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Improving Decommissioning Success using the Tool of Virtual Reality; Increasing Worker Safety and Project Schedule Stability - 17193

operations, especially underwater, is essential. Equally essential is a precise game plan for disassembly which focuses attention on the skilled remote handling operators who must produce the results. Project success is based on clean, efficient cuts and take-aways, prepared paths for waste placement and containment, programmed return paths; and practice, practice, practice on the part of the operators. Recently, our Partner, WAK Ruackbau- und Entsorgungs- GmbH (Decommissioning and Waste Management Company) was tasked with dismantling and decommissioning the Karlsruhe Reprocessing Plant. The most difficult task in this project is the dismantling of the vitrification plant. Waelischmiller was selected to address this high-consequence project. Together, WAK and Waelischmiller determined that development of a virtual reality suite, where management and operators could create a virtual vitrification layout and subsequently map and rehearse their dismantling plan was essential. This approach, using Virtual Reality (VR) as a tool in streamlining operations and rehearsing difficult moves and cuts, will be a game changer for this and future projects. It will be a first-of-a-kind in Germany. The VR suite is contained in a room at the Karlsruhe facility with a large screen, control cabinet, simulation computer, a Waelischmiller Joyarm and Masterarm. To support the dismantling of the vitrification plant, WAK/HWM will conduct interactive feasibility studies for each dismantling step. All movements; cuts, take-aways and vessel segment insertion into transportation and disposal casks will be established, programed and practiced within virtual test suite. This allows savings in cost-intensive and complex construction of test rigs. Operating personnel can be trained in the VR suite, without taking the risk of damaging expensive remote handling equipment.While the operators are working on the operating element, they stand in front of a wide screen. Instead of a real TELBOT{sup R}, a virtual TELBOT{sup R} is moving on the screen in virtual reality. While practicing, the operators cannot damage the arm and the equipment, which is a big advantage. Moreover an interactive feasibility study can be realized without building a real test rig (mock-up). Consequently significant cost-expenses can be reduced. This paper will describe the virtual suite used by the WAK in Karlsruhe and the advantages of this new and innovative approach, which is unique in decommissioning of nuclear facilities. The viewpoint of each (WAK and HWM), and the decisions and benefits realized along the project path will be detailed in the paper. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Laboratory testing options for FUSRAP projects - 15462

Remediation projects within the Formerly Used Sites Remedial Action Program (FUSRAP) have many options to consider when evaluating their analytical testing needs. Factors that should be considered in determination of a project's analytical testing needs include which parameter results are considered time-critical, the potential savings in reduction of construction-related delays when time-critical samples are analyzed onsite (including screening) instead of offsite, control of data quality for onsite versus offsite data, and the value of additional knowledge gained by programs such as FUSRAP by employing onsite laboratories. The most important factor turned out to be reduction in construction-related delays. We considered development of an optimum combination of onsite lab/offsite lab capability. This depends on: i. Time critical parameters and the methods required; ii. Estimated Cost for onsite lab construction or facility rental, maintenance, labor, chemicals (reagents and standards), and certification (if desired and deemed necessary) iii. Ability, flexibility, and cost of offsite lab sample testing using project-desired TATs and methods that will meet project action levels iv. Willingness of stakeholders, in particular regulators, in accepting some combination of onsite and offsite testing (for example, onsite screening followed by offsite confirmatory testing for certain parameters) Due to the significant costs in construction of an onsite lab and development of sample testing capability and all which that entails, the recommendations made in this paper will aid other FUSRAP projects in finding an acceptable combination of onsite and offsite testing that is acceptable to all stakeholders. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Waste Management Processing Projects in the PRC - 16551

