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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Electrochromic Window Demonstration at the John E. Moss Federal Building, 650 Capitol Mall, Sacramento, California

Dynamic windows have the potential to provide real-time optimization of perimeter zone energy use, peak demand, comfort, amenity, and cost criteria on a seasonal or even minute-to- minute basis in response to weather, occupant or regional grid demands. Electrochromic (EC) windows, a type of dynamic window, have the ability to adjust their tint dynamically in response to a small applied voltage. In previous studies, they have shown potential to reduce heating, ventilation and air conditioning (HVAC) energy consumption and increase occupant satisfaction. This technology is available in the U.S. as a commercial product from multiple vendors with high-capacity manufacturing facilities, and could be broadly deployed if successful in a pilot test. This Green Proving Ground (GPG) program study examines the energy and comfort performance of EC windows in south-facing perimeter zones of a typical U.S. General Services Administration GSA office building.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2018

Automated Clean Chemistry for Bulk Analysis of Environmental Swipe Samples – Final Report

Sample preparation methods for mass spectrometry are being automated using commercial-off-the-shelf (COTS) equipment to shorten lengthy and costly manual chemical purification procedures. This development addresses a serious need in the International Atomic Energy Agency’s (IAEA) Network of Analytical Laboratories (NWAL) to increase efficiency in the Bulk Analysis of Environmental Samples for Safeguards program with a method that allows unattended, overnight operation. In collaboration with Elemental Scientific Inc. (ESI), the prepFAST-MC2 was designed based on COTS equipment. It was modified for uranium/plutonium separations using renewable columns packed with Eichrom TEVA® and UTEVA® resins, with a chemical separation method based on the Oak Ridge National Laboratory (ORNL) NWAL chemical procedure. Initial verification of individual columns yielded small elution volumes with consistent elution profiles and good recovery. Combined column calibration demonstrated ample separation without crosscontamination of the eluent. Automated packing and unpacking of the built-in columns initially showed >15% deviation in resin loading by weight, which can lead to inconsistent separations. Optimization of the packing and unpacking methods led to a reduction in the variability of the packed resin to less than 5% daily. Based on the initial experience at ORNL with the prepFAST-MC2, a second-generation model, the prepFAST-SR, was built by ESI. The newly designed prepFAST-SR has several upgrades compared with the original prepFAST-MC2. The upgrades largely addressed issues with the reliability of unpacking the Eichrom columns and with ventilation to ensure adequate removal of acid vapors. Both systems are currently installed in the Ultra-Trace Forensics Science Center at ORNL. Separations of mixed uranium and plutonium samples containing certified reference materials were analyzed by multi-collector inductively coupled plasma mass spectrometry and yielded good results. Current efforts have demonstrated a wider applicability of the prepFAST system. Near-quantitative removal of metal interferences was achieved with the system in both uranium and plutonium separated fractions. Successful system validation was completed with several archived samples. Isotopic results from archived samples and certified reference materials were well within data quality limits for the IAEA NWAL. Additional COTS equipment has been evaluated for its potential to aid the prepFAST-SR system in reducing the time allotments and cleanroom infrastructure requirements for accurate separations. Overall, these efforts help ensure continued efficient and effective operation of the NWAL. Comparison of the amount of personnel time necessary for successful manual vs. automated chemical separations showed a significant decrease in hands-on time from 9.8 hours to 35 minutes for seven samples, respectively. This documented time savings and reduced labor translates to a significant cost savings per sample. Overall, the system will enable faster sample reporting times at reduced cost by limiting personnel hours dedicated to the chemical separation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Low-Cost Multi-Modal Wireless Sensor Platform for Smart Buildings

