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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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16 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Induction Heating for Tritium Storage Beds (FY19 PDRD Project Summary Report)

Metal hydride beds used for storing hydrogen isotopes at the Savannah River Site are conductively heated and cooled to desorb and absorb gases during storage cycling. While several storage bed configurations have been utilized over the years, many achieve heating by utilizing electric cartridge heaters positioned laterally along the longest axis of the storage bed (FACE Gen 2 Beds). Others achieve heating and cooling through hot and cold nitrogen flow (Gen 1 Beds). While these beds/heating configurations are well-designed for storage cycling operations, it is unclear if they can be regenerated to operating conditions once too much helium has accumulated in them. Full regeneration of hydride beds occurs around 625 - 650 °C. It is unclear if the currently employed electric cartridge heaters in Gen 2 beds can reach these temperatures. Furthermore, since swelling can occur during routine heating operations, it is unclear if existing cartridge heaters in Gen 2 beds can be swapped for higher-power cartridges that can reach 625 - 650 °C . Similarly, nitrogen air flow (to the best of our knowledge) cannot cause Gen 1 beds to reach these temperatures. Thus, existing Gen 1 and Gen 2 beds need to be heated through an alternative method to removal helium, so the beds can either return to normal operation or be disposed of. The goal of this PDRD was to investigate if induction heating can be used for various heating processes involving hydride storage beds (e.g. regeneration, gas cycling, helium heel removal). In the original call for proposals, this PDRD fell under "Gas Processing" area of interest # 3: "Develop methods to deploy alternate ways to heat existing process equipment to minimize impact to glove box environment."

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

PDRD Project 19039 - All metal vacuum scroll pump development for tritium

Currently the United States relies on a single source, foreign company, Eumeca (formerly Normetex) for the supply of an all metal vacuum scroll pump to process tritium. This “one of a kind”, all metal, vacuum scroll pump utilizes no “wetted”, polymeric materials that degrade prematurely when exposed to tritium. U.S. based vacuum scroll pump suppliers typically utilize a polymer, Teflon®, as a tip seal material at the edge of the scroll impellers for proper pump function. Teflon® is known to degrade within a relatively short time frame (approximately 1 year) when continually exposed to tritium gas. This degradation results in “flaking” of the Teflon® material which results in particulate contamination of the process gas stream. While filtration of the particulate is possible, doing so requires additional maintenance which is costly in a glovebox environment. In addition, filtration can degrade pumping system performance as particulate collects in the filter media over time. To date, all of the well established U.S and European based vacuum scroll pump manufacturers have been uninterested in developing an all metal vacuum scroll pump that does not use a polymeric scroll tip seal. This position is taken as the vacuum scroll pump manufacturers do not see a large enough market to make it profitable for them to develop and market an all metal vacuum scroll pump. In the mid 2000s, one company, Air Squared, Inc., a small Original Equipment Manufacturer (OEM) specializing in design and fabrication of custom scroll vacuum pumps and compressors, was willing to pursue the effort. The first design effort incorporated Vespel® as a polymeric tip seal material. Results of this effort led to realizing the affect that the Met-Bel MB-601 metal bellows pump has on performance when used as a backing pump for an all metal vacuum scroll pump without a scroll tip seal. As a result, Air Squared subsequently designed an all metal vacuum scroll pump without a tip seal material for evaluation. Although the initial, all metal version of the Air Squared pump was found deficient in regard to scroll impeller stiffness, which resulted in scroll contact, general design and pump performance was verified to be adequate. SRS PDRD Project 19039 was launched in 2019 as a 3rd attempt with Air Squared, Inc. in regard to development of an all metal vacuum scroll pump for consideration as an equivalent to the Eumeca/ Normetex pump. The effort specified 300 series stainless steel for the scroll impellers, all metal sealing, and design to meet tritium throughput and ultimate vacuum requirements. In addition, a 60 psig design pressure rating requirement was specified for the pump containment boundary. The 3rd generation Air Squared pump has been designed, fabricated, and has received preliminary testing. Preliminary testing has indicated proper leak tightness and pump performance. However, work continues regarding development of a pumping chamber containment bellows that can be subjected to 66 psig without damage to the bellows. Work will continue in 2020 and 2021 to pursue a pumping chamber containment bellows that meets the pressure rating requirement.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2020

