Standard No.:	GB/T 16702.2-2025
English Name:	Design specification for mechanical components in nuclear island of pressurized water reactor nuclear power plants―Part 2：Class 1 components
Chinese Name:	压水堆核电厂核岛机械设备设计规范第2部分：1级设备
Professional Classification:	GB    National Standard
Source Content Issued by:	SAMR; SAC
Issued on:	2025-02-28
Implemented on:	2025-2-28
Status:	valid
Superseding:	GB/T 16702-2019 Design code for mechanical components in nuclear island of pressurized water reactor nuclear power plants
Target Language:	English
File Format:	PDF
Word Count:	87500 words
Translation Price(USD):	2625.0
Delivery:	via email in 1~5 business day

GB/T 16702.2-2025 Design specification for mechanical components in nuclear island of pressurized water reactor nuclear power plants―Part 2：Class 1 components English, Anglais, Englisch, Inglés, えいご This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered. ICS 27.120.20 CCS F 69 National Standard of the People's Republic of China GB/T 16702.2-2025 Partially replaces GB/T 16702-2019 Design specification for mechanical components in nuclear island of pressurized water reactor nuclear power plants - Part 2: Class 1 components 压水堆核电厂核岛机械设备设计规范 第2部分：1级设备 (English Translation) Issue date: 2025-02-28 Implementation date: 2025-02-28 Issued by the State Administration for Market Regulation the Standardization Administration of the People's Republic of China Contents Foreword Introduction 1 Scope 2 Normative references 3 Terms and definitions 4 General rules 5 materials 6 Logo design guidelines 7 Manufacturing and Inspection 8 Pressure testing of Class 1 equipment 9 Overpressure protection Design specification for mechanical components in nuclear island of pressurized water reactor nuclear power plants - Part 2: Class 1 components 1 Scope This document specifies the requirements for materials, design, manufacturing, inspection and overpressure protection of Class 1 pressure-bearing equipment in the nuclear island machinery and equipment of PWR nuclear power plants, and describes the corresponding tests. This document is applicable to the design of Class 1 pressure-bearing equipment and its parts specified in Chapter 5 of GB/T 16702.1-2025. 2 Normative references The following documents contain requirements 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 16702.1-2025 Code for design of mechanical equipment for nuclear islands of pressurized water reactors - Part 1: General provisions GB/T 16702.3-2025 Code for the design of mechanical equipment for nuclear islands of pressurized water reactors - Part 3: Class 2 equipment GB/T 16702.6-2025 Code for the design of mechanical equipment for nuclear islands of pressurized water reactors - Part 6: Internals GB/T 16702.7-2025 Code for the design of mechanical equipment for nuclear islands of pressurized water reactors - Part 7: Supports for equipment NB/T 20001 Specification for manufacturing machinery and equipment of nuclear island in pressurized water reactor nuclear power plant NB/T 20002.1 Specification for welding mechanical equipment of nuclear islands in pressurized water reactors nuclear power plants - Part 1: General requirements NB/T 20002.2 Specification for welding machinery and equipment of nuclear islands in pressurized water reactor nuclear power plants - Part 2: Acceptance of welding filler materials NB/T 20002.3 Specification for welding of nuclear island machinery and equipment in pressurized water reactor nuclear power plants - Part 3: Qualification of welding process NB/T 20002.4 Specification for welding machinery and equipment of nuclear islands in pressurized water reactor nuclear power plants - Part 4: Acceptance of welding filler materials NB/T 20002.5 Code for welding mechanical equipment of nuclear islands in pressurized water reactors nuclear power plants - Part 5; Manufacturing workshop assessment NB/T 20002.6 Specification for welding machinery and equipment of nuclear islands in pressurized water reactors - Part 6: Product welding NB/T 20002.7 Specification for welding machinery and equipment of nuclear islands in PWR nuclear power plants - Part 7: Wear-resistant surfacing welding NB/T 20003.3 Non-destructive testing of nuclear island machinery and equipment in nuclear power plants - Part 3; Radiographic inspection NB/T 20003.4 Non-destructive testing of nuclear island machinery and equipment in nuclear power plants - Part 4; Penetration detection NB/T 20004 Physical and chemical inspection methods for mechanical equipment materials in nuclear power Nuclear Power Island NB/T 20005.1 Carbon and low alloy steels for pressurized water reactor nuclear power plants - Part 1: Forged and rolled pieces for class 1, 2 and 3 equipment NB/T 20005.5 Carbon and low alloy steels for pressurized water reactor nuclear power plants - Part 5: Class 1, 2 and 3 pressure castings NB/T 20005.6 Carbon and low alloy steels for pressurized water reactor nuclear power plants - Part 6: Reactor coolant pump motor frame castings NB/T 20005.7 Carbon and low alloy steels for pressurized water reactor nuclear power plants - Part 7: Steel plates for class 1, 2 and 3 equipment NB/T 20006.1 Alloy steels for pressurized water reactor nuclear power plants - Part 1: manganese-nickel aluminum alloy steel forgings for reactor pressure vessel cylinders subjected to intense irradiation 3 Terms and definitions The terms and definitions defined in GB/T 16702.1-2025 and the following are applicable to this document. 4 General rules 4.1 Boundaries of components and accessories of Class 1 equipment and piping 4.1.1 Boundaries of Components The equipment design specification shall specify the boundary extent between the component and the connected pipe or other component. The boundaries of containers, tanks, pumps or valves, etc. shall not be close to the following ranges: a) The first girth weld joint of the welded connection (the joining weld should be considered part of the pipe); b) The first flange face of the bolted connection (the bolt should be considered part of the pipe); c) The first threaded nipple of the screw connection. 4.1.2 Boundary of components and accessories 4.1.2.1 Accessories An accessory refers to an element that is in contact with or connected to the inside or outside of the pressure-bearing part of a component. Accessories may or may not have a pressure-bearing function. Accessories with pressure-bearing function include: pressure boundary reinforcement, opening reinforcement of branch pipes and containers. Accessories that do not have pressure-bearing features include: a) Valve guide sleeve, hot sleeve and rotating blade; b) Core support structures, internal structures or other permanent components within the reactor pressure vessel; c) Container saddles, supports or shear lugs, brackets, pipe clamps, trunnions, skirts and other items supporting the load path. The accessory may have a structural function or a non-structural function. Accessories with structural functions include: a) Accessories performing pressure-bearing functions; b) Core support structures, internal structures or other permanent components within the reactor pressure vessel; c) Support attachments on the load path Accessories for non-structural functions include: a) Accessories performing pressure-bearing functions; b) Accessories not on the supporting load path; c) Permanent or non-permanent attachments.