PROJECT DESCRIPTION
High-resolution measurements of void-fraction distributions at high pressure conditions and/or in complex geometry such as fuel are particularly challenging. Within this project we have designed and built a gamma-tomography system for non-intrusive measurements of void-fraction distributions in high pressure fuel bundle mock-ups.
In a tomography system, a source and a detector arc are placed around the object to be measured. Several “projections” of the object are measured at different angles around the object to build a “sinogram”. Then, tomographic algorithms are used to reconstruct the measured object.
In a tomography system, a source and a detector arc are placed around the object to be measured. Several “projections” of the object are measured at different angles around the object to build a “sinogram”. Then, tomographic algorithms are used to reconstruct the measured object.
Tomography System
Sinogram
Reconstructed Object
IN-HOUSE GAMMA-TOMOGRAPHY CHARACTERISTICS
- 15 Ci gamma source
- 1 mm spatial resolution
- modular built for detector arc and electronics, each module has 8 detectors
- Wi-fi capability => tomography operation, data acquisition and data retrieving can be carried out remotely with a single PC
- 2 energy thresholds per detector channel
- individual gain / bias control for each detector channel SiPM
- detector arc electronics works with any gamma source (Cs-137, Co-60, etc,) as well as for neutron tomography
RESULTS
SIEMENS STAR
Mock-up
Reconstruction
Setup Conditions
- 5cm diameter plastic Siemens star
- Stainless steel pipe
- 181 projections over 360 degree
- Spatial resolution of ~1mm confirmed
LARGE FIELD OF VIEW
- Left: plastic rod OD 15.3mm
- Center: Carbon Steel Hex socket OD 28mm, ID 17 mm
- 361 projections over 360 degree
FUEL BUNDLE MOCKUP
- 5x5 fuel bundle mock-up
- HT800 rods, wall thickness 0.9 mm
