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DOE OSTI2018

ARM Aerosol Measurement Plan

Over the past decade, the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility has been working toward developing a comprehensive (defined here as Tiers I-III in Appendix A) and consistent set of aerosol measurements across each of the ARM ground-based observatories. Along the way, the facility has deployed wide-ranging instruments including some for which ARM has had many years of operating experience and some which represent more cutting-edge capabilities. While there has been a clear motivation for this instrument suite, the adoption of these instruments has not been uniform. The reasons for this vary and include operational challenges, measurement complexity, and alignment with active research.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2024

3D high-fidelity automated neutronics guided optimization of fusion blanket designs

The compact Fusion Pilot Plant (FPP) is defined in the recent National Academies of Sciences, Engineering, and Medicine report as the next step of fusion energy demonstration with a $50$ MWe peak net electricity production, $Q_e$ greater than $1$, and at least $3$ hours of continuous operation. This fusion pilot plant will be a test bed enabling materials, designs, and fuel management assessment, and it will represent an engineering challenge because of its high-fusion power and compact design targets. Previous reactor data is limited to experiments operating in different design space ranges. Therefore, design iterations and assessments should rely on high-fidelity first-principle theoretical and computational models. The high-fidelity integrated modeling of the plasma is a fundamental part of fusion energy research. However, the whole device modeling is often neglected, utilizing low-fidelity, system-level analysis. Recently, the need for high-fidelity multi-physics modeling was recognized, resulting in a selection of integrated tools. Further, autonomous design optimization requires a streamlined framework that perturbs the design point, reruns the analysis, and examines the outputs. However, high-fidelity analysis requires complex geometry specification that is difficult to perturb. This work presents the parametric CAD generation tool TRACER and a new neutronic workflow. TRACER allows the perturbation of the geometry representation, creating geometry files ready for further analysis. The streamlined neutronic workflow allows efficient and accurate calculations. The two new tools coupled together were used to perform a 3D high-fidelity multi-objective, multi-input optimization of an "ARC Class" compact tokamak design. The workflow was driven by an optimization driver for full automation.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2016

Fluoride Salt-Cooled High-Temperature Demonstration Reactor Point Design

The fluoride salt-cooled high-temperature reactor (FHR) demonstration reactor (DR) is a concept for a salt-cooled reactor with 100 megawatts of thermal output (MWt). It would use tristructural-isotropic (TRISO) particle fuel within prismatic graphite blocks. FLiBe (2 LiF-BeF 2 ) is the reference primary coolant. The FHR DR is designed to be small, simple, and affordable. Development of the FHR DR is a necessary intermediate step to enable near-term commercial FHRs. Lower risk technologies are purposely included in the initial FHR DR design to ensure that the reactor can be built, licensed, and operated within an acceptable budget and schedule. These technologies include TRISO particle fuel, replaceable core structural material, the use of that same material for the primary and intermediate loops, and tube-and-shell primary-to-intermediate heat exchangers. Several preconceptual and conceptual design efforts that have been conducted on FHR concepts bear a significant influence on the FHR DR design. Specific designs include the Oak Ridge National Laboratory (ORNL) advanced high-temperature reactor (AHTR) with 3400/1500 MWt/megawatts of electric output (MWe), as well as a 125 MWt small modular AHTR (SmAHTR) from ORNL. Other important examples are the Mk1 pebble bed FHR (PB-FHR) concept from the University of California, Berkeley (UCB), and an FHR test reactor design developed at the Massachusetts Institute of Technology (MIT). The MIT FHR test reactor is based on a prismatic fuel platform and is directly relevant to the present FHR DR design effort. These FHR concepts are based on reasonable assumptions for credible commercial prototypes. The FHR DR concept also directly benefits from the operating experience of the Molten Salt Reactor Experiment (MSRE), as well as the detailed design efforts for a large molten salt reactor concept and its breeder variant, the Molten Salt Breeder Reactor. The FHR DR technology is most representative of the 3400 MWt AHTR concept, and it will demonstrate key operational features of that design. The FHR DR will be closely scaled to the SmAHTR concept in power and flows, so any technologies demonstrated will be directly applicable to a reactor concept of that size. The FHR DR is not a commercial prototype design, but rather a DR that serves a cost and risk mitigation function for a later commercial prototype. It is expected to have a limited operational lifetime compared to a commercial plant. It is designed to be a low-cost reactor compared to more mature advanced prototype DRs. A primary reason to build the FHR DR is to learn about salt reactor technologies and demonstrate solutions to remaining technical gaps.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2023