Buildings consume 73% of the energy produced in the United States [1, 2]. Advanced sensors, controls, and communications have the potential to reduce the energy consumption of buildings by 20–40% [3, 4]. Currently, installation and wiring costs for sensors are quite high, making it cost-prohibitive for building managers to deploy large quantities of advanced sensors [5]. Wireless sensors have recently been deployed in buildings to provide the information necessary for optimal control of heating, ventilation, and air-conditioning and lighting systems [6, 7]. Wireless sensors have the unique advantage of being suitable for easily retrofitting existing buildings at a minimal labor cost, and the flexibility to be placed at optimal, observable locations. However, current commercially available wireless sensors are still very expensive ($150–300/node). Thus, revolutionary technological improvements in wireless sensors are required to promote inherently low-cost manufacturing for building applications to successfully exploit the energy efficiency opportunities in buildings.In this report, we present the efforts carried out at Oak Ridge National Laboratory and Molex Inc. toward exploring the design, implementation, and performance evaluation of low-cost, self-powered wireless sensors—including temperature, relative humidity, occupancy, and indoor air quality sensors—to enable advanced control applications that reduce energy consumption in buildings. Our focus is to demonstrate a novel multifunctional sensor platform that will evolve with advances in materials technology, low-cost printing techniques, nano-antennas, and co-integration of monitoring, control, and communication circuitry. We also present a low-power and bandwidth-efficient wireless communication technology that can be driven by energy harvesting in self-powered wireless sensors. It is based on code-phase-shift keying (CPSK) spread-spectrum signaling that improves both transmitter range and power consumption. The objective is to minimize the number of components within the wireless transceiver and reduce power consumption to allow sensor networks powered by energy harvesting, thus eliminating the expense and effort of periodically replacing the sensor batteries. Current state-of-the-art radio technologies have demonstrated 25–30 mA current consumption for the transmitter. Our prototype demonstrations lowered the consumption to 4 mA using spread-spectrum-based CPSK so that solar cells can be used with indoor lighting to recharge a battery indefinitely. Therefore, the system can run with no attention or maintenance for the life of the components, which is expected to be 20 years. The developed technology has the potential to generate fully printable wireless sensors with costs on the order of $1–10/node.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Commercial Building Technology Demonstration (Final Scientific/Technical Report)

The background for this project was a unique and innovative concept that had been proposed and demonstrated by enVerid Systems, reducing the energy consumption in HVAC systems in commercial and public buildings by up to 50% at peak loads. The concept involves selective scrubbing of gas contaminants from indoor air as a practical substitute for outside air ventilation, the latter being the conventional practice today. This scrubbing enables recycling of most of the indoor air and significantly decreasing the amount of outside air, resulting in a reduced HVAC load and commensurate energy savings for the facility. Key to our approach is low cost scrubbing of all gas contaminants from indoor air using novel, efficient and regenerable sorbent materials. The total solution, labeled HLR (HVAC Load Reduction) is implemented by means of compact modules that can be retrofitted onto virtually any building, and utilizes novel sorbents that have been developed and brought to scale production by enVerid. Although the technology had been deployed and demonstrated, the US commercial building and HVAC markets, famously conservative with respect to innovation and new technologies, had yet to embrace the idea or the product. The overarching goal of the project was to help overcome market hesitancy and enable widespread adoption, by creating a critical mass of success stories across different regions and building types, all under oversight and verification of the DOE and NREL, to ensure credibility and accuracy. The project, overall, was a resounding success. Several installations were deployed and tested comprehensively for the impact on both energy consumption and indoor air quality, and results were not only excellent, but quantitatively in line with expectations. A total number of eight (8) installations were attempted, with 2 aborted due to building issues. Of the six successful installations, however, complete M&V was performed by NREL on 2 (Miami and NYC) and partial analysis on a third site (ArcBest), and these three, along with their results, were therefore presented from a financial and reporting standpoint. Although the number of case studies fell short of the original target of 10, we nevertheless had excellent demonstrations in vastly different climate zones: Southeast, Northeast and Midwest, and in very different building types. This included a modern high-rise office building in New York City and a University Campus health center in Miami, and a mid-rise high-density office in Arkansas. The cooling load reduction was shown to be significant, averaging 37% during the final cooling season in the Miami site. In the NYC site, the cooling energy savings were generally less, at around 12%, as expected. While this is a lower number for average/total savings, two comments are important to note: (i) the outside airflow (OA) reduction was not consistent during the data collection period, at least in part understating the attainable savings through incorrect measurement of the “high energy” reference state; and (ii) the peak impact in NYC is almost certainly as high as Miami, with critical ramifications for peak load reduction and equipment downsizing ability. Importantly, the measured energy savings in all locations were related to the outdoor climate conditions and the actual achievable reduction in outside air, very much in line with models and calculations; this leaves us with increased confidence in our understanding of the interaction between the technology and the building, and our ability to project the impact of this innovation in the future, through broad adoption. Simply put: the energy savings and load reduction impact of the HLR solution has been confirmed quantitatively. The results also confirmed the air quality objective. This may be even more significant, in that air quality is more complex and harder to measure and quantify, and the performance of the HLR as an air scrubber is the linchpin of the entire solution. In all sites, indoor air quality met or exceeded the required parameters, in terms of achieving the target (low) levels of indoor pollutants. Furthermore, the concentrations of outdoor sourced pollutants were markedly lower, as expected, mostly due to the reduction in outside air intake although in part also due to the scrubbing. The success was not immediate nor easy, and early challenges with the systems, especially (but not only) around controls and communication, caused delays in commissioning and undermined some of our M&V schedules. The good news is no fundamental issues were encountered and the number of such glitches was declining quickly by the end of the project. Other challenges had to do with coordinating the control of the building OA dampers, which the HLR needs to have in order to deliver the load reduction, but which the facility manager controls regularly and independently. This is not necessarily a problem for normal HLR operation but interferes with accurate M&V, where switching OA settings back and forth on a precise timetable is essential for clean data. The project provided valuable experience in retrofitting buildings that had been originally designed to operate with less recirculation and more outside air, and some key learnings related to the cyclical regeneration of the sorbents in the operational environment of the building. Some of these learnings gave already been incorporated into ongoing improvements in the design of the HLR module as well as the software that is used to control its operation. The cost and time of retrofit installations is much better understood; so is the test and balance procedure of the building that determines the available range of outside air reduction, which in turn determines the amount of load reduced. We had also implemented at least one annual cycle of sorbent cartridge replacement in the field, after which we tested the used sorbent to assess the rate of degradation of sorbent potency – an important factor affecting the long-term economics of HLR deployments. A notable shortfall of the project, other than the fact that the number of sites was below target, was that we had not (yet) completed testing to measure and verify (M&V) the winter energy savings. This is primarily due to late start on the NYC sites (Miami does not portend any heating savings associated with reduced outside air), combined with the issues of OA damper control. It is by no means suggested that such savings cannot be captured, only that the M&V with respect to winter in NYC has been incomplete. The value of this project and its interest to the general public are hard to overstate. The case studies created from Miami and especially from NYC have, without a doubt, opened up the interest of the broad HVAC industry to HLR in the past year. Major manufacturer reps have signed up to represent and promote the product, and dozens of top tier engineering consultants have introduced HLR as a base of design in upcoming construction and renovation projects – precisely the overarching goal of this project. These would not have happened without the highly visible installation in NYC and its ultimately satisfied customer. Furthermore, the DOE itself issued a report in late 2017 analyzing hundreds of candidate technologies for reducing energy consumption in HVAC; remarkably, the budding HLR solution ranked among the top 3(!); no doubt, its status as a viable and significant contender on this list is informed by the success of these demonstrations. And furthermore, in the wake of these demos, several major energy utilities, led by ConEdison in NYC, have endorsed the HLR solution and now routinely provide substantial cash rebates for customers choosing to incorporate the HLR in their buildings and reap the benefit of the reduced peak load as well as reduced cumulative energy demand. Last but not least, in January of 2019, as this report was being written, the HLR module won the AHR Expo Innovation Award for Green Buildings and, remarkably, the prestigious and only Product of the Year 2019, being selected by an independent professional panel of judges from AHR and ASHRAE. Given the confirmation of the enormous energy saving potential of HLR in widescale deployment, as well as ancillary but significant benefits in terms of equipment downsizing and indoor air quality, the benefit of this effort to the public speaks for itself. Accelerating adoption of HLR, without dependence on subsidies and driven by the private sector, is well under way. There is still much work to be done in terms of educating the HVAC and construction ecosystems and improving the product’s robustness and simplicity, to further facilitate the adoption of this technology and the capture of its potential value. But the American public will greatly benefit both directly and indirectly in the immediate future and beyond.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2019

