The long-term corrosion behavior of titanate ceramics for Pu disposition : rate-controlling processes.

Conference · Thu Dec 02 04:00:00 EST 1999

OSTI ID:750475

Bakel, A J; Mertz, C J; Hash, M C; Chamberlain, D C

The corrosion behavior of a titanate ceramic was investigated with the aim of describing the rate-controlling process or processes. These titanate ceramics are similar to SYNROC and are proposed as immobilization materials for surplus Pu. The corrosion behavior was described with results from MCC-I and PCT-B static dissolution tests. Three important observations were made: (a) Ca is released at a constant rate [6x10{sup -5}g/(m{sup 2} day)] in PCT-B tests for up to two years, (b) all of the test leachates are oversaturated with respect to rutile and anatase, and (c) the release rates for Pu and Gd increase with time (up to two years) in PCT-B tests. The first observation suggests that the ceramics continue to corrode at a low rate for at least 2 years in PCT-B tests. The second observation shows that the rate of the corrosion reaction is not affected by the concentration of Ti in solution, suggesting that the approach to saturation with respect to either rutile or anatase is not a rate-limiting process. The third observation shows that the rate of Pu and Gd release increases with time in these tests. While this observation cannot be fully explained at this point, two possible explanations, alteration phase formation and grain boundary corrosion, are forwarded.

• Research Organization: Argonne National Lab., IL (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 750475
• Report Number(s): ANL/CMT/CP-99412
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
CERAMICS
CORROSION RESISTANCE
DISSOLUTION
LEACHATES
PLUTONIUM
RADIOACTIVE WASTE DISPOSAL
RUTILE
TITANATES
WASTE FORMS