EnergySolutions continues to provide waste treatment solutions in the Peoples Republic of China (PRC). In 2015 ES had completed installation of systems at two different Nuclear power sites (Haiyang, an AP-1000{sup TM} site and Yangjiang, a CPR1000 site). This paper discusses progress on these two projects, and provides new information regarding the operation of the systems. The Yangjiang project became operational in the fall of 2015 while the Haiyang project will be done is nearly done with commissioning and is waiting for reactor operations. Haiyang Project: In the Shandong Province on China's northeast coast, EnergySolutions, as part of a consortium with China Power Investment (CPI) and Yuanda Environmental Protection Engineering Company (a PRC state-owned company), has designed and constructed the site's Site Rad Waste Treatment Facility (SRTF). The SRTF provides solid waste processing services for up to 8 AP-1000s{sup TM}. The SRTF performs the following functions: 1. Five year storage for HICs containing spent resin and filters from the nuclear power plants' waste liquid systems (WLS); 2. Sorting and Compaction System for solid waste generated from Nuclear Power Plant (NPP) operations. This system implements: a) Real time radiography to screen 200 liter waste drums for prohibited items, b) Pre-compaction, c) High Resolution Gamma Spectrophotometry (HRGS) for waste characterization, d) Supercompaction, e) Solidification of compacted drums inside overpack drums which are filled with 60 MPa compressive strength grout, and f) Automatic drum lidding which crimps the drum lid to the drum body. 3. Laundry services for NPP anti-contamination clothing. 4. At the nuclear islands, EnergySolutions is providing mobile liquid waste processing systems that utilize EnergySolutions Advanced Liquid Processing System ALPS{sup TM}/Advanced Injection Method System AIM{sup TM} processing systems to supplement the NPP's WLS system when radionuclide concentrations exceed release criteria. The spent resins and filters from the nuclear power plants are placed in EnergySolutions supplied HICs, dewatered using EnergySolutions Self Engaging Dewatering System (SEDS{sup TM}), and then placed in EnergySolutions 8-120B Type B cask for the transport of the HIC between the NPP and the SRTF and, ultimately, to a disposal site once it is ready for operations Yangjiang Project: EnergySolutions is providing liquid waste treatment system (TEU) and solid waste treatment system (TES) for Yangjiang units 3 and 4 for the China Nuclear Power Engineering Company (CNPEC). The Yangjiang site is located approximately 300 kilometers west of Hong Kong. The TEU system processes floor drain, chemical drain, and process drain tanks liquids to achieve a release concentration less than 37 Bq/l. The TES system receives spent resin and filters into HIC containers which are dewatered and subsequently transported to the Yangjiang sites QT building where they are stored for a period of up to 5 years or until a disposal site are available. TEU (Liquid waste treatment) consists of the following unit operations: - ALPS{sup TM}/AIM{sup TM} system, which includes two separate 8 vessel water treatment systems that consist of granular activated carbon (GAC), cation, anion ion and mixed bed media ion exchange (IX) columns; and: - A reverse osmosis system for final polishing, - TES (solid waste system), - SEDS (Self Engaging Dewatering System), - Shielding for the loading and storage of HICs, - Shielded transport container for the transfer of HIC to the QT building for storage, - Shielded transfer bell for the transport of spent filters from the NPP operating area to HIC. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Waste Encapsulation and Storage Facility Stabilization and Ventilation Project-18121