Test Plan for the Horizontal Dry Cask Simulator

The thermal performance of commercial spent nuclear fuel dry storage casks is evaluated through detailed numerical analysis. These modeling efforts are completed by the vendor to demonstrate performance and regulatory compliance. The calculations are then independently verified by the Nuclear Regulatory Commission(NRC). Canistered dry storage cask systems rely on ventilation between the inner canister and the overpack to convect heat away from the canister to the surrounding environment for both horizontal and vertical configurations. Recent advances in dry storage cask designs have significantly increased the maximum thermal load allowed in a cask in part by increasing the efficiency of internal conduction pathways and by increasing the internal convection through greater canister helium pressure. Carefully measured data sets generated from testing of full sized casks or smaller cask analogs are widely recognized as vital for validating these models. While several testing programs have been previously conducted, these earlier validation studies did not integrate all the physics or components important in a modern, horizontal dry cask system. The purpose of the investigation described in this test plan is to produce data sets that can be used to benchmark the codes and best practices presently used to determine cladding temperatures and induced cooling air flows in modern horizontal dry storage systems. The horizontal dry cask simulator(HDCS) has been designed to generate this benchmark data and add to the existing knowledgebase. The pressure vessel representing the canister has been designed, fabricated, and pressure tested for a maximum allowable pressure(MAWP)rating of 2,400 kPa at400 °C. An existing electrically heated but otherwise prototypic boiling water reactor(BWR), Incoloy-clad test assembly will be deployed inside of a representative storage basket and canister. An insulated sheet metal enclosure will be used to mimic the thermal properties of the concrete vault enclosure used in a modern horizontal storage system. Radial and axial temperature profiles along with induced cooling air flow will be measured for a wide range of decay powers and representative(and higher)cask pressures using various backfills of helium, argon, or air. The single assembly geometry with well-controlled boundary conditions simplifies computational requirements while preserving relevant physics. The proposed test apparatus integrates all the underlying thermal-hydraulics important to defining the performance of a modern horizontal storage system. These include combined-mode heat transfer from the electrically-heated assembly to the canister walls and the primarily natural-convective heat transfer from the canister to the cooling air flow passing through the horizontal vault enclosure. The objective of the HDCS is not to reproduce the performance of a commercial dry storage system for any given set of operational parameters. Rather ,the objective is to capture the dominant physics in a well-characterized test apparatus. The close coupling between the thermal response of the canister system and the resulting induced cooling air flow rate is of particular importance. While incorporating the best available information based on thermal-hydraulic scaling arguments as well as previous vertical testing, this test plan is subject to changes due to improved understanding or from as built deviations to designs. As-built conditions and actual procedures will be documented in the final test report.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Experimental Evaluation of Refrigerant Leak Characteristics for Different HVAC&R Equipment Types

