Considerations Related To Human Intrusion In The Context Of Disposal Of Radioactive Waste-The IAEA HIDRA Project (open access)

Considerations Related To Human Intrusion In The Context Of Disposal Of Radioactive Waste-The IAEA HIDRA Project

The principal approaches for management of radioactive waste are commonly termed ‘delay and decay’, ‘concentrate and contain’ and ‘dilute and disperse’. Containing the waste and isolating it from the human environment, by burying it, is considered to increase safety and is generally accepted as the preferred approach for managing radioactive waste. However, this approach results in concentrated sources of radioactive waste contained in one location, which can pose hazards should the facility be disrupted by human action in the future. The International Commission on Radiological Protection (ICRP), International Atomic Energy Agency (IAEA), and Organization for Economic Cooperation and Development/Nuclear Energy Agency (OECD/NEA) agree that some form of inadvertent human intrusion (HI) needs to be considered to address the potential consequences in the case of loss of institutional control and loss of memory of the disposal facility. Requirements are reflected in national regulations governing radioactive waste disposal. However, in practice, these requirements are often different from country to country, which is then reflected in the actual implementation of HI as part of a safety case. The IAEA project on HI in the context of Disposal of RadioActive waste (HIDRA) has been started to identify potential areas for improved consistency in consideration …
Date: January 9, 2014
Creator: Seitz, Roger; Kumano, Yumiko; Bailey, Lucy; Markley, Chris; Andersson, Eva & Beuth, Thomas
Object Type: Article
System: The UNT Digital Library
ILC Higgs White Paper (open access)

ILC Higgs White Paper

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Date: January 9, 2014
Creator: Barklow, T.; Asner, D. M.; Calancha, C.; Fujii, K.; Graf, N.; Haber, H. E. et al.
Object Type: Article
System: The UNT Digital Library
Mesoscale Modeling Framework Design: Subcontract Report (open access)

Mesoscale Modeling Framework Design: Subcontract Report

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Date: January 9, 2014
Creator: Chen, L Q; Tang, M; Heo, T W & Wood, B C
Object Type: Report
System: The UNT Digital Library
Performance Characteristics of HYDRA - a Multi-Physics simulation code from Lawrence Livermore National Laboratory (open access)

Performance Characteristics of HYDRA - a Multi-Physics simulation code from Lawrence Livermore National Laboratory

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Date: January 9, 2014
Creator: Langer, S. H.; Karlin, I. & Marinak, M. M.
Object Type: Report
System: The UNT Digital Library
Simulations of Failure via Three-Dimensional Cracking in Fuel Cladding for Advanced Nuclear Fuels (open access)

Simulations of Failure via Three-Dimensional Cracking in Fuel Cladding for Advanced Nuclear Fuels

Enhancing performance of fuel cladding and duct alloys is a key means of increasing fuel burnup. This project will address the failure of fuel cladding via three-dimensional cracking models. Researchers will develop a simulation code for the failure of the fuel cladding and validate the code through experiments. The objective is to develop an algorithm to determine the failure of fuel cladding in the form of three-dimensional cracking due to prolonged exposure under varying conditions of pressure, temperature, chemical environment, and irradiation. This project encompasses the following tasks: 1. Simulate 3D crack initiation and growth under instantaneous and/or fatigue loads using a new variant of the material point method (MPM); 2. Simulate debonding of the materials in the crack path using cohesive elements, considering normal and shear traction separation laws; 3. Determine the crack propagation path, considering damage of the materials incorporated in the cohesive elements to allow the energy release rate to be minimized; 4. Simulate the three-dimensional fatigue crack growth as a function of loading histories; 5. Verify the simulation code by comparing results to theoretical and numerical studies available in the literature; 6. Conduct experiments to observe the crack path and surface profile in unused fuel cladding …
Date: January 9, 2014
Creator: Lu, Hongbing; Bukkapatnam, Satish; Harimkar, Sandip; Singh, Raman & Bardenhagen, Scott
Object Type: Report
System: The UNT Digital Library
Study of Interfacial Interactions Using Thing Film Surface Modification: Radiation and Oxidation Effects in Materials (open access)

Study of Interfacial Interactions Using Thing Film Surface Modification: Radiation and Oxidation Effects in Materials