Watertight Tensor-Product Spline Reconstruction (KCNSC PDRD Technical Report)

The standard for representing geometric models in Computer Aided Design (CAD) systems is boundary representation with trimmed surfaces. However, the approximate nature of surface-surface intersections in CAD systems leaves many small gaps between mating surfaces. These gaps lead to problems for downstream analysis and manufacturing applications, requiring time consuming repair operations and further approximation of the geometry as polygonal meshes, which do not support design iteration. In this study, nVariate, Inc. evaluated its watertight reconstruction technology on a test part. The resulting watertight model has the same absolute model accuracy of the original model zero gaps, providing a representation that requires no repair and supports further design iterations in the CAD system.

42 ENGINEERING↗
DOE OSTI2020

Photo-cleaned Backgroundless Ion Chambers (Final Report for PDRD SR18010)

Ion chambers are often employed to measure the concentration of tritium within flowing gases. In real world environments the active surfaces of ion chambers become covered with tritiated surface contaminants. This tritiated surface contamination will create a large background response that can mask the signature of interest, which is the tritium concentration in the gas phase. Previous efforts to reduce the effects of surface contamination in ion chambers utilize inert coatings (e.g., gold) and low surface area electrodes (e.g., wire mesh), but this route only reduces the effect and does not necessarily alter the ratio of surface contamination to current collection area. Additionally, gold coating may add a substantial cost to the instrument. In the Tritium Facility, ion chambers are periodically cleaned using an alcohol-based process. This process is time consuming and often leads to ion chamber wear and breakage. In addition, periodic cleaning does not address tritium level ambiguities in gloveboxes. An ideal solution to this issue would be to either develop an ion chamber that does not accrue surface contamination, or one that is self-cleaning while it is in operation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2023

Porous Polymeric Materials FY24 PDRD Final Report

Fillers and pore formers are used in many materials at Kansas City National Security Campus (KCNSC) to fine tune density and stiffness. Current off-the-shelf options such as urea and Expancel do not always provide the desired properties. This project investigated several methods for introducing porosity in rigid polymers such as epoxy and polyurethane. This work was done at partnering universities to identify a variety of methods to create porous polymeric materials. The University of Oklahoma (OU) investigated emulsion templating of epoxy, where the epoxy is mixed with a surfactant and water to form an emulsion. The emulsion is then molded and cured. During the cure process, water droplets evaporate to form porous structures. Total porosity can be tuned by changing the concentration of water added to the polymer. The University of Kansas (KU) investigated the synthesis of phenolic microballoons by spray drying, as well as methods of incorporating removable porogens into epoxy and polyurethane materials to create polymeric foams.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1987

United States Space Station technical and programmatic interfaces

This paper describes the design of the U.S. Space Station and explains the control factors used for internal and external interfaces among the various government and contractor participants. It discusses the documentation of the U.S. Space Station Program including the Program Approval Document (PAD), the Program Plans (PPs), the Program Requirements Document (PRD), the Program Definition and Requirements Document (PDRD), the Level III project plans, and the Level III project design requirements documents. It discusses the relationship of Space Station documentation to the international Memoranda of Understanding (MOUs) and the Joint PP, PRD, and PDRD, the interrelationship of the Architectural Control Documents (ACDs), the Baseline Control Document (BCD), and the Interface Requirement Documents (IRDs) and Interface Control Documents (ICDs). Also included are the controlling functions of the various NASA and contractor participants and the international partners.