Department of Energy contractor CH2M HILL Plateau Remediation Company (CH2M) is responsible for the safe and compliant operation of the Waste Encapsulation and Storage Facility (WESF), a nuclear materials storage facility at Hanford containing 1,936 highly radioactive capsules containing cesium and strontium. The capsules are currently stored under approximately 4 m (13 ft) of water. The water shields workers from radiation and helps cool the capsules. WESF is a large, concrete structure nominally 48 m (160 ft) long, 30 m (98 ft) wide and 12 m (40 ft) high with the pool cells being approximately 4 m (13 ft) below grade level. It is a robust facility with walls ranging from 0.3 m to 1 m (1 ft to 3 ft) thick. While the capsules are currently in a safe configuration, WESF is an aging facility, and DOE and CH2M are modifying the facility to ensure continued safe and compliant operations and to support the eventual transfer of capsules to dry storage. Dry storage would eliminate the possibility of a release of radioactive material in the unlikely event of a major earthquake that might result in loss of pool storage water and overheating and breach of one or more capsules. The project was divided into two major deliverables: 1) Ventilation: replacement of the existing ventilation system which included a below-grade high efficiency particulate air (HEPA) filter pit with an above grade HEPA filter skid and new fans and ducting. 2) Stabilization: grouting deactivated facility hot cells and other void spaces to the maximum extent practical to reduce material at risk from legacy contamination. The aging ventilation system relied on HEPA filters that exceeded their operational life. Due to the high levels of radionuclide contamination, replacing the filters was impractical and highly hazardous. CH2M installed a new ventilation system to provide safe and compliant ventilation for future operations. The project used an existing, unused ventilation skid that was designed for another project. Repurposing the unused skid presented additional technical challenges to modify the system for the project specific requirements. The new system is above ground, easier to maintain and is built to current standards. New connections inside the facility were installed to allow the new ventilation to operate effectively. The stabilization project is unique in that core drilling and grouting was performed in an operating Hazard Category 2 nuclear facility, which brought forth safety basis and environmental regulatory challenges. The hot cells were isolated from all existing support utilities including electrical, process chemicals, manipulator ports, instrument air, etc. to seal the hot cells and prevent highly contaminated supernate or grout from leaking into adjacent galleries. A high flow grout was used to maximize the distance between injection ports. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Port Hope Area Initiative - Port Granby Project: Effectiveness of the Radiation Protection Program - 18595

The Port Granby Project is large remediation project currently underway. It is approximately 50% complete. A comprehensive and effective radiation protection program has been developed and implemented for the Port Granby Project. The potential radiation hazards associated with this project include: external (gamma) radiation, radon, inhalation, contamination and ingestion. The radiation protection program is highly effective and has succeeded in managing the significant radiation hazards associated with this remediation project. (authors)

61 RADIATION PROTECTION AND DOSIMETRY↗

Leveraging 3D CAD and Virtual Reality in Design of the Calcine Disposition Project - 20512

Fluor Idaho's Calcine Disposition Project (CDP) is leveraging the power of three-dimensional (3D) visualization, light detection and ranging (Lidar), and virtual reality to improve designs and worker safety. With the use of computer-aided design (CAD) modeling software, the CDP has created 3D models of the facility and systems to aid in the design, development, and operation of its retrieval and transfer system. This by itself is nothing new and has been done in industry for years. The CDP project however is taking this a few steps farther with the use of Lidar and virtual reality software. The CRP is tasked with removing a radioactive granular material from stainless steel bins located in concrete vaults that were constructed in the late 1950's and early 1960's. While construction drawings are available, it is not certain that the drawings are as-built or how accurate they truly are. Part of the project requires precise placement of equipment on to bins around multiple pipe, electrical lines, and bin stiffeners. Relying solely on the existing drawings and models created from these drawings is highly risky and prone to failure. The first step to determine the precise location and orientation of all obstructions in the vault the project will use a Lidar system to scan the vault structure and precisely locate all vault and bin components. Once this information is obtained, the data will be integrated into the CAD model. The model will then be verified, and a true as-built model developed. Precise component location, size, and orientation will be used for final design and placement of retrieval components. The second step will be to take the verified 3D model and scan data and import it into virtual reality software creating a virtual world. While some work on the project requires all work to be completed remotely due to high radiation fields, some areas have low enough radiation levels that personnel can enter and perform work. With the use of a virtual reality headset, operators and technicians will be able to enter our virtual world and become familiar with the surroundings and perform work prior to ever entering the radiation environment. This training is expected to pay dividends by improving worker efficiency, reducing errors, and improving confidence that the work can be performed as expected. It will play a key aspect in as low as reasonably achievable (ALARA) principles. An additional aspect in using the Lidar scans and virtual environment, is that it will give engineers and managers an opportunity to revisit the facility, especially radiation areas, at any time to obtain design information and measurements that may be costly or impossible to obtain once the facility transitions into radiation operations. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Exploring Professor Motivations and Implementations of a Real-World Problem-Solving Project: A Case Study in Preparing Students for the Emerging Building Science Industry: Preprint