The US Department of Energy (DOE) Building Technology Office (BTO) and the Air-conditioning, Heating & Refrigeration Technology Institute (AHRTI) collaborated to sponsor an experimental study of refrigerant leak characteristics at ORNL; AHRTI project 9012. The original objectives were to conduct refrigerant leak tests on several heating, ventilating, air conditioning and refrigeration (HVAC&R) systems under operating conditions representative of actual applications to document the pressure decay rate and the mass flow rate of leaked refrigerant as a function of time. Estimates of the quality (vapor versus liquid) of the leaking refrigerant and oil escaping with the leak were also desired. The project involved imposing refrigerant leaks on five systems and collecting data to meet the project objectives. Systems chosen covered three air-conditioning (AC) applications (packaged terminal AC or PTAC, 3-ton residential split system AC, and 5-ton packaged rooftop AC) and two refrigeration applications (split system unit cooler, and standalone display case). AHRTI members donated the test systems used for the project. The systems were to be tested at two different leak rates (catastrophic high rate simulating full line break and a lower flow rate), two leak locations (high-pressure side and low-pressure side), and two operating conditions (compressor on or off).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

Electrochromic Window Demonstration at the 911 Federal Building, 911 Northeast 11th Avenue, Portland, Oregon

Switchable electrochromic (EC) windows are part of a new class of dynamic, energy-efficient technologies that enable real-time, active load management in response to weather conditions and the unique operating conditions of individual buildings. Owners can now specify a solid-state technology that reacts to various stimuli like the skin of a living entity. The technology can be controlled to address multiple criteria to achieve a more optimal energy-efficient and comfortable indoor environment than one with static or manually operated technologies. Inputs can include data on outdoor solar conditions, utility rates, occupancy status, heating, ventilation, and air conditioning (HVAC), or operating emergency or security mode. The outputs then dictate how the EC window is controlled, whether as a self-contained autonomous unit that achieves specific zonal objectives or as a part of an integrated system designed to address whole building, campus and grid-related goals. Since windows typically have a 30-year life, these dynamic qualities enable the building to be adaptable and more resilient as the environmental, operating and economic context evolves.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

VOLTTRON-enabled Home Energy Management System

Home Energy Management Systems (HEMS) consist of software and hardware systems that provide communication, control, and management among different electronic devices, such as heating, ventilation, and air-conditioning (HVAC) systems. HEMS are a growing market sector in the era of smart grids and smart homes. HEMS can help both homeowners and utilities save money and energy by monitoring and controlling smart devices in a house. Based on the Department of Energy (DOE) Building Energy Data Book, 41% of the energy consumed in the United States is used by buildings (see Figure 1). This shows the importance of saving energy in the building sector. This report introduces two approaches that existing HEMS vendors can use to leverage VOLTTRON as their control and interoperability engine. The goal of this project is to make open-source, user-friendly HEMS available to the market so that everyone can benefit from them. The HEMS introduced as a result of this study should satisfy HEMS specifications such as device monitoring and control, seamless communication between devices, DR, intelligence, data management, and security.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2018

