs = 1,110 mBq kg(-1); 238Pu = 390 mBq kg(-1); 239+240Pu = 130 mBq kg(-1); and 241Am = 1,350 mBq kg(-1). There were no statistically significant differences in the radionuclide concentrations observed in samples from the Farallon Islands compared to reference samples from Point Arena, CA. Concentrations of both 238Pu and 241Am in fish tissues (from both sites) were notably higher than those reported in literature from any other sites world-wide, including potentially contaminated sites. Concentrations of 239+24OPu from both sites were typical of low values found at some contaminated sites worldwide. These results show approximately 10 times higher concentrations of 239+240Pu and approximately 40-50 times higher concentrations of 238Pu than those values reported for identical fish species from 1977 collections at the FINWDS. Radionuclide concentrations were converted to a hypothetical per capita annual radionuclide intake for adults, yielding the following values of annual Committed Effective Dose Equivalent (CEDE) from ionizing radiation emitted from these radionuclides: 0.000 mSv y(-1) for 137Cs, 0.009 mSv Y(-1) for 228Pu, and 0.003 mSv y(-1) for 239+240Pu. For 241Am, projected CEDE for Dover sole, sablefish, and thornyheads were higher, averaging 0.03 mSv y(-1). The observed isotopic ratio of 238Pu/239+240Pu was about 4 (which is two orders of magnitude higher than the ratio of 0.03 associated with fallout from weapons tests and accidental releases in the north temperate zone of the earth), indicating a considerably higher environmental mobilization for 238Pu compared to 239+240Pu. Likewise, the observed ratio of 241Am/239+240Pu of about 30 was nearly two orders of magnitude higher than the fallout ratio of 0.43 in the north temperate zone of the earth. The projected ionizing radiation CEDE to people from the ingestion of fish with fallout radionuclides was three times higher for 241Am than from the plutonium isotopes.

Experiences at Trombay in Monitoring Actinide Intakes by Occupational Workers by Direct External Counting

Direct assessment of lung/liver/skeletal burdens of actinides (Pu/Am/U) for monitoring intakes froms part of the ongoing internal dosimetry programmes for occupational workers at Trombay. The majority of the measurements are performed with a 200 mm diameter phoswich detector operating with pulse-shape discrimination based on ORTEC electronics. Additional detectors (NaI(Tl), a miniature CdTe and a special coaxial HPGe) are also employed whenever needed. All the detection systems are located inside a graded lined 20 cm thick steel chamber. Calibration techniques include both in vivo methods as well as the use of a realistic torso phantom. Utilising these facilities, routine, special/operational, confirmatory and follow-up monitoring programmes have been extensively conducted. A brief description is given of the facilities, procedures employed and methodologies for computation of committed effective dose equivalent (CEDE). Monitoring data have have also been analysed to observe elimination patterns with respect to actinide aerosols deposited in the lung. These have been compared with the metabolic models currently in use. In particular, unusually long retention half-times for natural uranium, class Y behavior of 241 AmO 2 (embedded in Pu matrix), and super class Y behaviour of Pu aerosols in human lungs have been observed. Likely effects of these findings on the estimates of internal doses are considered

Discrepancies in committed effective dose equivalents calculated using U.S. Nuclear Regulatory Commission Regulatory Guide 8.34.

Calculations of Committed Effective Dose Equivalent (CEDE) due to inhalation using four of the five methods suggested in the United States Nuclear Regulatory Commission Regulatory Guide 8.34 (1992a) were performed to determine if any significant differences in the calculated value of the CEDE exist for typical power plant radionuclides. These four methods included dose conversion factors from the United States Environmental Protection Agency Federal Guidance Report No. 11 (Eckerman et al. 1988), Annual Limit on Intake, Derived Air Concentrations, and Weighted Committed Dose Equivalents from ICRP Publication 30 (1979). Of the 68 radionuclides included, 48 demonstrated significant differences of 20% or greater in the calculated CEDE values for the four methods used. The differences in calculated values for the CEDE can be explained by the varied use of the 10% Rule and by rounding of tabulated values for ALIs and DACs to one significant digit.

