Two Dimensional Simulations of Plastic-Shell, Direct-Drive Implosions on OMEGA (open access)

Two Dimensional Simulations of Plastic-Shell, Direct-Drive Implosions on OMEGA

Multidimensional hydrodynamic properties of high-adiabat direct-drive plastic-shell implosions on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] are investigated using the multidimensional hydrodynamic code, DRACO. Multimode simulations including the effects of nonuniform illumination and target roughness indicate that shell stability during the acceleration phase plays a critical role in determining target performance. For thick shells that remain integral during the acceleration phase, target yields are significantly reduced by the combination of the long-wavelength ({ell} < 10) modes due to surface roughness and beam imbalance and the intermediate modes (20 {le} {ell} {le} 50) due to single-beam nonuniformities. The neutron-production rate for these thick shells truncates relative to one-dimensional (1-D) predictions. The yield degradation in the thin shells is mainly due to shell breakup at short wavelengths ({lambda} {approx} {Delta}, where {Delta} is the in-flight shell thickness). The neutron-rate curves for the thinner shells have significantly lower amplitudes and a fall-off that is less steep than 1-D rates. DRACO simulation results are consistent with experimental observations.
Date: September 27, 2004
Creator: Radha, P. B.; Goncharov, V. N.; Collins, T. B.; Delettrez, J. A.; Elbaz, Y.; Glebov, V. Y. et al.
Object Type: Article
System: The UNT Digital Library
The Confederated Tribes of the Warm Springs Indian Reservation of Oregon John Day Basin Office : Watershed Restoration Projects : 2003 Annual Report. (open access)

The Confederated Tribes of the Warm Springs Indian Reservation of Oregon John Day Basin Office : Watershed Restoration Projects : 2003 Annual Report.

The John Day is the nation's second longest free-flowing river in the contiguous United States and the longest containing entirely unsupplemented runs of anadromous fish. Located in eastern Oregon, the basin drains over 8,000 square miles, Oregon's fourth largest drainage basin, and incorporates portions of eleven counties. Originating in the Strawberry Mountains near Prairie City, the John Day River flows 284 miles in a northwesterly direction, entering the Columbia River approximately four miles upstream of the John Day dam. With wild runs of spring Chinook salmon and summer steelhead, westslope cutthroat, and redband and bull trout, the John Day system is truly a basin with national significance. The majority of the John Day basin was ceded to the Federal government in 1855 by the Confederated Tribes of the Warm Springs Reservation of Oregon (Tribes). In 1997, the Tribes established an office in the basin to coordinate restoration projects, monitoring, planning and other watershed activities on private and public lands. Once established, the John Day Basin Office (JDBO) formed a partnership with the Grant Soil and Water Conservation District (GSWCD), which contracts the majority of the construction implementation activities for these projects from the JDBO. The GSWCD completes the landowner contact, …
Date: February 27, 2004
Creator: Office., Confederated Tribes of the Warm Springs Reservation of Oregon. John Day Basin
Object Type: Report
System: The UNT Digital Library
Metals Processing Laboratory Users (MPLUS) Facility Annual Report FY 2002 (October 1, 2001-September 30, 2002) (open access)

Metals Processing Laboratory Users (MPLUS) Facility Annual Report FY 2002 (October 1, 2001-September 30, 2002)

