Welds are one of the main objects in inservice
inspections of reactor pressure vessel (RPV).
Circumferential core region weld is most critical for RPV
integrity and therefore complementary ultrasonic
inspection from the outside surface is found necessary.
In reactor pressure vessel inspection, there are some
factors that have an effect on the ultrasonic inspection.
It is important to know the temperature of outside vessel
wall during inspection. Temperature changes the angles
of incidence and affects on the detection capability of
defects. The state of cladding is important also for
detection of the defects at the interface between
cladding and base material.
The basic inspection techniques and the measurement of
transducer contact will be discussed in this overview. It
is very important to have similar noise level in the
validation block as in the cladding of the component. By
this way, the best verification of the technique for real
situation will be achieved.
The crack detection is depending on orientation, skew and
tilt angle of the crack. The optimisation for detection
of smaller defects requires certain angle of incidence.
Noise from the cladding can enlarge the size of
detectable defect. These factors are handled in the
qualification of ultrasonic inspection of pressure vessel
at Loviisa NPP performed from the outside surface.
|Title of host publication|| Plant Life Management|
|Subtitle of host publication||Midterm status of a R&D project|
|Place of Publication||Espoo|
|Publisher||VTT Technical Research Centre of Finland|
|Publication status||Published - 2001|
|MoE publication type||A4 Article in a conference publication|
|Event||Plant Life Management: Midterm status of a R&D project - Espoo, Finland|
Duration: 1 Jan 2001 → 1 Jan 2001
|Conference||Plant Life Management|
|Period||1/01/01 → 1/01/01|