Assessment of Nuclear Sensors and Instrumentation Maturity in Advanced Nuclear Reactors

In the last decade, 97% of the worldwide commercial nuclear reactors connected to the grid were Light Water Reactors (LWRs). LWRs are expected to stay the dominant type of nuclear reactors for the next few decades. Reliable and redundant safety systems are required in nuclear reactors to ensure safe operation and shutdown in abnormal conditions. These safety systems are actuated by the signals obtained from several sensors and instrumentation in and out of the reactor core. Research and Development (R&D) in advanced sensors and instrumentation has gained extra attention, particularly following the accident at the Three Mile Island Unit-2 (TMI-2). In LWRs, these sensors and instrumentation have shown a high level of maturity with long operating experience. Ensuring the compatibility of these sensors and instrumentation with advanced nuclear reactors (Generation IV) is necessary, particularly with the expected expansion of the nuclear industry in the next few decades. Nuclear Sensor and instrumentation technologies used in the current generation of LWRs were investigated. The compatibility of these technologies with advanced reactors was assessed by comparing the advanced reactors' environments with those of the currently operating reactors. In addition to that, the needed R&D for such technologies was highlighted. In comparison with the LWRs environment, it was shown that advanced reactor environments are expected to experience elevated temperatures, a fast neutron spectrum, and a harsh corrosion environment. It was demonstrated that R&D is required mainly for fixed in-core nuclear sensors and instrumentation, while it is not a priority for ex-core nuclear sensors and instrumentation.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2020

DAQExpert the service to increase CMS data-taking efficiency

The Data Acquisition (DAQ) system of the Compact Muon Solenoid (CMS) experiment at the LHC is a complex system responsible for the data readout, event building and recording of accepted events. Its proper functioning plays a critical role in the data-taking efficiency of the CMS experiment. In order to ensure high availability and recover promptly in the event of hardware or software failure of the subsystems, an expert system, the DAQ Expert, has been developed. It aims at improving the data taking efficiency, reducing the human error in the operations and minimising the on-call expert demand. Introduced in the beginning of 2017, it assists the shift crew and the system experts in recovering from operational faults, streamlining the post mortem analysis and, at the end of Run 2, triggering fully automatic recovery without human intervention. DAQ Expert analyses the real-time monitoring data originating from the DAQ components and the high-level trigger updated every few seconds. It pinpoints data flow problems, and recovers them automatically or after given operator approval. We analyse the CMS downtime in the 2018 run focusing on what was improved with the introduction of automated recovery; present challenges and design of encoding the expert knowledge into automated recovery jobs. Furthermore, we demonstrate the web-based, ReactJS interfaces that ensure an effective cooperation between the human operators in the control room and the automated recovery system. We report on the operational experience with automated recovery.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2015

SUPERCONDUCTING LINAC UPGRADE PLAN FOR THE SECOND TARGET STATION PROJECT AT SNS

The beam power of the Linac for the Second Target Station (STS) at the Spallation Neutron Source (SNS) will be doubled to 2.8 MW. For the energy upgrade, seven additional cryomodules will be installed in the reserved space at the end of the linac tunnel to produce linac output energy of 1.3 GeV. The cryomodules for STS will have the same physical length but will incorporate some design changes based on the lessons learned from operational experience over the last 10 years and from the high beta spare cryomodule developed in house. The average macro-pulse beam current for the STS will be 38 mA which is about a 40 % increase from the present beam current for 1.4 MW operation. Plans for the new cryomodules and for the existing cryomodules to support higher beam current for the STS are presented in this paper.

Kim, Sang-Ho↗

DOE OSTI2017

Performance of a Dual Fluidized Bed Reactor for Chemical Looping Combustion with Oxygen Uncoupling

