ISO 18075:2018 provides guidance for performing and validating the sequence of steady-state calculations leading to prediction, in all types of operating UO₂-fuel commercial nuclear reactors, of:

- reaction-rate spatial distributions;

- reactivity;

- change of nuclide compositions with time.

ISO 18075:2018 provides:

a) guidance for the selection of computational methods;

b) criteria for verification and validation of calculation methods used by reactor core analysts;

c) criteria for evaluation of accuracy and range of applicability of data and methods;

d) requirements for documentation of the preceding.