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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Laboratory Demonstration of Variable-Speed Packaged Air-Conditioning Units for Provision of Frequency Regulation Services

Buildings are responsible for more than 73% of the total electricity use in the United States and one-third of the building electricity use is attributed to heating, ventilation and air-conditioning (HVAC) systems. If properly used, buildings could offer significant frequency control reserves to the power grid. This paper presents laboratory test results demonstrating the potential to use variable-speed packaged rooftop units for frequency regulation services. The test unit along with the proposed feedback control represents an add-on solution that requires minimum control upgrades to enable the provision of ancillary services. Test results show that HVAC systems can provide high-quality frequency regulation services with performance scores of up to 0.95. A first-order economic analysis also reveals significant economic benefits for building owners to participate in ancillary services.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

Corrective Action Investigation Plan for Corrective Action Unit 541: Small Boy Nevada National Security Site and Nevada Test and Training Range, Nevada with ROTC 1

Corrective Action Unit (CAU) 541 is co-located on the boundary of Area 5 of the Nevada National Security Site and Range 65C of the Nevada Test and Training Range, approximately 65 miles northwest of Las Vegas, Nevada. CAU 541 is a grouping of sites where there has been a suspected release of contamination associated with nuclear testing. This document describes the planned investigation of CAU 541, which comprises the following corrective action sites (CASs): 05-23-04, Atmospheric Tests (6) - BFa Site; 05-45-03, Atmospheric Test Site - Small Boy. These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of viable CAAs that will be presented in the investigation report. The sites will be investigated based on the data quality objectives (DQOs) developed on April 1, 2014, by representatives of the Nevada Division of Environmental Protection; U.S. Air Force; and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office. The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 541. The site investigation process also will be conducted in accordance with the Soils Activity Quality Assurance Plan, which establishes requirements, technical planning, and general quality practices to be applied to this activity. The potential contamination sources associated with CASs 05-23-04 and 05-45-03 are from nuclear testing activities conducted at the Atmospheric Tests (6) - BFa Site and Atmospheric Test Site - Small Boy sites. The presence and nature of contamination at CAU 541 will be evaluated based on information collected from field investigations. Radiological contamination will be evaluated based on a comparison of the total effective dose at sample locations to the dose-based final action level. The total effective dose will be calculated as the total of separate estimates of internal and external dose. Results from the analysis of soil samples will be used to calculate internal radiological dose. Thermoluminescent dosimeters placed at the center of each sample location will be used to measure external radiological dose. Appendix A provides a detailed discussion of the DQO methodology and the DQOs specific to each CAS.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Pilot Scale Operation and Testing of Syngas Chemical Looping For Hydrogen Production

The Syngas Chemical looping (SCL) process provides efficient and economic means to utilize the abundant fossil reserve of coal. The main problem associated with coal utilization is the CO 2 emissions resulting from its combustion. Even though CO 2 regulation or carbon tax is currently not in place, its enforcement is expected in the near future. Such a greenhouse gas emission control, if adopted in current power plant systems, will drive the efficiency down and increase the cost of electricity, due to the energy and capital-intensive nature of current CO 2 separation techniques. This highlights the need to develop technologies that present a solution to the rising cost of electricity in the future. The integrated gasification combined cycle (IGCC) presents an improvement to the above predicament, but it is capital intensive due to the extensive unit operations involved. The efficiency for a CO 2 capture incorporated IGCC system is around ~32%, resulting in approximately 45% increase in cost of electricity. This is definitely a better path to traverse than the conventional pulverized coal (PC) power plants as it has improved economics and efficiencies accompanied by product flexibility. The SCL process advances the benefits even further when integrated with the IGCC process. The SCL process removes the expensive WGS system and CO 2 separation columns, thereby saving on capital and operational expenses. This integration results in a 12 – 21% increase in efficiency accompanied by a reduction in cost of electricity by 15 – 28%, over conventional IGCC systems. Therefore, SCL process provides the best route to harness the energy from coal. The overall project objective was to construct and operate a syngas chemical looping pilot scale test unit at the NCCC. The project scope of work was divided into 3 phases. In Phase I, cold flow model studies using a 1:1 scale acrylic test unit constructed at Particulate Solids Research, Inc. (PSRI) was successfully completed confirming robust solid flow control is achievable in the non-mechanical system design. In Phase II, the high pressure, high temperature, chemical looping reactor was successfully designed with all necessary equipment and safety instrumentation/controls specified to allow for fabrication, site construction, and assembly to commence in Phase III. In Phase III, the SCL pilot plant was successfully assembled and all necessary functional checks and pre-startup safety reviews completed. During unit commission over the course of 200 hours of testing, operational issues were observed with premix burner used for system startup. With the grants awarded by the National Energy Laboratory (NETL) and the Ohio Development Services Agency (ODSA) under awards DE-FE0023915 and D-14-18, the SCL pilot unit underwent three auxiliary equipment modifications to resolve all of the startup operational issues encountered. The unit was successfully demonstrated with 300+hr continuous operation. Key results obtained include high syngas conversion of 97.95% with 16.03% oxygen carrier conversion in the moving bed reducer and >99% purity H 2 produced from the moving bed oxidizer.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2025