Chemical looping with oxygen uncoupling (CLOU) is a variant of chemical looping combustion which uses as fluidized bed particles specific solid oxygen carriers which readily liberate gaseous oxygen (O2) in the fuel reactor. This enables much more efficient combustion of solid fuels such as coal than conventional chemical looping combustion, which relies on in situ gasification of char in to produce syngas that can react heterogeneously with the solid oxygen carrier. The CLOU process for coal is an especially interesting application of fluidized bed technology since several types of reactions take place within the reactors. For copper-based oxygen carrier particles, the copper cycles between cuprous and cupric oxide (Cu2O + ½ O2 ↔ 2 CuO). Volatiles released from coal during pyrolysis may react with oxidized copper or with released oxygen gas. Char reacts primarily with released oxygen. Balancing oxygen supply to the fuel reactor, heat generation and temperatures and global and internal circulation rates is a challenge. The University of Utah has been researching CLOU technology for 10 years, studying fundamental reaction kinetics for copper-based CLOU oxygen carriers, performing lab- and bench-scale experiments in single and dual fluidized beds, and developing reactor models through computational fluid dynamic modeling using Barracuda VR™. Recently the university began testing a 200 kWth dual circulating fluidized bed process development unit (PDU) for processing coal. The design process for that reactor, reactor simulations, operational experience and practical challenges of the PDU system are presented.

Whitty, Kevin J.↗

DOE OSTI2015

Characterization and use of the spent beam for serial operation of LCLS

X-ray free-electron laser sources such as the Linac Coherent Light Source offer very exciting possibilities for unique research. However, beam time at such facilities is very limited and in high demand. This has led to significant efforts towards beam multiplexing of various forms. One such effort involves re-using the so-called spent beam that passes through the hole in an area detector after a weak interaction with a primary sample. This beam can be refocused into a secondary interaction region and used for a second, independent experiment operating in series. The beam profile of this refocused beam was characterized for a particular experimental geometry at the Coherent X-ray Imaging instrument at LCLS. A demonstration of this multiplexing capability was performed with two simultaneous serial femtosecond crystallography experiments, both yielding interpretable data of sufficient quality to produce electron density maps.

43 PARTICLE ACCELERATORS↗

DOE OSTI2024

Characterization of Silicon Photomultiplier Photon Detection Efficiency at Liquid Nitrogen Temperature

The detection of individual photons at cryogenic temperatures is of interest to many experiments searching for physics beyond the Standard Model. Silicon photomultipliers (SiPMs) are often deployed in liquid argon or liquid xenon to detect scintillation light either directly or after it has been wavelength-shifted. Maximizing the photon detection efficiency (PDE) of the SiPMs used in these experiments optimizes the sensitivity to new physics; however, the PDEs of commercial SiPMs, although well known at room temperature, are not well characterized at the cryogenic temperatures at which many experiments operate them. Here we present results from an experimental setup that measures the photon detection efficiencies of silicon photomultipliers at liquid nitrogen temperature, 77 K. Results from a KETEK PM3325-WB-D0 and a Hamamatsu S13360-3050CS silicon photomultiplier — of R&D interest to the LEGEND experiment — exhibit a decrease in photon detection efficiency greater than 20% at liquid nitrogen temperature relative to room temperature for 562 nm light.

Cryogenic detectors↗

DOE OSTI2018

Leakage Rate Testing Considerations and Implementation of ANSI N 14.5-2014 Standard within EnergySolutions Type (B) cask fleet - 18629

In March 2016, Nuclear Regulatory Commission (NRC) staff issued Information Notice 2016-04: 'ANSI N14.5-2014 Revision and leakage rate testing considerations'. American National Standards Institute (ANSI) N14.5, 'American National Standard for Radioactive Materials-Leakage Tests on Packages for Shipment', applies to leakage rate testing of Low Level Radioactive Waste (LLRW) Type B packages operated under 10CFR71. In their information notice NRC is encouraging Type B cask license holders and licensees (cask users) to adapt a new version of ANSI N 14.5 standard. Typically, leakage rate testing for Type B packages (or casks) is performed at different stages of cask development (design and fabrication leak tests) and operations (periodic/maintenance and pre-shipment leak tests) with the purpose to reasonably assure that the packaging will contain radioactive material under both normal and hypothetical accident conditions of transport described in 10CFR71. The standard was updated to provide a modern, robust and standardized approach for performance of leak rate testing on Type B casks by the industry stakeholders. Although implementation of new version of the leak testing standard may not be problematic for a modern Type B package designs, it may be extremely challenging to apply its principles to the existing legacy Type B casks which were designed/fabricated more then 20-30 years ago based on older requirements. Majority of such casks are not 'leak test' friendly. Some of legacy Type B packages may not readily available to meet newer ANSI N 14.5 standard requirements and will require implementation of alternative compensatory measures in lieu of the standard's requirements. In addition, the new standard mandates implementation of additional requirements for leak rate testing performance and personnel qualifications during routine maintenance of Type B casks by owner and during operations of casks by users. The focus of the paper will be to discuss ANSI N 14.5-2014 requirements and provide specific examples on how these requirements will impact the current leak rate test practices. This will be illustrated based on several Type B cask models operated within EnergySolutions fleet (both newer and legacy cask designs). Finally, the paper will cover considerations of the cask closure design features that have to be considered by Type B cask designers in order to ensure robustness of leak testing during design, fabrication and, most importantly, operation of a package. This information shall benefit both owners and users of Type B casks with respect to improvement of the cask designs and Type B cask operational experience. (author)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2017

