skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Thermal Release of 3He from Tritium Aged LaNi 4.25Al 0.75 Hydride

Abstract

Recently, the demand for He-3 has increased dramatically due to widespread use in nuclear nonproliferation, cryogenic, and medical applications. Essentially all of the world’s supply of He-3 is created by the radiolytic decay of tritium. The Savannah River Site Tritium Facilities (SRS-TF) utilizes LANA.75 in the tritium process to store hydrogen isotopes. The vast majority of He-3 “born” from tritium stored in LANA.75 is trapped in the hydride metal matrix. The SRS-TF has multiple LANA.75 tritium storage beds that have been retired from service with significant quantities of He-3 trapped in the metal. To support He-3 recovery, the Savannah River National Laboratory (SRNL) conducted thermogravimetric analysis coupled with mass spectrometry (TGA-MS) on a tritium aged LANA.75 sample. TGA-MS testing was performed in an argon environment. Prior to testing, the sample was isotopically exchanged with deuterium to reduce residual tritium and passivated with air to alleviate pyrophoric concerns associated with handling the material outside of an inert glovebox. Analyses indicated that gas release from this sample was bimodal, with peaks near 220 and 490°C. The first peak consisted of both He-3 and residual hydrogen isotopes, the second was primarily He-3. The bulk of the gas was released by 600 °C

Authors:
 [1];  [1];  [1]
  1. Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
Publication Date:
Research Org.:
Savannah River Site (SRS), Aiken, SC (United States)
Sponsoring Org.:
USDOE Office of Environmental Management (EM)
OSTI Identifier:
1177877
Report Number(s):
SRNL-STI-2014-00110
Journal ID: ISSN 1536-1055; TRN: US1500499
Grant/Contract Number:
AC09-08SR22470
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Fusion Science and Technology
Additional Journal Information:
Journal Volume: 67; Journal Issue: 3; Journal ID: ISSN 1536-1055
Publisher:
American Nuclear Society
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; Tritium, hydrogen isotopologs, LANA.75, Savannah River Site Tritium Facilities (SRS-TF)

Citation Formats

Staack, Gregory C., Crowder, Mark L., and Klein, James E.. Thermal Release of 3He from Tritium Aged LaNi4.25Al0.75 Hydride. United States: N. p., 2015. Web. doi:10.13182/FST14-T84.
Staack, Gregory C., Crowder, Mark L., & Klein, James E.. Thermal Release of 3He from Tritium Aged LaNi4.25Al0.75 Hydride. United States. doi:10.13182/FST14-T84.
Staack, Gregory C., Crowder, Mark L., and Klein, James E.. Sun . "Thermal Release of 3He from Tritium Aged LaNi4.25Al0.75 Hydride". United States. doi:10.13182/FST14-T84. https://www.osti.gov/servlets/purl/1177877.
@article{osti_1177877,
title = {Thermal Release of 3He from Tritium Aged LaNi4.25Al0.75 Hydride},
author = {Staack, Gregory C. and Crowder, Mark L. and Klein, James E.},
abstractNote = {Recently, the demand for He-3 has increased dramatically due to widespread use in nuclear nonproliferation, cryogenic, and medical applications. Essentially all of the world’s supply of He-3 is created by the radiolytic decay of tritium. The Savannah River Site Tritium Facilities (SRS-TF) utilizes LANA.75 in the tritium process to store hydrogen isotopes. The vast majority of He-3 “born” from tritium stored in LANA.75 is trapped in the hydride metal matrix. The SRS-TF has multiple LANA.75 tritium storage beds that have been retired from service with significant quantities of He-3 trapped in the metal. To support He-3 recovery, the Savannah River National Laboratory (SRNL) conducted thermogravimetric analysis coupled with mass spectrometry (TGA-MS) on a tritium aged LANA.75 sample. TGA-MS testing was performed in an argon environment. Prior to testing, the sample was isotopically exchanged with deuterium to reduce residual tritium and passivated with air to alleviate pyrophoric concerns associated with handling the material outside of an inert glovebox. Analyses indicated that gas release from this sample was bimodal, with peaks near 220 and 490°C. The first peak consisted of both He-3 and residual hydrogen isotopes, the second was primarily He-3. The bulk of the gas was released by 600 °C},
doi = {10.13182/FST14-T84},
journal = {Fusion Science and Technology},
number = 3,
volume = 67,
place = {United States},
year = {Sun Feb 01 00:00:00 EST 2015},
month = {Sun Feb 01 00:00:00 EST 2015}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

