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DOE OSTI2015

Gary Laughlin IHNS Intro to 2015 HPC Annual Report

The International, Homeland, and Nuclear Security (IHNS) Program Management Unit (PMU) oversees a broad portfolio of Sandia’s programs in areas ranging from global nuclear security to critical asset protection. We use science and technology, innovative research, and global engagement to counter threats, reduce dangers, and respond to disasters. The PMU draws on the skills of scientists and engineers from across Sandia. Our programs focus on protecting US government installations, safeguarding nuclear weapons and materials, facilitating nonproliferation activities, securing infrastructures, countering chemical and biological dangers, and reducing the risk of terrorist threats. We conduct research in risk and threat analysis, monitoring and detection, decontamination and recovery, and situational awareness. We develop technologies for verifying arms control agreements, neutralizing dangerous materials, detecting intruders, and strengthening resiliency. Our programs use Sandia’s High-Performance Computing resources for predictive modeling and simulation of interdependent systems, for modeling dynamic threats and forecasting adaptive behavior, and for enabling decision support and processing large cyber data streams. In this report, we highlight four advanced computation projects that illustrate the breadth of the IHNS mission space.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

DOE OSTI2026

Computational Modeling of Atmospheric Processes at Texas Southern University

Texas Southern University (TSU) is strengthening its research program in atmospheric chemistry and physics with a climate science emphasis by leveraging partnerships with the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Facility, Brookhaven National Laboratory (BNL), and the Tracking Aerosol Convection Interactions ExpeRiment (TRACER). This RDPP-supported program focuses on secondary organic aerosols (SOAs) and reactive atmospheric species that influence cloud formation, precipitation processes, and radiative forcing. SOAs play a critical role in cloud microphysics and Earth’s energy balance, yet the chemical and physical mechanisms governing SOA–cloud interactions remain a significant source of uncertainty in predictive climate models. Through computational modeling, observational data analysis, and national laboratory collaboration, this program develops a skilled cohort of students trained in atmospheric science, environmental data analysis, and climate-relevant modeling. These research experiences build technical competencies that are transferable to careers in government laboratories, academia, and industry. By engaging students from historically underrepresented communities in high-impact climate research, TSU expands participation in the atmospheric sciences workforce while contributing meaningful scientific insights to DOE-supported ARM research activities. This partnership strengthens national capacity in climate science and supports the development of the next generation of atmospheric researchers.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2019

Sandia National Laboratories Early Career University Faculty Mentoring Program in International Safeguards

An international safeguards mentoring program was established by Sandia National Laboratories (SNL) for early career university faculty. The inaugural year of the program focused on course material development and connecting faculty to experts at national laboratories. Two faculty members were selected for participation; one developed a safeguards-by-design course, and the other created lecture material related to unmanned robotic systems in safeguards for integration in existing courses. Faculty members were paired with SNL subject matter experts based on the topic of their individual projects. The program also included a two week visit to SNL. The structure of this program not only supported the development of new course material, but also provided junior faculty members with an opportunity to make connections and build collaborations in the field of international safeguards. Programs like this are important for professional development of faculty members and to help strengthen connections between universities and the national laboratories.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

DOE OSTI2024

Supercharge NY

The Energy Program for Innovation Clusters (EPIC) Supercharge NY enabled The Clean Fight to execute an inaugural accelerator program focused on enabling world-class, growth-stage energy storage companies to successfully scale deployments and establish domestic manufacturing pathways in New York State. The Clean Fight has developed and tested a successful accelerator model designed to reduce the barriers growth-stage climate tech companies face by collapsing the sales cycle to scaling solutions at speed. The Clean Fight’s Supercharge NY project allowed for the exploration into the understanding of New York-focused energy storage opportunities, challenges, and methods for enabling successful projects. The Clean Fight’s Supercharge NY project enabled high-touch matchmaking with industry leading customer and capital partners, technical assistance to facilitate scaling supply chain and manufacturing capacity, and access to non-dilutive funding for first-of-a-kind or demonstration projects in New York State. The results of the program provide a public benefit by accelerating deployments of energy storage to provide value-added energy services and sustainability benefits to communities while boosting economic opportunity and job creation for all.