Interfaces play a key role in dictating the long-term stability of materials under the influence of radiation and high temperatures. For example, grain boundaries affect corrosion by way of providing kinetically favorable paths for elemental diffusion, but they can also act as sinks for defects and helium generated during irradiation. Likewise, the retention of high-temperature strength in nanostructured, oxide-dispersion strengthened steels depends strongly on the stoichiometric and physical stability of the (Y, Ti)-oxide particles/matrix interface under radiation and high temperatures. An understanding of these interfacial effects at a fundamental level is important for the development of materials for extreme environments of nuclear reactors. The goal of this project is to develop an understanding stability of interfaces by depositing thin films of materials on substrates followed by ion irradiation of the film-substrate system at elevated temperatures followed by post-irradiation oxidation treatments. Specifically, the research will be performed by depositing thin films of yttrium and titanium (~500 nm) on Fe-12%Cr binary alloy substrate. Y and Ti have been selected as thin-film materials because they form highly stable protective oxides layers. The Fe-12%Cr binary alloy has been selected because it is representative of ferritic steels that are widely used in nuclear systems. The …
Date: January 9, 2014
Creator: Sridharan, Kumar & Zhang, Jinsuo
Object Type: Report
System: The UNT Digital Library
Unveiling the Nature of the Unidentified gamma-rays Sources VIII: Computing the Association Probability (open access)

Unveiling the Nature of the Unidentified gamma-rays Sources VIII: Computing the Association Probability

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Date: January 9, 2014
Creator: Massaro, F.; D'Abrusco, R.; Masetti, N.; Omodei, N.; Smith, Howard A. & Funk, S.
Object Type: Article
System: The UNT Digital Library
Upper Bound on the First Star Formation History (open access)

Upper Bound on the First Star Formation History

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Date: January 9, 2014
Creator: Inoue, Yoshiyuki; Tanaka, Yasuyuki T.; Madejski, Grzegorz M. & Dominguez, Alberto
Object Type: Article
System: The UNT Digital Library
Web-based Tool Identifies and Quantifies Potential Cost Savings Measures at the Hanford Site - 14366 (open access)

Web-based Tool Identifies and Quantifies Potential Cost Savings Measures at the Hanford Site - 14366

The Technical Improvement system is an approachable web-based tool that is available to Hanford DOE staff, site contractors, and general support service contractors as part of the baseline optimization effort underway at the Hanford Site. Finding and implementing technical improvements are a large part of DOE’s cost savings efforts. The Technical Improvement dashboard is a key tool for brainstorming and monitoring the progress of submitted baseline optimization and potential cost/schedule efficiencies. The dashboard is accessible to users over the Hanford Local Area Network (HLAN) and provides a highly visual and straightforward status to management on the ideas provided, alleviating the need for resource intensive weekly and monthly reviews.
Date: January 9, 2014
Creator: Renevitz, Marisa J.; Peschong, Jon C.; Charboneau, Briant L. & Simpson, Brett C.
Object Type: Article
System: The UNT Digital Library
CAPABILITY TO RECOVER PLUTONIUM-238 IN H-CANYON/HB-LINE (open access)

CAPABILITY TO RECOVER PLUTONIUM-238 IN H-CANYON/HB-LINE

Plutonium-238 is used in Radioisotope Thermoelectric Generators (RTGs) to generate electrical power and in Radioisotope Heater Units (RHUs) to produce heat for electronics and environmental control for deep space missions. The domestic supply of Pu-238 consists of scrap material from previous mission production or material purchased from Russia. Currently, the United States has no significant production scale operational capability to produce and separate new Pu-238 from irradiated neptunium-237 targets. The Department of Energy - Nuclear Energy is currently evaluating and developing plans to reconstitute the United States capability to produce Pu-238 from irradiated Np-237 targets. The Savannah River Site had previously produced and/or processed all the Pu-238 utilized in Radioisotope Thermoelectric Generators (RTGs) for deep space missions up to and including the majority of the plutonium for the Cassini Mission. The previous full production cycle capabilities included: Np-237 target fabrication, target irradiation, target dissolution and Np-237 and Pu-238 separation and purification, conversion of Np-237 and Pu-238 to oxide, scrap recovery, and Pu-238 encapsulation. The capability and equipment still exist and could be revitalized or put back into service to recover and purify Pu-238/Np-237 or broken General Purpose Heat Source (GPHS) pellets utilizing existing process equipment in HB-Line Scrap Recovery, and …
Date: January 9, 2013
Creator: Fuller, K.; Smith, Robert H. Jr. & Goergen, Charles R.
Object Type: Article
System: The UNT Digital Library
Comparison between the United States and United Kingdom Criticality Safety Personnel Training Program Guidance (open access)

