scope:

This International Standard is applicable to NPP computer-system hardware for systems of Class 1 and 2 (as defined by IEC 61513).

The structure of this standard has not changed significantly from the o riginal 1989 issue; however, some issues are now covered by standards which have been issued in the interim (for example, IEC 61513 for system architecture design) and r eferences to n ew s tandards have been provided where applicable. The text o f the standard has also been modified to reflect developments in c omputer system hardware design, the use of pre-developed ( for example, COTS) hardware and changes in terminology.

Computer hardware facilities used f or software loading and checking are not considered to form an intrinsic part of a s ystem important to s afety and, as such, are outside the scope of this standard.

 NOTE 1 Class 3 c omputer-system hardware is not addressed by this standard, and it is recommended that such systems should be developed to commercial grade standards.

NOTE 2 In 2 006 the development of a new standard to address hardware requirements for "very complex" hardware was discussed within I EC S C 45A. If such a standard is developed then that standard would be used for the development of "very complex" hardware in preference to IEC 60987.