International Standard Bases and Safety Classification - Nuclear Power Plant Instrumentation and Control Systems for Safety and Security - page 34

provisions common for various NPP systems: ob-
jectives and concepts of safety; safety management
requirements; general technical requirements;
design requirements.
In group “Safety Guides” the standard IAEA
NS-G-1.3 “Instrumentation and Control Systems
Important to Safety in Nuclear Power Plants”
(IAEA, 2002) was issued in 2002. This document
evolves provisions of IAEA NS-R-1(IAEA, 2000).
In IAEA NS-G-1.3 various I&C systems important
to safety are considered, including I&C with the
use of programmable computers with frames of
considered systems - from a sensor to an actua-
tor inclusive. New document material is included
in the overall process of I&C system design, in
the processes of verification, validation, and
documentation, and in the integration of human
factors, and in the use of digital technology in
I&C systems important to safety. Harmonization
with proper international standards was improved
(including IEC). IAEA NS-G-1.3 was compiled
by leading experts of I&C of different countries
(USA, Germany, Great Britain and others) and
is one of the main IAEA documents on I&C im-
portant to safety. This document has determined
paths of NPP I&C development for range of years.
Contents of IAEA NS-G-1.3:

portant to safety in nuclear power plants” (IAEA,
2000,b). This standard is used together with IAEA
NS-G-1.3 and contains the following sections:

1. Introduction.
2. Technical considerations for computer based
systems.
3. Application of requirements for management
of safety to computer based systems.
4. Project planning.
5. Computer system requirements.
6. Computer system design.
7. Software requirements.
8. Software design.
9. Software implementation.
10. Verification and analysis.
11. Computer system integration.
12. Validation of computer systems.
13. Installation and commissioning.
14. Operation.
15. Post-delivery modifications.

Since 2009 a new structure of IAEA standards
has started operating. These standards have three
categories (see Figure1).
“Safety Fundamentals”: SF-1 “Fundamental
Safety Principles” (IAEA, 2006) presents the
fundamental safety objective and principles of
protection and safety and provides the basis for
the safety requirements.
“Safety Requirements”: An integrated and
consistent set of safety requirements establish
the requirements that must be met to ensure the
protection of people and the environment, both
now and in the future. The requirements are
governed by the objective and principles of the
safety fundamentals. If the requirements are not
met, measures must be taken to reach or restore
the required level of safety. The format and style
of the requirements facilitate their use for the
establishment, in a harmonized manner, of a
national regulatory framework.
The General Safety Requirements (GSR)
are applicable to all facilities and activities. The

1. Introduction.
2. Instrumentation and control systems impor-
tant to safety.
3. The design basis.
4. General design guidelines (set of common
requirements to I&C systems).
5. System specific design guidelines (protection
systems, power supplies, digital computer
systems, etc).
6. Human-machine interface.
7. Design process for I&C systems important
to safety, etc.

Another IAEA standard, included in “Safety
Guides” group and related to I&C, is IAEA NS-
G-1.1 “Software for computer based systems im-