Heat exchanger tubes (4 specimens) provided by Paks NPP Ltd. (Hungary) were investigated in order to study the efficiency of oxide layer removal, as well as the corrosion and solution chemical effects of the FRAMATOME CORD-UV technology. Decontamination factors of the treated surfaces were determined by γ-spectroscopic methods. The average corrosion rates of the inner surface of the heat exchanger tubes were measured by potentiostatic polarization technique. Modifications of the morphology, chemical and phase composition of the oxide layer were studied by SEM-EDX, XRD and Mössbauer Spectroscopy (CEMS) methods. The amount of disperse (colloid) and/or' dissolved corrosion products removed from the tube surface into the solutions during the chemical cleaning procedure and the boric acid treatment was analyzed by ICP-OES and gravimetric methods. The above studies reveal that the decontamination efficiency of the present version of the CORD-UV technology is basically low. The CORD-UV procedure does not exert detrimental effects on the passivity (average corrosion rate) of the inner surfaces. The thickness of the oxide layer removed is decisively dependent oh the chemical composition and stability of the surface oxide layer as well as on the appropriate application of the CORD-UV technology.
|Translated title of the contribution||A systematic study of the CORD-UV technology|
|Number of pages||12|
|Publication status||Published - nov. 10 2004|
ASJC Scopus subject areas
- Chemical Engineering(all)
- Surfaces, Coatings and Films
- Materials Chemistry