CORROSION ASSESSMENT OF METAL OVERPACKS FOR RADIOACTIVE WASTE DISPOSAL
The results and conclusions derived from the UK test programme on overpack materials for the geologic disposal of radioactive waste are described. Two concepts for producing long-life overpacks are currently under assessment involving the use of corrosion resistant and corrosion allowance materials. The candidate metals under evaluation are commercial purity Ti, Ti-0.2% Pd, Hastelloy C4 (resistant) and cast and forged carbon steel (Allowance). Recent work has concentrated on the corrosion allowance concept, and has shown that the rate of general dissolution is effectively controlled by the supply of oxidizing species to the overpack surface. Estimates taking account of groundwater flow rate and radiation dose suggest the metal loss will be of the order of 23 mm in 1000 years. Tests are described which are assessing the additional depth of metal likely to be penetrated by localized corrosion, and the results of experiments investigating the possibility of biological activity on the endurance of corrosion allowance overpacks is identified as a factor needing further evaluation. In the case of titanium based corrosion resistant overpacks it has been concluded that the first priority should be to establish the long term stability of the passivating Ti0-2 surface film.
Bibliographic Reference: EUROPEAN APPLIED RESEARCH REPORTS - NUCLEAR SCIENCE AND TECHNOLOGY SECTION, VOL. 5 (1983), NO. 2, PP. 223-252 (EUR 8658 E).
Availability: Can be ordered online
Record Number: 1989122014900 / Last updated on: 1987-01-01
Available languages: en