Investigation of the Performance and Explainability Tradeoffs for Machine-Learning Models for Predictive Maintenance of Circulating Water Systems in Nuclear Power Plants

Predictive maintenance (PdM) has shown great potential for achieving substantial cost savings and enhancing the economic competitiveness of nuclear power plants (NPPs) in today's energy market. Among the different modeling approaches that exist, machine learning (ML) tools in particular have a demonstrated ability to handle high dimensional and multivariate data and to extract hidden relationships within data in industrial environments. While ML methods show great potential, their lack of explainability---especially for black-box models---is a major hurdle to their adoption. Moreover, considering the supposed trade-off between explainability and performance challenges, careful consideration must be made as to which of these quality aspects takes precedence in light of multiple modeling options, resource availability, and domain characteristics. The present work evaluates the performance of six ML models, each with a different degree of explainability, in classifying the conditions of circulating water pumps (CWPs) by utilizing sensor data from nuclear power plants. To determine the drivers behind the trade-offs presented by this array of models, this work also tests different combinations of CWP units as the training and testing data, degrees of data imbalance, and objective functions for hyperparameter tuning. It was found that black-box models tend to afford superior performance in cases where there are far more instances of one type of labeled data than of any other type. It is recommended that a guided procedure be followed for designing and delivering an ML system that is sufficiently explainable to all involved stakeholders.

22 - GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2026

Data Management for Digital Twin Implementation: Enhancing Existing SCADA Architecture for INL's CITRC Test Distribution System

The United States power grid will continue to experience stress from aging infrastructure, extreme weather, and increasing loads. In order to strengthen resiliency, researchers need to run tests and simulations that model real-life infrastructure. Idaho National Laboratory (INL) is creating a digital twin of its Critical Infrastructure Test Range Complex (CITRC). CITRC is an at-scale grid testbed which can be configured in utility-realistic distribution scenarios for a variety of tests, such as advanced grid protection and control. A digital twin of this infrastructure would support in-depth tests/simulations without risking physical consequences, before trialing devices under test at-scale. This project focuses on the data acquisition part of constructing a digital twin. It investigates the Supervisory Data Acquisition and Control (SCADA) system of CITRC and explores ways to utilize this system for the twin. Future “ideal” at-scale implementations such as upgraded equipment, modern communication protocols, and automation applications are also explored.

24 - POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2016

Closure Report for Corrective Action Unit 412: Clean Slate I Plutonium Dispersion (TTR) Tonopah Test Range, Nevada, Revision 0

