Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

Technical Report · Sun May 01 00:00:00 EDT 1988

OSTI ID:7271997

Farmer, J C; Van Konynenburg, R A; McCright, R D ^[1]; Gdowski, G E ^[2]

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1. Lawrence Livermore National Lab., CA (USA)
2. Science and Engineering Associates, Inc., Pleasanton, CA (USA)

Three copper-based alloys --- CDA 102 (OFHC copper), CDA 613 (aluminum bronze), and CDA 715 (Cu-30Ni) --- are being considered as possible materials for the fabrication of high-level radioactive-waste disposal containers. Waste will include fuel assemblies from reactors as well as borosilicate glass forms, and will be sent to the prospective repository at Yucca Mountain, Nevada, for emplacement. The three copper-based alloys discussed here are being considered in addition to the iron- to nickel-based austenitic materials discussed in Volume 3. The decay of radionuclides will result in substantial heat generation and in fluxes of gamma radiation. In this environment, container materials may degrade by atmospheric oxidation, uniform aqueous phase corrosion, pitting, crevice corrosion, transgranular stress corrosion cracking (TGSCC) in tarnishing environments, or intergranular stress corrosion cracking (IGSCC) in nontarnishing environments. This report is a critical survey of available data on the stress corrosion cracking (SCC) of the three copper-based alloys. The requisite conditions for TGSCC and IGSCC include combinations of stress, oxygen, ammonia or nitrite, and water. Note that nitrite is generated by gamma radiolysis of moisture films in air but that ammonia is not. TGSCC has been observed in CDA 102 and CDA 613 exposed to moist ammonia-containing environments whereas SCC has not been documented for CDA 715 under similar conditions. SCC is also promoted in copper by nitrite ions. Furthermore, phosphorus-deoxidized copper is unusually susceptible to embrittlement in such environments. The presence of tin in CDA 613 prevents IGSCC. It is believed that tin segregates to grain boundaries, where it oxidizes very slowly, thereby inhibiting the oxidation of aluminum. 117 refs., 27 figs., 9 tabs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• Sponsoring Organization: DOE/RW
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7271997
• Report Number(s): UCID-21362-Vol.4; ON: DE90006360; TRN: 90-008079
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
42 ENGINEERING
36 MATERIALS SCIENCE
COPPER BASE ALLOYS
STRESS CORROSION
HIGH-LEVEL RADIOACTIVE WASTES
CONTAINERS
AMMONIA
AMMONIUM HYDROXIDES
BRONZE
CORROSIVE EFFECTS
CRACK PROPAGATION
EQUILIBRIUM
MICROORGANISMS
NITRITES
OXIDES
PH VALUE
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTE STORAGE
RAMAN SPECTRA
SPENT FUEL CASKS
STEAM
ALLOYS
AMMONIUM COMPOUNDS
CASKS
CHALCOGENIDES
CHEMICAL REACTIONS
COPPER ALLOYS
CORROSION
HYDRIDES
HYDROGEN COMPOUNDS
HYDROXIDES
MANAGEMENT
MATERIALS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
OXYGEN COMPOUNDS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
SPECTRA
STORAGE
TIN ALLOYS
WASTE DISPOSAL
WASTE MANAGEMENT
WASTE STORAGE
WASTES
052002* - Nuclear Fuels- Waste Disposal & Storage
420204 - Engineering- Shipping Containers
360105 - Metals & Alloys- Corrosion & Erosion
360103 - Metals & Alloys- Mechanical Properties