GB/T 13284-2025 Design criteria of safety systems in nuclear power plants
1 Scope
This document specifies the minimum functional and design requirements for the power source, instruments and control parts of safety system in nuclear power plants.
This document is applicable to the design of those systems necessary to prevent or mitigate the consequences of design reference events and to protect public health and safety. The design of all safety-related systems, structures and equipment required to protect the safety of the entire nuclear power plant shall be referred to for use.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 5204 Periodic tests and monitoring of the safety system of nuclear power plant
GB/T 12727 Qualification of electrical equipment important to safety for nuclear power plants
GB/T 12788 Criteria for class 1E power systems for nuclear power plants
GB/T 13286 Criteria for independence of class IE equipment and circuits in nuclear power plants
GB/T 13626 Application of the single failure criterion to safety systems in nuclear power plant
GB/T 13627 Criteria for accident monitoring instrumentation for nuclear power plants
GB/T 13629 Criteria for programmable digital devices in safety systems of nuclear power generating stations
NB/T 20061 Practice for application of human factors engineering to systems, equipment, and facilities of nuclear power plant
NB/T 20394 Design and qualification of class 1E control boards, panels and racks in nuclear power plants
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
safety function
specific functions that must be accomplished to ensure that nuclear facilities or activities can prevent and alleviate radioactive consequences under normal operation, anticipated transient operation and accident conditions of nuclear power plants for a purpose of ensuring nuclear safety
[Source: GB/T 41143-2021, 3.16, modified]
3.2
safety system
a system important to safety, provided to ensure the safe reactor trip or the residual heat removal from the core, or to limit the consequences of anticipated operational occurrences and design basis accidents
3.3
safety class
Class 1E
a safety classification of electrical equipment and systems in nuclear power plants
Note 1: These equipment and systems are essential to emergency reactor shutdown, containment isolation, reactor core cooling, and containment and reactor heat removal or those are otherwise essential in preventing significant release of radioactive material to the environment
Note 2: Safety class (Class 1E) is a functional term. Devices and systems that complete the functions listed in Note 1 are classified as safety class.
[Source: GB/T 41143-2021, 3.28]
3.4
safety group
a minimal set of components, modules, and equipment that can accomplish the required safety functions when a certain hypothetical initiating event occurs
Note: A safety group may include one or more divisions (see Annex A).
3.5
protective action
initiation of a signal within the sense and command features, or operation of equipment within the execute features, to accomplish a safety function
3.6
analytical limit
limit of the measured or calculated quantity determined based on the safety analysis to ensure that it does not exceed the safety limit
3.7
auxiliary supporting features
systems or components that provide services (e.g., cooling, lubrication, energy supply) that are required for the safety systems to accomplish their safety functions
Foreword II 1 Scope 2 Normative references 3 Terms and definitions 4 Design basis of safety system 5 Criteria of safety systems 6 Functions and design requirements of sense and command features 7 Functions and design requirements of execute feature 8 Requirements for power sources Annex A (Informative) Illustration of some basic concepts in the development process of safety system scope Bibliography