The Metals Processing Laboratory Users Facility (MPLUS) is a Department of Energy (DOE), Energy Efficiency and Renewable Energy, Industrial Technologies Program, user facility designated to assist researchers in key industries, universities, and federal laboratories in improving energy efficiency, improving environmental aspects, and increasing competitiveness. The goal of MPLUS is to provide access to the specialized technical expertise and equipment needed to solve metals processing issues that limit the development and implementation of emerging metals processing technologies. The scope of work can also extend to other types of materials. MPLUS has four primary user centers: (1) Processing--casting, powder metallurgy, deformation processing (including extrusion, forging, rolling), melting, thermomechanical processing, and high-density infrared processing; (2) Joining--welding, monitoring and control, solidification, brazing, and bonding; (3) Characterization--corrosion, mechanical properties, fracture mechanics, microstructure, nondestructive examination, computer-controlled dilatometry, and emissivity; and (4) Materials/Process Modeling--mathematical design and analyses, high-performance computing, process modeling, solidification/deformation, microstructure evolution, thermodynamic and kinetic, and materials databases A fully integrated approach provides researchers with unique opportunities to address technologically related issues to solve metals processing problems and probe new technologies. Access is also available to 16 additional Oak Ridge National Laboratory (ORNL) user facilities ranging from state-of-the-art materials characterization capabilities, and high-performance computing to …
Date: April 27, 2004
Creator: Angelini, P
Object Type: Report
System: The UNT Digital Library
Quantitative models of subduction zone fluids: How hydrous phases in the slab determine the composition of subduction zone lavas (open access)

Quantitative models of subduction zone fluids: How hydrous phases in the slab determine the composition of subduction zone lavas

None
Date: May 27, 2004
Creator: Feineman, M; Ryerson, F J & DePaolo, D
Object Type: Article
System: The UNT Digital Library
Atomistic Processes of Catalyst Degradation (open access)

Atomistic Processes of Catalyst Degradation

The purpose of this cooperative research and development agreement (CRADA) between Sasol North America, Inc., and the oak Ridge National Laboratory (ORNL) was to improve the stability of alumina-based industrial catalysts through the combination of aberration-corrected scanning transmission electron microscopy (STEM) at ORNL and innovative sample preparation techniques at Sasol. Outstanding progress has been made in task 1, 'Atomistic processes of La stabilization'. STEM investigations provided structural information with single-atom precision, showing the lattice location of La dopant atoms, thus enabling first-principles calculations of binding energies, which were performed in collaboration with Vanderbilt University. The stabilization mechanism turns out to be entirely due to a particularly strong binding energy of the La tom to the {gamma}-alumina surface. The large size of the La atom precludes incorporation of La into the bulk alumina and also strains the surface, thus preventing any clustering of La atoms. Thus highly disperse distribution is achieved and confirmed by STEM images. la also affects relative stability of the exposed surfaces of {gamma}-alumina, making the 100 surface more stable for the doped case, unlike the 110 surface for pure {gamma}-alumina. From the first-principles calculations, they can estimate the increase in transition temperature for the 3% loading of …
Date: November 27, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
CT Scan of NASA Booster Nozzle (open access)

CT Scan of NASA Booster Nozzle

We scanned a Booster Nozzle for NASA with our 9 meV LINAC, AmSi panel scanner. Three scans were performed using different filtering schemes and different positions of the nozzle. The results of the scan presented here are taken from the scan which provided the best contrast and lowest noise of the three. Our inspection data shows a number of indications of voids in the outer coating of rubber/carbon. The voids are mostly on the side of the nozzle, but a few small voids are present at the ends of the nozzle. We saw no large voids in the adhesive layer between the Aluminum and the inner layer of carbon. This 3D inspection data did show some variation in the size of the adhesive layer, but none of the indications were larger than 3 pixels in extent (21 mils). We have developed a variety of contour estimation and extraction techniques for inspecting small spaces between layers. These tools might work directly on un-sectioned nozzles since the circular contours will fit with our tools a little better. Consequently, it would be useful to scan a full nozzle to ensure there are no untoward degradations in data quality, and to see if our …
Date: July 27, 2004
Creator: Schneberk, D; Perry, R & Thompson, R
Object Type: Report
System: The UNT Digital Library
Slow Nonradiative Decay for Rare Earths in KPb2Br5 and RbPb2Br5 (open access)

