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Tests were performed on aluminum alloys to evaluate their behavior in high-temperature, high-pressure. watercooled and -moderated nuclear reactor enviromnents. Test equipment, sample preparation. and test procedures are discussed. Aluminum nickel alloys were found resistant to disintegration for periods up to 60 days in dynamic water at 600 ction prod- F. The corrosion rates of the aluminum alloys M-388 and X-2219 at 600 ction prod- F were found to be too high to merit consideration for cladding materials. The influence of pH. gas content, and velocity of the water on the corrosion of the above alloys was evaluated. Hydrogen addition at startup appeared to increase the degree of corrosion attack on the M-388 alloy. Irradiation tests on aluminum-nickel alloys revealed that the corrosion rate increased with distance from core. In-reactor samples of M-388 exhibited less corrosion attack than out-of-reactor samples. Boiling water corrosion tests were performed on M-388 for 1612 hr at 422 ction prod- F with an average heat flux of 25,000 Btu per hrft/sup 2/. The over- all corrosion rate was 2.9 mil per yr. It is concluded that the corrosion rate of M-388 is more » acceptable for the specified test conditions: (1) absence of radiation: (2) demineralized water at 422 ction prod- F; and (3) heat transfer rates not exceeding 40,000 Btu per ft/sup 2/. No accelerated corrosion attack due to boiling heat transfer and no significant buildup of corrosion products on heat transfer surfaces were noted. Accelerated corrosion of M-388 was noted when coupled with Type 304 stainless steel and exposed to tap water at room temperature, or air-saturated, demineralized water at 680 ction prod- F. A technique for stripping corrosion films from aluminum and aluminum-nickel alloys is given. (C.J.G.) « less |
