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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Development and evaluation of the conceptual design for a liquid radiological waste system in an advanced hybrid control room

As the current fleet of nuclear power plants are maintaining outdated or obsolete equipment it is common practice to replace worn-out equipment on an as-needed basis resulting in a series of like-for-like replacements of components on the control boards addressing an immediate need to replace equipment. Such upgrades rarely represent an encompassing or systematic vision for control room modernization and do not add the additional benefit of enhanced support for operators in the control room, which tend to overlook the opportunity to reduce operations and maintenance costs through enhanced efficiency. The purpose of the research is to provide guidance on how to realize these opportunities by designing control room human-system interfaces with advanced capabilities in mind. Further, the research seeks to ensure that control room modernizations are undertaken with a sound understanding of the impacts to human operators and are designed based on state-of-the art human factors principles. This report describes the conceptual design of the liquid radiological waste system and several research activities conducted to inform the design philosophy. The report also provides recommended updates to the original design philosophy (published by the researchers in 2018) based on the findings.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2018

RISA Industry Use Case Analysis

This report provides a status of development of utility RISA Use Case applications for which potential sponsoring utility partners have been identified. These applications were developed with utility participation during meetings held at Idaho National Laboratory (INL) on 15 May 2018. Each of these Use Case applications meets the needs of both plant owner / operators and the objectives of the LWRS Program. These applications also meet the needs of the host utilities and the overall industry in that they can be accomplished within a timeframe that can provide economic value to both the sponsoring host utility and the current operating fleet. In particular, the methods and tools that will be developed during these Use Case applications are be designed with the intent that they can be in place and supporting near term resolution of the issue (i.e. within the next 5 years) across the industry.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2018

Alternate Design Concepts for the High Flux Isotope Reactor using Low-Enriched Uranium Fuel Systems: Scoping Analysis

The Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) is a multi-mission research reactor dedicated mainly to isotope production, neutron scattering experiments, material irradiation, testing and activation. In the framework of non-proliferation policies, the international community is currently aiming to reduce or even eliminate, when and where possible, the use of Highly Enriched Uranium (HEU: 235 U/U ≥ 20 wt. %) in civilian applications. In that context, most research reactors worldwide still operating with HEU fuel are actively engaged in an effort to convert to Low Enriched Uranium fuel system (LEU: 235 U/U < 20 wt. %). Within the US, the High Performance Research Reactor (USHPRR) fleet (which includes HFIR) is expected to convert to LEU fuel using the UMo “monolithic” fuel system currently under development. ORNL is responsible for the development of a LEU design for HFIR. In the past years, Argonne National Laboratory (ANL) offered technical assistance to the ORNL LEU design team whenever deemed appropriate. Due to their complex nature, acceptable HFIR LEU designs identified so far, all based on the UMo monolithic fuel system, would require a substantial fabrication development effort before being proven commercially viable. In order to mitigate technical risks and reduce cost/schedule uncertainties, it appears appropriate to study alternate design solutions and alternate fuel systems as possible backup options for the HFIR conversion to LEU fuel. In that context, ANL has been exploring alternate design concepts for HFIR. Complementing the ORNL design activities, the goal is to find the best design solution for HFIR in term of cost, performance and safety. The present report summarizes the findings regarding two types of alternate conceptual design: U 3 Si 2 designs and un-contoured UMo design. Based on available tools and methods, preliminary analysis show that both concepts could probably meet performance and steady-state safety requirements but element fabrication would remain complex and would require a non-trivial fabrication development effort.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

