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DOE OSTI2015

Irradiation of electronic components and circuits at the Portuguese Research Reactor: Lessons learned

The behavior of electronic components and circuits under radiation is a concern shared by the nuclear industry, the space community and the high-energy physics community. Standard commercial components are used as much as possible instead of radiation hard components, since they are easier to obtain and allow a significant reduction of costs. However, these standard components need to be tested in order to determine their radiation tolerance. The Portuguese Research Reactor (RPI) is a 1 MW pool-type reactor, operating since 1961. The irradiation of electronic components and circuits is one area where a 1 MW reactor can be competitive, since the fast neutron fluences required for testing are in most cases well below 10{sup 16} n/cm{sup 2}. A program was started in 1999 to test electronics components and circuits for the LHC facility at CERN, initially using a dedicated in-pool irradiation device and later a beam line with tailored neutron and gamma filters. Neutron filters are essential to reduce the intensity of the thermal neutron flux, which does not produce significant defects in electronic components but produces unwanted radiation from activation of contacts and packages of integrated circuits and also of the printed circuit boards. In irradiations performed within the line-of-sight of the core of a fission reactor there is simultaneous gamma radiation which complicates testing in some cases. Filters can be used to reduce its importance and separate testing with a pure gamma radiation source can contribute to clarify some irradiation results. Practice has shown the need to introduce several improvements to the procedures and facilities over the years. We will review improvements done in the following areas: - Optimization of neutron and gamma filters; - Dosimetry procedures in mixed neutron / gamma fields; - Determination of hardness parameter and 1 MeV-equivalent neutron fluence; - Temperature measurement and control during irradiation; - Follow-up of reactor power operational fluctuations; - Study of gamma radiation effects only. The fission neutron spectrum can be limitative for some of the tests, as most neutrons are in the 1-2 MeV energy range. Significant progress has been made lately in compact neutron generators using D-D and D-T fusion reactions, achieving higher neutron fluxes and longer lifetime than previously available. The advantages of using compact neutron generators for testing of electronic components and circuits will be also discussed. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2015

The DOE Criticality safety support group - A retrospective perspective - 14580

The Department of Energy (DOE) Nuclear Criticality Safety Support Group (CSSG) came into being as a response to the DNFSB recommendation 1997-2 'Criticality Safety' which dealt with the continuation of criticality safety at defense nuclear facilities in the Department of Energy Enterprise. The DNFSB was concerned over the lack of capability management of practical experience pertinent to avoiding a criticality accident in non-reactor environments. One of the specific recommendations of 1997-2 was to 'Identify a core group of criticality experts experienced in the theoretical and experimental aspects of neutron chain reactions to advise on the above steps and assist in resolving future technical issues'. The CSSG, a group of 10 recognized experts in criticality safety, was chartered in late 1997 to address the recommendation. Members of the CSSG are drawn from DOE employees and contractor staff to provide advice and technical support to help meet the criticality safety needs of DOE missions, including stockpile stewardship, materials stabilization, transportation, storage, facilities life cycle (design through decommissioning), and waste disposal. The CSSG is an integral part of the DOE Nuclear Criticality Safety Program (NCSP) developed to maintain and enhance the operational and technical criticality safety expertise and capability within the Department of Energy Enterprise. This paper outlines the history, purpose and continuing contribution of the CSSG as well as providing an understanding of the interfaces between the DOE CSSG, the DOE Criticality Safety Coordinating Team (CSCT), the ANS Nuclear Criticality Safety Division and the EFCOG Criticality Safety Subgroup. (authors)

42 ENGINEERING↗

DOE OSTI2025

VISION: a modular AI assistant for natural human-instrument interaction at scientific user facilities