This Closure Report (CR) presents information supporting the clean closure of Corrective Action Unit (CAU) 412: Clean Slate I Plutonium Dispersion (TTR), located on the Tonopah Test Range, Nevada. CAU 412 consists of a release of radionuclides to the surrounding soil from a storage–transportation test conducted on May 25, 1963. Corrective action investigation (CAI) activities were performed in April and May 2015, as set forth in the Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 412: Clean Slate I Plutonium Dispersion (TTR), Tonopah Test Range, Nevada; and in accordance with the Soils Activity Quality Assurance Plan. The purpose of the CAI was to fulfill data needs as defined during the data quality objectives process. The CAU 412 dataset of investigation results was evaluated based on a data quality assessment. This assessment demonstrated the dataset is complete and acceptable for use in fulfilling the data needs identified by the data quality objectives process. This CR provides documentation and justification for the clean closure of CAU 412 under the FFACO without further corrective action. This justification is based on historical knowledge of the site, previous site investigations, implementation of the 1997 interim corrective action, and the results of the CAI. The corrective action of clean closure was confirmed as appropriate for closure of CAU 412 based on achievement of the following closure objectives: Radiological contamination at the site is less than the final action level using the ground troops exposure scenario (i.e., the radiological dose is less than the final action level): Removable alpha contamination is less than the high contamination area criterion: No potential source material is present at the site, and any impacted soil associated with potential source material has been removed so that remaining soil contains contaminants at concentrations less than the final action levels: and There is sufficient information to characterize investigation and remediation waste for disposal.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

SOFC Systems with Improved Reliability and Endurance

The overall goal of this U.S. Department of Energy (DOE) sponsored project was the development of Solid Oxide Fuel Cell (SOFC) technology suitable for ultra-efficient central power generation systems utilizing coal and natural gas fuels and featuring greater than 90% carbon dioxide capture. The specific technical objective of this project was to demonstrate, via analyses and testing, progress towards adequate stack life (≥ 4 years) and stack performance stability (degradation rate ≤ 0.2% per 1000 hours) in a low-cost SOFC stack design. This final technical report summarizes the progress made during the project period of 27 months. Significant progress was made in the areas of cell and stack technology development, stack module development, sub-scale module tests, and Proof-of-Concept Module unit design, fabrication and testing. The work focused on cell and stack materials and designs, balance-of-plant improvements, and performance evaluation covering operating conditions and fuel compositions anticipated for commercially-deployed systems. In support of performance evaluation under commercial conditions, this work included the design, fabrication, siting, commissioning, and operation of a ≥ 50 kWe proof-of-concept module (PCM) power plant, based upon SOFC cell and stack technology developed to date by FuelCell Energy, Inc. (FCE) under the Office of Fossil Energy’s Solid Oxide Fuel Cells program. The PCM system was operated for at least 1000 hours on natural gas fuel at FCE’s facility. The factory cost of the SOFC stack was estimated to be at or below the DOE’s high-volume production cost target (2011 $).