Hydropower Vision A New Chapter for America's 1st Renewable Electricity Source

The U.S. Department of Energy’s (DOE’s) Wind and Water Power Technologies Office has led a first-of-its- kind comprehensive analysis to evaluate future pathways for low-carbon, renewable hydropower (hydropower generation and pumped storage) in the United States, focused on continued technical evolution, increased energy market value, and environmental sustainability. Undertaken through a broad-based collaborative effort, the Hydropower Vision initiative had four principal objectives: characterize the current state of hydropower in the United States, including trends, opportunities, and challenges; identify ways for hydropower to maintain and expand its contributions to the electricity and water management needs of the nation from the present through 2030 and 2050; examine critical environmental and social factors to assess how existing hydropower operations and potential new projects can minimize adverse effects, reduce carbon emissions from electricity generation, and contribute to stewardship of waterways and watersheds; and develop a roadmap identifying stakeholder actions that could support responsible ongoing operations and potential expansion of hydropower facilities. The Hydropower Vision analysis finds that U.S. hydropower could grow from 101 gigawatts (GW) of capacity to nearly 150 GW by 2050. Growth under this modeled scenario would result from a combination of 13 GW of new hydropower generation capacity (upgrades to existing plants, adding power at existing dams and canals, and limited development of new stream-reaches), and 36 GW of new pumped storage capacity. If this level of growth is achieved, benefits such as a savings of $209 billion from avoided greenhouse gas (GHG) emissions could be realized, of which $185 billion would be attributable to operation of the existing hydropower fleet. Transformative technical innovations able to meet the co-objectives of environmental sustainability and low-carbon energy will be critical to enabling additional hydropower growth beyond these levels. The Hydropower Vision report specifically does not evaluate or recommend new policy actions but instead analyzes the feasibility and certain benefits and costs of various credible scenarios, all of which could inform policy decisions at the federal, state, tribal, and local levels.

13 HYDRO ENERGY↗
DOE OSTI2019

High Performance Gas Diffusion Layer (Phase I Final Report)

Hydrogen fuel cells are of interest for automotive applications because they produce zero emissions. However, fuel cells currently suffer from the high cost associated with the fuel cell stack. Power is limited by water management in the cathode. In this project, pH Matter, LLC synthesized and demonstrated the performance of next generation fuel cell Gas Diffusion Layers (GDLs). The materials out-performed current GDLs in terms of power density and cost per power. The materials were shown to meet the application requirements for key properties. At the commercial scale, these materials will be less expensive than GDLs currently used in hydrogen fuel cells, and enable higher power density, thus reducing fuel cell stack costs. Fuel cell system applications that will benefit most from the technology include automotive, materials handling (i.e. forklifts), fleet vehicles, and stationary back-up power.

25 ENERGY STORAGE↗
DOE OSTI2019

Reduced Mode Sapphire Optical Fiber and Sensing System

This is the final technical report for the Virginia Tech Center for Photonics Technology (VT-CPT) research project entitled “Reduced Mode Sapphire Optical Fiber and Sensing System”. The objective of the five-year effort was to develop a low modal volume (LMV) single crystal sapphire fiber and demonstrate its advantages in current state-of-the-art sapphire-based temperature sensors and in novel distributed ultra-high temperature sensing systems. The project, sponsored by the Crosscutting Research Program, began in 2014 and had the original goal of developing the next generation of harsh environment sensing systems. After successfully completing the original scope of the award, the project was expanded and extended to allow for the development of harsh environment packaging and testing of a prototype sensor system. These novel fiber optic sensing technologies provide real-time, accurate, and reliable temperature measurements at distributed locations in existing coal-fueled electricity generating units to improve the overall performance, reliability, and flexibility of the nation’s coal-fired power plant fleet. In the final year (2018) of the project, prototype sensing systems were successfully deployed and operated in small commercial coal and natural gas fired boilers at the Virginia Tech Power Plant. The harsh environment quasi-distributed temperature sensing technology was advanced from a (Technology Readiness Level) TRL=1 to a TRL=7 by demonstrating the full validation of the sensing system prototype in a relevant industrial environment. The real-time, accurate and reliable monitoring of temperatures at distributed locations is expected to lower operating costs by allowing more accurate measurement of the harsh conditions inside a boiler system to better control its operation. The technologies developed by Virginia Tech’s Center for Photonics Technology will support the mission of the National Energy Technology Laboratory (NETL) to advance energy options to fuel our economy, strengthen our security, and improve the environment.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2018

A Review of PJM Interconnection's April 13, 2018, Response to National Energy Technology Laboratory's Report on Reliability, Resilience and the Oncoming Wave of Retiring Baseload Units

