Westinghouse Electric Corporation

Shih-Ming Ho

Kenneth C Radford

Bulent E Yoldas

Douglas M Mattox

A burnable absorber-containing glaze is formed on nuclear fuel pellets by applying a finely divided mixture of a boron-containing burnable absorber and a boron-containing glass to the pellet surface as a coating and firing the coated pellets at 900.degree.-1100.degree. C., for about 5 to 15 minutes, to melt the boron-containing glass and encapsulate the boron-containing burnable absorber. The coating is of a thickness of 1 mil or less and contains an amount of B.sup.10 sufficient to provide desired absorption of neutrons during reactor operation. The resultant pellets exhibit good adhesion of the coating and excellent resistance to moisture adsorption.

Burnable absorber-containing nuclear fuel pellets and formation of the

Method for preparing finely divided high purity alumina doped with a small predetermined percentage of magnesia. In the preparation, there is first formed a mixed clear solution of aluminum alkoxide and a small amount of magnesium in the form of alkoxide or water soluble magnesium salt. There is then included with the clear solution a substantial excess of water over that required to completely hydrolyze the alkoxide and there is added thereto a small amount of selected acid which is effective to peptize the resulting slurry. The formed milky slurry is then allowed to become fully peptized to form a clear sol. The clear sol is converted to a finely divided and dried powder either by forming the sol into a gel, which is then dried, and mechanically reduced to a powder status or by spray drying the sol at elevated temperatures which produces the dried powder. Thereafter, the finely divided and dried powder is calcined at a temperature of from about 700.degree. C. to about 900.degree. C., with the crystalline structure of the powder predominately being that of a delta alumina. The preparation of this alumina is very economic and the resulting material is suitable for being isostatically pressed into a tubular form and then sintered to translucent tubular form to a density which closely approaches theoretical.

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Penn Hills, PA, United States of America

Shih-Ming Ho