Carlisle, Richard F.↗
DOE OSTI2019

Comprehensive Automated Welder System

The Comprehensive Automated Welder System - PDRD SR-17-007 project was initiated to develop hardware and software to eliminate possible error pre-cursor functions of the pinch welding process that require manual manipulation and data entry as well as leveraging 21st century technology advances by replacing obsolete hardware with state of the art maintainable equipment. The project plan targeted three primary areas for improvement: 1. Replacing the existing welding power supply system with a solid-state power supply, 2. Improving the data acquisition system, sensors and controls, and 3. Updating the software to a FPGA “real-time” program with automated steps. SRNL purchased, designed and installed in 723-A, a system to meet the requirements for these areas. While improvements in hardware controls and sensor selection were achieved and a successful software automation routine was demonstrated, the performance goals were not met with the custom solid-state power transformer.

42 ENGINEERING↗
DOE OSTI2020

SR19007 - Future TCAP Implementation Issues

This project demonstrates the success of the PDRD program in bringing a concept from the R&D phase to direct plant funding. Although Mini-TCAP technology is overall at a TRL of ~6.5, the specific questions addressed in this project were brought from a low (2-3 TRL) to a TRL 5 over the course of the project. This project successfully completed all initial goals ahead of schedule (inventory control, guard bed, ammonia impact, and cycle time) and furthermore addressed additional scope (continued TCAP evaluation, ion chamber) in FY20. First, this project resolved minor inventory control issues by introducing a new parameter tracking and correcting for inventory changes over multiple cycles. This project also involved modification of the previously constructed plant-configured Mini-TCAP in order to allow ammonia impurity studies. TCAP was tested with ammonia in the feed stream both with and without a guard bed present to determine guard bed efficacy and the effect of ammonia if it enters TCAP. The TCAP columns were then replaced with brazed columns, where the LN2 cooling coil is brazed to the column and the column is self-brazed along the coils. This drastically improved heat transfer and consequently reduced cycle time compared to the previous columns, in which the coils were mechanically held in place. Finally, additional scopes were taken on in FY20, including evaluation of TCAP with faster cycle time and procurement of ion chambers for future TCAP integration.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Fabricating and Testing Additively Manufactured Components for Tritium Service Consideration

This SRTE PDRD sponsored project produced test articles, tooling, and training articles for evaluation. In addition, the hydrogen compatibility of the alloys that can be readily produced by the Arcam A2X was tested. During the evaluation it was determined that the mechanical properties were more sensitive to build plate location than hydrogen exposure. Hydrogen pressure – volume-temperature experiments showed that the as-fabricated samples did not absorb hydrogen readily, but activated samples did.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Diffuser Braze Development

At the request of SRTE, through the PDRD project, SRNL is developing a vacuum brazing process to facilitate the fabrication of hydrogen purification systems. In particular, this effort is directed at tube-style hydrogen diffusers. The diffusers are comprised of numerous palladium-silver tubes that are brazed to a nickel fitting, which is subsequently welded to a stainless steel tube, fitting, or tube sheet. Historically, torch brazing has been used as a heat source; for this work vacuum furnace brazing was suggested to improve the uniformity of the process. This report describes the braze process development for braze selection and simple nickel fitting to tube brazing. Five braze alloys were selected and sessile drop testing was conducted over a range of temperatures from 25 to 75° C over the liquidus temperature. Samples were characterized for wetting angle, erosion, and brazability. The cup-to-tube braze joints were inspected using digital radiography, ultrasonic testing, and metallographic examination. Two of the five alloys exhibited excellent fabrication properties and are considered for further development.

36 MATERIALS SCIENCE↗
DOE OSTI2021

PD21A680: Additive Manufacturing Process Optimization and Qualification FY21 Year-end Report

This project builds upon knowledge gained from previous projects on Additive Manufacturing (AM) operation, process control and monitoring, repeatability, and process improvement. This project will exclusively focus on metal powder bed additive manufacturing (PBAM). Objective 1: Advance metal powder bed AM R&D capabilities. Perform enhanced R&D on increased build volumes and throughput, safety and handling controls, process monitoring, and diagnostics with a focus on production end-states. Objective 2: Build upon knowledge gained from previous PDRD projects to develop deeper understanding of process controls, essential for transitioning metal AM processes for future applications. Objective 3: Maintain business development and research advantages through collaborations with external industry and university partners.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Evaluation of Getters for Helium Purification

