Microstructural and Non-destructive Analysis

The MNA expert group

The microstructure and non-destructive analyses expert group at SCK•CEN is focussed on non-destructive examination of nuclear fuel on the one hand and microscopy and spectroscopy of nuclear materials on the other. More information can be found at http://www.sckcen.be/microstructure.

For the non-destructive analyses laboratory, the main object studied is irradiated nuclear fuel from various reactors and for various reasons. It can concern LWR (PWR, BWR) fuel, but also MTR or more exotic fuel. The objective of the examinations is to improve fuel performance or understand fuel behaviour to improve its behaviour or analyse its failure.

For the microstructural laboratory, the encountered materials encompass stainless steels, reactor pressure vessel steels, various nuclear fuel types, beryllium, zirconium alloys from fuel pin claddings, etc. The problems encountered are situated in the fields of corrosion, chemistry, fracture mechanics, thermodynamics, crystallography, etc.
Because of this vast range of materials, experimental techniques and materials science domains encountered, the focus is on the solution to the microstructural problem, rather than on the application of a technique or the knowledge of the material.
Essentially, we will attempt to acquire the necessary knowledge to solve technical or scientific questions using microstructural techniques.

Available techniques

Non-destructive testing techniques for irradiated fuel research:

• Visual inspection
• Length measurement
• Diameter measurement (profilometry)
• Oxide thickness measurement
• Cladding defect analysis
• X-ray radiography
• Gamma spectrometry
  • Gross gamma scanning
  • Quantitative spectrometry for burnup (137Cs) or power (140Ba-140La) evaluation
  • Quantitative spectrometry for fission gas release determination (85Kr method)
• Puncture analysis (destructive) and fission gas collection

Microstructural examination techniques:

• Sample Preparation Techniques
  • Cutting, embedding and polishing (metallography-ceramography)
  • Chemical Etching (metallography-ceramography)
  • Twin jet electropolishing (TEM)
  • Ion beam thinning (TEM)
• Optical microscopy (OM) and Vickers microhardness analysis
• Scanning Electron Microscopy with Energy Dispersive X-ray Analysis (SEM-EDS)
• Electron Probe Microanalysis (EPMA-WDS)
• X-ray Photoelectron Spectroscopy (XPS)
• X-ray Diffraction Analysis (XRD)
• Transmission Electron Microscopy (TEM)