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2017

Advanced, Energy-Efficient Hybrid Membrane System for Industrial Water Reuse

In the U.S. manufacturing sector, current industrial water use practices are energy-intensive and utilize and discharge high volumes of waters, rendering them not sustainable especially in light of the growing scarcity of suitable water supplies. To help address this problem, the goal of this project was to develop an advanced, cost-effective, hybrid membrane-based water treatment system that can improve the energy efficiency of industrial wastewater treatment while allowing at least 50% water reuse efficiency. This hybrid process would combine emerging Forward Osmosis (FO) and Membrane Distillation (MD) technology components into an integrated FO-MD system that can beneficially utilize low-grade waste heat (i.e., T < 450 °F) in industrial facilities to produce distilled-quality product water for reuse. In this project, laboratory-, bench-, and pilot-scale experiments on the hybrid FO-MD system were conducted for industrial wastewater treatment. It was demonstrated at laboratory, bench, and pilot scales that FO-MD membrane technology can concentrate brine to very high total dissolved solids (TDS) levels (>200,000 ppm) that are at least 2.5 times higher than the TDS level to which RO can achieve. In laboratory testing, currently available FO and MD membranes were tested to select for high-performing membranes with high salt rejection and high water flux. Multiple FO membrane/draw-salt solution combinations that gave high water flux with higher than 98% salt rejection were also identified. Reverse draw-salt fluxes were observed to be much lower for divalent salts than for monovalent salts. MD membranes were identified that had 99.9+% salt rejection and water flux as high as 50-90 L/(m 2 ·h) for flat-sheet membranes and >20 L/(m 2 ·h) for hollow fibers. In bench-scale testing, a single unit of commercially available FO and MD membrane modules were evaluated for continuous, integrated operation. Using the laboratory- and bench-scale test data, numerical modeling was performed on the FO and MD processes to estimate engineering parameters for a larger-scale pilot unit. Based on the experimental studies and modeling results, a pilot-scale, integrated FO-MD prototype unit was designed and built for trailer-mounted operation. This prototype system was fed real industrial wastewater, which could not be further treated by conventional technologies, from an oil production facility and was successfully operated for over 15 weeks without major stoppage. About 90% water recovery was possible, while concentrating the TDS from 12,000 ppm up to 190,500 ppm. The FO-MD prototype rejected most wastewater contaminants while producing water with <300 ppm TDS, even when the feed TDS was higher than 150,000 ppm. No chemical cleaning was necessary during the pilot testing period. Flushing the system with dechlorinated tap water was sufficient to reset the membranes for the next set of test conditions. Pilot performance and membrane autopsy showed that, even though the feed was concentrated more than 10 times, membrane fouling was unnoticeable and no defects were detected on the FO and MD membrane surfaces. This project demonstrated the technical feasibility of the hybrid FO-MD process by taking water already treated to the limit with the highest level of current technologies and further concentrating it 10-fold by using mostly low-cost materials. Because no membranes suitable for full-scale plant applications are available at present, economical feasibility of the hybrid technology is still uncertain, but it is expected that broader industry participation can further reduce FO-MD process costs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2017

Biomass Energy Generation Project

The Municipal Electric Utility of the City of Cedar Falls (dba Cedar Fals Utilities or CFU) received a congressionally directed grant funded through DOE-EERE to run three short (4 hour) duration test burns and one long (10 days) duration test burn to test the viability of renewable fuels in Streeter Station Boiler #6, a stoker coal fired electric generation unit. The long test burn was intended to test supply chain assumptions, optimize boiler combustion and assess the effects of a longer duration burn of biomass on the boiler.

09 BIOMASS FUELS↗
DOE OSTI2019

Managing Risks via Small/Pilot Scale Testing for INL's Integrated Waste Treatment Unit (IWTU) - 19268

In 2005, the THOR steam reforming fluidized-bed reactor (FBR) technology was selected by the U.S. Department of Energy (DOE) as the technology of choice for treatment of sodium- bearing waste (SBW) at the INL. The basis of the process was to use fluidized bed technology to convert an acidic radioactive nitrate-rich liquid waste into a solid carbonate product suitable for long-term disposal and storage. During initial commissioning, as well as subsequent start-ups, the plant faced many operational challenges, such as stagnant/de-fluidized bed, and wall-scale formation. Such operational issues prompted the original contractor to seek expertise in pilot-scale testing, thereby reaching out to Hazen Research Inc. (HRI, Golden, Co). Several tests were conducted, but the results did not seem to address the underlying issues observed in the full-scale plant, as evidenced by continued operational issues. A systematic approach was then taken by the Fluor-Idaho team (new contractor as of June 2016) with respect to solving these technical issues. First, two different bench-scale, 2-inch fluidized bed reactors (stainless-steal and quartz), were utilized to test several theories to better understand the underlying chemical reactions that may be taking place under expected normal operating conditions. Then, the team designed and built an 18-inch FBR unit, mimicking the full-scale main vessel at IWTU - Denitration Mineralization Reformer (DMR). This was used to test various aspects of operational challenges observed at IWTU, namely particle size control, wall-scale growth-rate control, long-term operational stability, process optimization, and process off- gas filtration challenges. An example of information obtained from bench-scale testing, which was then tested during pilot-scale testing, was the phenomena that an addition of 5 vol % of CO{sub 2} gas into the fluidizing gas system nearly eliminated the formation of agglomerates that had typically led to bed de-fluidization. This change proved to be correct in both the pilot and full-scale testing and will be implemented as part of a long-term operational strategy of IWTU. Several other findings that have provided answers with respect to IWTU operational issues will be discussed in this report. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Development of a Wide Range Segmented Gamma Scanner for Measuring Radioactive Wastes Arising in the Chinese Nuclear Industry - 16261