Slow Nonradiative Decay for Rare Earths in KPb2Br5 and RbPb2Br5

We report on spectroscopic investigations of Nd{sup 3+}- and Tb{sup 3+}- doped low phonon energy, moisture-resistant host crystals, KPb{sub 2}Br{sub 5} and RbPb{sub 2}Br{sub 5}, and their potential to serve as new solid state laser materials at new wavelengths, especially in the long wavelength infrared region. This includes emission spectra, emission lifetime measurements, Raman scattering spectra as well as calculations of the multiphonon decay rate, radiative lifetimes and quantum efficiencies for relevant (laser) transitions in these crystals.
Date: February 27, 2004
Creator: Rademaker, K.; Petermann, K.; Huber, G.; Krupke, W.; Page, R.; Payne, S. et al.
Object Type: Article
System: The UNT Digital Library
Search for Subthreshold Neutron Production in Be (open access)

Search for Subthreshold Neutron Production in Be

We have searched for neutrons from the 3-body photon-induced reaction {sup 9}Be + {gamma} {yields} {alpha} + {alpha} + n using bremsstrahlung produced by electrons from a 2-MV Van de Graaff. The target was located within a block of beryllium surrounded by an array of {sup 3}He proportional counters embedded in paraffin. Based on energy and intensity calibrations of the accelerator and detector using the {sup 9}Be + {gamma} {yields} {sup 8}Be + n reaction, an upper limit of 93 nb (4{sigma}) was placed on the cross section for neutron production between the 3-body and 2-body thresholds. This value is substantially below a previously experimental result using photoexcitation by a {sup 142}Pr gamma source and also below an earlier theoretical estimate. We suggest that bremsstrahlung due to beta rays between 1665 keV and the 2160-keV end-point of the {sup 142}Pr beta-ray spectrum could account for the photoneutron yield in the 3-body region that had previously been attributed to {sup 142}Pr gamma rays.
Date: September 27, 2004
Creator: Chrien, R. E.; Alburger, D. E.; Sutter, R. J. & Wishart, J. F.
Object Type: Article
System: The UNT Digital Library
Source-Search Sensitivity of a Large-Area, Coded-Aperture, Gamma-Ray Imager (open access)

Source-Search Sensitivity of a Large-Area, Coded-Aperture, Gamma-Ray Imager

We have recently completed a large-area, coded-aperture, gamma-ray imager for use in searching for radiation sources. The instrument was constructed to verify that weak point sources can be detected at considerable distances if one uses imaging to overcome fluctuations in the natural background. The instrument uses a rank-19, one-dimensional coded aperture to cast shadow patterns onto a 0.57 m{sup 2} NaI(Tl) detector composed of 57 individual cubes each 10 cm on a side. These are arranged in a 19 x 3 array. The mask is composed of four-centimeter thick, one-meter high, 10-cm wide lead blocks. The instrument is mounted in the back of a small truck from which images are obtained as one drives through a region. Results of first measurements obtained with the system are presented.
Date: October 27, 2004
Creator: Ziock, K P; Collins, J W; Craig, W W; Fabris, L; Lanza, R C; Gallagher, S et al.
Object Type: Article
System: The UNT Digital Library
Properties of RR Lyrae stars in the Inner Regions of the Large Magellanic Cloud (open access)