Scientific user facilities, such as synchrotron beamlines, are equipped with a wide array of hardware and software tools that require a codebase for human-computer-interaction. This often necessitates developers to be involved to establish connection between users/researchers and the complex instrumentation. The advent of generative AI presents an opportunity to bridge this knowledge gap, enabling seamless communication and efficient experimental workflows. Here we present a modular architecture for the Virtual Scientific Companion by assembling multiple AI-enabled cognitive blocks that each scaffolds large language models (LLMs) for a specialized task. With VISION, we performed LLM-based operation on the beamline workstation with low latency and demonstrated the first voice-controlled experiment at an x-ray scattering beamline. The modular and scalable architecture allows for easy adaptation to new instruments and capabilities. Development on natural language-based scientific experimentation is a building block for an impending future where a science exocortex—a synthetic extension to the cognition of scientists—may radically transform scientific practice and discovery.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Factors Affecting Gender-based Experiences for Residents in Radiation Oncology

Purpose: Although women constitute approximately half of medical school graduates, an uneven gender distribution exists among many specialties, including radiation oncology, where women fill only one third of residency positions. Although multiple social and societal factors have been theorized, a structured review of radiation oncology resident experiences has yet to be performed. Methods and Materials: An anonymous and voluntary survey was sent to 611 radiation oncology residents practicing in the United States. Residents were asked about their gender-based experiences in terms of mentorship, their professional and learning environment, and their partnerships and personal life. Results: A total of 203 participants submitted completed survey responses. Fifty-seven percent of respondents were men, and 43% were women, with a mean age of 31 years (standard deviation=3.7 years). Although residents in general value having a mentor, female residents prefer mentors of the same gender (P<.001), and noted having more difficulty finding a mentor (P=.042). Women were more likely to say that they have observed preferential treatment based on gender (P≤.001), and they were more likely to perceive gender-specific biases or obstacles in their professional and learning environment (P<.001). Women selected residency programs based on gender ratios (P<.001), and female residents preferred to see equal numbers of male and female faculty (P<.001). Women were also more likely to perceive work-related strain than their male counterparts (P<.001). Conclusions: Differences in experiences for male and female radiation oncology residents exist with regard to mentorship and in their professional and learning environment.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2018

Understanding the U.S. Commercial Building Stock: Building Envelope and HVAC Systems Characteristics Using 2012 CBECS Data Analysis

The U.S. Department of Energy (DOE) and its national labs developed a series of commercial reference building models in 2007. Over the past decade, the Pacific Northwest National Laboratory, in support of DOE’s Building Energy Codes Program, expanded these prototype building models to comply with multiple editions of national model codes and standards, including both ASHRAE Standard 90.1 and International Energy Conservation Code. The prototype building models established a credible foundation to develop new requirements in building codes and standards, track progress of codes and standards, and evaluate the energy saving potential of new technologies or systems in the commercial building sector. The 2003 Commercial Building Energy Consumption Survey (CBECS) was the primary data source used to develop the original models. Given the recent release of 2012 CBECS data, this paper characterizes the most representative design choices for building envelope and HVAC systems in recently-constructed commercial buildings. The results from this analysis provide actionable insight for future commercial building research in reflection of recent construction practices.

energy efficiency, building energy codes, CBECS, b↗

DOE OSTI2026

Distribution System Congestion Management - A Survey of Reliable Integration for Aggregated Resources and Microgrids

Rising penetration of consumer-owned Distribution Grid Resources (DGRs), increasingly managed by third party aggregators and enrolled in grid services and wholesale market programs, can create localized congestion in distribution networks. Managing these constraints is challenging due to a persistent coordination and information gap: utilities are accountable for reliability and have network topology and state visibility, while aggregators control the DGR capability needed to relieve congestion. This survey synthesizes congestion management solutions for distribution systems with high DGR penetration, covering both market-based mechanisms (distribution level markets, locational pricing, flexibility auctions) and non-market-based solutions (network reconfiguration, direct DGR control, demand response, curtailment, etc.). The literature is organized across three decision horizons: long term planning, operational planning, and real-time operation. Special attention is devoted to emerging distribution system operator architectures and coordination frameworks spanning transmission system operators, aggregators, and microgrids. Drawing on recent case studies and implementations, we distill best practices, identify key technical and economic barriers, and outline research directions. The evidence points to a shift toward integrated congestion management that combines market signals with technical controls, enabled by improved monitoring, forecasting, and closed loop control capabilities.

