GB/T 16702.6-2025Design specification for mechanical components in nuclear island of pressurized water reactor nuclear power plants - Part 6: Reactor vessel internals (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting.

This document is Part 6 of GB/T 16702 "Design Specifications for Mechanical Equipment of Nuclear Island in Pressurized Water Reactor Nuclear Power Plant". The following parts are published.

--- Part 1: General;

--- Part 2: Class 1 equipment;

--- Part 3: Level 2 equipment;

--- Part 4: Level 3 equipment;

--- Part 5: Small equipment;

--- Part 6: Reactor internals;

--- Part 7: Equipment support;

--- Part 8: Low-pressure or atmospheric pressure storage tanks.

This document replaces Chapter 9 of GB/T 16702-2019 "Design Specifications for Mechanical Equipment of Nuclear Island in Pressurized Water Reactor Nuclear Power Plants" and Compared with Chapter 9 in GB/T 16702-2019, in addition to structural adjustments and editorial changes, the main technical changes are as follows.

--- Changed the boundary division (see 4.2.3, 9.1.1.1.3 of the 2019 edition);

--- Changed the relevant requirements of the document (see 4.1, 4.1.2 of the 2019 edition);

--- Added relevant requirements for welding materials (see 5.2);

--- Changed the requirements for cobalt content in materials used for reactor internals (see 5.4, 9.2.4 of the 2019 edition);

--- Changed the material standards used for reactor internals (see Table 1, Table 75 of the 2019 edition);

--- Deleted the expression of "casting" and related content (see Table 75, 9.2.3.1, 9.2.3.2 of the 2019 edition).

--- Changed the lower limit of the temperature for intergranular corrosion sensitivity caused by welding, hot working or heat treatment during manufacturing (see 5.4, 2019 edition 9.2.3);

--- Added the weld coefficients corresponding to the two inspection combinations of "ultrasonic and penetrant inspection" and "penetrant inspection between welds" (see Table 8);

--- Added "Liquid penetrant testing and radiographic testing are performed in accordance with the requirements for Class 1 welds" (see 7.4.6.2);

--- Added "When the outer diameter of the pipe is phi< 90mm, the image quality meter can be placed parallel to the pipe weld" (see 7.5.1.5).

Introduction

GB/T 16702 "Design Specification for Mechanical Equipment of Nuclear Island of Pressurized Water Reactor Nuclear Power Plant" is a general technical specification for the design of mechanical equipment of nuclear island of pressurized water reactor nuclear power plant.

The standard is to implement the spirit of my country's nuclear safety regulations, actively promote the unification of the standard technical route of mechanical equipment of the nuclear island of pressurized water reactor nuclear power plants, and promote the development of pressurized water reactors.

GB/T 16702 is an important part of the relevant standards for the independent design and localization of nuclear island mechanical equipment.

The basic and universal standards for design activities of mechanical equipment in the nuclear island of a pressurized water reactor nuclear power plant are planned to consist of eight parts.

--- Part 1: General. The purpose is to specify the overall requirements and related requirements for the design of mechanical equipment in the nuclear island of a pressurized water reactor nuclear power plant. Appendix for his partial use.

--- Part 2: Class 1 equipment. The purpose is to specify the materials, design, manufacture, inspection, pressure test and overpressure of Class 1 pressure equipment.

Requirements that need to be followed in design such as protection.

--- Part 3: Class 2 equipment. The purpose is to specify the materials, design, manufacture, inspection, pressure test and overpressure of Class 2 pressure equipment.

Requirements that need to be followed in design such as protection.

--- Part 4: Class 3 equipment. The purpose is to specify the materials, design, manufacture, inspection, pressure test and overpressure of Class 3 pressure equipment.

Requirements that need to be followed in design such as protection.

--- Part 5: Small equipment. The purpose is to specify the materials, design, manufacture, inspection, hydraulic test and pump of small pressure equipment.

Requirements that need to be followed in the design, such as identification and acceptance testing.

--- Part 6: In-core components. The purpose is to specify the materials, design, manufacturing, inspection and other design requirements of in-core components. Require.

--- Part 7: Equipment Support. The purpose is to specify the requirements to be followed in the design of mechanical equipment supports in the nuclear island of a pressurized water reactor nuclear power plant. Require.

--- Part 8: Low-pressure or atmospheric pressure storage tanks. The purpose is to specify the materials, design, manufacture, inspection and hydraulic test of low-pressure or atmospheric pressure storage tanks.

Requirements that need to be followed in design, such as verification.

GB/T 16702 (all parts) together with NB/T 20001~NB/T 20009 series of standards constitute the pressurized water reactor nuclear power plant applicable to my country.

