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Advanced instrumentation for Positron Emission Tomography

Description: This paper summarizes the physical processes and medical science goals that underly modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost. 71 refs., 3 figs., 3 tabs.
Date: April 1, 1985
Creator: Derenzo, S.E. & Budinger, T.F.
Partner: UNT Libraries Government Documents Department

Concentration Ratios for Cesium and Strontium in Produce Near Los Alamos

Description: The ratios of the concentrations of radionuclides in produce (fruits, vegetables, and grains) to the concentrations in the soil have been measured for cesium and strontium at locations near Los Alamos. The Soil, Foodstuffs, and Biota Team of the Meteorology and Air Quality Group of the Los Alamos National Laboratory (LANL) obtained the data at locations within a radius of 50 miles of LANL. The concentration ratios are in good agreement with previous measurements: 0.01 to 0.06 for cesium-137 and 0.1 to 0.5 for strontium-90 (wet-weight basis).
Date: March 1, 2006
Creator: S. Salazar, M.McNaughton, P.R. Fresquez
Partner: UNT Libraries Government Documents Department

Determination Of Reportable Radionuclides For DWPF Sludge Batch 7B (Macrobatch 9)

Description: The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 7a (SB7a) and Sludge Batch 7b (SB7b) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 9 (MB9). This report develops the list of reportable radionuclides and associated activities as a function of time. Twenty-seven radionuclides have been identified as reportable for DWPF SB7b. Each of these radionuclides has a half-life greater than ten years and contributes more than 0.01% of the radioactivity on a Curie basis at some point from production through the 1100 year period between 2015 and 3115. For SB7b, all of the radionuclides in the Design Basis glass are reportable except for three radionuclides: Pd-107, Cs-135, and Th-230. At no time during the 1100- year period between 2015 and 3115 did any of these three radionuclides contribute to more than 0.01% of the radioactivity on a Curie basis. The radionuclide measurements made for SB7b are the most extensive conducted to date. Some method development/refinement occurred during the conduct of these measurements, leading to lower detection limits and more accurate measurement of some isotopes than was previously possible.
Date: December 17, 2012
Creator: Crawford, C. L. & Diprete, D. P.
Partner: UNT Libraries Government Documents Department

Determination Of Reportable Radionuclides For DWPF Sludge Batch 7B (Macrobatch 9)

Description: The Waste Acceptance Product Specifications (WAPS) 1.2 require that “The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115”. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 7a (SB7a) and Sludge Batch 7b (SB7b) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 9 (MB9). This report develops the list of reportable radionuclides and associated activities as a function ...
Date: August 22, 2013
Creator: Crawford, C. L. & DiPrete, D. P.
Partner: UNT Libraries Government Documents Department

Potential Application Of Radionuclide Scaling Factors To High Level Waste Characterization

Description: Production sources, radiological properties, relative solubilities in waste, and laboratory analysis techniques for the forty-five radionuclides identified in Hanford�s Waste Treatment and Immobilization Plant (WTP) Feed Acceptance Data Quality Objectives (DQO) document are addressed in this report. Based on Savannah River Site (SRS) experience and waste characteristics, thirteen of the radionuclides are judged to be candidates for potential scaling in High Level Waste (HLW) based on the concentrations of other radionuclides as determined through laboratory measurements. The thirteen radionuclides conducive to potential scaling are: Ni-59, Zr-93, Nb-93m, Cd-113m, Sn-121m, Sn-126, Cs-135, Sm-151, Ra-226, Ra-228, Ac-227, Pa-231, and Th-229. The ability to scale radionuclides is useful from two primary perspectives: 1) it provides a means of checking the radionuclide concentrations that have been determined by laboratory analysis; and 2) it provides a means of estimating radionuclide concentrations in the absence of a laboratory analysis technique or when a complex laboratory analysis technique fails. Along with the rationale for identifying and applying the potential scaling factors, this report also provides examples of using the scaling factors to estimate concentrations of radionuclides in current SRS waste and into the future. Also included in the report are examples of independent laboratory analysis techniques that can be used to check results of key radionuclide analyses. Effective utilization of radionuclide scaling factors requires understanding of the applicable production sources and the chemistry of the waste. As such, the potential scaling approaches identified in this report should be assessed from the perspective of the Hanford waste before reaching a decision regarding WTP applicability.
Date: September 30, 2013
Creator: Reboul, S. H.
Partner: UNT Libraries Government Documents Department

