Resource Type

Synthesis of Novel Extended Phases of Molecular Solids at High Pressures and Temperatures (open access)

Synthesis of Novel Extended Phases of Molecular Solids at High Pressures and Temperatures

This study is for in-situ investigation of chemical bonding and molecular structure of low z-elements and simple molecular solids at high pressures and temperatures using 3rd-generation synchrotron x-ray diffraction. To understand the contribution of the empty d-electron orbital of Mg in relation to the formation of molecular solids like MgO, which is one of the important Earth lower mantle materials and MgB{sub 2}, which has recently been the focus of intense superconducting material research, we have performed double-sided laser heating experiments using a diamond anvil cell (DAC). Understanding the structural stability and the formation of the above Mg-compounds requires studying Mg itself as well as the relevant compounds. BL10XU at the Spring-8 was used to study phase stability and make accurate equation of state (EOS) determinations of Mg coupled with external heating and the double-sided laser heating technique. Monochromatic x-ray at 30 keV (0.4135 {angstrom}) was focused to about 40 {micro}m at the sample and the diffracted x-ray were recorded using a high-resolution image plate (3000 x 3000 pixels with a 0.1 mm resolution per pixel). EOS parameters for hcp and bcc Mg were determined by fitting to a Birch-Murnaghan equation. An isothermal compression of Mg at 300 K up …
Date: March 30, 2004
Creator: Yoo, C; Evans, W & Cynn, H
System: The UNT Digital Library
Tc Reductant Chemistry and Crucible Melting Studies with Simulated Hanford Low-Activity Waste (open access)

Tc Reductant Chemistry and Crucible Melting Studies with Simulated Hanford Low-Activity Waste

The FY 2003 risk assessment (RA) of bulk vitrification (BV) waste packages used 0.3 wt% of the technetium (Tc) inventory as a leachable salt and found it sufficient to create a significant peak in the groundwater concentration in a 100-meter down-gradient well. Although this peak met regulatory limits, considering uncertainty in the actual Tc salt fraction, peak concentrations could exceed the maximum concentration limit (MCL) under some scenarios so reducing the leachable salt inventory is desirable. The main objective of this study was to reduce the mobile Tc species available within a BV disposal package by reducing the oxidation state of the Tc in the waste feed and/or during melting because Tc in its reduced form of Tc(IV) has a much lower volatility than Tc(VII). Reduced Tc volatility has a secondary benefit of increasing the Tc retention in glass.
Date: March 30, 2005
Creator: Kim, Dong-Sang; Soderquist, Chuck Z.; Icenhower, Jonathan P.; McGrail, B PETER.; Scheele, Randall D.; McNamara, Bruce K. et al.
System: The UNT Digital Library
Feasibility Study on Using Two Mixer Pumps for Tank 241-AY-102 Waste Mixing (open access)

Feasibility Study on Using Two Mixer Pumps for Tank 241-AY-102 Waste Mixing

The current waste retrieval plan at Hanford calls for using two mixer pumps to mix the waste stored in double-shell Tank 214-AY-102. The objective of this evaluation was to determine whether two rotating 300-hp mixer pumps placed 22 ft (6.7 m) off-center in the tank could adequately mix the AY-102 waste. The tank currently contains high-level waste that is 248 inches (6.3 m) deep, comprising 62 inches (1.58 m) of sludge and 186 inches (4.72 m) of supernatant liquid (Galbraith et al. 2002). Based on the available data, AY-102 waste properties were determined, including the densities of liquid and agglomerated settled solids and crystals, the volume fraction of settled solids, the solid particle size distribution, the liquid and slurry viscosities, and the yield stress in shear (shear strength) of the settled solids layer. To evaluate the likely and bounding cases of AY-102 waste mixing, sludge erosion modeling was performed with a median value of 1,090 Pa (likely condition) and a conservative (more difficult to erode) 97.5 percentile value of 2,230 Pa for shear strength. According to model predictions, the two rotating mixer pumps would erode 89% of the sludge with shear strength of 1,090 Pa. They would erode sludge up …
Date: August 30, 2004
Creator: Onishi, Yasuo & Wells, Beric E.
System: The UNT Digital Library
Time Reversal Signal Processing in Communications - A Feasibility Study (open access)