There is a requirement to measure a variety of challenging radioactive waste forms generated by the Chinese nuclear industry. These range from low activity waste to high activity waste with a high content of Cs-137 and waste in high density 200 litre drums. This paper describes the design, development and testing of an updated and automated Wide Range Segmented Gamma Scanner (WR-SGS) specifically configured for Chinese nuclear industry radioactive waste measuring requirements. The instrument retains the capabilities of the original SGS developed by Parker and Martin at the Los Alamos National Laboratory and now widely used for radioactive waste assay. It also incorporates additional features to improve measurement efficiency and reduce cost. These features include continuous helical scanning of the waste drum, and separate lifting pillars to lift the detector and the transmission source. In place of a transmission source shutter mechanism, the source is placed in a shielded safe when not in use. The design also incorporates a variable aperture collimator, and tungsten filters that can be deployed for the measurement of high activity, high dose-rate drums. Updated motion control electronics, based on the use of a programed logic controller have been incorporated to address potential future obsolescence. The WR-SGS employs a 40% high purity Germanium detector with electro-mechanical cooling and state of the art digital spectroscopy counting electronics for gamma ray spectrum data acquisition. Testing of the unit has been performed with both point sources and rod sources, which are traceable to international standards. Typical test drums, each with six distributed re-entrant tubes and with different density matrices, have been employed with the rod sources to validate both the calibration and the measurement performance of the WR-SGS for drums of different density. The measurement results have been compared with the reference decay corrected activity values and very good agreement is achieved, confirming the measurement performance of the instrument. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Integrate Power Conversion Unit with MAGNET to Enable Integrated Microreactor Heat Transfer System Testing

Idaho National Laboratory obtained a closed, Brayton-cycle, power conversion unit (PCU) from Sandia National Laboratories. This PCU began as a commercially available, 30 kWe, C30, gas turbine from Capstone. The C30 was modified to use heat from an electric heater in a closed-loop system pressurized with nitrogen or dry air. INL has modified the unit further to integrate it with MAGNET and use heat from a microreactor test article.

42 - ENGINEERING↗
DOE OSTI2015

Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 411: Double Tracks Plutonium Dispersion (Nellis), Nevada Test and Training Range, Nevada (Rev. 0)

This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 411, Double Tracks Plutonium Dispersion (Nellis). CAU 411 is located on the Nevada Test and Training Range and consists of a single corrective action site (CAS), NAFR-23-01, Pu Contaminated Soil. There is sufficient information and historical documentation from previous investigations and the 1996 interim corrective action to recommend closure of CAU 411 using the SAFER process. Based on existing data, the presumed corrective action for CAU 411 is clean closure. However, additional data will be obtained during a field investigation to document and verify the adequacy of existing information, and to determine whether the CAU 411 closure objectives have been achieved. This SAFER Plan provides the methodology to gather the necessary information for closing the CAU. The results of the field investigation will be presented in a closure report that will be prepared and submitted to the Nevada Division of Environmental Protection (NDEP) for review and approval. The site will be investigated based on the data quality objectives (DQOs) developed on November 20, 2014, by representatives of NDEP, the U.S. Air Force (USAF), and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office. The DQO process was used to identify and define the type, amount, and quality of data needed to determine whether CAU 411 closure objectives have been achieved. The following text summarizes the SAFER activities that will support the closure of CAU 411; Collect environmental samples from designated target populations to confirm or disprove the presence of contaminants of concern (COCs) as necessary to supplement existing information; If COCs are no longer present, establish clean closure as the corrective action; If COCs are present, the extent of contamination will be defined and further corrective actions will be evaluated with the stakeholders (NDEP, USAF); and Confirm the preferred closure option is sufficient to protect human health and the environment.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Closure Report for Corrective Action Unit 413: Clean Slate II Plutonium Dispersion (TTR) Tonopah Test Range, Nevada, Revision 0