25 ENERGY STORAGE↗

DOE OSTI2024

Guidance for Integrating Energy Justice and Equity in Building Technology Deployment Programs: Tracking, Reporting, and Maximizing the Flow of Benefits from Building System Technology Deployment Activities to Disadvantaged Communities and Target Sectors

The Federal Justice40 Initiative directs at least 40% of the overall benefits of certain clean energy investments to flow to disadvantaged communities and requires that all federal programs covered by Justice40 consult stakeholders to determine the program benefits, and that the flow of benefits to disadvantaged communities is tracked and reported. Unequal distribution of benefits, in terms of access to clean energy research, design, development, and deployment, can disproportionately benefit or burden certain communities. This can result in higher rates of pollution, negative health effects, and increased energy burdens and insecurities in disadvantaged communities. Programs focused on decarbonizing the built environment can enhance health, quality of life, and economic opportunities for impacted communities. This guidance document, developed by Pacific Northwest National Laboratory and funded by the U.S. Department of Energy’s Building Technologies Office, provides best practices and approaches for incorporating energy justice and equity principles into building technology deployment activities. It provides best practices and recommendations for communicating with and involving disadvantaged communities and target building sectors in program activities, along with methods to monitor and report the distribution of benefits to these sectors. This document lays out a set of strategies, metrics, and best practices that can be implemented over time to apply energy justice and equity approaches, whether the program is just starting out or ongoing. Although this guidance was designed for Building Technologies Office technology deployment programs, the best practices, recommendations, and methods can be valuable to any program concerned with the equitable deployment of clean energy technologies. The goal of this project is to enable the equitable development, deployment, and adoption of clean energy technologies and practices.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2018

Test of Point-Source Helicity Injection for Non-Solenoidal Startup in NSTX

This grant supported research activity focused on the development of Local Helicity Injection (LHI) as a technique for initiation and growth of spherical tokamak plasmas without the use of a traditional ohmic solenoid for magnetic induction. The LHI technique consists of injection of high-density current streams into a vacuum magnetic field consisting of toroidal and vertical fields. Under appropriate conditions, these streams become unstable and support magnetic reconnection to allow the system to reconfigure itself into a tokamak-like plasma magnetic configuration. This research program focused on three aspects of this plasma startup technique: 1) development and tests of appropriate electron current sources that provide sufficiently high injection currents into the near-plasma edge without strongly contaminating the resultant tokamak plasma with impurities; 2) development and validation of a 0-D power balance model to describe the evolution of the plasma current I p (t) during this startup process; and 3) initial estimates of I p levels achievable with this technique in NSTX-U scale plasmas. The 0-D model development included extremely low aspect ratio corrections to analytical formulae for the plasma inductances that produce voltages due to rapid changes in plasma size and location. Applications of this model to sample plasmas in the Pegasus ultra-low aspect ratio tokamak confirms the expectation that I p (t) is dominated by these induced voltages when injection occurs from the outer low-field side of the plasma. Conversly, I p (t) is dominated by an effective toroidal loop voltage arising from helicity conservation when injectors are placed in the inner high-field side divertor region. The activities pursued here, combined with more general research on LHI followed by the Pegasus experiment group, provide the tools needed for initial consideration of a MA-level plasma startup capability for the NSTX-U experiment. Simplified modeling for LHI on NSTX-U indicates that no showstoppers exist, and ~ 0.8MA appears accessible using a moderate current injection facility. However, many issues remain to be resolved to address extrapolating this technique to the larger sizes and magnetic field strengths of NSTX-U and larger fusion-grade tokamaks. These include, among others: I p scaling with helicity drive input; extending current injector technology; understanding electron confinement and the resulting helicity dissipation processes that determine the achievable I p ; the role of plasma stability in controlling the current evolution; and controlling plasma-material interactions and impurity content. These open issues will be further explored in a future experiment dedicated to integrated studies of non-solenoidal startup at higher magnetic fields and plasma currents.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2019

Robust RF Photocathodes (Phase II Final Report)

