International Standard Bases and Safety Classification - Nuclear Power Plant Instrumentation and Control Systems for Safety and Security - page 39

and electrical functions and associated systems
and equipment used in the instrumentation and
control systems important to safety of nuclear
power plants.
SC45A standards cover the entire lifecycle of
these I&C systems, from conception, through de-
sign, manufacture, test, installation, commission-
ing, operation, maintenance, aging management,
modernization and decommissioning.
A major aspect of SC45A is the application of
emerging electronic techniques in order to meet
nuclear instrumentation and control requirements,
particularly computer systems and advances in
information processing and control.
SC-45A now has 7 active Working Groups:

• WG A7: Reliability of electrical equip-
ment in reactor safety systems.
• WG A8: Control rooms.
• WG A9: Instrumentation systems.
• WG A10: Upgrading and modernization
of I&C systems in NPPs.

The second subcommittee of technical com-
mittee ТС-45 is SC45B (Radiation monitoring
instrumentation).
In Figure3 shows the structure of standards,
developed SC45A and related to NPP I&C and its
components important to safety, is n. Standards
are arranged in 4 levels.
The top-level document is IEC 61513 (IEC,
2011,a). It provides general requirements for I&C
systems and equipment that are used to perform
functions important to safety in NPPs.
IEC 61513 covers:

• WG A2: Sensors and measurement
technique.
• WG A3: Application of digital processors
to safety in NPPs.
• WG A5: Special process measurements
and radiation monitoring.

• Unit overall control systems and individual
information and control systems.

Figure 3. Structure of IEC standards devoted to safety important NPP I&C systems and their components