Time Reversal Signal Processing in Communications - A Feasibility Study

A typical communications channel is subjected to a variety of signal distortions, including multipath, that corrupt the information being transmitted and reduce the effective channel capacity. The mitigation of the multipath interference component is an ongoing concern for communication systems operating in complex environments such as might be experienced inside buildings, urban environments, and hilly or heavily wooded areas. Communications between mobile units and distributed sensors, so important to national security, are dependent upon flawless conveyance of information in complex environments. The reduction of this multipath corruption necessitates better channel equalization, i.e., the removal of channel distortion to extract the transmitted information. But, the current state of the art in channel equalization either requires a priori knowledge of the channel or the use of a known training sequence and adaptive filtering. If the ''assumed'' model within the equalization processor does not at least capture the dominant characteristics of the channel, then the received information may still be highly distorted and possibly useless. Also, the processing required for classical equalization is demanding in computational resources. To remedy this situation, many techniques have been investigated to replace classical equalization. Such a technique, the subject of this feasibility study, is Time Reversal Signal …
Date: January 30, 2002
Creator: Meyer, A W; Candy, J V & Poggio, A J
System: The UNT Digital Library
High Performance Diskless Linux Workstations in AX-Division (open access)

High Performance Diskless Linux Workstations in AX-Division

AX Division has recently installed a number of diskless Linux workstations to meet the needs of its scientific staff for classified processing. Results so far are quite positive, although problems do remain. Some unusual requirements were met using a novel, but simple, design: Each diskless client has a dedicated partition on a server disk that contains a complete Linux distribution.
Date: September 30, 2003
Creator: Councell, E & Busby, L
System: The UNT Digital Library
Final ROI Report - Technology Transfer of Waste-Reducing Groundwater Sampling Systems (open access)

Final ROI Report - Technology Transfer of Waste-Reducing Groundwater Sampling Systems

This report presents the findings of a U.S. DOE Environmental Management technology transfer initiative of waste-reducing ground water sampling systems between Savannah River Site (SRS) and Lawrence Livermore National Laboratory (LLNL) which occurred during fiscal years 2001 and 2002. The report describes the collaboration between the two sites, the deployment of the Savannah River Site Purge Water Management System at LLNL, the changes made to that system for use at LLNL, and documents the return-on-investment derived from the system's use at LLNL as well as other benefits generated through this inter-laboratory collaboration. An evaluation of the deployment of the LLNL EasyPump sampling technology at SRS will be covered in a separate report from SRS.
Date: September 30, 2002
Creator: Noyes, Charles; Howard, Greg; Bishop, Dorothy; Tuckfield, Cary & Hiergesell, Robert
System: The UNT Digital Library
Modeling of High-altitude Atmospheric Dispersion Using Climate and Meteorological Forecast Data (open access)

Modeling of High-altitude Atmospheric Dispersion Using Climate and Meteorological Forecast Data

The overall objective of this study is to provide a demonstration of capability for importing both high altitude meteorological forecast and climatological datasets from NRL into the NARAC modeling system to simulate high altitude atmospheric droplet release and dispersion. The altitude of release for the proposed study is between 60 and 100km altitude. As either standard climatological data (over a period of 40 years) or daily meteorological forecasts can drive the particle dispersion model, we did a limited comparison of simulations with meteorological data and simulations with climatological data. The modeling tools used to address this problem are the National Atmospheric Release Advisory Center (NARAC) modeling system at LLNL which are operationally employed to assist DOE/DHS/DOD emergency response to an atmospheric release of chemical, biological, and radiological contaminants. The interrelation of the various data feeds and codes at NARAC are illustrated in Figure 1. The NARAC scientific models are all verified to both analytic solutions and other codes; the models are validated to field data such as the Prairie Grass study (Barad, 1958). NARAC has multiple real-time meteorological data feeds from the National Weather Service, from the European Center for Medium range Weather Forecasting, from the US Navy, and from …
Date: March 30, 2005
Creator: Glascoe, L G & Chin, H S
System: The UNT Digital Library
Global Security Rule Sets An Analysis of the Current Global Security Environment and Rule Sets Governing Nuclear Weapons Release (open access)

Global Security Rule Sets An Analysis of the Current Global Security Environment and Rule Sets Governing Nuclear Weapons Release

