PEDRA: Different & Beyond Tradition

Here you will find examples of the PEDRA approach both from my own research at Atomic Energy Canada Limited (now Canadian Nuclear Labs) and those submitted to me for analysis.

EIS of Coatings - Overview

This Electrical Impedance Spectroscopy of Coatings article describes PEDRA model and three examples: 1) a simulated coating failure, 2) anodic oxide film development, and 3) thermal oxide film degradation.

EIS of Coatings
Word – 1.5 MB 59 downloads

Anodic Films

The PEDRA approach was first demonstrated using Anodic Films; oxide growth under controlled high induced stress conditions.

Anodic Film Report Docx
Word – 1.5 MB 57 downloads

EIS and AFM; Correlating the Power Law Term, n, with Fractal Character of Barrier Film Surface

Interpretation of the powder law term, n, to the surface oxide fractal character. Click to link to publication

Developing an Accelerated Test Capable of Predicting In-Service Behavior

TEM cross section were prepared using the FIBs technique in an effort to correlate visual internal porosity with EIS characterization.

Development Of A Screening Test For Candu Pressure Tubes Docx
Word – 941.7 KB 58 downloads

Effect Extrusion Variables on Oxidation of Zr2.5Nb

EIS at multiple 28 day, 300C water autoclave exposures. Can EIS predict long term performance. Oxidation of Zr2.5Nb having different pre-extrusion conditions.

Weight Gain Oxide thickness is compared to EIS oxide characterization. EIS results are reported as a Gaussian line graph overlay. Peaks: height - thickness, position - series resistance, width - proportional to the power law term.

Correlating In-service Behavior to EIS Characterization

EIS characterization of oxide film after low term exposures in CANDU power reactors performed remotely in Hot Cell stations.

Developing a Screening Technique to Predict In-Service Behavior

Four different accelerated exposure techniques on CANDU off-cuts were compared to in-service behavior.