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Qualification of
the Improved Rotating Probe Process for Steam Generator tubes
inspection
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Denis
CASTON - CEGELEC NDT
Bourg de Péage - France |
In 1997, EDF invited tenders for supplying
Eddy Current (EC) probes in order to improve the inspection
of the roll transition zone of Steam Generator (SG) tubes.
Several manufacturers met EDF’s requirements, and after
full assessment, EDF chose one between several EC rotating
probe prototypes.
After consultation, EDF chose CEGELEC
NDT’s services from French SG NDT subcontractors, to
inspect a limited number of tubes with this prototype, on
site FESSENHEIM 2 and BUGEY 2, in 2000.
Improved Rotating Probe process requirements
were provided by EDF with the SG contract specifications.
They dictate technique performances level and acquisition
rate of this new process using two techniques at the same
time :
- STL classic technique, applied
for detection and sizing of axial cracks,
- STT technique, applied for detection
and sizing of circumferential cracks and wear.
It has to be used, instead of classic
STL process, without increasing inspection duration and SG
occupancy.
In competition for the qualification,
CEGELEC NDT decided to design a new probe, including the two
EC sensors and meeting EDF’s requirements.
Two another new equipment, designed
in CEGELEC NDT laboratories, have been integrated into Improved
Rotating Probe Process :
- « STL Lift », new rotating
probe push-puller for roll transition zone inspection,
- « ANASTL », on-line
STL and STT data quality check, on-line data processing
and analysis software.
This paper presents the different
phases of the qualification conducted according to RSE-M rules,
and the first field experiences in August 2001.
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