America is in a unique position in its history. In maintaining its position as the world's only superpower, the US consistently finds itself taking on the role of a global cop, chief exporter of hard and soft power, and primary impetus for globalization. A view of the current global situation shows an America that can benefit greatly from the effects of globalization and soft power. Similarly, America's power can be reduced significantly if globalization and its soft power are not handled properly. At the same time, America has slowly come to realize that its next major adversary is not a near peer competitor but terrorism and disconnected nations that seek nuclear capabilities. In dealing with this new threat, America needs to come to terms with its own nuclear arsenal and build a security rule set that will establish for the world explicitly what actions will cause the US to consider nuclear weapons release. This rule set; however, needs to be established with sensitivity to the US's international interests in globalization and soft power. The US must find a way to establish its doctrine governing nuclear weapons release without threatening other peaceful nations in the process.
Date: September 30, 2004
Creator: Mollahan, K & Nattrass, L
System: The UNT Digital Library
Physical and Liquid Chemical Simulant Formulations for Transuranic Waste in Hanford Single-Shell Tanks (open access)

Physical and Liquid Chemical Simulant Formulations for Transuranic Waste in Hanford Single-Shell Tanks

CH2M HILL Hanford Group, Inc. (CH2M HILL) is in the process of identifying and developing supplemental process technologies to accelerate the tank waste cleanup mission. A range of technologies is being evaluated to allow disposal of Hanford waste types, including transuranic (TRU) process wastes. Ten Hanford single-shell tanks (SSTs) have been identified whose contents may meet the criteria for designation as TRU waste: the B-200 series (241-B-201, -B-202, -B 203, and B 204), the T-200 series (241-T-201, T 202, -T-203, and -T-204), and Tanks 241-T-110 and -T-111. CH2M HILL has requested vendor proposals to develop a system to transfer and package the contact-handled TRU (CH-TRU) waste retrieved from the SSTs for subsequent disposal at the Waste Isolation Pilot Plant (WIPP). Current plans call for a modified ''dry'' retrieval process in which a liquid stream is used to help mobilize the waste for retrieval and transfer through lines and vessels. This retrieval approach requires that a significant portion of the liquid be removed from the mobilized waste sludge in a ''dewatering'' process such as centrifugation prior to transferring to waste packages in a form suitable for acceptance at WIPP. In support of CH2M HILL's effort to procure a TRU waste handling …
Date: July 30, 2003
Creator: Rassat, Scot D.; Bagaasen, Larry M.; Mahoney, Lenna A.; Russell, Renee L.; Caldwell, Dustin D. & Mendoza, Donaldo P.
System: The UNT Digital Library
The Search for Meterorites with Complex Exposure Histories Amoung Ordinary Chondrites with Low 3HE/21NE Ratios (open access)

The Search for Meterorites with Complex Exposure Histories Amoung Ordinary Chondrites with Low 3HE/21NE Ratios

In calculating cosmic-ray exposure ages of meteorites it is generally assumed that the meteoroids were expelled from a shielded position within their parent body and then experienced a single stage exposure before colliding with Earth. The combination of noble gas and radionuclide measurements in several large meteorites, such as Jilin and Bur Ghelaui, have revealed complex exposure histories: i.e. an initial exposure on the surface of an asteroid (or within meter-sized meteoroid), followed by a second exposure as a smaller object. In fact, orbital dynamics calculations predicted that at least 30% of the meteorites arriving on Earth experienced two- or multiple-stage exposure histories [1]. More recently, after the recognition that the Yarkovsky effect plays an important role in delivering meteorites from the asteroid belt to Earth-crossing orbits, it was confirmed that complex exposure histories should be common [2]. Nevertheless, despite the ability to measure a wide range of radionuclides with accelerator mass spectrometry (AMS), only a few meteorites with complex exposure histories have been identified [e.g. 3,4]. The question is whether the relatively paucity of complex exposure histories is real or have we simply overlooked complex-exposure histories. In this work we focus on meteorites with low {sup 3}He/{sup 21}Ne ratios, …
Date: April 30, 2001
Creator: Welton, K C; Nishiizumi, K & Caffee, M W
System: The UNT Digital Library
PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT. (open access)

PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.

We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigation of the properties of the dense nuclear medium created in heavy ion collisions, and for the exploration of the nucleon spin-structure functions. In addition, the VTX will also considerably improve other measurements with PHENIX. The main physics topics addressed by the VTX are: (1) Hot and dense strongly interacting matter--Potential enhancement of charm production; Open beauty production; Flavor dependence of jet quenching and QCD energy loss; Accurate charm reference for quarkonium; Thermal dilepton radiation; High p{sub T} phenomena with light flavors above 10-15 GeV/c in p{sub T}; and Upsilon spectroscopy in the e{sup +}e{sup -} decay channel. (2) Gluon spin structure of the nucleon--{Delta}G/G with charm; {Delta}G/G with beauty; and x dependence of {Delta}G/G with {gamma}-jet correlations. (3) Nucleon structure in nuclei--Gluon shadowing over …
Date: March 30, 2004
Creator: AKIBA,Y.
System: The UNT Digital Library
Sealed Combustion System With Diagnostic Self-Tuning. (open access)

Sealed Combustion System With Diagnostic Self-Tuning.