Engineering education literature offers a variety of theoretical and conceptual frameworks for project-based learning. This study explores the implementation of real-world problem-solving projects in engineering education. The research team analyzed the motivations and methods behind professors' adoption of such projects through exploratory qualitative interviews with seven professor participants who integrated a nation-wide student competition into their courses. We analyzed the resulting data using a constructivist grounded theory approach to identify key themes of professor practices. Findings reveal that the real-world aspect of the projects and alignment with values and research interests were primary motivators for implementation. While implementation methods varied significantly based on context (i.e., university setting, course type), we found that these projects could be effectively integrated into various classroom settings. The findings support the recommendation for non-academic institutions to develop and manage competitions that can be integrated into classrooms and which offer a point of engagement that is available to professors from a wide range of disciplines.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

High‐Resolution Dynamical Downscaling Ensemble Projections of Future Extreme Temperature Distributions for the United States

Abstract The aim of this study is to examine projections of extreme temperatures over the continental United States (CONUS) for the 21st century using an ensemble of high spatial resolution dynamically downscaled model simulations with different boundary conditions. The downscaling uses the Weather Research and Forecast model at a spatial resolution of 12 km along with outputs from three different Coupled Model Intercomparison Project Phase 5 global climate models that provide boundary conditions under two different future greenhouse gas (GHG) concentration trajectories. The results from two decadal‐length time slices (2045–2054 and 2085–2094) are compared with a historical decade (1995–2004). Probability density functions of daily maximum/minimum temperatures are analyzed over seven climatologically cohesive regions of the CONUS. The impacts of different boundary conditions as well as future GHG concentrations on extreme events such as heat waves and days with temperature higher than 95°F are also investigated. The results show that the intensity of extreme warm temperature in future summer is significantly increased, while the frequency of extreme cold temperature in future winter decreases. The distribution of summer daily maximum temperature experiences a significant warm‐side shift and increased variability, while the distribution of winter daily minimum temperature is projected to have a less significant warm‐side shift with decreased variability. Using “business‐as‐usual” scenario, 5‐day heat waves are projected to occur at least 5–10 times per year in most CONUS and ≥95°F days will increase by 1–2 months by the end of the century.

54 ENVIRONMENTAL SCIENCES↗

Climate Change Projection in the Twenty-First Century Simulated by NIMS-KMA CMIP6 Model Based on New GHGs Concentration Pathways

Abstract The National Institute of Meteorological Sciences-Korea Meteorological Administration (NIMS-KMA) has participated in the Coupled Model Inter-comparison Project (CMIP) and provided long-term simulations using the coupled climate model. The NIMS-KMA produces new future projections using the ensemble mean of KMA Advanced Community Earth system model (K-ACE) and UK Earth System Model version1 (UKESM1) simulations to provide scientific information of future climate changes. In this study, we analyze four experiments those conducted following the new shared socioeconomic pathway (SSP) based scenarios to examine projected climate change in the twenty-first century. Present day (PD) simulations show high performance skill in both climate mean and variability, which provide a reliability of the climate models and reduces the uncertainty in response to future forcing. In future projections, global temperature increases from 1.92 °C to 5.20 °C relative to the PD level (1995–2014). Global mean precipitation increases from 5.1% to 10.1% and sea ice extent decreases from 19% to 62% in the Arctic and from 18% to 54% in the Antarctic. In addition, climate changes are accelerating toward the late twenty-first century. Our CMIP6 simulations are released to the public through the Earth System Grid Federation (ESGF) international data sharing portal and are used to support the establishment of the national adaptation plan for climate change in South Korea.