Properties of RR Lyrae stars in the Inner Regions of the Large Magellanic Cloud

We present the radial velocities, metallicities and the K-band magnitudes of 74 RR Lyrae stars in the inner regions of the LMC. The intermediated resolution spectra and the infrared images were obtained with FORS1 at the ESO VLT and with the SOFI infrared imager at the ESO NTT. The best 43 RR Lyrae with measured velocities yield an observed velocity dispersion of {sigma}=61{+-} 7 km s{sup -1}. We obtain a true LMC RR Lyrae velocity dispersion of {sigma}=53 km s{sup -1}, which is higher than the velocity dispersion of any other LMC population previously measured. This is the first empirical evidence for a kinematically hot, metal-poor halo in the LMC as discussed in Minniti et al. (2003). Using Layden's (1994) modification for the {Delta}S method we measured the metallicity for 23 of our stars. The mean value is [Fe/H]=-1.46{+-}0.09 dex. The absolute magnitudes M{sub v} and M{sub K} of RR Lyrae stars are linear functions of metallicity. In the V band, our data agree with the Olech et al. (2003) relation, in the K band the slope is flatter. The average apparent V luminosity of 70 RR Lyrae stars is <V>=19.45{+-}0.04 and the average K luminosity of 37 RR Lyrae …
Date: May 27, 2004
Creator: Borissova, J; Minniti, D; Rejkuba, M; Alves, D; Cook, K H & Freeman, K C
Object Type: Article
System: The UNT Digital Library
Science and Technology Review October 2004 (open access)

Science and Technology Review October 2004

None
Date: August 27, 2004
Creator: Henson, V. E.
Object Type: Report
System: The UNT Digital Library
Implementation of the United States-Russian Highly Enriched Uranium Agreement: Current Status & Prospects (open access)

Implementation of the United States-Russian Highly Enriched Uranium Agreement: Current Status & Prospects

The National Nuclear Security Administration's (NNSA) Highly Enriched Uranium (HEU) Transparency Implementation Program (TIP) monitors and provides assurance that Russian weapons-grade HEU is processed into low enriched uranium (LEU) under the transparency provisions of the 1993 United States (U.S.)-Russian HEU Purchase Agreement. Meeting the Agreement's transparency provisions is not just a program requirement; it is a legal requirement. The HEU Purchase Agreement requires transparency measures to be established to provide assurance that the nonproliferation objectives of the Agreement are met. The Transparency concept has evolved into a viable program that consists of complimentary elements that provide necessary assurances. The key elements include: (1) monitoring by technical experts; (2) independent measurements of enrichment and flow; (3) nuclear material accountability documents from Russian plants; and (4) comparison of transparency data with declared processing data. In the interest of protecting sensitive information, the monitoring is neither full time nor invasive. Thus, an element of trust is required regarding declared operations that are not observed. U.S. transparency monitoring data and independent instrument measurements are compared with plant accountability records and other declared processing data to provide assurance that the nonproliferation objectives of the 1993 Agreement are being met. Similarly, Russian monitoring of U. S. …
Date: July 27, 2004
Creator: R.rutkowski, E; Armantrout, G; Mastal, E; Glaser, J & Benton, J
Object Type: Article
System: The UNT Digital Library
The Supersymmetric Fat Higgs (open access)

The Supersymmetric Fat Higgs

Supersymmetric models have traditionally been assumed to be perturbative up to high scales due to the requirement of calculable unification. In this note I review the recently proposed `Fat Higgs' model which relaxes the requirement of perturbativity. In this framework, an NMSSM-like trilinear coupling becomes strong at some intermediate scale. The NMSSM Higgses are meson composites of an asymptotically-free gauge theory. This allows us to raise the mass of the Higgs, thus alleviating the MSSM of its fine tuning problem. Despite the strong coupling at an intermediate scale, the UV completion allows us to maintain gauge coupling unification.
Date: October 27, 2004
Creator: Harnik, Roni
Object Type: Article
System: The UNT Digital Library
Constraints and Superspin for SuperPoincare Algebras in Diverse Dimensions (open access)

Constraints and Superspin for SuperPoincare Algebras in Diverse Dimensions

We generalize to arbitrary dimension the construction of a covariant and supersymmetric constraint for the massless superPoincare algebra, which was given for the eleven-dimensional case in a previous work. We also contrast it with a similar construction appropriate to the massive case. Finally we show that the constraint uniquely fixes the representation of the algebra.
Date: April 27, 2004
Creator: Pasqua, Andrea & Zumino, Bruno
Object Type: Article
System: The UNT Digital Library
An efficient parallel termination detection algorithm (open access)

