1 Scope
This standard specifies the classification method for instrumentation and control function important to safety for nuclear power plants and their functional system and equipment, and determines the technical requirements and quality assurance requirements of each category in terms of functionality, reliability, performance, environmental durability and seismic performance.
This standard is applicable to the design of all instrumentation and control systems (including safety systems and safety-related instrumentation systems) important to safety for new nuclear power plants.
Note: Reference power plants and new nuclear power plants that have been designed may conditionally implement this standard according to the actual situation.
2 Normative References
The following normative document contains provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 12727 Nuclear Power Plants — Electrical Equipment of the Safety System — Qualification (GB/T 12727-2002, IEC 60780:1998, MOD)
GB/T 13625 Seismic Qualification of Electrical Equipment of the Safety System for Nuclear Power Plants (GB 13625-1992, eqv IEC 60980:1988)
GB/T 13626 Application of the Single Failure Criterion to Safety Systems in Nuclear Power Plant (GB/T 13626-2008, IEEE 379-2000, MOD)
GB/T 13630 Design for Control Rooms of Nuclear Power Plants (GB/T 13630-1992, eqv IEC 60964)
EJ/T 1143 Nuclear Power Plants — Design of Control Rooms — Function Analysis and Assignment (IEC 61839, MOD)
HAF 003 Safety Provisions for Quality Assurance of Nuclear Power Plants
HAD 102/14 Safety-related Instrumentation and Control Systems for Nuclear Power Plants
3 Terms and Definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
Anticipated operational occurrences
All operational processes deviating from normal operation which are expected to occur once or several times during the operating life of the plant and which, in view of appropriate design provisions, do not cause any significant damage to items important to safety or lead to accident conditions.
3.2
Design basis accident (DBA)
Accident conditions against which the nuclear power plant is designed according to established design criteria, and for which the damage to the fuel and the release of radioactive material are kept within authorized limits.
3.3
Design basis event (DBE)
Term used to address the group of design basis accidents and anticipated operational occurrences.
3.4
I&C function
Controlling, operating and/or monitoring implemented on the identified processes.
3.5
Functionality
Attribute of a function which defines the operations which transform input information into output information.
3.6
I&C systems important for safety
I&C systems (includes safety systems and safety related I&C systems.) whose malfunction or failure could lead to undue radiation exposure of the site personnel or members of the public, and those I&C systems that prevent anticipated operational occurrences from leading to a unacceptable consequences.
3.7
Safety systems
Systems important to safety, provided to assure the safe shutdown of the reactor or the residual heat removal from the core, or to limit the consequences of anticipated operational occurrences and design basis accidents.
3.8
Safety related I&C systems
Those I&C systems important for safety that are not part of the safety systems.
3.9
Postulated initiating events (PIE)
Events identified during design as capable of leading to anticipated operational occurrences or accident conditions.
Foreword II
Introduction IV
1 Scope
2 Normative References
3 Terms and Definitions
4 Classification Criteria and Methods
5 Description of Function Categories
6 Classification Procedure
7 Assignment of Technical Requirements to Categories
Annex A (Informative) Applicable Standards and Technical Requirements on Different Categories of Functions
Annex B (Informative) Comparison List of the Clauses in This Standard and the Equivalent Clauses in IEC 61226:2005
Annex C (Informative) Examples of Categories