In a March 2018 report entitled Reliability, Resilience and the Oncoming Wave of Retiring Baseload Units , the National Energy Technology Laboratory (NETL) analyzed the fleet performance of market areas impacted by a 13-day storm known colloquially as the “Bomb Cyclone.” Special attention was paid to northeastern areas, as these were most impacted. With respect to PJM Interconnection LLC (PJM), the report found that 1) without coal units, the system would have experienced shortfalls; 2) approximately 25 gigawatts (GW) of heretofore underutilized coal-fired plants provided crucial capacity, lending the system resilience; 3) nearly 28 GW of natural gas-fired capacity did not deploy, due to severe spikes in natural gas prices caused in turn by constrained gas deliverability, in the face of tremendous space heating demand and transmission deliverability constraints on the bulk electric system. In April 2018, PJM issued a response that argued the NETL analysis was misplaced, asserting that gas-fired capacity was available and that it could have been called into service but was not, due to “economics.” This brief represents NETL’s reaction to PJM’s assertions in its April 2018 response.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2019

Transportation Planning for Irradiated Fuel-Cladding and Integral FeCrAl Experiments

Building the material database for accident tolerant fuel concepts requires movement of experiments to ORNL from other national laboratories, commercial reactors, and international collaborators. This report summarizes the current fleet of available and proposed casks for handling small scale fuel shipments and the immediate challenges to be addressed in order to perform shipments in support of accident tolerant fuels development under the Advanced Fuels Campaign. Shipping recommendations and a description of unresolved issues associated with the shipment are provided for three experiments: ATF-1 LOCA (ATF-18), the Halden irradiated Instrumented Fuel Assembly (IFA) 796 experiment, and the Hatch lead test rods. Each of these experiments represents an important step in continuing the accelerated testing of FeCrAl cladding for commercial applications.

10 SYNTHETIC FUELS↗
DOE OSTI2019

Metals Analysis of Biodiesel Blends

The goal of this study was to compare metals analysis methods for biodiesel blends. Thirty-five B20 samples were collected from public stations and private fleets throughout the United States. All samples were analyzed for blend content and critical properties under the ASTM D7467 specification. Although not part of the specification, metals content, specifically Na, K, Ca, Mg, and P, is becoming an increasingly larger concern for industry. This study compared the metals content of the B20 samples using inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), and microwave plasma atomic emission spectroscopy (MP-AES) methods. All three techniques showed improvements over the current detection limits of 1 ppm for Na, K, Ca, and Mg, and 5 ppm for P. Some differences were found between methods, but agreement was generally acceptable at the very low levels present in these samples. The MP-AES technique showed good promise for future development for this type of analysis.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2019

Materials and Fuels Complex FY19 - FY23 Five-Year Investment Strategy

The Department of Energy Office of Nuclear Energy (DOE-NE) mission is to provide the research, development, and demonstration foundation to extend the lives of the current operating reactor fleet, develop the next generation of nuclear reactors, and provide integrated nuclear fuel cycle solutions. The Materials and Fuels Complex (MFC) serves as the foundation of a nuclear research, development, and demonstration (RD&D) enabling test bed at Idaho National Laboratory (INL) and is an integral part of a National Reactor Innovation Center strategy. MFC facilities focus on developing and maintaining RD&D capabilities that can increase research throughput, reduce barriers to deployment, and facilitate commercialization of new ideas and technologies for clean and secure sources of energy.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2019

Foothill Transit Agency Battery Electric Bus Progress Report, Data Period Focus: Jul. 2018 through Dec. 2018

This report summarizes results of a battery electric bus (BEB) evaluation at Foothill Transit, located in the San Gabriel Valley area of Los Angeles. Foothill Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) to evaluate the buses in revenue service. The focus of this evaluation is to compare the performance and the operating costs of the BEBs to that of conventional technology buses and to track progress over time. Previous reports documented results from April 2014 through June 2018. This report extends the data analysis through the end of 2018. The data period focus of this report is July 2018-December 2018. NREL plans to publish progress reports on the Foothill Transit fleet every 6 months through 2020.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2016

Mission Analysis for using Preventive Rad/Nuc Detection Equipment for Consequence Management