This task grew out of a proposal to develop a ''concept'' oil-fired heating system that would incorporate advanced technologies available and suitable for a residential system. Discussions among the program and project personnel resulted in the identification of a sealed combustion system as of programmatic interest and the objective was to develop an approach to a sealed system with diagnostic self-tuning. The major conclusion with regard to the specific objective for this task is that a measurement of the static pressure in the input pipe can be used to provide a measure of the excess air for a limit control. Its implementation would require a suitable pressure sensor, and a circuit to combine its output signal, at the appropriate time in the operating cycle, to the burner control. The sensor and control combination will also have to be tested successfully under all conceivable contingencies that can cause the airflow to decrease. It could also be implemented, possibly even more reliably, if a mass flow sensor, such as is used in automobile engines and hence may be cheap, could be used. The pressure measurements reported here, both steady and transient, represent only the subset of a much larger set that gave …
Date: September 30, 2004
Creator: Krishna, C. R.
System: The UNT Digital Library
An Experiment on Graph Analysis Methodologies for Scenarios (open access)

An Experiment on Graph Analysis Methodologies for Scenarios

Visual graph representations are increasingly used to represent, display, and explore scenarios and the structure of organizations. The graph representations of scenarios are readily understood, and commercial software is available to create and manage these representations. The purpose of the research presented in this paper is to explore whether these graph representations support quantitative assessments of the underlying scenarios. The underlying structure of the scenarios is the information that is being targeted in the experiment and the extent to which the scenarios are similar in content. An experiment was designed that incorporated both the contents of the scenarios and analysts’ graph representations of the scenarios. The scenarios’ content was represented graphically by analysts, and both the structure and the semantics of the graph representation were attempted to be used to understand the content. The structure information was not found to be discriminating for the content of the scenarios in this experiment; but, the semantic information was discriminating.
Date: September 30, 2005
Creator: Brothers, Alan J.; Whitney, Paul D.; Wolf, Katherine E.; Kuchar, Olga A. & Chin, George
System: The UNT Digital Library
A Catalog of Vadose Zone Hydraulic Properties for the Hanford Site (open access)

A Catalog of Vadose Zone Hydraulic Properties for the Hanford Site

To predict contaminant release to the groundwater, it is necessary to understand the hydraulic properties of the material between the release point and the water table. Measurements of the hydraulic properties of the Hanford unsaturated sediments that buffer the water table are available from many areas of the site; however, the documentation is not well cataloged nor is it easily accessible. The purpose of this report is to identify what data is available for characterization of the unsaturated hydraulic properties at Hanford and Where these data can be found.
Date: September 30, 2002
Creator: Freeman, Eugene J.; Khaleel, Raziuddin & Heller, Paula R.
System: The UNT Digital Library
The 75As(n,2n) Cross Sections into the 74As Isomer and Ground State (open access)

The 75As(n,2n) Cross Sections into the 74As Isomer and Ground State

The {sup 75}As(n, 2n) cross section for the population of the T{sub 1/2} = 26.8-ns isomer at E{sub x} = 259.3 keV in {sup 74}As has been measured as a function of incident neutron energy, from threshold to E{sub n} = 20 MeV. The cross section was measured using the GEANIE spectrometer at LANSCE/WNR. For convenience, the {sup 75}As(n, 2n) population cross section for the {sup 74}As ground state has been deduced as the difference between the previously-known (n, 2n) reaction cross section and the newly measured {sup 75}As(n, 2n){sup 74}As{sup m} cross section. The (n, 2n) reaction, ground-state, and isomer population cross sections are tabulated in this paper.
Date: June 30, 2003
Creator: Younes, W.; Garrett, P. E.; Becker, J. A.; Bernstein, L. A.; Ormand, W. E.; Dietrich, F. S. et al.
System: The UNT Digital Library
Neutron and Charged-Particle Induced Cross Sections for Radiochemistry in the Region of Samarium, Europium, and Gadolinium (open access)

Neutron and Charged-Particle Induced Cross Sections for Radiochemistry in the Region of Samarium, Europium, and Gadolinium