54 ENVIRONMENTAL SCIENCES↗

Construction of energy-stable projection-based reduced order models

Our paper aims to unify and extend several approaches for building stable projection-based reduced order models (ROMs) using the energy method and the concept of “energy-stability”. Attention is focused on linear time-invariant (LTI) systems. First, an approach for building energy stable Galerkin ROMs for linear hyperbolic or incompletely parabolic systems of partial differential equations (PDEs) using continuous projection is proposed. The key idea is to apply to the system a transformation induced by the Lyapunov function for the system, and to build the ROM in the transformed variables. The result of this procedure will be a ROM that is energy-stable for any choice of reduced basis. It is shown that, for many PDE systems, the desired transformation is induced by a special inner product, termed the “symmetry inner product”. Next, attention is turned to building energy-stable ROMs via discrete projection. A discrete counterpart of the continuous symmetry inner product, termed the “Lyapunov inner product”, is derived. Moreover, it is shown that the Lyapunov inner product can be computed in a black-box fashion for a stable LTI system ari sing from the discretization of a system of PDEs in space. Projection in this inner product guarantees a ROM that is energy-stable, again for any choice of reduced basis. Connections between the Lyapunov inner product and the inner product induced by the balanced truncation algorithm are made. We also made comparisons between the symmetry inner product and the Lyapunov inner product. Performance of ROMs constructed using these inner products is evaluated on several benchmark test cases.

97 MATHEMATICS AND COMPUTING↗

Projection pursuit adaptation on polynomial chaos expansions

Here, the present work addresses the issue of accurate stochastic approximations in high-dimensional parametric space using tools from uncertainty quantification (UQ). The basis adaptation method and its accelerated algorithm in polynomial chaos expansions (PCE) were recently proposed to construct low-dimensional approximations adapted to specific quantities of interest (QoI). The present paper addresses one difficulty with these adaptations, namely their reliance on quadrature point sampling, which limits the reusability of potentially expensive samples. Projection pursuit (PP) is a statistical tool to find the “interesting” projections in high-dimensional data and thus bypass the curse-of-dimensionality. In the present work, we combine the fundamental ideas of basis adaptation and projection pursuit regression (PPR) to propose a novel method to simultaneously learn the optimal low-dimensional spaces and PCE representation from given data. While this projection pursuit adaptation (PPA) can be entirely data-driven, the constructed approximation exhibits mean-square convergence to the solution of an underlying governing equation and thus captures the supports and probability distributions associated with the physics constraints. The proposed approach is demonstrated on a borehole problem and a structural dynamics problem, demonstrating the versatility of the method and its ability to discover low-dimensional manifolds with high accuracy with limited data. In addition, the method can learn surrogate models for different quantities of interest while reusing the same data set.

97 MATHEMATICS AND COMPUTING↗

The retailed gasoline price in China: Time-series analysis and future trend projection

This study introduces a method to systematically project retailed gasoline prices in China and provides projection results. Based on oil taxation and pricing mechanisms in China, this study establishes the statistical relationship between the retailed gasoline prices in China and international crude oil prices using error correction models (ECM), time-series models. Detailed comparison among asymmetric ECM, threshold ECM, and threshold asymmetric ECM are provided. By adopting the ECMs, the study projects the retailed gasoline prices from 2019 to 2050 based on the international crude oil prices from the Annual Energy Outlook provided by the U.S. Energy Information Administration. The results show that the asymmetric responsiveness and the threshold effect exist under current Chinese oil pricing policy with a lag of one month or even shorter in gasoline price adjustment. Moreover, the analysis informs one that, in the short-run, the retailed gasoline prices in China are more sensitive to international crude oil price increases; while in the long-run, the retailed gasoline prices are more sensitive to international crude oil price decreases. Compared with the national average gasoline price in China of 6.04 CNY/Liter in 2017, the national average gasoline price in China is projected to be about 7.64 CNY/Liter (2017 dollar) by 2050.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Application of emerging monitoring techniques at the Illinois Basin – Decatur Project

The Illinois Basin – Decatur Project is a large-scale carbon capture and storage demonstration project located in Decatur, Illinois, USA. In this project, one million metric tons of carbon dioxide (CO 2 ) was captured from an ethanol production facility and successfully injected into a deep saline reservoir over a period of three years. The scale of this project presented an opportunity to explore emerging technologies for effective long-term monitoring of the carbon capture and storage site. This research documents the application of three emerging monitoring techniques: (1) a prototype “open-path” sensor, a method of continuously monitoring atmospheric CO 2 by applying tunable diode laser absorption spectroscopy to provide a warning system for personnel safety along pipelines and at wellheads; (2) the Greenhouse Gas Laser Imaging Tomography Experiment (GreenLITE), an automated system for measuring two-dimensional spatial distribution of atmospheric CO 2 concentrations; and (3) periodic aerial imagery, a method of documenting surface-vegetation dynamics to detect vegetative responses to CO 2 leaks. The objective of this work was to assess the advantages and limitations of these monitoring techniques and quantify their reliability over an extended deployment at an active industrial site. These results will aid in determining viability of long-term monitoring on a commercial scale.