The overall objective of this project is to research, evaluate, and test first responder preventive radiological/nuclear detection equipment (PRND) to provide state and local agencies with guidance on how to best use radiological search and interdiction systems and equipment for consequence management and response after a radiological/nuclear release or detonation. While the equipment being tested in this effort has been specifically designed by technology manufacturers and purchased by responders for preventive detection and source interdiction operations, the fleet of PRND equipment will help fill the needs for radiological instrumentation should a consequence management response take place, as it is currently the most widely available and fielded radiological instrumentation by state and local agencies. This effort will provide scientific guidance on the best way to deploy and operate this class of equipment for consequence management missions. Gaining a better understanding of how PRND equipment can operate and perform for these missions will allow for recommendations on the tactical approach responders can use for consequence management operations. With the support of the US Department of Homeland Security’s (DHS) Domestic Nuclear Detection Office (DNDO), PRND equipment has been placed into service at federal, state, and local agencies throughout the nation. If the equipment capability and limitations are taken into account, this large inventory and capability can be repurposed to support the emergency response in the aftermath of a radiological of nuclear event.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2019

Grid Ready, Flexible Large Power Transformer

GE Research and its partner Prolec GE have proposed a novel and breakthrough concept to improve the flexibility and interchangeability of large power transformers (LPTs). LPTs refer in this report to transformers with a power rating equal or greater than 100 MVA. The concept consists of a 3-phase autotransformer bank having one specified high voltage side (HV) voltage and three configurable low voltage side (LV) voltage taps. Moreover, the leakage impedance is adjustable offline using taps which allows to accommodate short-circuit requirements for a wide range of LPTs applications. The research performed aimed to develop and validate a cost-effective design of a flexible LPT and to demonstrate its competitiveness with the LPT fleet currently in operation in the U.S. The concept is intended for the long-term replacement of existing LPTs. In this project, the U.S based population of LPTs was analyzed to determine their commonality in power, voltage classes, and impedance range. Up to 9,700 units, currently deployed in the NERC’s Eastern and Western interconnection regions, were evaluated. This analysis yielded the specifications of two flexible LPTs to be designed to demonstrate the manufacturability and competitiveness of the concept: a 345 kV, 230 MVA and a 230 kV, 100 MVA LPTs. The two LPTs are both configurable to 161 kV, 138 kV, and 115 kV on the LV side and allow leakage impedance variation between 4% and 14%. The design output showed that the flexible LPT is manufacturable and competitive with conventional LPT. The proposed design has a power efficiency of 99.5% and a total active part weight increase ranging only between 15% and 28% relative to conventional LPTs it can be substituted with. Indeed, for the flexible LPT, the higher the LV side voltage is, the higher is its power rating. Hence, flexible LPTs are more competitive when compared with the largest conventional LPT they can replace. Power systems analyses were carried out to evaluate the performance of the flexible LPT when replacing an existing conventional LPT. These analyses showed that short-circuit and inrush currents will remain respectively within 15% and 9.4% of their original levels suggesting that no substations equipment is likely to be replaced due the installation of the flexible LPT. In addition, the analyses showed that the transient overvoltage anticipated at the impedance configuration switch will be manageable and will not pose any particular risk during lightning or switching events. This research proved that the deployment of flexible LPTs in the U.S power grid can greatly improve the grid reliability and its resiliency especially in the event of the loss of multiple LPTs. Moreover, the concept can significantly help reduce LPTs’ spare inventory by providing a high spare coverage level. The performed analysis showed that the designed 345 kV flexible LPT can serve as a spare for up to 34 units currently in operation in the U.S while the designed 230 kV flexible LPT can replace up to 101 units. Flexible LPTs offer new opportunities to U.S utilities to improve interchangeability of LPTs in the transmission system and to better strategize the upcoming renewal of about 70% of the population of LPTs anticipated to retire within the next two decades.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2019

Zero Emission Delivery Vehicle Demonstration Project (Final Technical Report)

The purpose of the project was to demonstrate thirty (30) fully developed, operational, advanced vehicle technology prototypes for on-road delivery applications within the Houston-Galveston-Brazoria Nonattainment Region. After some initial project delays related to difficulties related to financial difficulties from the initial manufacturing partners, the project began to move forward in late 2014 using a fleet-first approach. Ultimately, this project was able to deploy 18 trucks within the Houston region. These vehicles were developed and manufactured by Workhorse and purchased by United Parcel Service (UPS) according to UPS specifications and to be operated out of three different facilities located in the Houston region. Following final delivery of these vehicles during the summer of 2016, the demonstration period began in earnest in December 2016 and continued until the end of November 2018. Once deployed and operating in regular delivery service, the 18 battery electric delivery trucks encountered challenges typical to any new vehicle deployment. In addition to the expected difficulties related to any new vehicle deployments, there were unexpected persistent and ongoing performance issues related to the all-electric technology integrated into the vehicles. This caused significant downtime for many of the project vehicles and lower than anticipated utilization rates over the entire two-year demonstration period.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2013

