FY2005 AND FY2006 CORROSION SURVEILLANCE RESULTS FOR L BASIN

Vormelker, P ; Cynthia Foreman, C

关键词: ALUMINIUM;    CONFIGURATION;    CORROSION;    EVALUATION;    KINETICS;    PITTING CORROSION;    SAND;    SLOWING-DOWN;    SPECTROSCOPY;    SPENT FUELS;    STORAGE;    WATER QUALITY;   

DOI  :  10.2172/923047
RP-ID  :  WSRC-STI-2007-00692
PID  :  OSTI ID: 923047
Others  :  TRN: US0802198

学科分类：核能源与工程

美国|英语

来源: SciTech Connect

【 摘 要 】

This report documents the results of the L-Basin Corrosion Surveillance Program for the fiscal years 2005 and 2006. The water quality and basin conditions for the coupon immersion period are compared to the corrosion evaluation results from detailed metallurgical analysis of the coupons. Test coupons were removed from the basin on two occasions, March 29, 2005 and May 23, 2006, examined and photographed. Selected coupons were metallurgically characterized to evaluate the extent of general corrosion and pitting. Crystallographic and energy dispersive spectroscopy analysis were performed on a typical specimen, as-removed from the basin, to characterize the surface debris. Marked changes were noted in both the 2005 and 2006 specimens compared to previous years corrosion results. A new pitting incidence has occurred on the faces of the aluminum coupons compared to localized pitting at crevice regions only on specimens withdrawn in 2003 and 2004. The pitting incidence is attributed to sand filter fines that entered the basin on July 27, 2004 from an inadvertent backflush of the new sand filter. Pitting rate results show a trend of slowing down over time which is consistent with aluminum pit kinetics. Average pit growth rates were equal to or lower in all 2006 aluminum coupons than those removed in 2005. A trend line shows that pitting corrosion rates on Al1100, 6061, and 6063 coupons are slowing down since pit depth measurements were initiated in 2003. No impact to stored spent fuel is expected from the debris. The storage configuration of the majority of L-Basin spent fuel, in bundles, should provide a measure of isolation from debris settling in the basin.