42 ENGINEERING↗

An Eulerian projection method for quasi-static elastoplasticity

A well-established numerical approach to solve the Navier-Stokes equations for incompressible fluids is Chorin's projection method, whereby the fluid velocity is explicitly updated, and then an elliptic problem for the pressure is solved, which is used to orthogonally project the velocity field to maintain the incompressibility constraint. In this paper, we develop a mathematical correspondence between Newtonian fluids in the incompressible limit and hypo-elastoplastic solids in the slow, quasi-static limit. Using this correspondence, we formulate a new fixed-grid, Eulerian numerical method for simulating quasi-static hypo-elastoplastic solids, whereby the stress is explicitly updated, and then an elliptic problem for the velocity is solved, which is used to orthogonally project the stress to maintain the quasi-staticity constraint. We develop a finite-difference implementation of the method and apply it to an elasto-viscoplastic model of a bulk metallic glass based on the shear transformation zone theory. We show that in a two-dimensional plane strain simple shear simulation, the method is in quantitative agreement with an explicit method. Like the fluid projection method, it is efficient and numerically robust, making it practical for a wide variety of applications. We also demonstrate that the method can be extended to simulate objects with evolving boundaries. Here, we highlight a number of correspondences between incompressible fluid mechanics and quasi-static elastoplasticity, creating possibilities for translating other numerical methods between the two classes of physical problems.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

A reduced-order model for nonlinear radiative transfer problems based on moment equations and POD-Petrov-Galerkin projection of the normalized Boltzmann transport equation

A data-driven projection-based reduced-order model (ROM) for nonlinear thermal radiative transfer (TRT) problems is presented. The TRT ROM is formulated by (i) a hierarchy of low-order quasidiffusion (aka variable Eddington factor) equations for moments of the radiation intensity and (ii) the normalized Boltzmann transport equation (BTE). The multilevel system of moment equations is derived by projection of the BTE onto a sequence of subspaces which represent elements of the phase space of the problem. Exact closure for the moment equations is provided by the Eddington tensor. A Petrov-Galerkin (PG) projection of the normalized BTE is formulated using a proper orthogonal decomposition (POD) basis representing the normalized radiation intensity over the whole phase space and time. The Eddington tensor linearly depends on the solution of the normalized BTE. By linear superposition of the POD basis functions, a low-rank expansion of the Eddington tensor is constructed with coefficients defined by the PG projected normalized BTE. The material energy balance (MEB) equation is coupled with the effective gray low-order equations which exist on the same dimensional scale as the MEB equation. The resulting TRT ROM is structure and asymptotic preserving. A detailed analysis of the ROM is performed on the classical Fleck-Cummings (F-C) TRT multigroup test problem in 2D geometry. Numerical results are presented to demonstrate the ROM's effectiveness in the simulation of radiation wave phenomena. Importantly, the ROM is shown to produce solutions with sufficiently high accuracy while using low-rank approximation of the normalized BTE solution. Essential physical characteristics of supersonic radiation wave are preserved in the ROM solutions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Foreword Special issue on the Kilopower Project, Kilowatt Reactor Using Stirling TechnologY (KRUSTY) Test