Conventional Generation Asset Management with Renewable Portfolio Standards Using Real Options

The transition to a more renewable generation mix under a competitive electricity market will require individual power producers to use sophisticated tools to value conventional generators. Owners will need to understand what market prices signal new investments, temporarily suspending operation, reactivating mothballed generators or permanently abandoning a plant. Net present valuation from a traditional discounted cash flow analysis is limited in capturing the value of generation technologies, and it does not provide an optimal investment criterion. We present and evaluate a closed-form decision support framework using a Spark Spread Real Options approach to value generation assets and to capture optimal market price signals that minimizes financial risks of individual power producers under a transition towards a more renewable energy fleet. We evaluate the Spark Spread options valuation for capital budgeting without capacity payments. As an example, for a fixed heat rate of 10,000 Btu/kWh and a combined electricity and fuel price annual volatility1 of 58%, the Spark Spread option valuation gives a positive value for a unit of installed generating capacity at electricity prices below $\$$40/MWh. Given the same conditions, a traditional net present value (NPV) cash flow has no value for a unit of installed capacity for electricity prices below $\$$40/MWh. Accounting for the inevitable volatility in electricity and fuel prices can allow firms to see more value in fossil plants than does the traditional approach.

17 WIND ENERGY↗
DOE OSTI2019

Methods to Automate Assessing the Outage Risk and Technical Specification Compliance for Planned Work and Current Plant Conditions. Light Water Reactor Sustainability Program report

This research effort is a part of the Light Water Reactor Sustainability (LWRS) Program, which is a research and development (R&D) program sponsored by the Department of Energy. The LWRS Program is performed in close collaboration with industry R&D programs that provide the technical foundations for licensing and managing the long term, safe, and economical operation of current nuclear power plants (NPPs). The LWRS Program serves to help the United States (U.S.) nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of these NPPs and the extension of their current operating licenses. The Outage Risk Management Improvement Pilot Project seeks to improve the management of nuclear power plant outages. This is done through the development of tools to assist in evaluating pending activities against requirements to detect undesired interactions. Significant efforts are expended to manage the nuclear risk of an outage. The utilities conduct pre outage risk assessments, based on a very detailed review of the outage schedule, to identify where combinations of outage work and out of service equipment would result in degraded conditions with respect to nuclear safety or regulatory compliance. Probabilistic risk assessment studies are conducted to quantify incremental core damage frequency as a result of the outage activities and system unavailability. These studies are usually presented to site and fleet management, the site plant operational review committee, and the NPP’s independent Nuclear Safety Review Board for concurrence that the outage is planned safely and that reasonable measures have been taken to reduce the added risk of conducting the outage. During the outage, the plant configuration is monitored continuously to ensure that it conforms to the approved safety plan. Deviations must be assessed and approved by management committees and, in some cases, the plant operational review committee. In virtually all outage meetings and job briefings, the current nuclear safety status of the plant is communicated, including information on the specific equipment necessary to meet the requirements of the nuclear safety plan. In addition, the operations and outage organizations implement several layers of physical and administrative barriers to prevent unintended interaction with the systems and equipment credited for nuclear safety. In spite of all these efforts, nuclear safety challenges still occur too frequently during outages. While some of these are due to failures of equipment credited for safety, the majority occur because of human error. These typically involve some form of interaction between work activities and plant configuration changes. Some of them are very subtle and are extremely challenging to detect in advance. Nevertheless, they are not acceptable and represent clear opportunities to improve nuclear safety during outages. This particular report will provide a demonstration of the capabilities in the development of a predictive software platform for improving configuration control and accessing the plant risks associated with outage work protocols and illustrate how the software assists in strategies to minimize these interactions. In addition to maintaining nuclear safety, there are numerous administrative requirements that must be complied with during an outage. This report will discuss the use of logic modelling to monitor planned work against technical specification requirements for given plant conditions and to integrate these requirements with shutdown risk models, clearance order requirements and other plant condition requirements.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2019