Active Distribution Networks (ADN)↗

DOE OSTI2024

Toward a long-lifetime polarized photoelectron gun for the Ce+BAF positron source

The addition of spin-polarized, continuous-wave (c.w.) positron beams to the 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF) would provide a significant capability to the experimental nuclear physics program at Jefferson Lab. Based on bremsstrahlung and pair-production in a high-Z target, the positron source requires a 120 MeV spin-polarized c.w. electron beam of several milliamperes. While the beam dynamics of the high-current electron beam are tenable, sustaining this current for weeks of user operations requires an unprecedented charge lifetime from a high-polarization GaAs-based photocathode. A promising approach to exceed the kilocoulomb charge lifetime barrier is reducing the ion back-bombardment fluence at the photocathode. By increasing the laser size and managing the emittance growth with an adequate cathode/anode design, significantly enhanced charge lifetime may be achieved. Based upon a new simulation model that qualitatively explains the lifetime data previously measured at different spot sizes, we describe the practical implications on the parameter space available for a kilocoulomb-lifetime polarized photogun design.

Bruker, M.↗

DOE OSTI2023

NEAMS Model Contributions in 2023 to the National Reactor Innovation Center Virtual Test Bed for Use by Industry and Other Stakeholders

The U.S. Department of Energy (DOE) Office of Nuclear Energy’s Advanced Modeling and Simulation (NEAMS) Program develops models of advanced reactor phenomena to demonstrate code applicability to challenging physics problems, drive code development through user assessment, and perform code verification and validation. Meanwhile, the U.S. DOE’s National Reactor Innovation Center (NRIC) hosts an open-source website and associated GitHub repository called the Virtual Test Bed (VTB) on which computational models for advanced reactors are documented and shared with the reactor community. This work documents NEAMS efforts to support industry adoption of advanced modeling tools through contribution of 10 NEAMS models to the NRIC Virtual Test Bed including models for the High Temperature Test Facility (HTTF), TRISO fuel failure in a microreactor, and multiphysics models of a molten chloride fast reactor, among others. The open sharing of these models benefits the reactor community by providing “best practice” examples using NEAMS tools for advanced reactor physics problems. In particular, the HTTF model is being used for code validation and benchmarking activities. The microreactor and molten chloride fast reactor models are representative of analysis that may be useful for current candidates of DOME and LOTUS, NRIC’s physical testbeds. This report summarizes and provides links to these new models, among others.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2024

Toward a long-lifetime polarized photoelectron gun for the Ce+BAF positron source

Bruker, M.↗

DOE OSTI2018

Easy and Enticing: How a Collaborative Approach to Emerging Technology Adoption in the Commercial Building Sector Has Made Its Mark

In 2012, the U.S. Department of Energy (DOE), in collaboration with interested partners (e.g., applicable trade groups), initiated a novel market transformation approach, technology adoption campaigns, to speed the adoption of new technologies that save energy and money in buildings—first with lighting and later with other building technologies. This approach couples technical performance evaluation, guidance, data tracking and technical assistance with recognition for exemplary performance and best practices. Campaigns can be designed around emerging technologies that have significant, cost-effective national energy savings potential and where there is strong public- and private-sector interest in sharing performance criteria and outcomes. Participants in the campaigns share project data with the national laboratories and DOE, benefit from technical support and assistance from objective experts, and highly value recognition for their accomplishments. DOE and its campaign partners benefit from accelerated adoption of new energy-saving technologies and engagement with manufacturers and end users that allows for data collection and insights into technology research needs. This paper documents the success, challenges, lessons learned, and energy and cost savings of lighting campaigns, and in many cases compares these findings with other campaign efforts. This paper also presents recommendations for how other programs of various sizes can employ this model.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2018