This special issue of Nuclear Technology contains full-length, peer-reviewed papers describing the design work leading up to and the results of the Kilowatt Reactor Using Stirling TechnologY (KRUSTY) test. KRUSTY was the centerpiece of the National Aeronautics and Space Administration (NASA) Kilopower Project to design, build, and test a space nuclear reactor. This test was the first such test since the end of the Space Nuclear Auxiliary Power (SNAP) project at the end of the 1960s. In this issue, the introduction paper presents the goals of the Kilopower Project and the potential missions this reactor concept could serve in NASA. Kilopower was intended to serve both human exploration needs on planetary surfaces as well as science needs for deep-space exploration. The design work for the experiment by Poston and the power conversion development by Gibson present the pre-work required to perform the eventual KRUSTY test. A paper on regulatory analysis follows, to show the path used to gain approval of the proposed experiment. Then, the early zero-power critical experiments are presented by Sanchez and Grove. These experiments were essential data used to enhance model predictions prior to the high-temperature test. Next, Poston presents the three experiments (warm criticals) that increase the temperature in an incremental fashion prior to the final experiment. These experiments were used to achieve final regulatory approval of the final high-temperature experiment. The last paper by Poston presents the results of the steady-state and transient testing of the reactor at full power and at the design temperature. These results show that the reactor design and as-built experiment met all of the requirements that NASA had developed for the system. Any experiment of this magnitude was accomplished only because of the hard work and dedication of a large number of people at multiple institutions, including the NASA Glenn Research Center, NASA Marshall Space Flight Center, Y-12 National Security Site, Los Alamos National Laboratory, and the Nevada National Security Site prime contractor (formerly National Security Technologies and now the Mission Support and Test Services). The project was jointly funded by the Space Technology Mission Directorate at NASA and the Criticality Safety Program at the National Nuclear Security Administration (NNSA). A special thanks to Jerry McKamy and Angela Chambers at the NNSA and Lee Mason and Don Palac at NASA for their support and guidance. For the authors and multitude of staff that performed this work, the passion for space nuclear reactors was the key to making this experiment a reality.

99 GENERAL AND MISCELLANEOUS↗

The implications of uncertain renewable resource potentials for global wind and solar electricity projections

Studies exploring long-term energy system transitions rely on resource cost-supply curves derived from estimates of renewable energy (RE) potentials to generate wind and solar power projections. However, estimates of RE potentials are characterized by large uncertainties stemming from methodological assumptions that vary across studies, including factors such as the suitability of land and the performance and configuration of technology. Based on a synthesis of modeling approaches and parameter values used in prior studies, we explore the implications of these uncertain assumptions for onshore wind and solar photovoltaic electricity generation projections globally using the Global Change Analysis Model. We show that variability in parametric assumptions related to land use (e.g. land suitability) are responsible for the most substantial uncertainty in both wind and solar generation projections. Additionally, assumptions about the average turbine installation density and turbine technology are responsible for substantial uncertainty in wind generation projections. Under scenarios that account for climate impacts on wind and solar energy, we find that these parametric uncertainties are far more significant than those emerging from differences in climate models and scenarios in a global assessment, but uncertainty surrounding climate impacts (across models and scenarios) have significant effects regionally, especially for wind. Our analysis suggests the need for studies focusing on long-term energy system transitions to account for this uncertainty.

14 SOLAR ENERGY↗

Field Quality Measurement of a 4.2-m-Long Prototype Low- $\beta$ Nb $_3$ Sn Quadrupole Magnet During the Assembly Stage for the High-Luminosity LHC Accelerator Upgrade Project

The U.S. High-Luminosity LHC Accelerator Upgrade Project, in collaboration with CERN, is developing Nb 3 Sn quadrupole magnets (MQXFA) to be installed at the interaction region of the LHC. The project will deliver 20 MQXFA magnets in 10 cold masses. These magnets need to meet the stringent requirements on field quality at the nominal operating current. Compared to the mature NbTi accelerator magnet technology, achieving excellent field quality can be challenging for Nb 3 Sn magnets. To help track, understand, and allow effective correction of geometric field errors, field quality measurements at room temperature during the MQXFA assembly stage was planned for the project. The measurements also intend to evaluate the magnetic axis and twist angle along the magnet aperture. We report the first measurement on a prototype MQXFA magnet using a recently developed measurement system. The magnetic axis and twist angle met the acceptance criteria. Further development needs for the room-temperature measurements were discussed. Here, we expect that statistics obtained from such measurements throughout the project will provide insight into future applications of high-performance Nb 3 Sn accelerator magnets.

43 PARTICLE ACCELERATORS↗