An efficient parallel termination detection algorithm

Information local to any one processor is insufficient to monitor the overall progress of most distributed computations. Typically, a second distributed computation for detecting termination of the main computation is necessary. In order to be a useful computational tool, the termination detection routine must operate concurrently with the main computation, adding minimal overhead, and it must promptly and correctly detect termination when it occurs. In this paper, we present a new algorithm for detecting the termination of a parallel computation on distributed-memory MIMD computers that satisfies all of those criteria. A variety of termination detection algorithms have been devised. Of these, the algorithm presented by Sinha, Kale, and Ramkumar (henceforth, the SKR algorithm) is unique in its ability to adapt to the load conditions of the system on which it runs, thereby minimizing the impact of termination detection on performance. Because their algorithm also detects termination quickly, we consider it to be the most efficient practical algorithm presently available. The termination detection algorithm presented here was developed for use in the PMESC programming library for distributed-memory MIMD computers. Like the SKR algorithm, our algorithm adapts to system loads and imposes little overhead. Also like the SKR algorithm, ours is tree-based, …
Date: May 27, 2004
Creator: Baker, A H; Crivelli, S & Jessup, E R
Object Type: Article
System: The UNT Digital Library
Advancing the Ion Beam Thin Film Planarization Process for the Smoothing of Substrate Particles (open access)

Advancing the Ion Beam Thin Film Planarization Process for the Smoothing of Substrate Particles

This report addresses the advancement of the ion beam thin film planarization process for the smoothing of substrate particles.
Date: October 27, 2004
Creator: Mirkarimi, P.; Spiller, E.; Baker, S.; Robinson, J.; Stearns, D.; Liddle, J. A. et al.
Object Type: Article
System: The UNT Digital Library
Dynamic Testing of Gasifier Refractory (open access)

Dynamic Testing of Gasifier Refractory

The University of North Dakota (UND) Chemical Engineering Department in conjunction with the UND Energy & Environmental Research Center (EERC) have initiated a program to thoroughly examine the combined chemical (reaction and phase change) and physical (erosion) effects experienced by a variety of refractory materials during both normal operation and thermal cycling under slagging coal gasification conditions. The goal of this work is to devise a mechanism of refractory loss under these conditions. The controlled-atmospheric dynamic corrodent application furnace (CADCAF) is being utilized to simulate refractory/slag interactions under dynamic conditions that more realistically simulate the environment in a slagging coal gasifier than any of the static tests used previously by refractory manufacturers and researchers. Shakedown testing of the CADCAF has been completed. Samples of slag and refractory from the Tampa Electric Polk Power Station have been obtained for testing in the CADCAF. The slag has been dried and sieved to the size needed for our flowing slag corrosion tests. Screening tests are in currently in progress. Detailed analysis of corrosion rates from the first tests is in progress.
Date: September 27, 2004
Creator: Mann, Michael D.; Shukla, Devdutt; Hong, Xi & Hurley, John P.
Object Type: Report
System: The UNT Digital Library
Advanced Reactor Licensing: Experience with Digital I&C Technology in Evolutionary Plants (open access)

Advanced Reactor Licensing: Experience with Digital I&C Technology in Evolutionary Plants

This report presents the findings from a study of experience with digital instrumentation and controls (I&C) technology in evolutionary nuclear power plants. In particular, this study evaluated regulatory approaches employed by the international nuclear power community for licensing advanced l&C systems and identified lessons learned. The report (1) gives an overview of the modern l&C technologies employed at numerous evolutionary nuclear power plants, (2) identifies performance experience derived from those applications, (3) discusses regulatory processes employed and issues that have arisen, (4) captures lessons learned from performance and regulatory experience, (5) suggests anticipated issues that may arise from international near-term deployment of reactor concepts, and (6) offers conclusions and recommendations for potential activities to support advanced reactor licensing in the United States.
Date: September 27, 2004
Creator: Wood, RT
Object Type: Report
System: The UNT Digital Library
THERMAL CONDUCTIVITY OF THE POTENTIAL REPOSITORY HORIZON (open access)