Easy and Enticing: How a Collaborative Approach to Emerging Technology Adoption in the Commercial Building Sector Has Made its Mark

In 2012, the U.S. Department of Energy (DOE), in collaboration with interested partners (e.g., applicable trade groups), initiated a novel market transformation approach, technology adoption campaigns, to speed the adoption of new technologies that save energy and money in buildings - first with lighting and later with other building technologies. This approach couples technical performance evaluation, guidance, data tracking and technical assistance with recognition for exemplary performance and best practices. Campaigns can be designed around emerging technologies that have significant, cost-effective national energy savings potential and where there is strong public- and private-sector interest in sharing performance criteria and outcomes. Participants in the campaigns share project data with the national laboratories and DOE, benefit from technical support and assistance from objective experts, and highly value recognition for their accomplishments. DOE and its campaign partners benefit from accelerated adoption of new energy-saving technologies and engagement with manufacturers and end users that allows for data collection and insights into technology research needs. This paper documents the success, challenges, lessons learned, and energy and cost savings of lighting campaigns, and in many cases compares these findings with other campaign efforts. This paper also presents recommendations for how other programs of various sizes can employ this model.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2018

Easy and Enticing: How a Collaborative Approach to Emerging Technology Adoption in the Commercial Building Sector Has Made Its Mark

Myer, Michael↗

DOE OSTI2017

California GAMA Special Study: Excess Nitrogen and Methane in Noble Gas Samples

The most prominent constituent causing concern for drinking water resources in California is nitrate. Denitrification in the unsaturated zone and in groundwater naturally reduces nitrate concentrations, controls the fate of groundwater nitrate and determines the time scale over which changes in management practice will result in improvements in water quality. Quantifying denitrification is also important in estimating nutrient loading to groundwater through time. Measurements of dissolved nitrogen gas can detect and quantify saturated zone denitrification; and LLNL with GAMA funding has developed benchtop instrumentation to measure dissolved nitrogen in groundwater. This technique, membrane-inlet mass spectrometry (MIMS) requires the collection of an additional sample and is not routinely included in current GAMA water quality monitoring surveys. Incorporating dissolved nitrogen analysis into current water quality monitoring protocols without requiring an additional sample or separate analysis is the most cost-effective way to expand the database of dissolved nitrogen concentrations and document the prevalence of saturated-zone denitrification in California groundwater. The GAMA Priority Basin, Shallow Aquifer Assessment, and Special Study water quality monitoring programs routinely use dissolved noble gas and tritium analyses to constrain groundwater travel times and recharge. Noble gases are collected as a 10-mL water sample in a crimped copper tube and are analyzed by noble gas mass spectrometry (NGMS). Nitrogen, methane and carbon dioxide, can now also be measured in copper tubes and analyzed by the same LLNL NGMS system, which has been upgraded to allow such analyses. In the case of the GAMA Shallow Aquifer Assessment project, this will automatically provide dissolved nitrogen analyses at little or no incremental cost. A significant advantage of this technique is that archival copper tube noble gas samples can be analyzed using the technique. The dissolved nitrogen analyses – combined with nitrate analyses and the NGMS age information – will provide unique insight into nitrate sources, inputs, transport, and reaction rates.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2024

Compiling Quantum Circuits for Dynamically Field-Programmable Neutral Atoms Array Processors

