Identification of Volume of Distribution for 239Pu in Rats.

The work within identifies the volume of distribution (VD) of plutonium using data from studies in which rats were administered an intravenous bolus injection of 239Pu4+-citrate. The research investigated two separate datasets. Data published by Durbin and colleagues in "Plutonium Deposition Kinetics in Rats" and studies conducted by Lovelace Respiratory Research Institute (LRRI) were examined.

Optimization of the ICRP 67 and NCRP 156 Transfer Rates Applied to Nonhuman Primates Intramuscularly Injected With 241Am.

Nonhuman primates intramuscularly injected with Am have been investigated using the International Commission on Radiological Protection Report 67 model coupled with National Council on Radiation Protection and Measurements Report 156 model. Default parameters from these models were input into the Integrated Modules for Bioassay Analysis software to predict the intake and skeleton retention in 20 tested nonhuman primates. The predictions generated were compared to the experimental data from the Durbin nonhuman primate studies.

A Case Study of the NCRP 156 Wound Model of Embedded DU Using Data From Urine Uranium Concentrations of Wounded Veterans.

Depleted uranium (DU) munitions were initially used by the United States (U.S.) military during the first Persian Gulf War in 1991 in order to penetrate heavily armored vehicles.

Application of the ICRP 67 and NCRP 156 Biokinetic Models to 241 Am Wound Data from Nonhuman Primates.

Distribution, retention, and excretion of intramuscularly injected Am citrate have been investigated in cynomolgus and rhesus nonhuman primates (NHP). Bioassay and retention data, obtained from experiments done by Patricia Durbin and her colleagues at Lawrence Berkeley National Laboratory, were evaluated against the International Commission on Radiological Protection (ICRP 67) Am systemic model coupled with to the National Council on Radiation Protection and Measurement wound model (NCRP 156). The default transfer rates suggested in these models were used with the urine and feces excretion data to predict the intake as well as liver and skeleton tissue contents at the time of death.

Investigating Uranium Isotopic Ratios and Activity Ratios in Groundwaters in the State of Idaho.

Analyzing uranium isotopic and activity ratios can give valuable information for hydrologic and environmental studies such as insights to weathering processes, estimating water mixing ratios, and identifying water sources. The authors employed an inductively coupled plasma mass spectrometer (ICP-MS) to perform environmental level concentration measurements of isotopic uranium on 380 groundwater samples from various locations within the state of Idaho. The U:U uranium activity ratios (UAR) for these samples range between 0.

Plasma Retention and Systemic Kinetics of 90Sr Intramuscularly Injected in Female Nonhuman Primates.

Thirteen female Rhesus macaques were intramuscularly injected with Sr(NO3)2 diluted in sodium citrate solution. The biokinetic data from these animals were compared against the predictions of the NCRP 156 wound models combined with the ICRP systemic models. It was observed that the activities measured in plasma of these nonhuman primates (NHPs) were consistently lower than those predicted by the default human biokinetic models.

Behavior of Americium in Simulated Wounds in Nonhuman Primates.

An americium solution injected intramuscularly into several nonhuman primates (NHPs) was found to behave differently than predicted by the wound models described in the NCRP Report 156. This was because the injection was made along with a citrate solution, which is known to be more soluble than chlorides, oxides, or nitrates on which the NCRP Report was based. A multi-exponential wound model specific to the injected americium solution was developed based on the retention in the intramuscular sites.

ICRP 67 Biokinetic Models for AM-241 Applied to Nonhuman Primates.

Between 1960 and 1985, Patricia Durbin and colleagues performed studies on the distribution of intravenously and intramuscularly injected Am citrate with dosages ranging from 16 to 32 kBq kg in 30 male and female non-human primates (NHP). Dr. Durbin died unexpectedly in March of 2009, leaving much of the extensive serial blood, bioassay, and autopsy data from these NHP studies unanalyzed.

Investigating Uranium Concentrations in Groundwaters in the State of Idaho Using Kinetic Phosphorescence Analysis and Inductively Coupled Plasma Mass Spectrometry.

The determination of uranium concentrations in natural water samples is of great interest due to the environmental consequences of this radionuclide. In this study, 380 groundwater samples from various locations within the state of Idaho were analyzed using two different techniques. The first method was Kinetic Phosphorescence Analysis (KPA), which gives the total uranium concentrations in water samples.

Biokinetics of Plutonium in Nonhuman Primates.

A major source of data on metabolism, excretion and retention of plutonium comes from experimental animal studies. Although old world monkeys are one of the closest living relatives to humans, certain physiological differences do exist between these nonhuman primates and humans. The objective of this paper was to describe the metabolism of plutonium in nonhuman primates using the bioassay and retention data obtained from macaque monkeys injected with plutonium citrate.

Application of NCRP 156 Wound Model and ICRP 67 Systemic Plutonium Model for Analysis of Urine Data from Simulated Wounds in Nonhuman Primates.

The predictions of the wound model described in NCRP Report No. 156, coupled with the systemic model described in ICRP 67, were compared with the actual urinary excretion data and wound retention data from nonhuman primates injected intramuscularly or subcutaneously with Pu(IV) citrate. The results indicated that the early behavior of Pu(IV) citrate in wounds can be adequately described by the default retention parameters for moderately retained radionuclides suggested by the report.

Biokinetics of 90Sr in Male Nonhuman Primates.

The current study tests the hypothesis that the biokinetics of Sr can be represented by simplification of the ICRP publication 78 Sr model. Default and proposed models were evaluated by their ability to predict injected activity and more thoroughly define the activity residing in the skeleton of rhesus monkeys. The data obtained from studies done by Patricia Durbin and her colleagues at the Lawrence Berkley National Laboratory were used to create a profile of the activity residing in the skeleton at the time of sacrifice.

