In this paper capability and reliability studies of NDT procedures for
the inspection of wrought and cast stainless steel piping used in nuc
lear power plants will be presented. The capability study was designed
to identify procedures that have the potential to detect and size def
ects and to discriminate between flawed and unflawed material. The rel
iability study was undertaken to quantify on real and realistic flaws
in-service inspection performance (detection and false call capability
) under realistic field conditions. Furthermore parametric studes were
performed to complement the capability and reliability studies by eva
luating the effect of important material and flaw variables. The speci
mens used in these studies were cast-to-cast, cast-to-wrought, and wro
ught-to-wrought pipework welds. The evaluation methods used to quantif
y the inspection performance were selected to be as comparable as poss
ible to the PISC II methods. These were adapted to allow also the eval
uation of the effect of false calls. During the PISC II screening exer
cise for the cast-to-cast stainless steel round robin test and other p
iping round robin studies, it was indeed found that false call probabi
lities were large and could not be ignored in the evaluation of the in
spection performance. The matrix of samples has also been designed to
allow the implementation of specific statistical analysis procedures f
or the evaluation of results such as for example the relative operativ
e characteristics analysis.