Dynamically field-programmable qubit arrays (DPQA) have recently emerged as a promising platform for quantum information processing. In DPQA, atomic qubits are selectively loaded into arrays of optical traps that can be reconfigured during the computation itself. Leveraging qubit transport and parallel, entangling quantum operations, different pairs of qubits, even those initially far away, can be entangled at different stages of the quantum program execution. Such reconfigurability and non-local connectivity present new challenges for compilation, especially in the layout synthesis step which places and routes the qubits and schedules the gates. In this paper, we consider a DPQA architecture that contains multiple arrays and supports 2D array movements, representing cutting-edge experimental platforms. Within this architecture, we discretize the state space and formulate layout synthesis as a satisfiability modulo theories problem, which can be solved by existing solvers optimally in terms of circuit depth. For a set of benchmark circuits generated by random graphs with complex connectivities, our compiler OLSQ-DPQA reduces the number of two-qubit entangling gates on small problem instances by 1.7x compared to optimal compilation results on a fixed planar architecture. To further improve scalability and practicality of the method, we introduce a greedy heuristic inspired by the iterative peeling approach in classical integrated circuit routing. Using a hybrid approach that combined the greedy and optimal methods, we demonstrate that our DPQA-based compiled circuits feature reduced scaling overhead compared to a grid fixed architecture, resulting in 5.1X less two-qubit gates for 90 qubit quantum circuits. These methods enable programmable, complex quantum circuits with neutral atom quantum computers, as well as informing both future compilers and future hardware choices.

Physics↗

DOE OSTI2015

Integrating regulatory, programmatic and technical needs for modeling tools to support decision-making - 15219

The U.S. Department of Energy (US DOE) Office of Environmental Management (EM), Office of Soil and Groundwater Remediation, is supporting development of the Advanced Simulation Capability for Environmental Management (ASCEM). ASCEM provides a modeling work-flow to support decision-making for site restoration, tank closure and waste management activities. Potential users involved in regulatory applications (e.g., performance and risk assessments and other activities supporting regulatory decisions) are a key target group for the tool-set. Decision-making in these applications often requires consideration of multiple perspectives, including: regulators and the public, oversight and project management personnel, as well as practitioners involved in conducting the calculations, each with different interests. From its inception, a key objective of the ASCEM project has been to actively seek input from these different user perspectives to help guide development. ASCEM formed a User Steering Committee (USC) with membership representing interests from management/staff at DOE Site Contractors, DOE-HQ and Field offices and Regulators (State and Federal). The project also provides opportunities for input from the broader user community through participation in meetings of the Performance and Risk Assessment (P and RA) Community of Practice (CoP), routine briefings and participation in meetings of the Low-Level Waste Disposal Facility Federal Review Group, and direct interactions with users involved in regulatory applications. Interactions with users involved in regulatory applications have influenced the requirements for the tool-sets and are reflected in capabilities that have been and are being implemented. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2016

Improved ligand geometries in crystallographic refinement using AFITT in PHENIX

Modern crystal structure refinement programs rely on geometry restraints to overcome the challenge of a low data-to-parameter ratio. While the classical Engh and Huber restraints work well for standard amino-acid residues, the chemical complexity of small-molecule ligands presents a particular challenge. Most current approaches either limit ligand restraints to those that can be readily described in the Crystallographic Information File (CIF) format, thus sacrificing chemical flexibility and energetic accuracy, or they employ protocols that substantially lengthen the refinement time, potentially hindering rapid automated refinement workflows. PHENIX – AFITT refinement uses a full molecular-mechanics force field for user-selected small-molecule ligands during refinement, eliminating the potentially difficult problem of finding or generating high-quality geometry restraints. It is fully integrated with a standard refinement protocol and requires practically no additional steps from the user, making it ideal for high-throughput workflows. PHENIX – AFITT refinements also handle multiple ligands in a single model, alternate conformations and covalently bound ligands. Here, the results of combining AFITT and the PHENIX software suite on a data set of 189 protein–ligand PDB structures are presented. Refinements using PHENIX – AFITT significantly reduce ligand conformational energy and lead to improved geometries without detriment to the fit to the experimental data. Finally, for the data presented, PHENIX – AFITT refinements result in more chemically accurate models for small-molecule ligands.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2014

Hood River Passive House, Hood River, Oregon (Fact Sheet)

The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50%" (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2014

Hood River Passive House

The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