Summary Report for the Development of Materials for Volatile Radionuclides

Description: The materials development summarized here is in support of the Waste Forms campaign, Volatile Radionuclide task. Specifically, materials are being developed for the removal and immobilization of iodine and krypton, specifically 129I and 85Kr. During FY 2010, aerogel materials were investigated for removal and immobilization of 129I. Two aerogel formulations were investigated, one based on silica aerogels and the second on chalcogenides. For 85Kr, metal organic framework (MOF) structures were investigated.
Date: November 22, 2010
Creator: Strachan, Denis M.; Chun, Jaehun; Henager, Charles H.; Matyas, Josef; Riley, Brian J.; Ryan, Joseph V. et al.
Partner: UNT Libraries Government Documents Department

Surface Environmental Surveillance Procedures Manual, PNL-MA-580, Rev. 5

Description: This manual contains the procedures that are used for the collection of routine Surface Environmental Surveillance Project environmental samples and field measurements on and around the Hanford Site. Specific responsibilities for project personnel are also defined.
Date: July 1, 2007
Creator: Hanf, Robert W.; Poston, Ted M. & Bisping, Lynn E.
Partner: UNT Libraries Government Documents Department

[Computer simulated images of radiopharmaceutical distributions in anthropomorphic phantoms]. Performance report

Description: We have constructed an anatomically correct human geometry, which can be used to store radioisotope concentrations in 51 various internal organs. Each organ is associated with an index number which references to its attenuating characteristics (composition and density). The initial development of Computer Simulated Images of Radiopharmaceuticals in Anthropomorphic Phantoms (CSIRDAP) over the first 3 years has been very successful. All components of the simulation have been coded, made operational and debugged.
Date: May 17, 1991
Partner: UNT Libraries Government Documents Department

Nuclear medicine program progress report for quarter ending March 31, 1994

Description: The authors` new radioiodinated ``IQNP`` agent, an analogue of ``4-IQNB``, has a high affinity for the muscarinic-cholinergic receptor (m-AChR). Iodine is stabilized in ``IQNP`` by attachment as a vinyl iodide. To evaluate the potential usefulness of a [Br-76]-labeled analogue as a candidate for positron emission tomography (PET), they have synthesized the trans-3-bromopropenyl analogue (BrQNP) and evaluated its ability in vivo to block uptake of [I-125]-Z-(R,R)-IQNP. Reaction of bromine with the trans-tributylstannyl substrate prepared from ethyl -{alpha}-hydroxy -{alpha}-phenyl-{alpha}-(1-propyn-3-yl)acetate, followed by column purification and transesterification with (R,S)-3-quinuclidinol gave BrQNP. Female rats were pre-treated with the oxalate salt of BrQNP one hour prior to I.V. injection of [I-125]-IQNP. While the brain and heart uptake in BrQNP pre-treated animals was significantly decreased, the control animals showed the expected high uptake of IQNP in these tissues. The ease of preparation and ability to block m-AChR suggest that [Br-76]-labeled BrQNP is a potential candidate for PET studies. In this report, the authors also summarize their current on-going collaborative studies assessing the usefulness of various rhenium-188-labeled therapeutic agents. In addition, collaborative programs have been established to evaluate rhenium-188-labeled particles for treatment of arthritis (synovectomy), treatment of bone pain resulting from cancer metastheses with rhenium-188-phosphonates (palliation), and other applications.
Date: May 1, 1994
Creator: Knapp, F. F. Jr.; Ambrose, K. R.; Beets, A. L.; Lambert, C. R.; McPherson, D. W.; Mirzadeh, S. et al.
Partner: UNT Libraries Government Documents Department

Initial recommendations for restricting gamma-ray spectrometry measurements of radionuclides for on-site inspections