This program addressed requirements for photocathodes with high quantum efficiency (QE) and long lifetimes. Currently, photocathodes with QEs above 1% exhibit lifetimes measured in a few hours. This is unacceptable for commercial devices using photocathodes as the electron source. This includes accelerators for industrial, medical, defense, and educational applications as well as emerging applications, such as time resolved electron microscopy. Calabazas Creek Research, Inc. (CCR) and the University of Maryland (UMD) attempted to develop reservoir photocathodes that dramatically increased lifetime and increased the ability to recover from contaminating events, such as loss of system vacuum. The Phase I program demonstrated the viability of the reservoir approach for higher QE cathodes. The Phase II program focused on design, fabrication, and delivery. This included increasing understanding of photocathode physics, investigating design options, addressing performance issues, and developing fabrication and packaging techniques leading to commercial products. The initial task identified specific photocathode materials that provide high QE and are compatible with the reservoir approach. The goal was that these photocathodes be manufacturable in a production environment, understanding that the “environment” is highly specialized. The photocathode geometry was modified to address several photogun performance issues related primarily to emittance. A goal was to reduce or eliminate thermal emittance issues arising from the reservoir heater. The program developed fabrication, handling, and transport techniques and facilities to allow commercial photocathode production for certain materials. Not only was complex chemistry involved, but practical issues of transporting and installing the cathodes into user systems were addressed. A critical goal was demonstration of reservoir photocathodes in operating RF guns, where performance could be directly measured. Success depended on clear demonstration that the cathodes could be produced, delivered, installed, and provide the required performance. The principal effort in this program was to develop reservoir cesium antimonide photocathodes. Cesium antimonide cathodes provide a work function in excess of the 1% goal, while the current generation exhibits lifetimes measured in hours. The reservoir in CCRs’ controlled porosity reservoir (CPR) cathodes provides a mechanism for replacing cesium evaporating from the surface by transporting replacement cesium from the reservoir. This is accomplished by gently heating the reservoir to induce cesium diffusion through micron-scale pores in the reservoir cap and photocathode emitter. Experiments at the UMD determined that cesium diffused from the reservoir would only react with antimony on the surface if the temperature exceeded 300C. At this temperature, however, the surface cesium evaporated faster than it could be replenished from the reservoir. Consequently, the QE decreased each time recessiation was attempted. This appears to be a fundamental problem with this approach. The sections below provide information on accomplishments for each task in the program. Once the issue with cesium antimonide cathodes was identified, CCR refocused the program to begin investigation of graphene coated photocathodes in collaboration with SLAC National Accelerator Laboratory (SLAC). The photocathode test chamber developed in the program was transferred to SLAC for use in the graphene research. This is described below in a task added to the program.

43 PARTICLE ACCELERATORS↗

DOE OSTI2022

The international research reactor conversion effort and its contribution to the validation of reactor physics and thermal-hydraulics codes

Full text of publication follows. With about 200 reactors in operation, civilian Research and Test Reactors (RTRs) represent approximately a third of the global nuclear fleet. RTRs make use of core designs that are drastically different from commercial power plants to perform a wide variety of non-power applications that greatly benefit society. Because they often rely on high neutron fluxes, RTRs are designed with relatively compact cores and as a result, prior to the 1980's, were often deployed using Highly Enriched Uranium fuel (HEU, {sup 235}U/U = 20 wt. %). Due to proliferation concerns, the international community aims at eliminating the use of HEU in civilian facilities and favor instead the use of Low Enriched Uranium fuel (LEU, {sup 235}U/U < 20 wt. %). A program to support conversion of the world's RTRs to LEU fuel has been initiated in 1978 by the U.S. Department of Energy (DOE). This program is still alive today and has achieved more than 103 conversion metrics. Today, the program focuses heavily on the conversion of so-called high-performance RTRs, which are far more challenging than previous conversions as they require new fuel element designs and the use of new, higher density LEU fuel forms. Development and qualification of new LEU fuel elements is ongoing and requires extensive engineering analysis and testing. Both activities require the development and validation of codes and methods for reactor physics, thermal-hydraulics, and multi-physics, which in turn rely on experiments performed in RTRs or other experimental facilities. This talk will present the collection of RTR experimental data and benchmark analyses from the international conversion program that contribute to the validation of computer codes and methods.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2015