Uptake of uranium and thorium series radionuclides by the waterlily, Nymphaea violacea

The waterlily Nymphaea violacea is a major aquatic macrophyte in the waters of the Alligator Rivers Region, Northern Teritory, Australia. It is also a traditional Aboriginal diet item, and is considered to be potentially one of the main contributors to the effective dose equivalent arising from consumption of so called ‘bush’ food in the region. Because of the proximity of the Ranger Uranium Mine (RUM), the activity concentrations of the U and Th series radionuclides have been studied in water, sediment and waterlily during different seasons at five sites downstream of the mine site. The objectives of the study are: 1. 1. To identify the major source of radionuclide uptake by the plant; i.e. water or sediment. 2. 2. To assess the concentration factors/ratios needed for predicting the radiation exposure of the critical group resulting from any discharge of water to the aquatic environment from the Ranger uranium mine. 3. 3. To estimate the natural radiation exposure of the public arising from consumption of waterlilies. Results show that sediment is the major source of U and Th series radionuclides to waterlily roots, rhizomes and foliage. Waterlily to sediment concentration ratios, based on wet weights, are of the order of 0·01–0·03 for roots and rhizomes and 0·005–0·015 for foliage. The naturally occurring committed effective dose equivalent (CEDE) from an estimated annual intake of 3 kg waterlily rhizomes from the forage areas are of the order of 0·02 mSv.

Mathematical Modelling Methods for Assessing Radiation Doses Received by Populations in the Vicinity of a Nuclear Site from Atmospheric Discharges

This paper looks at some relevant work being done by the Ministry's Food Safety (Radiation) Unit in connection with obligations under the Radioactive Substances Act. 1960. MAFF, in conjunction with Her Majesty's Inspectorate of Pollution (HMIP) issues certificate of authorisation to nuclear sites to control operations and limit the environmental impact of discharges. Requirements in the UK now call for the current annual discharge from any one nuclear site to be limited so that no individual member of the public receives more than 0.5 mSv Committed Effective Dose Equivalent (CEDE) from all pathways. Doses to the general public should also be limited by the ALARA principle. From a knowledge of atmospheric concentration and deposition of the radionuclides, radiation doses via the foodchain, inhalation and immersion pathways may be calculated. Based upon this, the Authorising Departments are currently engaged in setting numerical limits to atmospheric discharges from sites in England and Wales. This paper assess the likely radiation dose distribution via different pathways to critical groups from these discharges. Results are presented here of some recent investigations; in particular, the predicted doses received via food products and via radionuclide are examined to obtain possible useful insights. Methods for identifying the critical group and its location are fully explained as well as the results and methodology for additivity of dose.

Mathematical Modelling Methods for Assessing Radiation Doses Received by Populations in the Vicinity of a Nuclear Site from Atmospheric Discharges

This paper looks at some relevant work being done by the Ministry's Food Safety (Radiation) Unit in connection with obligations under the Radioactive Substances Act. 1960. MAFF, in conjunction with Her Majesty's Inspectorate of Pollution (HMIP) issues certificate of authorisation to nuclear sites to control operations and limit the environmental impact of discharges. Requirements in the UK now call for the current annual discharge from any one nuclear site to be limited so that no individual member of the public receives more than 0.5 mSv Committed Effective Dose Equivalent (CEDE) from all pathways. Doses to the general public should also be limited by the ALARA principle. From a knowledge of atmospheric concentration and deposition of the radionuclides, radiation doses via the foodchain, inhalation and immersion pathways may be calculated. Based upon this, the Authorising Departments are currently engaged in setting numerical limits to atmospheric discharges from sites in England and Wales. This paper assess the likely radiation dose distribution via different pathways to critical groups from these discharges. Results are presented here of some recent investigations; in particular, the predicted doses received via food products and via radionuclide are examined to obtain possible useful insights. Methods for identifying the critical group and its location are fully explained as well as the results and methodology for additivity of dose.

Ingestion pathway factor in dose assessment for annual airborne releases of radioactivity.

An analytic model is derived for use in a simplified assessment of the committed effective dose equivalent to the public due to routine airborne releases of radioactive materials. The model uses the dosimetry in ICRP Publication 30 and determines the ratio of the committed effective dose equivalent (CEDE) via a specified ingestion pathway relative to that CEDE by inhalation per annual airborne release of a radionuclide. This ratio is defined as the ingestion pathway factor (IPF) and is shown to depend upon the radionuclide annual limits of intake, the atmospheric deposition velocity, and an ingestion parameter, the effective contamination intake area. The IPF values are tabulated for several radionuclides. These resultant IPF values often exceed unity, suggesting that the ingestion path is often the critical or limiting pathway for off-site CEDE to an individual. An application of this assessment is demonstrated in a review of a hypothetical nuclear facility to determine the appropriate extent of radiologic effluent and environmental monitoring at the facility.