Voltron Compatible Whole Building Root-Fault Detection and Diagnosis

Buildings consume more than 40% of primary energy in the U.S. Malfunctioning sensors, components, and control systems, as well as degrading components in Heating, Ventilating and Air-conditioning (HVAC) and lighting systems are main reasons for energy waste and unsatisfactory indoor environment. Field studies have shown that an energy saving of 5-30% of total building energy consumption and improved indoor air quality can be achieved by simply applying automated fault detection and diagnosis (AFDD), followed by corrections even if these are not done in real time. Extensive research has been made on the development of component level AFDD tools in the past two decades. However, in recent years, the development of method for a whole building level AFDD has received much attention. Here, a whole building fault refers to a fault happening in one subsystem but impact on more than one subsystems, or has a significant impact on building performances, such as building’s energy consumption. Existing component level AFDD tools could fail to detect or give false alarm for faults that trigger abnormalities in multiple subsystems. Isolating such whole building faults, which have impacts on multiple subsystems, is also challenging by simply using component based AFDD solutions. On the other hand, it might be more cost-effective for medium- or small-sized commercial buildings that have subsystems (e.g. primary cooling subsystem, air loop subsystem, heating subsystem, lighting subsystem, etc.) to install one whole building level AFDD tool, rather than many component level AFDD tools, to focus on significant faults. The focus of this project is firstly to provide training opportunities in building AFDD research area for undergraduate students and to develop a workforce pipeline in building sciences. The objective of the proposed research activities is to develop cost-effective and scalable AFDD solutions for whole building level faults. The developed AFDD solution is VOLTTRONTM compatible to further increase its plug-n-play capacity and the market penetration. VOLTTRONTM is an open-source innovative distributed control and sensing software platform developed by the Pacific Northwest National Laboratory. A VOLTTRONTM compatible AFDD tool brings the benefits such as low-cost deployment, and better building to grid integration, etc. The performance of the developed whole building AFDD tools is evaluated using data collected from a mixed-use medium-sized university campus building. Another significant goal of this project is to engage undergraduate students in research activities and expose them to building control and AFDD fields. A demonstration building – Nesbitt Hall at Drexel University is identified for this study. This demonstration building has a typical HVAC system configuration, which includes a water-cooled chiller system, three variable air volume (VAV) air handling unit (AHU) systems, and a hydronic heating system. Faults, that are expected to have a whole building level impact, are artificially implemented in this demonstration building for three different seasons. Building data have been collected in this project, which include fault free building automation system (BAS) data and BAS data that contain system behaviors caused by artificially implemented and naturally occurred faults. These collected data are used to evaluate the developed whole building AFDD tools. A data-driven method, which includes a weather and schedule-based pattern matching (WPM) method and Feature based Principal Component Analysis (FPCA) method, is developed for whole building level fault detection. Parameter sensitivity tests, including snapshot window size, data sample searching pool size, etc., are implemented to evaluate the impacts of various WPM-FPCA parameters. A data-driven and expert knowledge/rule-based method using Bayesian Network (BN) and WPM is developed for whole building level fault diagnosis. The developed WPM-BN method, which includes a two-layer BN structure model and BN parameters, are either learned from baseline data or developed from expert knowledge. The developed whole building AFDD tools are evaluated using BAS data collected from the demonstration building. Using the evaluation data set, the WPM-FPCA fault detection method is evaluated under two different Principle Component (PC) retention rates, i.e., 0.65 retention rate and 0.95 retention rate. It is observed that when using 0.65 PC retention rate, the WPM-FPCA fault detection method achieves a 79% fault detection rate (this rate reaches to 85% when including the six make-up fault test cases discussed in the next bullet), while when using 0.95 PC retention rate, the WPM-FPCA fault detection method achieves 100% fault detection rate (this rate remains to be 100% when including the six make-up fault test cases). Under both PC retention rates, the WPM-FPCA fault detection method demonstrates 0% false alarm rates. Using the evaluation data set, the developed WPM-BN fault diagnosis method has successfully diagnosed thirteen (13) faults out of the fourteen (14) fault test cases. The one mis-diagnosed case exhibits fewer fault symptoms in different subsystems, when compared with other fault test cases. Overall speaking, the developed whole building AFDD solutions demonstrate satisfactory fault detection/diagnosis accuracy with very low false alarm rate. Lastly, a survey and market study has been performed to understand the existing AFDD market, including its gaps and needs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Sealed and Insulated Attic Hygrothermal Performance in New California Homes Using Vapor and Air Permeable Insulation—Field Study and Simulation