Description: The US paper �Radionuclide Sampling, Sample Handling and Analytical Laboratory Equipment for Comprehensive Test Ban Treaty On-Site Inspections,� CTBT/PC/V/OSI/WSII/PR/29 identified the radionuclides of interest to an OS1 as <sup>144</sup>Ce, <sup>147</sup>Nd, <sup>141</sup>Ce, <sup>149</sup>Ba<sup>140</sup>La), <sup>95</sup> Zr(<sup>95</sup>Nb), <sup>131m</sup>Xe, <sup>133m</sup>Xe, <sup>133g</sup>Xe, <sup>135g</sup>Xe, and <sup>37</sup>Ar. All of these nuclides (except <sup>37</sup>Ar) can be measured via some form of conventional or coincidence-based gamma-ray spectrometry. The non-gaseous radionuclides [<sup>144</sup>Ce, <sup>147</sup>Nd, <sup>141</sup>Ce, <sup>140</sup>Ba(<sup>140</sup>La), and <sup>95</sup>Zr(<sup>95</sup>Nb)] can be measured via conventional high-resolution gamma-ray spectrometry using a shielded, high-purity germanium (HPGe) detector. The gaseous radionuclides <sup>131m</sup>Xe, <sup>133m</sup>Xe, <sup>133g</sup>Xe, and <sup>135g</sup>Xe are best measured (after separation from their homologous elements) via a gamma & beta/electron coincidence technique such as that described in CTBT/WGB/TL-11/5 which could utilize either a HPGe or low-resolution (NaI(TI)) gamma-ray spectrometer to detect the gamma-ray/x-ray and a plastic scintillator to detect the beta particle/electron from the decay of the various Xe isotopes. The US paper CTBT/PC/V/IOSI/WSII/PR/29 (and other papers) identified a need to limit the information that can be extracted from high-resolution gamma-ray spectra to ensure that only information relevant to an OSI is accessible. The term �blinding� has been used to describe the need to limit the information available to the Inspection Team from the high-resolution gamma-ray measurement. A better term is �measurement restriction�; the need for restricting the information is particularly relevant to conventional high-resolution gamma-ray spectrometry measurements, but not to the gamma & beta/electron coincidence-type measurements envisioned for Xe isotopes because the separation process for these radionuclides will likely eliminate any other observables. The purpose of this paper is to define functional requirements for restricting measurements via conventional high- resolution gamma-ray spectrometry systems to ensure that only the nuclides of interest to an OSI can be identified and quantified. Options discussed below include 1) acquisition and analysis of the entire high-resolution gamma-ray spectrum combined with ...
Date: November 6, 1998
Creator: Buckley, W. F.; Kreek, S. A. & Wild, J. F.
Partner: UNT Libraries Government Documents Department

Removal of Radioactive Cations and Anions from Polluted Water using Ligand-Modified Colloid-Enhanced Ultrafiltration

Description: The purpose of this project was to develop, optimize, and evaluate new separation methods for removal of hazardous (radionuclides and toxic non-radioactive contaminants) metal ions from either ground water or aqueous waste solutions produced during Decontamination and Decommissioning operations at DOE sites. Separation and concentration of the target ions will result in a substantial reduction in the volume of material requiring disposal or long-term storage. The target metal ions studied were uranium, thorium, lead, cadmium, and mercury along with chromium (as chromate). The methods tested use membrane ultrafiltration in conjunction with water-soluble polymers or surfactants with added metal-selective chelating agents. Laboratory scale tests showed removal of 99.0-99.9% of each metal tested in a single separation stage. The methods developed for selective removal of radionuclides (UO22+, Th4+) and toxic heavy metals (Pb2+, Cd2+, Hg2+) are applicable to two DOE focus areas; decontamination of sites and equipment, and in remediation of contaminated groundwater. Colloid-enhanced ultrafiltration methods have potential to be substantially less expensive than alternative methods and can result in less waste. Results of studies with varying solution composition (concentration, acidity) and filtration parameters (pressure, flow rate) have increased our understanding of the fundamental processes that control the metal ion separation and colloid recovery steps of the overall process. Further laboratory studies are needed to improve the ligand/colloid recovery step and field demonstration of the technology is needed to prove the applicability of the integrated process. A number of graduate students, post-doctoral associates, and research associates have received training and research experience in the areas of separation science, colloid chemistry, and metal ion coordination chemistry of radionuclides and toxic metals. These scientists, some with positions in industry and academia, have the necessary background to address problems related to environmental remediation and. management. The results of this research show the technical feasibility of ...
Date: December 17, 2001
Creator: Scamehorn, Dr. John F.; Taylor, Dr. Richard W. & Palmer, Dr. Cynthia E.
Partner: UNT Libraries Government Documents Department

Signal Amplification Technique (SAT): an approach for improving resolution and reducing image noise in computed tomography

Description: Spatial resolution improvements in computed tomography (CT) have been limited by the large and unique error propagation properties of this technique. The desire to provide maximum image resolution has resulted in the use of reconstruction filter functions designed to produce tomographic images with resolution as close as possible to the intrinsic detector resolution. Thus, many CT systems produce images with excessive noise with the system resolution determined by the detector resolution rather than the reconstruction algorithm. CT is a rigorous mathematical technique which applies an increasing amplification to increasing spatial frequencies in the measured data. This mathematical approach to spatial frequency amplification cannot distinguish between signal and noise and therefore both are amplified equally. We report here a method in which tomographic resolution is improved by using very small detectors to selectively amplify the signal and not noise. Thus, this approach is referred to as the signal amplification technique (SAT). SAT can provide dramatic improvements in image resolution without increases in statistical noise or dose because increases in the cutoff frequency of the reconstruction algorithm are not required to improve image resolution. Alternatively, in cases where image counts are low, such as in rapid dynamic or receptor studies, statistical noise can be reduced by lowering the cutoff frequency while still maintaining the best possible image resolution. A possible system design for a positron CT system with SAT is described.
Date: January 1, 1981
Creator: Phelps, M.E.; Huang, S.C.; Hoffman, E.J.; Plummer, D. & Carson, R.
Partner: UNT Libraries Government Documents Department