Charge Recombination, Transport Dynamics, and Interfacial Effects in Organic Solar Cells

The need for renewable sources of energy is well known. Conversion of sunlight to electricity using solar cells is one of the most important opportunities for creating renewable energy sources. The research carried out under DE-FG02-08ER46535 focused on the science and technology of “Plastic” solar cells comprised of organic (i.e. carbon based) semiconductors. The Bulk Heterojunction concept involves a phase separated blend of two organic semiconductors each with dimensions in the nano-meter length scale --- one a material that functions as a donor for electrons and the other a material that functions as an acceptor for electrons. The nano-scale inter-penetrating network concept for “Plastic” solar cells was created at UC Santa Barbara. A simple measure of the impact of this concept can be obtained from a Google search which gives 244,000 “hits” for the Bulk Heterojunction solar cell. Research funded through this program focused on four major areas: 1. Interfacial effects in organic photovoltaics, 2. Charge transfer and photogeneration of mobile charge carriers in organic photovoltaics, 3. Transport and recombination of the photogenerated charge carriers in organic photovoltaics, 4. Synthesis of novel organic semiconducting polymers and semiconducting small molecules, including conjugated polyelectrolytes. Following the discovery of ultrafast charge transfer at UC Santa Barbara in 1992, the nano-organic (Bulk Heterojunction) concept was formulated. The need for a morphology comprising two interpenetrating bicontinuous networks was clear: one network to carry the photogenerated electrons (negative charge) to the cathode and one network to carry the photo-generated holes (positive charge) to the anode. This remarkable self-assembled network morphology has now been established using Transmission electron Microscopy (TEM) either in the Phase Contrast mode or via TEM-Tomography. The steps involved in delivering power from a solar cell to an external circuit are the following: • Photo-excitation of the donor (or the acceptor). • Charge transfer with holes in the donor domain and electrons in the acceptor domain. • Sweep-out to electrodes prior to recombination by the internal electric field. • Energy delivered to the external circuit. Each of these four steps was studied in detail using a wide variety of organic semiconductors with different molecular structures. This UC Santa Barbara group was the first to clarify the origin and the mechanism involved in the ultrafast charge transfer process. The ultrafast charge transfer (time scale approximately 100 times faster than the first step in the photo-synthesis of green plants) is the fundamental reason for the potential for high power conversion efficiency of sunlight to electricity from plastic solar cells. The UCSB group was the first to emphasize, clarify and demonstrate the need for sweep-out to electrodes prior to recombination by the internal electric field. The UCSB group was the first to synthesize small molecule organic semiconductors capable of high power conversion efficiencies. The results of this research were published in high impact peer-reviewed journals. Our published papers (40 in number) provide answers to fundamental questions that have been heavily discussed and debated in the field of Bulk Heterojunction Solar Cells; scientific questions that must be resolved before this technology can be ready for commercialization in large scale for production of renewable energy. Of the forty publications listed, nineteen were co-authored by two or more of the PIs, consistent with the multi-investigator approach described in the original proposal. The specific advantages of this “plastic” solar cell technology are the following: a. Manufacturing by low-cost printing technology using soluble organic semiconductors; this approach can be implemented in large scale by roll-to-roll printing on plastic substrates. b. Low energy cost in manufacturing; all steps carried out at room temperature (approx. a factor of ten less than the use of Silicon which requires high temperature processing). c. Low carbon footprint d. Lightweight, flexible and rugged Because of the resolution of many scientific issues, a significant fraction of which were addressed in the research results of DE-FG02-08ER46535, the power conversion efficiencies are improving at an ever increasing rate. During the funding period of DE-FG02-08ER46535, the power conversion efficiencies of plastic solar cells improved from just a few per cent to values greater than 11% with contributions from our group and from researchers all over the world.