We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron and proton induced nuclear reaction cross sections in the mass region of samarium, europium and gadolinium (62 {le} Z {le} 64, 82 {le} N {le} 96).
Date: November 30, 2004
Creator: Hoffman, R. D.; Kelley, K.; Dietrich, F. S.; Bauer, R. & Mustafa, M.
System: The UNT Digital Library
Recharge Data Package for the 2005 Integrated Disposal Facility Performance Assessment (open access)

Recharge Data Package for the 2005 Integrated Disposal Facility Performance Assessment

Pacific Northwest National Laboratory assisted CH2M Hill Hanford Group, Inc., (CHG) by providing estimates of recharge rates for current conditions and long-term scenarios involving disposal in the Integrated Disposal Facility (IDF). The IDF will be located in the 200 East Area at the Hanford Site and will receive several types of waste including immobilized low-activity waste. The recharge estimates for each scenario were derived from lysimeter and tracer data collected by the IDF PA Project and from modeling studies conducted for the project. Recharge estimates were provided for three specific site features (the surface barrier; possible barrier side slopes; and the surrounding soil) and four specific time periods (pre-Hanford; Hanford operations; surface barrier design life; post-barrier design life). CHG plans to conduct a performance assessment of the latest IDF design and call it the IDF 2005 PA; this recharge data package supports the upcoming IDF 2005 PA.
Date: June 30, 2004
Creator: Fayer, Michael J. & Szecsody, Jim E.
System: The UNT Digital Library
Technical Documentation and Verification for the Buildings Module in the Visual Sample Plan (VSP) Software (open access)

Technical Documentation and Verification for the Buildings Module in the Visual Sample Plan (VSP) Software

Visual Sample Plan (VSP) is an easy-to-use visual and graphic statistically-based software tool being developed by the Pacific Northwest National Laboratory (PNNL) to help determine the appropriate number and location of environmental samples so that environmental decisions can be made with the required confidence. The VSP software, which is available free at http://dqo.pnl.gov/vsp, is a significant aid in developing probability-based sampling designs (number and location of samples and measurements) using the Data Quality Objectives (DQO) planning process developed by the U.S. Environmental Protection Agency (EPA). VSP also has the capability of conducted statistical analyses to provide descriptive statistical summaries of data sets, to test whether data are normally distributed, and to compute upper confidence limits on means. This report is the latest in a series of reports that document the statistical methods used in VSP [Davidson (2001), Gilbert et al. (2001), Gilbert et a l. (2002), and Gilbert et al. (2003)] and the quality assurance (QA) activities conducted by PNNL to verify that VSP computations are correct and accurate. This report focuses on the VSP buildings module that was developed with support from the Department of Homeland Security (DHS), Combating Terrorism Technology Support Office (CTTSO), Technical Support Working Group (TSWG). …
Date: June 30, 2005
Creator: Gilbert, Richard O.; Wilson, John E.; Pulsipher, Brent A.; Hassig, Nancy L. & Nuffer, Lisa L.
System: The UNT Digital Library
Design of 3x3 focusing array for heavy ion driver. Final report on CRADA (open access)

Design of 3x3 focusing array for heavy ion driver. Final report on CRADA

This memo presents a design of a 3 x 3 quadrupole array for HIF. It contains 3 D magnetic field computations of the array build with racetrack coils with and without different shields. It is shown that it is possible to have a low error magnetic field in the cells and shield the stray fields to acceptable levels. The array design seems to be a practical solution to any size array for future multi-beam heavy ion fusion drivers.
Date: March 30, 2005
Creator: Martovetsky, N. N.
System: The UNT Digital Library
Laboratory Testing of Bulk Vitrified and Steam Reformed Low-Activity Waste Forms to Support A Preliminary Risk Assessment for an Integrated Disposal Facility (open access)

Laboratory Testing of Bulk Vitrified and Steam Reformed Low-Activity Waste Forms to Support A Preliminary Risk Assessment for an Integrated Disposal Facility

Laboratory testing was conducted on bulk vitrified and steam reformed waste forms to supply the input parameters needed for reactive chemical transport calculations with the Subsurface Transport Over Reactive Multiphases (STORM) code. This same code was used to conduct the 2001 ILAW performance assessment. The required input parameters for both waste forms are derived from a mechanistic model that describes the effect of solution chemistry on contaminant release rates. The single-pass flow-through test was the principal method used to obtain these input parameters, supplemented by product consistency test measurements and physical property measurements.
Date: September 30, 2003
Creator: McGrail, B. Peter; Pierce, Eric M.; Schaef, Herbert T.; Rodriguez, Elsa A.; Steele, Jackie L.; Owen, Antionette T. et al.
System: The UNT Digital Library
Neutron and Charged-Particle Induced Cross Sections for Radiochemistry for Isotopes of Scandium, Titanium, Vanadium, Chromium, Manganese, and Iron (open access)