Leveraging Electron Transfer Dissociation for Site Selective Radical Generation: Applications for Peptide Epimer Analysis

Traditional electron-transfer dissociation (ETD) experiments operate through a complex combination of hydrogen abundant and hydrogen deficient fragmentation pathways, yielding c and z ions, side-chain losses, and disulfide bond scission. Herein, a novel dissociation pathway is reported, yielding homolytic cleavage of carbon–iodine bonds via electronic excitation. This observation is very similar to photodissociation experiments where homolytic cleavage of carbon–iodine bonds has been utilized previously, but ETD activation can be performed without addition of a laser to the mass spectrometer. Both loss of iodine and loss of hydrogen iodide are observed, with the abundance of the latter product being greatly enhanced for some peptides after additional collisional activation. These observations suggest a novel ETD fragmentation pathway involving temporary storage of the electron in a charge-reduced arginine side chain. Subsequent collisional activation of the peptide radical produced by loss of HI yields spectra dominated by radical-directed dissociation, which can be usefully employed for identification of peptide isomers, including epimers. .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2013

PROJECTED CONSTRAINTS ON THE COSMIC (SUPER)STRING TENSION WITH FUTURE GRAVITATIONAL WAVE DETECTION EXPERIMENTS

We present projected constraints on the cosmic string tension, G{mu}/c {sup 2}, that could be achieved by future gravitational wave detection experiments and express our results as semi-analytic relations of the form G{mu}({Omega}{sub gw} h {sup 2})/c {sup 2}, to allow for direct computation of the tension constraints for future experiments. These results can be applied to new constraints on {Omega}{sub gw} h {sup 2} as they are imposed. Experiments operating in different frequency bands probe different parts of the gravitational wave spectrum of a cosmic string network and are sensitive to different uncertainties in the underlying cosmic string model parameters. We compute the gravitational wave spectra of cosmic string networks based on the one-scale model, covering all the parameter space accessed by each experiment that is strongly dependent on the birth scale of loops relative to the horizon, {alpha}. The upper limits on the string tension avoid any assumptions on the model parameters. We perform this investigation for Pulsar Timing Array experiments of different durations, as well as ground-based and space-borne interferometric detectors.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2013

Neutrino Cross Sections II: Neutrino Boogaloo. UF Task P3, Accelerator-Based Experimental Neutrino Physics. Final Report

We report on progress in a series of different directions within high energy physics research. 1. Neutrino research in hardware and software on the Minerva and MiniBooNE experiments 2. Experimental particle physics at the hadron colliders, with emphasis on research and development and data analysis on the CMS experiment operating at the CERN LHC. This includes research on the discovery and properties on the Higgs Boson. 3. Educational outreach through the Quarknet program, taking physics research into High School classrooms. 4. Theoretical and Phenomenological High Energy research, covering a broad range of activities ranging from fundamental theoretical issues to areas of immediate phenomenological importance. 5. Experiment searches for the Axion, as part of the ADMX experiment.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2018

A 4 tonne demonstrator for large-scale dual-phase liquid argon time projection chambers

A 10 kilo-tonne dual-phase liquid argon TPC is one of the detector options considered for the Deep Underground Neutrino Experiment (DUNE). The detector technology relies on amplification of the ionisation charge in ultra-pure argon vapour and offers several advantages compared to the traditional single-phase liquid argon TPCs. A 4.2 tonne dual-phase liquid argon TPC prototype, the largest of its kind, with an active volume of \three has been constructed and operated at CERN. In this paper we describe in detail the experimental setup and detector components as well as report on the operation experience. We also present the first results on the achieved charge amplification, prompt scintillation and electroluminescence detection, and purity of the liquid argon from analyses of a collected sample of cosmic ray muons.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2016