Comparison between the United States and United Kingdom Criticality Safety Personnel Training Program Guidance

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Date: January 9, 2013
Creator: Wysong, A R; Heinrichs, D P & Tancock, N P
Object Type: Article
System: The UNT Digital Library
COMPUTATIONAL MODELING OF CIRCULATING FLUIDIZED BED REACTORS (open access)

COMPUTATIONAL MODELING OF CIRCULATING FLUIDIZED BED REACTORS

Details of numerical simulations of two-phase gas-solid turbulent flow in the riser section of Circulating Fluidized Bed Reactor (CFBR) using Computational Fluid Dynamics (CFD) technique are reported. Two CFBR riser configurations are considered and modeled. Each of these two riser models consist of inlet, exit, connecting elbows and a main pipe. Both riser configurations are cylindrical and have the same diameter but differ in their inlet lengths and main pipe height to enable investigation of riser geometrical scaling effects. In addition, two types of solid particles are exploited in the solid phase of the two-phase gas-solid riser flow simulations to study the influence of solid loading ratio on flow patterns. The gaseous phase in the two-phase flow is represented by standard atmospheric air. The CFD-based FLUENT software is employed to obtain steady state and transient solutions for flow modulations in the riser. The physical dimensions, types and numbers of computation meshes, and solution methodology utilized in the present work are stated. Flow parameters, such as static and dynamic pressure, species velocity, and volume fractions are monitored and analyzed. The differences in the computational results between the two models, under steady and transient conditions, are compared, contrasted, and discussed.
Date: January 9, 2013
Creator: Ibrahim, Essam A
Object Type: Report
System: The UNT Digital Library
FY12 Summary Report on Liquid-Liquid Contactor Experiments for CFD Model Validation (open access)

FY12 Summary Report on Liquid-Liquid Contactor Experiments for CFD Model Validation

None
Date: January 9, 2013
Creator: Wardle, K. E.
Object Type: Report
System: The UNT Digital Library
The National Center for Radioecology: A Network of Excellence for Environmental and Human Radiation Risk Reduction (open access)

The National Center for Radioecology: A Network of Excellence for Environmental and Human Radiation Risk Reduction

Radioecology in the United States can be traced back to the early 1950s when small research programs were established to address the fate and effects of radionuclides released in the environment from activities at nuclear facilities. These programs focused primarily on local environmental effects, but global radioactive fallout from nuclear weapons testing and the potential for larger scale local releases of radioisotopes resulted in major concerns about the threat, not only to humans, but to other species and to ecosystems that support all life. These concerns were shared by other countries and it was quickly recognized that a multi-disciplinary approach would be required to address and understand the implications of anthropogenic radioactivity in the environment. The management, clean-up and long-term monitoring of legacy wastes at Department of Energy (DOE), Department of Defense (DOD), and Nuclear Regulatory Commission (NRC)-regulated facilities continues to be of concern as long as nuclear operations continue. Research conducted through radioecology programs provides the credible scientific data needed for decision-making purposes. The current status of radioecology programs in the United States are: fragmented with little coordination to identify national strategies and direct programs; suffering from a steadily decreasing funding base; soon to be hampered by closure of …
Date: January 9, 2013
Creator: Jannik, T.
Object Type: Article
System: The UNT Digital Library
Reevaluation Of Vitrified High-Level Waste Form Criteria For Potential Cost Savings At The Defense Waste Processing Facility (open access)

Reevaluation Of Vitrified High-Level Waste Form Criteria For Potential Cost Savings At The Defense Waste Processing Facility