14 SOLAR ENERGY↗

DOE OSTI2019

Mesoscale convective systems over the Amazon basin: The GoAmazon2014/5 program

The Green Ocean Amazon (GoAmazon2014/5) scientific program focused on the influence of aerosols and surface fluxes on tropical cloud formation. This major research effort gathered high-quality environmental data over the central Amazon basin during 2014 and 2015. The present work is a contribution to the GoAmazon2014/5 investigations with an emphasis on the behaviour of the most important mechanism of precipitation over the tropics: mesoscale convective systems (MCSs). To provide a background, MCSs' tracks obtained from infrared satellite images over the entire Amazon basin in 2014–2015 are compared with climatological values. We report the number of MCSs and precipitation in the basin is about 50% lower than compared to the climatology for 2000–2013. We argue that the below average occurrence of MCSs during the GoAmazon2014/5 program can be explained, at least in part, by the effects of positive anomalies in sea surface temperature over the equatorial Pacific Ocean, negative moisture transport toward the Amazon basin, and by the anticyclonic phase of the mode of interannual and intraseasonal variability over South America. Special attention is given to the 99 MCSs that occurred over the GoAmazon2014/5 site. The impact of MCSs on the meteorological variables over the GoAmazon2014/5 sites is examined, and the contribution of MCSs to rainfall over that region is estimated to be about 70% of the total. Finally, the synoptic and thermodynamic conditions related to the MCSs' genesis and dissipation are discussed. It is suggested that in days with reduced MCS genesis over the GoAmazon2014/5 region, the ventilation over the continent by easterly winds from the relative cold South Atlantic Ocean favours convection at locations near the ocean as compared to those inland.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2013

The National Center for Radioecology (NCoRE): A Network of Excellence for Environmental and Human Radiation Risk Reduction - 13365

Radioecology in the United States can be traced back to the early 1950's 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 key infrastructure; hampered by aging and retiring workforce (loss of technical expertise); and in need of training of young scientists to ensure continuation of the science (no formal graduate education program in radioecology remaining in the U.S.). With these concerns in mind, the Savannah River National Laboratory (SRNL) took the lead to establish the National Center for Radioecology (NCoRE) as a network of excellence of the remaining radioecology expertise in the United States. As part of the NCoRE mission, scientists at SRNL are working with six key partner universities to re-establish a graduate education training program for radioecology. Recently, NCoRE hosted a workshop to identify the immediate needs for science-driven discoveries, tool development and the generation of scientific data to support the legislative decision-making process for remediation strategies, long-term monitoring of radiologically- contaminated sites and protection of human health and the environment. Some of the immediate strategic research needs were identified in the fields of functional genomics for determining low-dose effects, improved low-level dosimetry, and mixed (radiological and chemical) contaminant studies. Longer term strategic research and tool development areas included development of radioecology case study sites, comprehensive decision-making tools, consequence response actions, and optimized scenario based ecosystem modeling. A summary of the NCoRE workshop findings related to waste management needs and priority areas will be presented in this paper. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2013

Development of ITM Oxygen Technology for Integration in IGCC and Other Advanced Power Generation DECISION POINT 1 UNDER PHASE 3

Air Products and the DOE have partnered over a number of years in the development of ITM Oxygen technology in support of gasification technology. Throughout this process, studies of application of the technology to IGCC and oxy-coal combustion have shown significant reduction in capital and operating costs compared to similar systems using conventional cryogenic air separation. Phase 3, the current phase of the program, focuses on the design, construction and operation of a 30- to 100-TPD pilot facility, the Intermediate Scale Test Unit (ISTU). Execution of this phase to date has resulted in significant advances in a number of areas including ceramic membrane material development, module design and production, ceramic-to-metal seal design, process control strategies, and engineering development of process cycles. Phase 3 will be complete upon successful operation of the ISTU in a series of tests making oxygen from ceramic membrane modules and producing power from a hot gas expander. Phase 3 work has extended beyond the planned schedule due to a delay in delivery of equipment from vendors. Air Products is currently managing the equipment delay by close involvement with the vendor to redesign the problematic equipment and oversee its fabrication. The result of these unforeseen challenges is that the ISTU project completion date has been delayed. Tight cost controls have been implemented both by DOE program management and APCI to meet budget constraints despite increased costs due to budget delays. Total project costs have increased in several areas. Increased costs in the ISTU project include purchased equipment, instruments, construction, and contractor engineering. Increased costs for other tasks include additional work in support of module production by Ceramatec, Inc, and increased Air Products labor for component testing. Air Products plans to complete testing as outlined in the SOPO and successfully complete all project objectives by the end of FY14.