Save / Share:
  • The Savannah River Site Tritium Facilities (SRS-TF) utilizes LANA.75 (LaNi{sub 4.25}Al{sub 0.75})in the tritium process to store hydrogen isotopes. The vast majority of {sup 3}He born from the radioactive decay of tritium stored in LANA.75 is trapped in the hydride metal matrix. The SRS-TF has multiple LANA.75 tritium storage beds that have been retired from service with significant quantities of He-3 trapped in the metal. To support He-3 recovery, the Savannah River National Laboratory (SRNL) conducted thermogravimetric analysis coupled with mass spectrometry (TGA-MS) on a tritium aged LANA.75 sample. TGA-MS testing was performed in an argon environment. Prior to testing,more » the sample was isotopically exchanged with deuterium to reduce residual tritium and passivated with air to alleviate pyrophoric concerns associated with handling the material outside of an inert glovebox. Analyses indicated that gas release from this sample was bimodal, with peaks near 220 and 490 C. degrees. The first peak consisted of both {sup 3}He and residual hydrogen isotopes, the second was primarily {sup 3}He. The bulk of the gas was released by 600 Celsius degrees. (author)« less
  • Metal hydrides are being used as electrodes in nickel/metal-hydride batteries because of their ability to store large quantities of hydrogen and because of their many advantages over conventional lead-acid and nickel-cadmium batteries. The performance of a metal hydride electrode is determined by both the kinetics of the processes occurring at the metal/electrolyte interface and the rate of hydrogen diffusion within the bulk of the metal. The constant potential and constant current discharge techniques were used to determine the hydrogen diffusion coefficients in an LaNi{sub 4.25}Al{sub 0.75} electrode. The values obtained were 2.97 {times} 10{sup {minus}11} and 3.30 {times} 10{sup {minus}11}more » cm{sup 2}/s, respectively. The advantages and disadvantages of these two techniques are discussed.« less
  • A comparison is made of the electrochemical and structural properties of LaNi{sub 4.25}Al{sub 0.75} alloys in thin film and powder forms. X-ray diffraction (XRD) revealed that both the LaNi{sub 4.25}Al{sub 0.75} thin film and powder materials are crystalline. Atomic force microscopy (AFM) and focused ion beam microscopy (FIB) proved that the film appeared to have a hill-like surface morphology, but was rather dense with a thickness of about 4.2 {mu}m. Simulated battery tests indicate that both exhibit similar electrochemical behavior, possibly due to their crystal structure, as it requires a primary activation to reach its fully active state. However itmore » took a longer activation period for the film to be activated; an apparent initial decrease of charging voltage with cycle number was observed, as were abnormal discharge processes during activation. After 30 charge/discharge cycles, small needle-shaped aluminium oxide particles were formed on both the powder and film surfaces.« less
  • Tritium desorption isotherms and helium release properties are reported for three different LaNi4.25Al0.75 samples having 11-1/2 and 13 years of tritium exposure, and are compared to earlier data from similar samples with less exposure. The isotherms show a complete loss of the typical plateau structure, and a decreasing absorption capacity. However, the capacity loss is not due to further increase in heel content. Helium breakout is shown to occur in one sample when the T content became low.
  • Tritium aging studies have shown that LaNi{sub 4.25}Al{sub 0.75} (LANA .75) tritide storage material undergoes significant degradation with tritium aging. After 5.4 years of dormant storage at full stoichiometry, which is considered a worst-case condition for this material, the performance is still acceptable for SRS tritium processing applications. The isotherms change, decreasing the desorption pressures, increasing the isotherm plateau slopes, and decreasing the total storage capacity. Eventually, the material will degrade with time to the point where it may no longer be useful for tritium processing applications. At the end of life, the tritium heel can be exchanged with protiummore » or deuterium to produce a final material containing very little tritium.« less