THERMAL CONDUCTIVITY OF THE POTENTIAL REPOSITORY HORIZON

The primary purpose of this report is to assess the spatial variability and uncertainty of bulk thermal conductivity in the host horizon for the repository at Yucca Mountain. More specifically, the lithostratigraphic units studied are located within the Topopah Spring Tuff (Tpt) and consist of the upper lithophysal zone (Tptpul), the middle nonlithophysal zone (Tptpmn), the lower lithophysal zone (Tptpll), and the lower nonlithophysal zone (Tptpln). Design plans indicate that approximately 81 percent of the repository will be excavated in the Tptpll, approximately 12 percent in the Tptpmn, and the remainder in the Tptul and Tptpln (BSC 2004 [DIRS 168370]). This report provides three-dimensional geostatistical estimates of the bulk thermal conductivity for the four stratigraphic layers of the repository horizon. The three-dimensional geostatistical estimates of matrix and lithophysal porosity, dry bulk density, and matrix thermal conductivity are also provided. This report provides input to various models and calculations that simulate heat transport through the rock mass. These models include the ''Drift Degradation Analysis, Multiscale Thermohydrologic Model, Ventilation Model and Analysis Report, Igneous Intrusion Impacts on Waste Packages and Waste Forms, Drift-Scale Coupled Processes (DST and TH Seepage) Models'', and ''Drift Scale THM Model''. These models directly or indirectly provide input …
Date: September 27, 2004
Creator: BEAN, J.E.
Object Type: Report
System: The UNT Digital Library
Field Test Program to Develop Comprehensive Design, Operating and Cost Data for Mercury Control Systems on Non-Scrubbed Coal-Fired Boilers, Quarterly Technical Report: January-March 2004 (open access)

Field Test Program to Develop Comprehensive Design, Operating and Cost Data for Mercury Control Systems on Non-Scrubbed Coal-Fired Boilers, Quarterly Technical Report: January-March 2004

With the nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Mercury is known to have toxic effects on the nervous systems of humans and wildlife. Although it exists only in trace amounts in coal, mercury is released when coal burns and can accumulate on land and in water. In water, bacteria transform the metal into methylmercury, the most hazardous form of the metal. Methylmercury can collect in fish and marine mammals in concentrations hundreds of thousands times higher than the levels in surrounding waters. One of the goals of DOE is to develop technologies by 2005 that will be capable of cutting mercury emissions 50 to 70 percent at well under one-half of projected DOE/EPA early cost estimates. ADA Environmental Solutions (ADA-ES) is managing a project to test mercury control technologies at full scale at four different power plants from 2000--2003. The ADA-ES project is focused on those power plants that are not equipped with wet flue gas desulfurization systems. ADA-ES has developed a portable system that will be tested at four …
Date: April 27, 2004
Creator: Bustard, Jean
Object Type: Report
System: The UNT Digital Library
Improved searching for spatial features in spatio-temporal data (open access)

Improved searching for spatial features in spatio-temporal data

Scientific data analysis often requires mining large databases or data warehouses to find features in space. One important task is to find regions of interest such as stellar objects in astrophysics or flame fronts in combustion studies. Typically, this task is performed in two steps. The first step (searching) identifies records satisfying certain conditions specified by the user and outputs a set of cells. The second step (region-growing) groups these cells into connected regions. Most common approaches essentially perform a brute-force scan for these arching step. A number of indexing schemes have been proposed to speed up the searching step. Because they usually also slow down the region-growing step, these schemes have not reduced the overall time. In this article, we propose an approach based on compressed bitmap indices. Our approach speeds up not only the searching step, but also the region-growing step. In the literature, the time complexity of the region-growing step is demonstrated to be linear in the number of records in the dataset. In our tests, we show that the response time of our region-growing algorithm is linear in the number of records close to the surface of the regions of interest which is a small subset …
Date: September 27, 2004
Creator: Stockinger, Kurt & Wu, Kesheng
Object Type: Report
System: The UNT Digital Library
Computational Accelerator Physics Working Group Summary (open access)

