NB/T 20001-2023 Manufacturing specifications for nuclear island machinery and equipment in pressurized water reactor nuclear power plants
1 Scope
This document specifies the technical requirements, such as identification and marking, cutting and trimming without repair welding, forming and tolerance, assembly alignment of weldments, expansion joint of heat exchanger tube and tube plate, surface treatment, cleaning, flange bolt connection, heat treatment, test and inspection, preparation, packaging and transportation of welding witness parts and base material witness parts in the fabrication process of mechanical components of PWR nuclear island within the scope specified in GB/T 16702.
This document is applicable to the fabrication and inspection of mechanical components of PWR nuclear island.
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 1031 Geometrical product specifications (GPS) - Surface texture: Profile method - Surface roughness parameters and their values
GB/T 1184 Geometrical tolerancing - Geometrical tolerance for features without individual tolerance indications
GB/T 1239.2-2009 Cold coiled helical springs technical specifications - Part 2: Compressions spring
GB/T 1804 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications
GB/T 1958 Geometrical Product Specifications (GPS) - Geometrical tolerance - Verification
GB/T 3216 Rotodynamic pumps - Hydraulic performance acceptance tests - Grades 1, 2 and 3
GB/T 4334 Corrosion of metals and alloys - Test methods for intergranular corrosion of austenitic and ferritic-austenitic (duplex) stainless steels
GB/T 4340.1 Metallic materials - Vickers hardness test - Part 1: Test method
GB/T 4955 Metallic coatings - Measurement of coating thickness - Coulometric method by anodic dissolution
GB/T 4956 Non-magnetic coatings on magnetic substrates - Measurement of coating thickness - Magnetic method (GB/T 4956-2003, ISO 2178:1982, MOD)
GB/T 5270 Metallic coatings on metallic substrates - Electrodeposited and chemically deposited coatings - Review of methods available for testing adhesion (GB/T 5270-2005, ISO 2819:1980, IDT)
GB/T 6462 Metallic and oxide coatings - Measurement of coating thickness - Microscopical method
GB/T 6463 Metallic and other inorganic coatings - Review of methods of measurement of thickness
GB/T 7232 Terminology of metal heat treatment
GB/T 9239.1-2006 Mechanical vibration - Balance quality requirements for rotors in a constant (rigid) state - Part 1: Specification and verification of balance tolerances (ISO 1940-1: 2003, IDT)
GB/T 9239.12 Mechanical vibration - Rotor balancing - Part 12:Procedures and tolerances for rotors with flexible behaviour (ISO 21940-12: 2016, IDT)
GB/T 10125 Corrosion tests in artificial atmospheres - Salt spray tests
GB/T 11354 Determination of nitrided case depth and metallographic microstructure examination for steel and iron parts
GB/T 11376-1997 Phosphate conversion coatings for metals (ISO 9717:1990, EQV)
GB/T 11378 Metallic coatings - Measurement of coating thickness - Profilometric method
GB/T 11379 Metallic coatings - Electroplated coatings of chromium for engineering purposes
GB/T 13346 Metallic and other inorganic coatings - Electroplated coatings of cadmium with supplementary treatments on iron or steel
GB/T 13744 The measurement of coating thickness for electrodeposited nickel coatings on magnetic and non-magnetic substrates
GB/T 13927-2008 Industrial valves - Pressure testing
GB/T 16702 Design code for mechanical components in nuclear island of pressurized water reactor nuclear power plants
GB/T 16921 Metallic coatings - Measurement of coating thickness - X-ray spectrometric methods
GB/T 19349 Metallic and other inorganic coatings - Pretreatment of iron or steel to reduce the risk of hydrogen embrittlement
GB/T 29531 Methods of measuring and evaluating vibration of pumps
GB/T 29529 Methods of measuring and evaluating noise of pumps
JB/T 6050 Generalization of hardness test for heat treated iron and steel parts
NB/T 20002
(All parts) Welding code for mechanical components of PWR nuclear islands - Part 1: General requirements
NB/T 20003
(All parts) Non-destructive testing for mechanical components in nuclear island of nuclear power plants
NB/T 20004 Physical and chemical test methods for materials used in nuclear island components of nuclear power plants
NB/T 20008.23 Other material for pressurized water reactor nuclear power plants - Part 23: Ni-base-alloy wires used for CRDM
NB/T 20008.25 Other material for pressurized water reactor nuclear power plants - Part 25: GH4169 alloy wires for reactor vessel internals
NB/T 20133
(All parts) Specifications for protective coatings used in pressurized water reactor nuclear power plants
NB/T 20408 Requirements for packaging, shipping, handling, receiving, storage and maintaining of item for nuclear power plants
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 16702 and the following apply.
