Characterization of LaNi{sub 4.25}Al{sub 0.75} tritide for use as a long term tritium storage medium
Applications of metal hydride technology has offered numerous safety as well as operating advantages for tritium processing operations. The SRS Replacement Tritium Facility (RTF) utilizes this technology extensively. During design of the RTF systems, LaNi{sub 4.25}Al{sub 0.75} (LANA.75) was chosen as the primary tritium storage material. This material was selected largely because of the isotherm plateau pressure, which allows the tritium to be stored as a metal tritide at subatmospheric pressures while still being able to generate pressures of >1000 mm Hg needed for process applications. A benefit of this substitution is an increase in the stability of this material to tritium aging effects and to disproportionation. The LANA.75 material, like many metal tritides used for tritium processing, retains insoluble helium-3 which is born in the metal lattice through radiolytic decay of tritium. This causes changes in the thermodynamics of the metal-hydrogen system, decreasing the {alpha}-{beta} plateau pressure, increasing the plateau slope, and decreasing the reversible hydriding capacity. The latter also includes the growth of a tritium {open_quotes}heel{close_quotes} which cannot be removed under normal processing conditions. All of these factors affect the long-term performance of LANA.75-tritide in processing applications. Tritium aging studies have been underway on LANA.75 since 1987 in the SRTC Materials Test Facility. Material characterization of LANA.75-tritide has been completed on material exposed to tritium for 5.4 years at full stoichiometry.
- Research Organization:
- Westinghouse Savannah River Co., Aiken, SC (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC09-89SR18035
- OSTI ID:
- 10188182
- Report Number(s):
- WSRC-MS-94-0476; CONF-9409181-8; ON: DE95001239; TRN: 94:021098
- Resource Relation:
- Conference: 19. Department of Energy conference on compatibility, aging and service life,Los Alamos, NM (United States),28-30 Sep 1994; Other Information: PBD: [1994]
- Country of Publication:
- United States
- Language:
- English
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