Computational Accelerator Physics Working Group Summary

The working group on computational accelerator physics at the 11th Advanced Accelerator Concepts Workshop held a series of meetings during the Workshop. Verification, i.e., showing that a computational application correctly solves the assumed model, and validation, i.e., showing that the model correctly describes the modeled system, were discussed for a number of systems. In particular, the predictions of the massively parallel codes, OSIRIS and VORPAL, used for modeling advanced accelerator concepts, were compared and shown to agree, thereby establishing some verification of both codes. In addition, a number of talks on the status and frontiers of computational accelerator physics were presented, to include the modeling of ultrahigh-brightness electron photoinjectors and the physics of beam halo production. Finally, talks discussing computational needs were presented.
Date: August 27, 2004
Creator: Cary, John R. & Bohn, Courtlandt L.
Object Type: Article
System: The UNT Digital Library
Laboratory directed research and development program FY 2003 (open access)

Laboratory directed research and development program FY 2003

The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab or LBNL) is a multi-program national research facility operated by the University of California for the Department of Energy (DOE). As an integral element of DOE's National Laboratory System, Berkeley Lab supports DOE's missions in fundamental science, energy resources, and environmental quality. Berkeley Lab programs advance four distinct goals for DOE and the nation: (1) To perform leading multidisciplinary research in the computing sciences, physical sciences, energy sciences, biosciences, and general sciences in a manner that ensures employee and public safety and protection of the environment. (2) To develop and operate unique national experimental facilities for qualified investigators. (3) To educate and train future generations of scientists and engineers to promote national science and education goals. (4) To transfer knowledge and technological innovations and to foster productive relationships among Berkeley Lab's research programs, universities, and industry in order to promote national economic competitiveness. In FY03, Berkeley Lab was authorized by DOE to establish a funding ceiling for the LDRD program of $15.0 M, which equates to about 3.2% of Berkeley Lab's FY03 projected operating and capital equipment budgets. This funding level was provided to develop new scientific ideas and opportunities and …
Date: March 27, 2004
Creator: Hansen, Todd
Object Type: Report
System: The UNT Digital Library
Analysis of Cladding Residues from the Dissolution of Irradiated Dresden-1 Reactor Fuel (open access)

Analysis of Cladding Residues from the Dissolution of Irradiated Dresden-1 Reactor Fuel

The primary goal of this work was to evaluate the efficacy of the chop-leach spent fuel dissolution process, with nitric acid dissolvent, for removing actinides and fission products from Zircaloy cladding to produce a cladding capable of meeting low-level waste (LLW) disposal criteria. Analysis of the cladding shows that actinides are present in the cladding at concentrations 50 to 400 times greater than the acceptable TRU limit in LLW. It appears that the nitric acid used for dissolution (initial concentration 4 M, with 10 M added as the dissolution proceeded) was inadequate for solubilizing the fuel meat. Scanning electron micrographs of the as-sampled cladding surface showed particles of material high in U on the surface of the cut samples, suggesting the fuel meat was not completely dissolved. If the cladding is to meet LLW disposal limits, it is likely that a more robust chemical treatment will be required to more completely digest the fuel meat. Based on the available analytical results, and the interpretation of those results, the following conclusions are drawn. The chop-leach method, as performed initially was inadequate for complete digestion of the fuel meat present in the Dresden-1 fuel samples studied. This failure of the dissolution process …
Date: May 27, 2004
Creator: KESSINGER, GF.
Object Type: Report
System: The UNT Digital Library