U.S. Efforts in Support of Examinations at Fukushima Daiichi: 2019 Evaluations

Much is still not known about the end-state of core materials in each unit that was operating on March 11, 2011 at the Fukushima Daiichi Nuclear Power Station (Daiichi). Information obtained from Daiichi is required to inform Decontamination and Decommissioning (D&D) activities, improving the ability of the Tokyo Electric Power Company Holdings, Incorporated (TEPCO Holdings) to characterize potential hazards and to ensure the safety of workers involved with cleanup activities. This document, which has been updated to include Fiscal Year 2019 (FY2019) information, summarizes results from a U.S. effort to review Daiichi information and extract insights to enhance the safety of existing and future nuclear power plant designs. This U.S. effort, which was initiated in 2014 by the Department of Energy Office of Nuclear Energy (DOE-NE), is completed by a group of experts in reactor safety and plant operations that identify examination needs and evaluate recent Daiichi examination data to address these needs. Each year, annual reports are issued that document significant safety insights being obtained in areas of special emphasis. For FY2019, the areas emphasized by the expert panel include component performance, radionuclide surveys and sampling, debris end-state location, combustible gas effects, and plant operations and maintenance. In addition to reducing uncertainties related to severe accident modeling progression, these insights have and continue to be used to update guidance for severe accident prevention, mitigation, and emergency planning. Reduced uncertainties in modeling the events at Daiichi improve the realism of reactor safety evaluations that inform future D&D activities. In addition, the process established by this U.S. effort provides an example that Japan may wish to implement in future international efforts to support D&D. As emphasized in this FY2019 report, important insights are being gained from examinations of the affected units at Daiichi. Although many results from prior years have been moved to appendices, key areas of interest are highlighted in the main document. For example, larger intact components and fuel containing materials observed on the floor of the primary containment and retained on ex-vessel structures continue to be emphasized because of insights that may be gained with respect to vessel failure and ex-vessel interactions with structures and concrete. In addition, the main report presents insights gained by focused evaluations of plant data because of potential use of systems and components during severe accident conditions and alternate perspectives regarding accident progression that may be inferred from such data. The report also illustrates how systems analysis codes can be applied to reduce uncertainties about the progression of events at Daiichi and how practical insights obtained from Daiichi can be used to enhance radiation safety for the existing fleet. Recent and planned updates to systems analysis codes are also discussed. As in prior years, this report contains an appendix with a list of examination needs that was updated after U.S. experts reviewed recently obtained information from Daiichi. Additional details for higher priority, near-term, examination activities are also provided. This report also includes an appendix with a description of a website that was developed to assist U.S. experts by providing information in an archived retrievable location.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2019

Development of a Corrosion Monitoring System for Advanced Molten Salt Reactors

Molten salt reactors (MSRs) have been identified as one of several possible next-generation advanced reactor designs that could replace the aging fleet. There are many inherent advantages to MSRs, including higher power density, lower pressure, low stored energy, and prompt negative temperature reactivity coefficient Ezell et al. [2018]. However, there are challenges related to the operating temperatures, as well as, the corrosive salts attacking the structural materials. During the Molten Salt Reactor Experiment (MSRE), which was operated at Oak Ridge National Laboratory (ORNL) (Ignatiev et al. [2014], Forsberg et al. [2007], Forsberg et al. [2008], Delpech et al. [2009], Serp et al. [2014], Ignatiev and Surenkov [2017]) corrosion was monitored by sampling the salt for chromium. However, this type of monitoring does not identify the location of corrosion. In FY18, ORNL developed a novel in-situ corrosion sensor that could be placed on the outside of the structure to monitor changes in magnetic susceptibility of salt-wetted alloys as corrosion occurs Holcomb et al. [2019]. Initial testing with this novel sensor demonstrated a correlation between the change in signal output from the sensor to the various levels of pre-corroded test specimens. However, all initial testing was performed at room temperatures, which is not realistic for the harsh MSR environment. Based on this research, FY19 funding allowed for development of a high-temperature version of the sensor to be installed at various locations on the reactor infrastructure. The high-temperature sensor can operate at up to 750°C and can monitor development of corrosion inside the pipe. This sensor measures the increase in magnetic susceptibility that occurs as chromium dissolves from the inner surface of the pipe, when paramagnetic structural alloys become ferromagnetic with the loss of chromium. This report will discuss the development of corrosion monitoring sensor and the testing with results of corroded specimens at increasing temperatures.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