Comparison of ICRP 67 and Other Plutonium Systemic Model Predictions with the Biokinetic Data from Nonhuman Primates.

Despite the presence of a relatively large amount of human data available on the metabolism of plutonium, the experimental animal data is still important in constructing and parameterizing the biokinetic models. Recognizing this importance, the biokinetic data obtained from studies done by P.W.

Strontium-90 Biokinetics from Simulated Wound Intakes in Non-human Primates Compared with Combined Model Predictions from National Council on Radiation Protection and Measurements Report 156 and International Commission on Radiological Protection Publication 67.

This study had a goal to evaluate the predictive capabilities of the National Council on Radiation Protection and Measurements (NCRP) wound model coupled to the International Commission on Radiological Protection (ICRP) systemic model for 90Sr-contaminated wounds using non-human primate data. Studies were conducted on 13 macaque (Macaca mulatta) monkeys, each receiving one-time intramuscular injections of 90Sr solution. Urine and feces samples were collected up to 28 d post-injection and analyzed for 90Sr activity.

Effect of a Simulation of 241Am Deposition Pattern in the Leg Bones on the Detection Efficiency of a High Purity Germanium Detector.

A computational model using an MCNPX version 2.6.0 code and a leg voxel phantom was previously constructed and validated against the in vivo measurements of the United States Transuranium and Uranium Registries (USTUR) case 0846 leg.

Particle size characterization of aerosols generated during surface contaminated concrete demolition.

The purpose of this study was to measure mass and activity distributions from the aerosols generated during the demolition of surface contaminated concrete. Air samples were collected using a cascade impactor during the mechanical hammering and dismantlement of radiologically contaminated high level waste process vaults from which the piping and components had been previously removed. The experimentally determined distribution parameters were compared with the 5.

Monte Carlo simulation of in vivo measurement of the most suitable knee position for the optimal measurement of activity.

A new computational model has been developed using the Monte Carlo (MC) technique to simulate in vivo measurements with the objective of understanding the most precise measurement location with respect to quantifying the activity of Am in the bones. To benchmark the model, in vivo measurements were performed on the U.S.

Reevaluation of (241)Am content in the USTUR case 0102 leg phantom.

The (241)Am contents in the United States Transuranium and Uranium Registries' (USTUR) case 0102 leg phantom were previously estimated to be 1,243 ± 11 Bq. Recent analysis of the computed tomography images of the phantom revealed multiple bone structures missing from various regions of the phantom skeleton including: posterior ilium, anterior ilium, ischium, femur proximal end, femur middle shaft, femur distal end, patella, tibia distal shaft, fibula distal shaft, and fibula distal end. Additionally, the fifth metatarsal and all of the fifth-digit phalanges were found to be completely missing from the foot.

Contamination analysis of radioactive samples in focused ion beam instruments.

The use of Focused Ion Beam (FIB) instrument's to analyze and prepare samples that are radioactive requires attentiveness to the materials that are dislodged and free inside the chamber. Radioactive sputtered material must be understood even when observed at trace concentrations. Measurements using liquid scintillation counting and high purity germanium detectors were used to evaluate contamination on accessible surfaces inside a focused ion beam chamber that was used in the preparation of samples that were radioactive.

Evaluation of (241)Am deposited in different parts of the leg bones and skeleton to justify in vivo measurements of the knee for estimating total skeletal activity.

The percentage of Am deposited in different parts of leg bones relative to the total leg activity was calculated from radiochemical analysis results from six whole body donors participating in the U.S. Transuranium and Uranium Registries (USTUR).

A new leg voxel model in two different positions for simulation of the non-uniform distribution of (241)Am in leg bones.

A new leg voxel model in two different positions (straight and bent) has been developed for in vivo measurement calibration purposes. This voxel phantom is a representation of a human leg that may provide a substantial enhancement to Monte Carlo modeling because it more accurately models different geometric leg positions and the non-uniform distribution of Am throughout the leg bones instead of assuming a one-position geometry and a uniform distribution of radionuclides. This was accomplished by performing a radiochemical analysis on small sections of the leg bones from the U.

Reevaluation of USTUR plutonium wound case 0262 using Bayesian methodology and new data.

Skin penetration by radionuclide contaminants serves as a route of entry into the body and may pose a serious health risk to humans depending on the magnitude of intake. The United States Transuranium and Uranium Registry whole body Case 0262 was involved in a wound intake of plutonium at the Hanford Site. The registrant died about 33 years later.

Cancer deaths and occupational exposure in a group of plutonium workers.

An exploratory epidemiological study was conducted for 319 deceased nuclear workers who had intakes of transuranic radionuclides and histories of employment during the time period from 1943 to 1995. The workers were employed at various facilities throughout the United States, including the Department of Energy defense facilities and uranium mining and milling sites. The majority of individuals were involved in documented radiological incidents during their careers.

Measurements of activation products associated with Havar foils from a GE PETtrace medical cyclotron using high resolution gamma spectroscopy.

Havar foils are specially engineered for beam-line windows used in the General Electric (GE) PETtrace medical cyclotron that can withstand the high pressure differentials and also temperatures developed near the target with proton bombardment. These foils effectively separate components along the beam line of the cyclotron. Various activation products are produced in the foils from the primary proton beam and other secondary radiations.

Continuous flow PCB radiolysis with real-time assessment by gas chromatography.

We report the e-beam radiolysis of polychlorinated biphenyls (PCBs) in a continuous flow system, and the development of remote, real-time detection using gas chromatography. Aroclor-containing transformer oil was recirculated through an irradiation cell irradiated with 13-MeV electrons, at a flow rate of approximately 0.1L/min.