At the Savannah River Site (SRS) the Defense Waste Processing Facility (DWPF) has been immobilizing SRS's radioactive high level waste (HLW) sludge into a durable borosilicate glass since 1996. Currently the DWPF has poured over 3,500 canisters, all of which are compliant with the U. S. Department of Energy's (DOE) Waste Acceptance Product Specifications for Vitrified High-Level Waste Forms (WAPS) and therefore ready to be shipped to a federal geologic repository for permanent disposal. Due to DOE petitioning to withdraw the Yucca Mountain License Application (LA) from the Nuclear Regulatory Commission (NRC) in 2010 and thus no clear disposal path for SRS canistered waste forms, there are opportunities for cost savings with future canister production at DWPF and other DOE producer sites by reevaluating high-level waste form requirements and compliance strategies and reducing/eliminating those that will not negatively impact the quality of the canistered waste form.
Date: January 9, 2013
Creator: Ray, J. W.; Marra, S. L. & Herman, C. C.
Object Type: Article
System: The UNT Digital Library
Summary report on liquid-liquid contactor scoping experiments and validation test case definition (open access)

Summary report on liquid-liquid contactor scoping experiments and validation test case definition

None
Date: January 9, 2013
Creator: Wardle, K.E. (Chemical Sciences and Engineering Division)
Object Type: Report
System: The UNT Digital Library
Tank 48 - Chemical Destruction (open access)

Tank 48 - Chemical Destruction

Small tank copper-catalyzed peroxide oxidation (CCPO) is a potentially viable technology to facilitate the destruction of tetraphenylborate (TPB) organic solids contained within the Tank 48H waste at the Savannah River Site (SRS). A maturation strategy was created that identified a number of near-term development activities required to determine the viability of the CCPO process, and subsequent disposition of the CCPO effluent. Critical activities included laboratory-scale validation of the process and identification of forward transfer paths for the CCPO effluent. The technical documentation and the successful application of the CCPO process on simulated Tank 48 waste confirm that the CCPO process is a viable process for the disposition of the Tank 48 contents.
Date: January 9, 2013
Creator: Simner, Steven P.; Aponte, Celia I. & Brass, Earl A.
Object Type: Article
System: The UNT Digital Library
A Theoretical Evaluation of Possible Transition Metal Electro-catalysts for N-2 Reduction (open access)

A Theoretical Evaluation of Possible Transition Metal Electro-catalysts for N-2 Reduction

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Date: January 9, 2013
Creator: Skulason, Egill; Bligaard, Thomas; Gudmundsdottir, Sigridur; Felix Studt3, Jan a Felix Studt; Rossmeisl, Jan; Abild-Pedersen, Frank et al.
Object Type: Article
System: The UNT Digital Library
Tuning the LULESH Mini-app for Current and Future Hardware (open access)

Tuning the LULESH Mini-app for Current and Future Hardware

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Date: January 9, 2013
Creator: Karlin, I; McGraw, J; Keasler, J & Still, B
Object Type: Article
System: The UNT Digital Library
Ultra Barrier Topsheet (UBT) for Flexible Photovoltaics (open access)

Ultra Barrier Topsheet (UBT) for Flexible Photovoltaics

This slideshow presents work intended to: Scale-up the Generation -1 UBT to 1+meter width full-scale manufacturing; Develop a Generation-2 UBT on the pilot line, targeting improved performance, longer lifetime and lower cost; Transfer Generation-2 UBT from the pilot line to the full-scale manufacturing line in 2014; and Validate service life of Generation-1 UBT for the 25+ year lifetime. 3M has scaled up UBT for production at 1.2 meter width. 3M is conducting extensive lifetime studies including: –Evaluation of customer processing and installation conditions; –Indoor accelerated testing of UBT film and full CIGS modules; –Outdoor testing of UBT film and CIGS modules. Results have been used to improve ultra barrier film performance for flex module applications.
Date: January 9, 2013
Creator: Schubert, Charlene
Object Type: Article
System: The UNT Digital Library
Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report October 1–December 31, 2011 (open access)

Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report October 1–December 31, 2011

Individual raw datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent approximately daily to the ARM Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of processed data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.
Date: January 9, 2012
Creator: Voyles, JW
Object Type: Text
System: The UNT Digital Library
FROM CONCEPT TO REALITY, IN-SITU DECOMMISSIONING OF THE P AND R REACTORS AT THE SAVANNAH RIVER SITE (open access)