This project investigated the thermal and moisture performance of a low-cost approach to sealing and insulating attics using glass fiber insulation. The work included a combination of: (1) field measurements of attic and HVAC system performance in two new, high-performance homes in California’s Central Valley (Fresno), and (2) hygrothermal simulations of attic performance. Each field study attic was continuously monitored at multiple locations for over a year for wood moisture content, air humidity, condensation, temperature, and heat flux, together with on-site weather and solar conditions. The Fresno test home showed periodic condensation and high surface wood moisture content, but no surface mold or degradation upon visual inspection at the end of the test period. The Clovis test home showed less indication of high moisture levels—either from surface condensation or wood moisture content—but did have visible suspected mold growth on the inside of the North sheathing at the end of the field testing. These results show the limitations of current moisture measurement techniques focused on wood moisture content, rather than potential for mold growth. From a thermal/energy perspective the attics were close to indoor conditions thereby realizing the design intent for reducing duct system losses. Simulated site HVAC energy savings for sealed vs. vented attics averaged 18% across California climate regions (8% TDV energy savings). Savings were dominated by heating energy reductions; cooling savings were substantially lower. The moisture issues are investigated in greater detail in the simulations. First, we identified the climate regions and house characteristics that are associated with increased risk of mold growth or wood rot in new CA homes. Climate region was very important in determining risk, as were house features that reduced outside air exchange (e.g., 1-story homes, very tight envelopes, very tight attics, no IAQ fan), along with those that increased flow of moist air from the living space to the attic (e.g., supply ventilation fans, larger ceiling leaks, duct leakage). Second, we investigated several approaches to reduce moisture risks, and the best approach was to use a vapor retarder on the inner face of the fiberglass insulation. Both the field and simulation results indicate that the use of air and vapor permeable insulation can be acceptable from a thermal/energy point of view, but additional measures need to be taken to reduce moisture risks, primarily from mold growth.

42 ENGINEERING↗
DOE OSTI2019

Wall Upgrades for Residential Deep Energy Retrofits: A Literature Review

In the United States, 39% of total energy consumption comes from the building sector, 20% of which is attributed to residential buildings. New, high-performance homes incorporate a combination of tight building envelopes, mechanical ventilation and efficient components to ensure comfort, adequate airflow and moisture control. These systems work together to create energy efficient homes that employ measures to manage moisture and indoor pollutants. Older homes, built before 1992 when DOE’s Building Energy Codes Program was established represent approximately 68% of building stock in the country, and often have significant air leakage and inadequate insulation. Homes with little to no air sealing or insulation result in heating and cooling losses, which can represent a substantial portion of utility bills. Done correctly, deep energy retrofits (DERs) can significantly improve the energy performance of a home’s thermal envelope, decrease indoor pollutants and increase homeowner comfort. This literature review summarizes current practices for exterior wall retrofits for existing homes, provides an overview of techno-economic approaches to investigate residential wall systems, and discusses thermal and hygrothermal modeling strategies. Accompanying this literature review is a larger effort to identify state-of-the-art technologies for existing wall energy efficiency retrofit systems that can be applied over existing siding and are suitable for the cold/very cold climates.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Fire- and Water-Resistant Prefilter

The goal of this project was to modify existing LLNL ceramic HEPA filter technology to create ceramic prefilters, which could first be implemented in nuclear facilities or hospitals and universities. The objectives were as follows: 1) Demonstrate sealing technology capable of withstand ≥ 400°C, 2) Design and fabricate a ceramic prefilter unit for flow rates ≥ 50 cfm, 3) Test prefilter prototype filtration efficiency and pressure drop before and after a relevant thermal exposure. Concurrently to prototype creation was a preliminary effort to develop a custom nuclear prefilter sealant, improving upon what is commercially available. An advantage to using prefilters that are not credited for HEPA filtration, but to protect HEPA filters in nuclear ventilation systems, is that absolute qualified performance to HEPA standards (e.g. pressure drop, filtration efficiency) is not required. This prefilter prototype aligns our technology with the more viable, lower risk market entry point which can be used to establish costs, performance and manufacturing principles necessary to overcome the primary market barrier.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Summary of available data for estimating chloride-induced SCC crack growth rates for 304/316 stainless steel