Anderson, Lori↗

DOE OSTI2014

Chemical Imaging and Dynamical Studies of Reactivity and Emergent Behavior in Complex Interfacial Systems. Final Technical Report

This research program explored the efficacy of using molecular-level manipulation, imaging and scanning tunneling spectroscopy in conjunction with supersonic molecular beam gas-surface scattering to significantly enhance our understanding of chemical processes occurring on well-characterized interfaces. One program focus was on the spatially-resolved emergent behavior of complex reaction systems as a function of the local geometry and density of adsorbate-substrate systems under reaction conditions. Another focus was on elucidating the emergent electronic and related reactivity characteristics of intentionally constructed single and multicomponent atom- and nanoparticle-based materials. We also examined emergent chirality and self-organization in adsorbed molecular systems where collective interactions between adsorbates and the supporting interface lead to spatial symmetry breaking. In many of these studies we combined the advantages of scanning tunneling (STM) and atomic force (AFM) imaging, scanning tunneling local electronic spectroscopy (STS), and reactive supersonic molecular beams to elucidate precise details of interfacial reactivity that had not been observed by more traditional surface science methods. Using these methods, it was possible to examine, for example, the differential reactivity of molecules adsorbed at different bonding sites in conjunction with how reactivity is modified by the local configuration of nearby adsorbates. At the core of this effort was the goal of significantly extending our understanding of interfacial atomic-scale interactions to create, with intent, molecular assemblies and materials with advanced chemical and physical properties. This ambitious program addressed several key topics in DOE Grand Challenge Science, including emergent chemical and physical properties in condensed phase systems, novel uses of chemical imaging, and the development of advanced reactivity concepts in combustion and catalysis including carbon management. These activities directly benefitted national science objectives in the areas of chemical energy production and advanced materials development.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2016

Evidence-based evaluation of the cumulative effects of ecosystem restoration

Evaluating the cumulative effects of large-scale ecological restoration programs is necessary to inform adaptive ecosystem management and provide society with resilient and sustainable services. However, complex linkages between restorative actions and ecosystem responses make evaluations problematic. Despite long-term federal investments in restoring aquatic ecosystems, no standard evaluation method has been adopted and most programs focus on monitoring and analysis, not synthesis and evaluation. In this paper, we demonstrate a new transdisciplinary approach integrating techniques from evidence-based medicine, critical thinking, and cumulative effects assessment. Tiered hypotheses are identified using an ecosystem conceptual model. The systematic literature review at the core of evidence-based assessment becomes one of many lines of evidence assessed collectively, using critical thinking strategies and causal criteria from a cumulative effects perspective. As a demonstration, we analyzed data from 166 locations on the Columbia River and estuary representing 12 indicators of habitat and fish response to floodplain restoration actions intended to benefit threatened and endangered salmon. Synthesis of seven lines of evidence showed that hydrologic reconnection promoted macrodetritis export, prey availability, and fish access and feeding. The evidence was sufficient to infer cross-boundary, indirect, compounding and delayed cumulative effects, and suggestive of nonlinear, landscape-scale, and spatial density effects. On the basis of causal inferences regarding food web functions, we concluded that the restoration program has a cumulative beneficial effect on juvenile salmon. As a result, this evidence-based approach will enable the evaluation of restoration in complex coastal and riverine ecosystems where data have accumulated without sufficient synthesis.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2020

The Effect of Size on Postrelease Survival of Head-Started Mojave Desert Tortoises