FROM CONCEPT TO REALITY, IN-SITU DECOMMISSIONING OF THE P AND R REACTORS AT THE SAVANNAH RIVER SITE

SRS recently completed an approximately three year effort to decommission two SRS reactors: P-Reactor (Building 105-P) and R-Reactor (Building 105-R). Completed in December 2011, the concurrent decommissionings marked the completion of two relatively complex and difficult facility disposition projects at the SRS. Buildings 105-P and 105-R began operating as production reactors in the early 1950s with the mission of producing weapons material (e.g., tritium and plutonium-239). The 'P' Reactor and was shutdown in 1991 while the 'R' Reactor and was shutdown in 1964. In the intervening period between shutdown and deactivation & decommissioning (D&D), Buildings 105-P and 105-R saw limited use (e.g., storage of excess heavy water and depleted uranium oxide). For Building 105-P, deactivation was initiated in April 2007 and was essentially complete by June 2010. For Building 105-R, deactivation was initiated in August 2008 and was essentially complete by September 2010. For both buildings, the primary objective of deactivation was to remove/mitigate hazards associated with the remaining hazardous materials, and thus prepare the buildings for in-situ decommissioning. Deactivation removed the following hazardous materials to the extent practical: combustibles/flammables, residual heavy water, acids, friable asbestos (as needed to protect workers performing deactivation and decommissioning), miscellaneous chemicals, lead/brass components, Freon(reg …
Date: January 9, 2012
Creator: Musall, J.; Blankenship, J. & Griffin, W.
Object Type: Article
System: The UNT Digital Library
HARE: Final Report (open access)

HARE: Final Report

This report documents the results of work done over a 6 year period under the FAST-OS programs. The first effort was called Right-Weight Kernels, (RWK) and was concerned with improving measurements of OS noise so it could be treated quantitatively; and evaluating the use of two operating systems, Linux and Plan 9, on HPC systems and determining how these operating systems needed to be extended or changed for HPC, while still retaining their general-purpose nature. The second program, HARE, explored the creation of alternative runtime models, building on RWK. All of the HARE work was done on Plan 9. The HARE researchers were mindful of the very good Linux and LWK work being done at other labs and saw no need to recreate it. Even given this limited funding, the two efforts had outsized impact: _ Helped Cray decide to use Linux, instead of a custom kernel, and provided the tools needed to make Linux perform well _ Created a successor operating system to Plan 9, NIX, which has been taken in by Bell Labs for further development _ Created a standard system measurement tool, Fixed Time Quantum or FTQ, which is widely used for measuring operating systems impact on …
Date: January 9, 2012
Creator: Mckie, Jim
Object Type: Report
System: The UNT Digital Library
Laboratory-Scale Melter for Determination of Melting Rate of Waste Glass Feeds (open access)

Laboratory-Scale Melter for Determination of Melting Rate of Waste Glass Feeds

The purpose of this study was to develop the laboratory-scale melter (LSM) as a quick and inexpensive method to determine the processing rate of various waste glass slurry feeds. The LSM uses a 3 or 4 in. diameter-fused quartz crucible with feed and off-gas ports on top. This LSM setup allows cold-cap formation above the molten glass to be directly monitored to obtain a steady-state melting rate of the waste glass feeds. The melting rate data from extensive scaled-melter tests with Hanford Site high-level wastes performed for the Hanford Tank Waste Treatment and Immobilization Plant have been compiled. Preliminary empirical model that expresses the melting rate as a function of bubbling rate and glass yield were developed from the compiled database. The two waste glass feeds with most melter run data were selected for detailed evaluation and model development and for the LSM tests so the melting rates obtained from LSM tests can be compared with those from scaled-melter tests. The present LSM results suggest the LSM setup can be used to determine the glass production rates for the development of new glass compositions or feed makeups that are designed to increase the processing rate of the slurry feeds.
Date: January 9, 2012
Creator: Kim, Dong-Sang; Schweiger, Michael J.; Buchmiller, William C. & Matyas, Josef
Object Type: Report
System: The UNT Digital Library