Advantages gained by Optimized ZIRLO and AXIOM PWR cladding materials

In support of industry's demands for higher performance cladding alloy materials, the Optimized ZIRLO alloy was developed as an evolutionary improvement of the ZIRLO alloy to obtain a significant improvement in corrosion performance and hydrogen pickup while maintaining the overall robust performance of ZIRLO alloy. Currently with operating experience in over 40 plants and burnup reaching over 70 GWd/MTU, a majority of the Westinghouse-fueled US PWR fleet, covering almost all Westinghouse fuel designs, has adopted full regions of Optimized ZIRLO cladding. Across all of these applications, Optimized ZIRLO cladding has demonstrated greatly improved corrosion performance and structural stability. These demonstrated improvements offer increased operational margin and flexibility, in support of industry trends toward increased core operating fuel duties and evolving regulatory requirements such as accident scenarios. Underpinning these benefits are the extensive post irradiation exam (PIE) data obtained from both pool-side and hot-cell exams for Optimized ZIRLO cladding. Building on the successes of Optimized ZIRLO cladding, and in recognition of increasingly challenging fuel management practices, and revised LOCA regulatory rules restricting cladding hydrogen content, AXIOM cladding is being rolled out for full lead test assembly irradiation. The AXIOM alloy, Westinghouse's next generation robust alloy targeting very high fuel duties, is designed to provide improved corrosion resistance, lower hydrogen pick-up, and lower creep and growth compared to current Westinghouse products. AXIOM cladding has been irradiated in a variety of reactors worldwide, including both commercial and test reactors. Extensive PIE data is available for various burnup levels, with leading rods approaching 75 GWd/MTU. The AXIOM composition was selected to ensure enhanced operating performance on multiple fronts, including the optimum combination of corrosion resistance and wear resistance, reduced hydrogen pick-up, improved dimensional stability, and robustness in aggressive coolant chemistry conditions. The present paper provides high burnup performance data, capturing the advantages gained by introducing Optimized ZIRLO and AXIOM alloy as PWR cladding materials. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2016

Managing Risks Associated with Global Nuclear Energy Expansion: Emerging Challenges and Cooperative Solutions Workshop Summary Report.

Global nuclear energy has reached a critical juncture. The footprint of nuclear energy is growing and will continue to grow in coming decades to meet increasing global energy demands, desires for energy security, and mounting concerns about climate change. This growth includes construction of reactors in countries new to the nuclear energy enterprise, in addition to expansion of existing programs. The lack of operational experience coupled with weak regulatory systems in some countries raises the potential of a nuclear accident. The expansion of nuclear energy is also met with an increasingly complex threat environment, with threats to nuclear security from non-state actors as well as the continued risks of state proliferation. The trend towards increasingly digitized and networked nuclear facilities significantly expands operational uncertainty and adds complexity to implementing safeguards and security. These factors merit fresh consideration of potential safety, safeguards, security, and cyber (3SC) risks, as well as approaches for managing those risks in an integrated, sustainable, and internationally cooperative manner. In an effort to explore the emerging challenges and cooperative solutions to the global expansion of nuclear energy The George Washington University Elliott School of International Affairs and Sandia National Laboratories convened a group of more than thirty experts from government, national laboratories, non-government organizations, and academia on May 5th, 2016 at George Washington University to discuss these issues in a not-for-attribution environment.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2024

MiniDAQ-3: Providing concurrent independent subdetector data-taking on CMS production DAQ resources

The data acquisition (DAQ) of the Compact Muon Solenoid (CMS) experiment at CERN, collects data for events accepted by the Level-1 Trigger from the different detector systems and assembles them in an event builder prior to making them available for further selection in the High Level Trigger, and finally storing the selected events for offline analysis. In addition to the central DAQ providing global acquisition functionality, several separate, so-called “MiniDAQ” setups allow operating independent data acquisition runs using an arbitrary subset of the CMS subdetectors. During Run 2 of the LHC, MiniDAQ setups were running their event builder and High Level Trigger applications on dedicated resources, separate from those used for the central DAQ. This cleanly separated MiniDAQ setups from the central DAQ system, but also meant limited throughput and a fixed number of possible MiniDAQ setups. In Run 3, MiniDAQ-3 setups share production resources with the new central DAQ system, allowing each setup to operate at the maximum Level-1 rate thanks to the reuse of the resources and network bandwidth. Configuration management tools had to be significantly extended to support the synchronization of the DAQ configurations needed for the various setups. We report on the new configuration management features and on the first year of operational experience with the new MiniDAQ-3 system.