• Helium-3 is a vital commodity in both medical and defense applications • Ultra-low cryogenic coolant (MRI imaging, etc.) • Neutron detectors • Being investigated as possible fusion fuel • Managed and distributed by DOE-OS • New PDRD project exploring helium isotope separation • Limited supply • Only available from tritium decay • Prohibitively difficult to separate from helium-4 • SRS Tritium Facility provides a steady source

Angelette, Lucas M.↗
NASA NTRS1991

Dynamic and control assessment of the Space Station Freedom payload pointing system

An analysis of the proposed Space Station Freedom Payload Pointing System (PPS) was performed to assess its dynamic payload pointing capability in the dynamic environment of the Space Station Freedom (SSF). In addition, the stability and control the the SSF was examined to verify the capability of its control devices to accommodate the impact of PPS operations. An analysis of the PPS ability to provide continuous, accurate pointing was performed and compared to the program requirements specified in the 1988 Program Definition and Requirement Document (PDRD). Results indicated that the PPS was not able to perform within the program requirements during the worst case scenario of a shuttle hard docking maneuver to the port side SSF docking adapter. The PPS maintained marginal pointing accuracy during crew treadmill activity. The Space Station attitude control system easily accommodated all PPS operations simulated. The PPS caused a negligible impact on the SSF's control environment.

Shannon, David T., Jr.↗
NASA NTRS1992

Evolution design requirements and design strategy

Space Station Freedom (SSF) has undergone numerous design changes during the rephasing and restructuring activities occurring in 1989 and 1990/91, respectively. One direct result of these changes is that the Station has become more complex and compact which requires that future modifications to the Station be carefully planned and analyzed in conjunction with the baseline design process. This will ensure that the configuration has adequate design features and flexibility to accommodate the future capability and element upgrades. Six critical growth requirements (electrical power, thermal control, pressurized volume, structures, EVA equipment, and data management) have been identified and baselined in the Level I Program Requirements Document (PRD) and the Level II Program Definition and Requirements Document (PDRD). The approach to meeting the growth requirements will be to minimize the impact on the baseline design in the areas of weight, power, and development cost. The specifics of these requirements, with regard to scarring and implementation during the Follow-On and Evolution phases of SSF, are detailed in this paper.

Monell, D. W.↗
NASA NTRS1993

Using computer graphics to design Space Station Freedom viewing

Viewing requirements were identified early in the Space Station Freedom program for both direct viewing via windows and indirect viewing via cameras and closed-circuit television (CCTV). These requirements reside in NASA Program Definition and Requirements Document (PDRD), Section 3: Space Station Systems Requirements. Currently, analyses are addressing the feasibility of direct and indirect viewing. The goal of these analyses is to determine the optimum locations for the windows, cameras, and CCTV's in order to meet established requirements, to adequately support space station assembly, and to operate on-board equipment. PLAID, a three-dimensional computer graphics program developed at NASA JSC, was selected for use as the major tool in these analyses. PLAID provides the capability to simulate the assembly of the station as well as to examine operations as the station evolves. This program has been used successfully as a tool to analyze general viewing conditions for many Space Shuttle elements and can be used for virtually all Space Station components. Additionally, PLAID provides the ability to integrate an anthropometric scale-modeled human (representing a crew member) with interior and exterior architecture.

Goldsberry, Betty S.↗
NASA NTRS1994

Space Station Freedom secondary power wiring requirements

Secondary power is produced by DDCU's (direct current to direct current converter units) and routed to and through secondary power distribution assemblies (SPDA's) to loads or tertiary distribution assemblies. This presentation outlines requirements of Space Station Freedom (SSF) EEE (electrical, electronic, and electromechanical) parts wire and the approved electrical wire and cable. The SSF PDRD (Program Definition and Requirements Document) language problems and resolution are reviewed. The cable routing to and from the SPDA's is presented as diagrams and the wire recommendations and characteristics are given.

Sawyer, C. R.↗