Materials in Nuclear Energy Systems (MiNES) 2021: Advanced and Novel Materials- Session I
Program Organizers: Todd Allen, University of Michigan; Clarissa Yablinsky, Los Alamos National Laboratory; Anne Campbell, Oak Ridge National Laboratory
Wednesday 4:00 PM
November 10, 2021
Room: Urban
Location: Omni William Penn Hotel
Session Chair: Steven Zinkle, University of Tennessee
4:00 PM Invited
Overview of Fuel System Options for Nuclear Thermal Propulsion: Kelsa Palomares1; Douglas Burns2; Harold Gerrish3; 1Analytical Mechanics Associates; 2Idaho National Laboratory; 3NASA Marshall Space Flight Center
An in-space propulsion technology, nuclear thermal propulsion (NTP) has the potential to enable faster interplanetary transit times compared to traditional chemical propulsion methods due to its capacity for high specific impulse (900+ s) and thrust (~5 – 250 klbf). Because of these performance attributes, NTP is currently an advanced propulsion technology under consideration by the National Aeronautics and Space Administration (NASA) for future crewed Mars missions. The performance of NTP systems is directly contingent upon the development of a robust fuel form capable of withstanding high power densities and operation in a hydrogen environment at temperatures in excess of 2500 K. NASA, supported by the Department of Energy, is leading the development of NTP fuels and reactor materials under the space nuclear propulsion project. This presentation will overview development needs for fuels in NTP systems, historic and current fuel system options, and their remaining challenges prior to successful implementation.
4:40 PM
Grain Growth and Mechanical Properties of Nano ZrO2 Oxide Dispersion Strengthened Mo30W: Neal Gaffin1; Kelsa Palomares2; Justin Milner3; Caen Ang1; Steven Zinkle1; 1University of Tennessee - Knoxville; 2Analytical Mechanics Associates Inc.; 3NASA Glenn Research Center
Molybdenum alloys are ideal candidates for the metal matrix of a cermet based nuclear thermal propulsion system due to their high melting points, hydrogen compatibility, low neutron absorption cross-section, and good strength retention at high temperatures. A molybdenum alloy with 30 wt% tungsten (Mo30W) has been produced by consolidating pre-alloyed powders using spark plasma sintering. Given the high operating temperature of an NTP system (above 2500 K), run away grain growth can be an issue. Oxide dispersion strengthening with nano zirconium dioxide (ZrO2) is being considered to both strengthen the material and to pin grain boundaries at high temperatures. Pure Mo30W and samples with 1.5 and 10 wt% ZrO2 have been fabricated. These samples will undergo heat treatments up to 2200 ºC (2473 K) to compare the change in grain growth. Both hardness and compressive strength testing will be conducted to determine the strengthening effect of the YSZ additions.
5:00 PM
A Study of the Corrosion Behavior of Cold-sprayed 304L Stainless Steel for Dry Storage Canisters: Richard Chiang1; Harsha Naralasetty1; Venkata Bhattiprolu2; Christopher Roper2; Paul Allison2; Luke Brewer2; Vijay Vasudevan1; 1University of Cincinnati; 2University of Alabama
Dry storage canisters to store SNF are mainly fabricated from 304L SS. Under certain conditions of humidity, temperature and salt chemistry, their weldments are known to be susceptible to localized corrosion and SCC. Cold spray is emerging as a promising technique for repairing pits and cracks. In this investigation, the corrosion behavior of cold-sprayed 304L was compared to the baseline 304L substrate using DLEPR and EIS. Additionally, changes to the corrosion behavior after heat treatment (recrystallization and sensitization) and with the mechanical surface treatments of LSP and UNSM was also investigated. Characterization of the microstructure was conducted using SEM, EBSD, EDS and TEM. The results indicate a notable difference between the cold-sprayed 304L and baseline material with significant impacts from the heat treatments on the corrosion behavior. The specific complexities as effected by the cold spray process, heat treatment and surface treatment will be presented and discussed.
5:20 PM
Cold Spray for Repair of Nuclear Power Plant Components: Mike Ickes1; Arash Parsi1; 1Westinghouse Electric Company
Cold spray is a materials deposition process in which small metallic particles, or blends of metallic and non-metallic particles, are accelerated using a high pressure gas stream above a critical threshold velocity out of a de Laval type rocket nozzle. and bind to a surface of a suitable substrate upon impact. The temperature of the particles are significantly below the melting point of the impinging particles, giving rise to the ‘cold’ in cold spray. Westinghouse is developing cold spray technology for a wide variety of applications that benefit from cold spray’s ability to apply continuous high hardness corrosion resistant material deposits. These include protection from stress corrosion cracking, repair and mitigation of erosion and corrosion damage in carbon steel piping, and dimensional restoration of components.Key results of Westinghouse’s research in cold spray will be presented, with applications focused on repair and mitigation of degradation in nuclear power plant equipment.
5:40 PM Cancelled
Metal and Amorphous Ceramic Composites for Extreme Conditions: Jian Wang1; Kaisheng Ming2; Binqiang Wei1; Michael Nastasi3; 1University of Nebraska-Lincoln; 2Hebei University of Technology; 3Texas A&M University
Strong, ductile, and irradiation tolerant structural materials are in urgent demand for improving the safety and efficiency of advanced nuclear reactor. Amorphous ceramics could be very promising candidates for high radiation tolerance since they do not contain conventional crystal defects that are induced in crystalline materials under irradiation. However, amorphous ceramics exhibit ‘brittle-like’ behavior. We realized the strength-ductility-irradiation tolerance combination of amorphous ceramic composites (ACCs) through tailoring nanosized heterogeneities. Principles for the design of such ACCs are that metal elements should prefer to form nanosized metal-rich clusters in ACCs. Moreover, the phase structure and properties of the heterogeneity can be modified by synthesis and annealing conditions. By averting plastic flow localization and enhancing irradiation tolerance, we impart to ACCs the ability to undergo both uniform plastic deformation and irradiation tolerance, markedly advancing their potential for use in nuclear industry as core structural materials.