Amoiridis, Vassileios↗

DOE OSTI2020

Sensitive Resources Assessment and Forest Analysis for the Proposed Versatile Test Reactor, Oak Ridge, Tennessee

The US Department of Energy’s (DOE’s) Oak Ridge National Laboratory (ORNL) is a leading institution in advanced materials, supercomputing, neutrons, and nuclear science. As a research laboratory managed by UT-Battelle, LLC for DOE, ORNL has national priorities in energy, security, and scientific discovery that necessitate facility improvements and expansions. DOE is also committed to environmental stewardship. The laboratory is located on the ~32,000-acre (~13,000-ha) Oak Ridge Reservation (ORR), much of which is categorized as a National Environmental Research Park (NERP) and a state Wildlife Management Area. DOE works with the Tennessee Wildlife Resources Agency (TWRA), Tennessee Department of Environment and Conservation (TDEC), US Fish and Wildlife Service (USFWS), US Department of Agriculture, and other agencies to serve as an effective steward of the ORR. Accordingly, project managers must conform to environmental regulations, agreements, and policies at the federal, state, and institutional levels. Per 40 CFR (Code of Federal Regulations) 1508.14, potential effects on research and science education also represent potential effects of federal actions on the NERP, and impacts on, e.g., deer harvest, must be considered on the Oak Ridge Wildlife Management Area when other aspects of the human environment are affected. The United States currently has no fast neutron testing capability to support advanced nuclear research and development. The proposed Versatile Test Reactor (VTR) will take advantage of current investments by the US government and private industry in nuclear reactors to expedite the design and construction process, using proven technology to create a world-class scientific infrastructure. The VTR will take advantage of fast neutrons provided by this proven technology, along with a capability to rapidly insert, conduct, and remove state-of-the-art experiments. An advantage of the VTR is that it can support future innovations in experimental capabilities without modifying the facility. The VTR will support progress in a variety of science and technology areas, including testing and qualification of advanced reactor fuels; testing and qualification of innovative structural materials; testing of innovative components and instruments; validation of advanced modeling and simulation tools; and versatility for future technical missions. Through proven technology, the VTR can take advantage of existing reactor designs and operating experience to reduce the risk, cost, and time for design and construction. The top available resources of DOE laboratories, industry, and universities will be used to expedite reactor design and construction toward developing the scientific infrastructure that affords a strong testing capability that can be sustained over many years. This report summarizes current knowledge of natural and cultural resources primarily within the VTR construction area. At the time of this report, the proposed VTR site design includes a construction area of ~150.4 acres (~69.9 ha), which contains an ~51.3-acre (~20.8-ha) operations area, located within forested natural areas of the ORR. The primary goal of the work presented here was to evaluate potential effects on sensitive resources that might result from development and construction activities associated with VTR. In addition to on-the-ground surveys during spring and summer 2020 by the ORNL Natural Resources Management Program and Aquatic Ecology Group staff, this report makes use of historical (pre-1995) and contemporary (1995 to present) data from additional confirmed sources (e.g., TDEC). Likewise, forest conditions were compiled from a 2011 forest inventory and supplemented with limited ground observations in 2020. The individuals who obtained and compiled the data presented here are familiar with and routinely assess sensitive resources on the ORR. Anyone who references this report must consider that the timing of surveys did not permit a complete delineation of the resources that will be affected. If the VTR project proceeds, additional surveys will be required to account for the seasonal patterns of various threatened and endangered species. Data deficiencies and potential resources that likely went undetected are indicated where possible. Accordingly, this report should facilitate more environmentally sound decisions during planning and 2 development of the VTR site, provide a foundation for further assessment of sensitive and cultural resources, and help project managers better address regulatory guidance and DOE policies on sustainable development in compliance with, for example, the US Endangered Species Act (ESA), Migratory Bird Treaty Act (MBTA), Tennessee Rare Plant Protection and Conservation Act of 1985, Tennessee Nongame and Endangered or Threatened Wildlife Species Conservation Act of 1974, several federal and state regulations regarding aquatic resource protection, and site-specific policies as outlined in various ORR management plans developed by ORNL and TWRA for DOE.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