The technical standard system for the design and manufacture of nuclear island mechanical equipment in power plants. This standard system is based on independent nuclear power engineering experience and incorporates nuclear island mechanical equipment The standard technical route unifies the research results, conforms to the requirements of my country's nuclear power regulatory system and industrial foundation, and is the standard and guide for my country's pressurized water reactor nuclear power plants.

It is an important basis for the design and manufacturing of nuclear island mechanical equipment and other related activities.

This document focuses on the design principles of the reactor internals, clarifies the boundary division of the reactor internals, and updates the material standard numbers, thus completing the Improves the requirements for the design of materials, design, manufacturing, inspection, pressure testing and overpressure protection of reactor internals. For use in conjunction with GB/T 16702.1-2025.

1 Scope

This document specifies the requirements for materials, design, manufacturing and inspection of the internal components of the nuclear island mechanical equipment of a pressurized water reactor nuclear power plant.

This document applies to the design of reactor internals and their components.

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document.

For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to This document.

GB/T 16702.1-2025 Specification for design of mechanical equipment of nuclear island of pressurized water reactor nuclear power plant Part 1: General

GB/T 16702.2-2025 Specification for design of mechanical equipment of nuclear island of pressurized water reactor nuclear power plant Part 2: Level 1 equipment

NB/T 20001-2023 Specification for the manufacture of mechanical equipment for nuclear island of pressurized water reactor nuclear power plant

NB/T 20002.1 Specification for welding of mechanical equipment in nuclear island of pressurized water reactor nuclear power plant Part 1: General requirements

NB/T 20002.5-2013 Specification for welding of mechanical equipment in nuclear island of pressurized water reactor nuclear power plant Part 5: Assessment of manufacturing workshop

NB/T 20002.6-2021 Specification for welding of mechanical equipment in nuclear island of pressurized water reactor nuclear power plant Part 6: Product welding

NB/T 20002.7 Specification for welding of mechanical equipment in nuclear island of pressurized water reactor nuclear power plant Part 7: Wear resistant cladding

NB/T 20003.1-2021 Nondestructive testing of mechanical equipment in nuclear island of nuclear power plant Part 1: General requirements

NB/T 20003.2-2021 Nondestructive testing of mechanical equipment in nuclear island of nuclear power plant Part 2: Ultrasonic testing

NB/T 20003.3 Nondestructive testing of mechanical equipment in nuclear island of nuclear power plant Part 3: Radiographic testing

NB/T 20003.4 Nondestructive testing of mechanical equipment in nuclear island of nuclear power plant Part 4: Penetrant testing

NB/T 20004-2014 Physical and chemical testing methods for mechanical equipment materials in nuclear islands of nuclear power plants

NB/T 20007.1 Stainless steel for pressurized water reactor nuclear power plants Part 1: Grade 1, 2, 3 austenitic stainless steel forgings

NB/T 20007.3 Stainless steel for pressurized water reactor nuclear power plants Part 3: Austenitic stainless steel forgings for core support plates and upper support plates

NB/T 20007.5 Stainless steel for pressurized water reactor nuclear power plants Part 5: Austenitic stainless steel plates for level 1, 2 and 3 equipment

NB/T 20007.6 Stainless steel for pressurized water reactor nuclear power plants Part 6: Austenitic stainless steel plates for reactor internals

NB/T 20007.8 Stainless steel for pressurized water reactor nuclear power plants Part 8: Austenitic stainless steel seamless steel pipes for level 1, 2 and 3 equipment

NB/T 20007.15 Stainless steel for pressurized water reactor nuclear power plants Part 15: Cold rolled steel for fasteners of reactor internals and core measurement seal assemblies Hardened austenitic stainless steel bars

NB/T 20007.17 Stainless steel for pressurized water reactor nuclear power plants Part 17: Martensitic stainless steel forgings for compression elastic rings of reactor internals

NB/T 20007.41 Stainless steel for pressurized water reactor nuclear power plants Part 41: Austenitic stainless steel seamless steel pipes for reactor internals

NB/T 20007.45 Stainless steel for pressurized water reactor nuclear power plants Part 45.04Cr13Ni5Mo martensitic stainless steel for compression elastic rings Steel Forgings

NB/T 20007.49 Stainless steel for pressurized water reactor nuclear power plants Part 49: Cold-worked hardened stainless steel bars for safety-class equipment

NB/T 20007.50 Stainless steel for pressurized water reactor nuclear power plants Part 50: Austenitic stainless steel forgings for safety-related equipment

NB/T 20007.51 Stainless steel for pressurized water reactor nuclear power plants Part 51: Austenitic stainless steel plates for safety grade equipment

NB/T 20007.52 Stainless steel for pressurized water reactor nuclear power plants Part 52: Austenitic stainless steel bars and sections for safety-related equipment