Humic Substances in Natural Waters and Their Complexation With Trace Metals and Radionuclides : A Review

Description: Section I introduces the material contained in the rest of the report. Section II presents the origin and characteristics of humic materials as we understand them today and outlines the methods that have been used to separate and analyze these substances. Section III focuses on the general problem of metal-organic interactions and treats some of the factors that are important in chelating and complexing of metal ions by humic substances. Section IV deals specifically with the complexing of radionuclides by organic substances, treated from the standpoint of both empirical and experimental studies.
Date: July 1985
Creator: Boggs, Sam, Jr.; Livermore, David & Seitz, Martin G.
Partner: UNT Libraries Government Documents Department

Comparison of Different Internal Dosimetry Systems for Selected Radionuclides Important to Nuclear Power Production

Description: This report compares three different radiation dosimetry systems currently applied by various U.S. Federal agencies and dose estimates based on these three dosimetry systems for a set of radionuclides often identified in power reactor effluents. These dosimetry systems were developed and applied by the International Commission on Radiological Protection at different times over the past six decades. Two primary modes of intake of radionuclides are addressed: ingestion in drinking water and inhalation. Estimated doses to individual organs and to the whole body based on each dosimetry system are compared for each of four age groups: infant, child, teenager, and adult. Substantial differences between dosimetry systems in estimated dose per unit intake are found for some individual radionuclides, but differences in estimated dose per unit intake generally are modest for mixtures of radionuclides typically found in nuclear power plant effluents.
Date: August 1, 2013
Creator: Leggett, Richard Wayne; Eckerman, Keith F & Manger, Ryan P
Partner: UNT Libraries Government Documents Department

The Case for the Application of Worldwide Marine Radioactivity Studies In the Search for Undeclared Facilities and Activities

Description: Undeclared nuclear facilities unequivocally remain the most difficult safeguards challenge facing the International Atomic Energy Agency (IAEA). Recent cases of undeclared facilities revealed in Iran and Syria, which are NPT signatory States, show both the difficulty and the seriousness of this threat to nonproliferation. In the case of undeclared nuclear facilities, the most effective deterrent against proliferation is the application of Wide-Area Environmental Sampling (WAES); however, WAES is currently cost-prohibitive. As with any threat, the most effective countering strategy is a multifaceted approach. Some of the approaches applied by the IAEA include: open source analysis, satellite imagery, on-site environmental sampling, complementary access under the Additional Protocol (where in force), traditional safeguards inspections, and information provided by member States. These approaches, naturally, are focused on specific States. Are there other opportunities not currently within the IAEA purview to assess States that may provide another opportunity to detect clandestine facilities? In this paper, the author will make the case that the IAEA Department of Safeguards should explore the area of worldwide marine radioactivity studies as one possible opportunity. One such study was released by the IAEA Marine Environment Laboratory in January 2005. This technical document focused on 90Sr, 137Cs, and 239/240Pu. It is clearly a challenging area because of the many sources of anthropogenic radionuclides in the world’s oceans and seas including: nuclear weapons testing, reprocessing, accidents, waste dumping, and industrial and medical radioisotopes, whose distributions change based on oceanographic, geochemical, and biological processes, and their sources. It is additionally challenging where multiple States share oceans, seas, and rivers. But with the application of modern science, historical sampling to establish baselines, and a focus on the most relevant radionuclides, the potential is there to support this challenging IAEA safeguards mission.
Date: June 1, 2013
Creator: Schanfein, Mark
Partner: UNT Libraries Government Documents Department

Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

Description: The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10^(-10) nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.
Date: November 20, 2009
Creator: Xun, Luying
Partner: UNT Libraries Government Documents Department

Radioimmunotherapy: Development of an effective approach. Progress report, 1987

Description: Goals of this program are to answer the fundamental scientific questions for the development of an effective approach for delivering radiation therapy to cancer on antibody-based radiopharmaceuticals. The following list consists of highlights of developments from our program: documented therapeutic response of lymphoma in patients receiving radioimmunotherapy; development and application of quantitative radionuclide imaging techniques for therapy planning and dosimetry calculations; multicompartmental modeling and analysis of the in vivo MoAb kinetics in patients; a MoAb macrocycle chelate for Cu-67: development, production, in vitro and in vivo testing; NMR analysis of immunoradiotherapeutic effects on the metabolism of lymphoma; analysis of the variable molecular characteristics of the MoAb radiopharmaceutical, and their significance; in vivo studies in mice and patients of the metabolism of radioiodinated MoAb as well as In-111 CITC MoAb; and biodistribution of Cu-67 TETA MoAb in nude mice with human lymphoma.
Date: December 31, 1987
Partner: UNT Libraries Government Documents Department