Abstract Captive-rearing conservation programs focus primarily on maximizing postrelease survival. Survival increases with size in a variety of taxa, often leading to the use of enhanced size as a means to minimize postrelease losses. Head-starting is a specific captive-rearing approach used to accelerate growth in captivity prior to release in the wild. We explored the effect of size at release, among other potential factors, on postrelease survival in head-started Mojave desert tortoises Gopherus agassizii. Juvenile tortoises were reared for different durations of captivity (2–7 y) and under varying husbandry protocols, resulting in a wide range of juvenile sizes (68–145 mm midline carapace length) at release. We released all animals (n = 78) in the Mojave National Preserve, California, United States, on 25 September 2018. Release size and surface activity were the only significant predictors of fate during the first year postrelease. Larger sized head-starts had higher predicted survival rates when compared with smaller individuals. This trend was also observed in animals of the same age but reared under different protocols, suggesting that accelerating the growth of head-started tortoises may increase efficiency of head-starting programs without decreasing postrelease success. Excluding five missing animals, released head-starts had 82.2% survival in their first year postrelease (September 2018–September 2019), with all mortalities resulting from predation. No animals with >90-mm midline carapace length were predated by ravens. Our findings suggest the utility of head-starting may be substantially improved by incorporating indoor rearing to accelerate growth. Target release size for head-started chelonians will vary among head-start programs based on release site conditions and project-specific constraints.

Biodiversity & Conservation↗

DOE OSTI2017

Review of Tools for Identifying, Planning, and Implementing Habitat Restoration for Pacific Salmon and Steelhead

Abstract A key challenge in watershed restoration is identifying the appropriate assessments, data, and analyses needed to identify disrupted natural processes, lost and degraded habitats, and limiting factors to ultimately identify and design successful restoration projects. This has proven particularly challenging for large restoration programs focused on recovery of threatened and endangered salmon and trout where numerous tools, models, and other assessments have been developed to assist with habitat restoration at the watershed, reach, and project scale. Unfortunately, it is often unclear which step in the restoration process these various assessment tools will actually address. To assist with identifying the appropriate assessment tool (e.g., model, data collection, analysis, and survey), we reviewed major categories of watershed restoration assessment tools to determine their goals, inputs, outputs, and their utility in helping plan, prioritize, and implement restoration actions. The major categories of assessment tools reviewed were: (1) life cycle and fish–habitat models, (2) watershed assessment methods and techniques, (3) reach assessments, (4) prioritization tools, and (5) common monitoring methods to identify, prioritize, and plan river and watershed restoration projects. We specifically indicated whether these assessment tools directly or indirectly assisted with the key steps in the restoration process that are required to develop successful restoration plans and projects. These steps involve assessing watershed conditions, identifying limiting habitats and life stages, identifying problems and restoration actions, selecting restoration techniques, prioritizing restoration actions, or designing actual restoration projects. It is important to recognize that no single assessment tool will address all the steps in the restoration process. Selecting appropriate assessment tools requires a clear understanding of the goals of the restoration program and which step in the restoration process will be addressed by a particular tool. We provide recommendations for how restoration practitioners and managers can use our review to help select the appropriate assessment tools needed for their watershed.

Roni, Philip↗

DOE OSTI2018

The Michigan New Technology Training and Research (MNTR) Translational Program in Nuclear Medicine (Final Report)