This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 413: Clean Slate II Plutonium Dispersion (TTR), located on the Tonopah Test Range, Nevada. CAU 413 consists of the release of radionuclides to the surface and shallow subsurface from the conduct of the Clean Slate II storage-transportation test conducted on May 31, 1963. The purpose of this CR is to provide documentation and justification for the clean closure of CAU 413 under the FFACO without further corrective action. This justification is based on historical knowledge of the site, previous site investigations, closure activities conducted at the site, and the results of verification samples. Clean closure activities included excavating and disposing of radiologically contaminated soil and debris in the vicinity of ground zero, and collecting verification samples to support the corrective action of clean closure. Results confirmed that further corrective action is not required at CAU 413. Based on the corrective action activities conducted, clean closure of the site is complete; the closure objectives established in the CADD/CAP have been achieved; and no further corrective action at the site is required.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Light Water Reactor Sustainability Program: Report on the Completion of the Machining of Zion Unit 1 Reactor Pressure Vessel Blocks into Mechanical and Microstructural Test Specimens and Chemical Analysis Coupons

The decommissioning of the Zion Units 1 and 2 Nuclear Generating Station in Zion, Illinois, presented a unique opportunity for developing a better understanding of materials degradation and other issues associated with extending the lifetime of existing nuclear power plants (NPPs) beyond 60 years of service. In support of extended service and current operations of the US nuclear reactor fleet, the Oak Ridge National Laboratory (ORNL), through the Department of Energy (DOE), Light Water Reactor Sustainability (LWRS) Program, coordinated with Zion Solutions, LLC, a subsidiary of Energy Solutions (ES), the selective procurement of materials, structures, and components, from the decommissioned reactors including multiple segments of the Zion Unit 1 Reactor Pressure Vessel (RPV).

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

TREAT Neutronics Analysis and Design Support, Part I: Multi-SERTTA

Experiment vehicle design is necessary in preparation for Transient Reactor Test (TREAT) facility restart and the resumption of transient testing to support Accident Tolerant Fuel (ATF) characterization and other future fuels testing requirements. Currently the most mature vehicle design is the Multi-SERTTA (Static Environments Rodlet Transient Test Apparatuses), which can accommodate up to four concurrent rodlet-sized specimens under separate environmental conditions. Robust test vehicle design requires neutronics analyses to support design development, optimization of the power coupling factor (PCF) to efficiently maximize energy generation in the test fuel rodlets, and experiment safety analyses. Calculations were performed to support analysis of a near-final design of the Multi-SERTTA vehicle, the design process for future TREAT test vehicles, and establish analytical practices for upcoming transient test experiments. Models of the Multi-SERTTA vehicle containing typical PWR-fuel rodlets were prepared and neutronics calculations were performed using MCNP6.1 with ENDF/B-VII.1 nuclear data libraries. Calculation of the PCF for reference conditions of a PWR fuel rodlet in clean water at operational temperature and pressure provided results between 1.10 and 1.74 W/g-MW depending on the location of the four Multi-SERTTA units with the stack. Basic changes to the Multi-SERTTA secondary vessel containment and support have minimal impact on PCF; using materials with less neutron absorption can improve expected PCF values, especially in the primary containment. An optimized balance is needed between structural integrity, experiment safety, and energy deposition in the experiment. Type of medium and environmental conditions within the primary vessel surrounding the fuel rodlet can also have a significant impact on resultant PCF values. The estimated reactivity insertion worth into the TREAT core is impacted more by the primary and secondary Multi-SERTTA vehicle structure with the experiment content and contained environment having a near negligible impact on overall system reactivity. Additional calculations were performed to evaluate the peak-to-average assembly powers throughout the TREAT core, as well as the nuclear heat generation for the various structural components of the Multi-SERTTA assembly. Future efforts include the evaluation of flux collars to shape the PCF for individual Multi-SERTTA units during an experiment such as to achieve uniformity in test unit environmental conditions impacted by the non-uniform axial flux/power profile of TREAT. Upon resumption of transient testing, experimental results from both the Multi-SERTTA and Multi-SERTTA-CAL will be compared against calculational results and methods for further optimization and design strategies.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