The majority of existing dry storage systems used for spent nuclear fuel (SNF) consist of a welded 304 stainless steel container placed within a passively-ventilated concrete or steel overpack. More recently fielded systems are constructed with dual certified 304/304L and in some cases, 316 or 316L. In service, atmospheric salts, a portion of which will be chloride bearing, will be deposited on the surface of these containers. Initially, the stainless steel canister surface temperatures will be high (exceeding the boiling point of water in many cases) due to decay heat from the SNF. As the SNF cools over time, the container surface will also cool, and deposited salts will deliquesce to form potentially corrosive chloride-rich brines. Because austenitic stainless steels are prone to chloride-induced stress corrosion cracking (CISCC), the concern has been raised that SCC may significantly impact long-term canister performance. While the susceptibility of austenitic stainless steels to CISCC in the general sense is well known, the behavior of SCC cracks (i.e., initiation and propagation behavior) under the aforementioned atmospheric conditions is poorly understood. A literature survey has been performed to identify SCC crack growth rate (CGR) studies conducted utilizing conditions that may be relevant to existing SNF interim storage canisters, the results of which are presented in this document. The data presented here have been restricted to those representing atmospheric corrosion of stainless steels due to deliquescence of marine salts, or marine salt components, on the metal surface. A suite of experimental studies representing both long-term field tests and accelerated laboratory tests has been identified. Potentially relevant data are summarized in Figures 1-1 (304 SS) and Figure 1-2 (316 SS). In the Figures, when a particular reference utilized a series of samples, the range is shown as a bar, and the average value shown with a symbol. A summary of the test methods, sample geometry, and environmental conditions for each study is given in Table 1-1. While the surveyed studies all explore SCC of austenitic stainless steels under atmospheric conditions, the methods through which each researcher approached the problem do differ, as illustrated in Table 1-1. The surveyed studies utilized a variety of metal treatments including as-fabricated, solution annealed, welded, and sensitized material. Furthermore, different surface treatments (polished vs ground) were also used. In addition, most of these studies were accomplished using techniques that are not generally accepted for high-fidelity crack growth rate measurements, and in cases where more traditional approaches were taken, these methodologies may not be applicable to the atmospheric conditions of interest here. The wide variety of methods and materials results in the observed large scatter in measured CGRs. Each of the data sets in Figures 1-1 and 1-2 is described in more detail in the following sections. A short summary of crack growth rates based on operational experience is also presented.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Performance Evaluation of the ThermoLift Natural Gas Fired Air Conditioner and Cold-Climate Heat Pump

ThermoLift is currently developing its Thermal Compression Heat Pump (TCHP™), a natural-gas driven air conditioner and cold-climate heat pump, which can provide space heating, water heating, and air conditioning simultaneously in a single device. The system has broad application as a combined heating, ventilation, and air-conditioning (HVAC) solution with the benefit of substantial energy, cost, and greenhouse gas (GHG) reductions. Unlike traditional vapor compression heat-pumps, the TCHP™ uses helium as a working fluid in place of high global warming potential (GWP) refrigerants. The development effort has produced three iterations or generations of prototypes with advancement of the technology readiness level (TRL) from TRL-1 (TCHP™ Gen 1.0) to TRL-5 (TCHP™ Gen 3.0). In August of 2013, the US DOE solicited the submission of proposals through funding opportunity announcement DE-FOA-0000823, Building Technologies Innovations Program. The Office of Energy Efficiency and Renewable Energy (EERE) subsequently accepted ThermoLift’s proposal to develop a heat pump system based on the Hofbauer cycle, a new cycle that supplants the Vuilleumier cycle and provided funding for prototype evaluation at Oak Ridge National Laboratory (ORNL). ORNL is a widely known research center for developing and evaluating building technologies. Through its Building Technologies Research and Integration Center, ORNL has unique capabilities which allows them to collaborate with industry and academia to advance building component technologies. The TCHP™ Gen 3.0 prototype was shipped to ORNL on July 23, 2018. After installation and integration of the heat pump into ORNL’s test facility and performing instrumentation validation and calibration, extended operation of the heat pump was achieved during continuous operation on August 6, 2018, and includes various heating and cooling temperature ranges and performance analysis. The Gen 3.0 prototype was evaluated at four “ambient” temperatures: −25°C, −8.33°C, 8.33°C, and 20°C, (−13°F, 17°F, 47°F, and 68°F) denoted as test points 1-4, respectively. For heating, cycle coefficients of performance (COP) at the four “ambient” temperatures were found to be 1.30, 1.46, 1.52, and 1.61, respectively. Furthermore, there is no capacity reduction as the inlet temperature to the cold heat exchanger (HX) decreases. The heating capacity delivered by the TCHP was found to be 12 kW at -25°C. Finally, this final report identifies measures for obtaining further efficiency improvements.

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DOE OSTI2019

MARSAME Release Report for TA46 Building 1

Environmental Protection and Compliance, Environmental Stewardship (EPC-ES) has identified materials associated with technical area 46, Building 1 (TA-46-001) that meet the criteria for unrestricted release to the public under Department of Energy (DOE) Order 458.1 Radiation Protection for the Public and the Environment (DOE 2013). We have also identified materials in certain rooms, e.g., ventilation systems and liquid drains and piping, which do not meet the criteria for unrestricted release and are to be treated as Low Level Waste (LLW). These conclusions are based on the known history of the structures combined with radiation survey data collected in 2018, and findings are consistent with DOE Order 458.1 and Los Alamos National Laboratory (LANL) Functional Series Document EPC-ES-FSD-004, Environmental Radiation Protection (LANL 2017). Sampling and data analysis, as described in this report, were sufficient to meet measurement quality objectives under the Multi-Agency Radiation Survey and Assessment of Materials and Equipment (MARSAME) manual (MARSAME 2009) and LANL procedures (LANL 2015). Final approvals for waste disposition will come from LANL’s Waste Management Program. The scope of this final release report includes structure TA-46-001. Floorplans for building 46-001 are provided in Figures 2 through 4. Metal materials included in this report are not subject to the DOE metal moratorium. While MARSAME provides guidance on statistical sampling for residual radionuclides in bulk materials, smaller miscellaneous items can be released via the release procedures outlined in LANL Policy 121 Radiation Protection (LANL 2018).