The Michigan New Technology Training and Research (MNTR) Translational Program in Nuclear Medicine and Molecular Imaging This project established the Michigan New Technology Training and Research (MNTR) translational program, focused on the acceleration of new clinical molecular imaging methods. Molecular imaging approaches to imaging are a very flexible and powerful development, with many recent examples advancing the diagnosis and guiding the management of human disease. These methods depend on the design, synthesis and testing of new radiotracers (molecules designed to target specific cells or tissues in the body), labeled with short-lived radioactive atoms (positron emitters). The new radiotracers are imaged in the human body using positron emission tomography (PET) imaging. The University of Michigan PET Center has considerable experience in the discovery, development, refinement and initial human applications of new PET radiotracers. An emerging impediment to efficient availability of new PET radiotracers, however, involves the regulatory environment at multiple levels. Many potentially successful ideas are delayed or even prevented from entering human use by these barriers. In the current grant, we provided hands-on experience for the next generation of young scientists working in molecular imaging so that they are equipped to effectively move new ideas and radiotracers from the research laboratory to the nuclear medicine clinic (bench-to-bedside). For new radiotracer development, oversight by the Food and Drug Administration (FDA), the Nuclear Regulatory Commission (NRC), and local institutional committees and reviews are required. These aspects of translation from laboratory to clinic are often omitted from the formal training of new scientists, but were provided to three trainees via direct mentorship in the MNTR program. The MNTR training program built on the translational successes of the University of Michigan Division of Nuclear Medicine and capitalized on our strengths (facilities, faculty, a wide-ranging selection of projects, and the experience and commitment to bring new radiotracers into human studies) to systematically train three fellows in radiochemistry and nuclear medicine. Integrated training in development, validation and clinical translation of new PET radiotracers occurred through practical involvement in multiple research projects, each at a different stage along the pathway from bench-to-bedside. Each trainee obtained experience of the entire process over about 2 years. Projects involved development of new radiotracers for neurodegenerative disorders (e.g. Alzheimer disease), movement disorders (e.g. Parkinson disease, progressive supranuclear palsy) and neurodevelopmental syndromes (e.g. Tourette syndrome) as well as new radiochemistry methods for synthesizing radiotracers. Each project was pursued in a close collaboration between the fellow trainee and both the clinical and basic science faculty at the University of Michigan PET Center, and provided an unprecedented opportunity for the highest-level training in academic radiochemistry and nuclear medicine research. The project has resulted in 17 peer-reviewed publications to date, and at least 4 more are in preparation. Additionally, 1 book chapter and 26 conference presentations have resulted from this grant. Upon completion of the MNTR Program, the trainees have emerged as translational scientists wielding the necessary skill-set (practical research experience, multidisciplinary training, regulatory know-how) to embark on successful careers in translational molecular imaging, bringing continued advances in the field to bear on important human disorders. As a metric of the Program’s success, one fellow has already secured employment in the field, while the other two are finishing writing papers; they wish to also stay in the radiochemistry and nuclear medicine community, and are currently applying for jobs.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

DOE OSTI2025

Age at release affects developmental physiology and sex-specific phenotypic diversity of hatchery steelhead trout (Oncorhynchus mykiss)

Most steelhead trout hatcheries increase growth rate during rearing to produce and release yearling smolts for harvest augmentation, but natural steelhead exhibit variable age of smoltification, so this common rearing practice may not be ideal for programs focused on recovering imperiled wild stocks; therefore, it is important to investigate and compare alternative hatchery rearing methods that promote life history diversity. Over six consecutive years, the Winthrop National Fish Hatchery on the Methow River, WA reared and released paired groups of age-1 (S1) and age-2 (S2) steelhead smolts. To understand how the two rearing methods affected developmental ontogeny and life-history, fish were sampled prior to hatchery release for factors associated with smoltification (size, gill Na+/K+ ATPase activity, and a qualitative smolt phenotype) and sexual maturation (sex, pituitary and testis mRNA transcripts, gonadosomatic index, and plasma 11-ketotestosterone). Our objectives were to quantify levels of smoltification and male maturation during hatchery rearing, combine metrics to estimate residualism (failure to migrate upon release), and compare the treatments by sex. Overall, S2 rearing produced 7.8% more smolts and 44-fold (4.4 vs. 0.1%) more precociously mature males than S1 rearing. Conversely, S1 rearing produced 31.6% more residuals than S2 rearing. While the proportion of total male residuals was comparable between treatments, the S1 treatment produced approximately five-fold more female residuals (20.6 vs. 4.2%). Because residuals contribute minimally to adult returns and the number of returning adult females is critical to the success of salmonid supplementation efforts, developing rearing techniques that maximize migration in females is a management priority. Physiological assessments are useful for characterizing and quantifying the effects and risks of different hatchery rearing regimes on steelhead life-history, in addition to providing sex-specific guidance to inform and optimize conservation management goals in supplementation programs.

Middleton, Mollie A. (ORCID:0009000905577865)↗