RT Conference Proceedings
T1 Corrosion of several components of the "in-situ" test performed in a deep geological granite disposal site
A1 Madina, Virginia
A1 Azkarate, Iñaki
A1 Insausti, Mikel
AB The corrosion damage experienced by different components in a deep geological disposal in a granite formation has been analysed. This "in-situ" test is part of the Full-scale Engineered Barriers EXperiment project (FEBEX) carried out in Grimsel (Switzerland). Two heaters, simulating the canister and the heat generated, were installed horizontally inside the guide tubes or liners and surrounded by highly compacted bentonite blocks. Coupons of several candidate metals for manufacturing HLW containers were introduced in these bentonite blocks, as well as sensors in order to monitor different physicochemical parameters during the test. The "in- situ" test began in July 1996 and in June 2002 one of the heaters, a section of the liner, several corrosion coupons and four sensors were extracted. The studied heater is a carbon steel cylinder with welded lids, with a wall thickness of 100 mm and 4.54 m long. The liner consists of a perforated carbon steel tube, 970 mm in diameter and 15 mm thick. Corrosion coupons were made of carbon steel, stainless steel, titanium, copper and cupro-nickel alloys. Two extensometer type sensors with an outer protection tube made of austenitic stainless steel were also analysed. Visual inspection of the above mentioned components, optical and scanning electron microscope study, together with EDS and XRD analyses of corrosion products, have been performed in order to analyse the corrosion suffered by these components. This has been complemented with the chemical and microbiological characterisation of bentonite samples. Results obtained in the study indicate a slight generalised corrosion for the heater, liner and corrosion coupons. The low humidity content of the bentonite surrounding the liner and the corrosion coupons, is the responsible of this practical absence of corrosion. The sensors studied show, however, an important corrosion damage. The sulphur rich corrosion products, the presence of Sulphate Reducing Bacteria (SRB) in the bentonite covering the sensors, as well as the morphology of the damage, indicate a corrosion phenomena induced by bacteria. This factor, together with the high humidity of the bentonite blocks housing the sensors, are responsible for the significant corrosion damage observed in these components.
YR 2004
FD 2004
LK https://hdl.handle.net/11556/4639
UL https://hdl.handle.net/11556/4639
LA eng
NO Madina , V , Azkarate , I & Insausti , M 2004 , ' Corrosion of several components of the "in-situ" test performed in a deep geological granite disposal site ' , Paper presented at European Corrosion Conference: Long Term Prediction and Modelling of Corrosion, EUROCORR 2004 , Nice , France , 12/09/04 - 16/09/04 .
NO conference
DS TECNALIA Publications
RD 1 sept 2024