Neutron and Charged-Particle Induced Cross Sections for Radiochemistry for Isotopes of Scandium, Titanium, Vanadium, Chromium, Manganese, and Iron

We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Local systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron and proton induced nuclear reaction cross sections in the mass region of scandium, titanium, vanadium, chromium, manganese, and iron (21 {le} Z {le} 26, 20 {le} N {le} 32).
Date: November 30, 2004
Creator: Kelley, K.; Hoffman, R. D.; Dietrich, F. S.; Bauer, R. & Mustafa, M.
System: The UNT Digital Library
Recommendations for Advanced Design Mixer Pump Operation in Savannah River Site Tank 18F (open access)

Recommendations for Advanced Design Mixer Pump Operation in Savannah River Site Tank 18F

This report discusses technical issues and presents recommendations for operating the advanced design mixer pump (ADMP) in Tank 18 at the Savannah River Site (SRS). Also presented are the results obtained from simulated scaled pump-down tests carried out in the 1/4-scale double shell tank (DST) test facility at Pacific Northwest National Laboratory (PNNL). The work was conducted for the DOE Tanks Focus Area (TFA) by the Retrieval Process Development and Enhancement (RPD&E) program. The ability of the Tank 18 retrieval system to mobilize the solid waste and transport it through the retrieval pump, efficiently removing the solids from the tank, are evaluated.
Date: October 30, 2003
Creator: Enderlin, Carl W.; Terrones, Guillermo; Bates, Cameron J.; Hatchell, Brian K. & Adkins, Brannen
System: The UNT Digital Library
ASSESSMENT OF RADIONUCLIDE RELEASE FROM INTACT STRUCTURES BACKFILLED WITH CONTAMINATED CONCRETE AT THE YANKEE NUCLEAR POWER STATION. (open access)

ASSESSMENT OF RADIONUCLIDE RELEASE FROM INTACT STRUCTURES BACKFILLED WITH CONTAMINATED CONCRETE AT THE YANKEE NUCLEAR POWER STATION.

This calculation determines the release of residual radioactivity (including H-3, C-14, Co-60, Ni-63, Sr-90, and Cs-137), from subsurface structures filled with concrete debris at the Yankee Nuclear Power Station. Analyses were performed to assess the rate of release from the source of contamination and the resulting dose in the groundwater pathway. Two mechanisms were considered, diffusive release from the concrete structures (walls and floors) that remain intact and sorption onto concrete backfill placed within these structures. RESRAD was used to calculate the predicted maximum dose assuming a unit loading of 1 pCi/g on the intact structures. To the extent possible, the same assumptions in the soil DCGL calculations performed for Yankee Atomic were used in the calculation. However, modifications to some input parameter values were needed to represent the geometry of the subsurface facilities, flow through these facilities, and releases from the backfill and intact structures. Input parameters specific to these calculations included the leach rate, disposal geometry, pumping rate, porosity and bulk density. The dose results for a unit loading of 1 pCi/g on intact structures showed that Sr-90 had the highest dose (3.67E-02 mrem/yr).
Date: September 30, 2004
Creator: SULLIVAN, T.
System: The UNT Digital Library
Underwater Determination of Radionuclide Levels in 105-KE Basin Floor and Walls Using a Gamma-Ray Detector System (open access)

Underwater Determination of Radionuclide Levels in 105-KE Basin Floor and Walls Using a Gamma-Ray Detector System

Activities to remove spent fuel, sludge and debris from K East Basin have begun. Once all the radioactive hazards (i.e., fuel, sludge and debris) are removed from the basin, the basin water will be removed and the basin will be turned over to a deactivation and decommission contractor. However, the specific approach to achieving this end state is dependent on knowledge of contamination levels in the concrete walls and floor once the water is removed. PNNL researchers have developed a one-of-a-kind technology for performing non-destructive evaluation of the highly contaminated K East fuel storage basin for the purpose of determining concrete contamination levels from selected wall and floor locations below the basin waterline.
Date: September 30, 2003
Creator: Arthur, Richard J.; Schlahta, Stephan N.; Scherpelz, Robert I.; MacFarlan, Paul J. & Catalan, Michael A.
System: The UNT Digital Library