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DOE OSTI2019

MELCOR Modeling of Accident Scenarios at a Facility for Aqueous Reprocessing of Spent Nuclear Fuel

The work presented in this report applies the MELCOR code to evaluate potential accidents in non-reactor nuclear facilities, focusing on Design Basis Accidents. Ten accident scenarios were modeled using NRC's best-estimate severe accident analysis code, MELCOR 2.2. The accident scenarios simulated a range of explosions and/or fires related to a nuclear fuel reprocessing facility. The objective was to evaluate the radionuclide source term to the environment following initiating explosion and/or fire events. The simulations were performed using a MELCOR model of the Barnwell Nuclear Fuel Plant, which was decommissioned before beginning reprocessing operations. Five of the accident scenarios were based on the Class 5 Design Basis Accidents from the Final Safety Analysis Report. Three of the remaining accident scenarios include sensitivity studies on smaller solvent fires. The final two accidents included an induced fire from an initial explosion. The radionuclide inventory was developed from ORIGEN calculations of spent PWR fuel with an initial enrichment of 4.5% U-235 by weight. The fuel aged for five years after a final 500-day irradiation cycle. The burn-up was conservatively increased to 60 GWd/MTU to bound current US operations. The results are characterized in terms of activity release to the environment and the building decontamination factor, which is related the leak path factor used in Department of Energy safety analyses. The MELCOR 2.2 results consider adverse consequences to the filters, ventilation system, and structures as a result of the explosions and fires. The calculations also include best-estimate models for aerosol transport, agglomeration, and deposition. The new calculations illustrate best-estimate approaches for predicting the source term from a reprocessing facility accident.

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DOE OSTI2020

Protocol for Determining Actual Flow Rate in FTWC Duct Systems

This paper is intended to document the theory and methods to determine the actual flow rate in the exhaust system used to ventilate the Flanged Tritium Waste Containers based on realtime instrument readings. Section 1 provides introductory and background material; Section 2 details the various correction factors used to adjust flow readings for ambient air pressure and temperature and other operational parameters. Section 3 provides guidance on implementing this process during venting operations, and Section 4 provides supporting documentation and also a field checklist that can be used by personnel during venting. For Revision 1, a summary of editorial changes made to the paper was added as Section 4.4, as well as a section documenting peer review (Section 4.5).

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DOE OSTI2014

Investigations of Dual-Purpose Canister Direct Disposal Feasibility (FY14)

Results reported here continue to support the FY13 conclusion that direct disposal of DPCs is technically feasible, at least for some DPCs, and for some disposal concepts (geologic host media). Much of the work performed has reached a point where site-specific information would be needed for further resolution. Several activities in FY14 have focused on clay/shale media because of potential complications resulting from low thermal conductivity, limited temperature tolerance, and the need to construct hundreds of kilometers of emplacement drifts that will remain stable for at least 50 years. Technologies for rapid excavation and liner installation have significantly advanced in the past 20 years. Tunnel boring machines are the clear choice for large-scale excavation. The first TBM excavations, including some constructed in clay or shale media, are now approaching 50 years of service. Open-type TBMs are a good choice but the repository host formation would need to have sufficient compressive strength for the excavation face to be self-supporting. One way to improve the strength-stress relationship is to reduce the repository depth in soft formations (e.g., 300 m depth). The fastest construction appears to be possible using TBMs with a single-pass liner made of pre-fabricated concrete segments. Major projects have been constructed with prefabricated segmented liner systems, and with cast-in-place concrete liners. Cost comparisons show that differences in project management and financing may be larger cost factors than the choice of liner systems. Costs for large-scale excavation and construction in clay/shale media vary widely but can probably be limited to $10,000 per linear meter, which is similar to previous estimates for repository construction. Concepts for disposal of DPC-based waste packages in clay/shale media are associated with thermal management challenges because of the relatively low thermal conductivity and limited temperature tolerance. Peak temperature limits of 100°C or lower for clay-rich materials have been selected by some international programs, but a limit above 100°C could help to shorten the duration of surface decay storage and repository ventilation. The effects of locally higher peak temperatures on repository performance need to be evaluated (in addition to the effects at lower temperatures). This report describes a modeling approach that couples the TOUGH2 and FLAC3D codes to represent thermally driven THM processes, as a demonstration of the types of models needed.

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