Topics in nuclear and radiochemistry for college curricula and high school science programs

Description: The concern with the current status and trends of nuclear chemistry and radiochemistry education in academic institutions was addressed in a recent workshop. The 1988 workshop considered the important contributions that scientist with nuclear and radiochemistry backgrounds have made and are continuing to make to other sciences and to various applied fields. Among the areas discussed were environmental studies, life sciences, materials science, separation technology, hot atom chemistry, cosmochemistry, and the rapidly growing field of nuclear medicine. It is intent of the organizer and participants of this symposium entitled Topics in Nuclear and Radiochemistry for College Curricula and High School Science Program'' to provide lecture material on topics related to nuclear and radiochemistry to educators. It is our hope that teachers, who may or may not be familiar with the field, will find this collections of articles useful and incorporate some of them into their lectures.
Date: January 1, 1990
Partner: UNT Libraries Government Documents Department

Inventory Data Package for Hanford Assessments

Description: This document presents the basis for a compilation of inventory for radioactive contaminants of interest by year for all potentially impactive waste sites on the Hanford Site for which inventory data exist in records or could be reasonably estimated. This document also includes discussions of the historical, current, and reasonably foreseeable (1944 to 2070) future radioactive waste and waste sites; the inventories of radionuclides that may have a potential for environmental impacts; a description of the method(s) for estimating inventories where records are inadequate; a description of the screening method(s) used to select those sites and contaminants that might make a substantial contribution to impacts; a listing of the remedial actions and their completion dates for waste sites; and tables showing the best estimate inventories available for Hanford assessments.
Date: June 1, 2006
Creator: Kincaid, Charles T.; Eslinger, Paul W.; Aaberg, Rosanne L.; Miley, Terri B.; Nelson, Iral C.; Strenge, Dennis L. et al.
Partner: UNT Libraries Government Documents Department

Processes for Removal and Immobilization of 14C, 129I, and 85Kr

Description: This is a white paper covering the results of a literature search and preliminary experiments on materials and methods to remove and immobilize gaseous radionuclided that come from the reprocessing of spent nuclear fuel.
Date: October 5, 2009
Creator: Strachan, Denis M.; Bryan, Samuel A.; Henager, Charles H.; Levitskaia, Tatiana G.; Matyas, Josef; Thallapally, Praveen K. et al.
Partner: UNT Libraries Government Documents Department

Distilling Complex Model Results into Simple Models for use in Assessing Compliance with Performance Standards for Low Level Waste Disposal Facilities

Description: Assessing the long term performance of waste disposal facility requires numerical simulation of saturated and unsaturated groundwater flow and contaminant transport. Complex numerical models have been developed to try to realistically simulate subsurface flow and transport processes. These models provide important information about system behavior and identify important processes, but may not be practical for demonstrating compliance with performance standards because of excessively long computer simulation times and input requirements. Two approaches to distilling the behavior of a complex model into simpler formulations that are practical for demonstrating compliance with performance objectives are examined in this paper. The first approach uses the information obtained from the complex model to develop a simple model that mimics the complex model behavior for stated performance objectives. The simple model may need to include essential processes that are important to assessing performance, such as time-variable infiltration and waste emplacement rates, subsurface heterogeneity, sorption, decay, and radioactive ingrowth. The approach was applied to a Low-Level Waste disposal site at the Idaho National Laboratory where a complex three dimensional vadose zone model was developed first to understand system behavior and important processes. The complex model was distilled down to a relatively simple one-dimensional vadose zone model and three-dimensional aquifer transport model. Comparisons between the simple model and complex model of vadose zone fluxes and groundwater concentrations showed relatively good agreement between the models for both fission and activation products (129I, 36Cl, 99Tc) and actinides (238U, 239Pu, 237Np). Application of the simple model allowed for Monte Carlo uncertainty analysis and simulations of numerous disposal and release scenarios. The second approach investigated was the response surface model. In the response surface model approach, the temporal response of a complex model to an instantaneously-released unit mass of a conservative tracer at a defined point is calculated and stored (the ...
Date: February 1, 2007
Creator: Rood, Arthur S.
Partner: UNT Libraries Government Documents Department