The Nuclear Regulatory Commission (NRC) has developed draft guidance for po
wer reactor licenses on acceptable methods for using probabilistic risk ass
essment (PRA) information and insights in support of plant-specific applica
tions to change the current licensing basis (CLB) for inservice inspection
(ISI) of piping. This process is also known as risk-informed inservice insp
ection programs (RI-ISI). The risk-informed inservice inspection process fo
r operating nuclear power plants provides an alternative method for selecti
ng and categorizing piping components that are inspected for the purposes o
f meeting the requirements of ASME Section XI. A RI-ISI approach will incor
porate probabilistic techniques to help define the scope, type and frequenc
y of inservice inspection. The risk-informed process may support a decrease
in the number of inspection and inspection intervals but will also identif
y areas where increased resources should be allocated to enhance safety. Th
e approach discussed in this paper follows the method developed by NRC staf
f. (C) 2000 Published by Elsevier Science S.A. All rights reserved.