3.1
process fluid
liquid or gas in various systems or equipment of a nuclear power plant
3.2
thermal contraction
contraction deformation process in which pipe fittings or pipe sections are partially heated, and no mechanical means are used during the cooling
3.3
corrosion resistant surface
equipment surface made of corrosion resistant materials such as austenitic stainless steel or nickel-based alloy that are in (no) contact with process fluid
3.4
critical surface
surface subjected to friction (e.g. bearings, pivots, bearing surfaces and sealing contact surfaces) and heat transfer tube surface of heat exchanger
3.5
invisible surface
surface not visible to naked eyes or with the aid of an endoscope, and inner surface of a tube having a nominal diameter of not greater than 150mm during cleanliness inspection
3.6
lixiviation
physical process of dissolving an extracted compound with water, saturated steam or other solvent
3.7
identification
number corresponding to an item or a batch of items, which is used to establish a clear connection between equipment parts and their related documents
3.8
marking
mark indicating the assembly position, welding position and other state information of an item
4 General provisions
This document specifies the basic requirements for the fabrication of mechanical components of PWR nuclear island. The fabrication of mechanical components of PWR nuclear island shall also meet the supplementary requirements of GB/T 16702 and the equipment specifications.
5 Identification and marking
5.1 General requirements
The identification and marking shall meet the following general requirements:
a) the characters of identification and marking shall be legible;
b) the identification and marking shall be made by a method that neither contaminate materials nor cause obvious work hardening or stress concentration;
c) the identification and marking shall be located in areas where the member is least stressed, avoiding stress concentration areas (especially areas of sudden shape change) and heat-affected zones of welded joints;
d) the identification and marking shall not hinder the judgment of nondestructive testing results;
e) the identification and marking removed or erased during processing shall be transplanted or remade;
f) the identification and marking procedures shall be prepared, which shall include the requirements for permanent identification and marking methods, temporary identification and marking methods, restrictions on identification and marking methods, identification and marking content, identification and marking locations as well as identification and marking records.
Foreword i
Introduction iv
1 Scope
2 Normative references
3 Terms and definitions
4 General provisions
5 Identification and marking
5.1 General requirements
5.2 Methods
5.3 Position marking
5.4 State marking
5.5 Identification list
6 Cutting and trimming without repair welding
6.1 Cutting
6.2 Trimming without repair welding
7 Forming and tolerance
7.1 Forming
7.2 Tolerance
7.3 Springs
8 Machining
8.1 General requirements
8.2 Process test or evaluation
8.3 Preparation before machining
8.4 Clamping requirements for tools and workpiece
8.5 Machining requirements
8.6 Machining cleanliness control
8.7 Inspection
9 Assembly alignment of weldments
9.1 General requirements
9.2 Assembly alignment tolerances of double-welding joint or single-welded joint accessible from the other side
9.3 Assembly alignment tolerance of welded joints for external welding when inner surfaces are inaccessible
9.4 Assembly alignment tolerance of welded joints of welded heads
9.5 Assembly alignment tolerance of tubes and pipes
9.6 Trimming in case of out of tolerance
10 Welding requirements
11 Expansion joint of heat exchanger tube and tube plate
11.1 General requirements
11.2 Expansion joint
11.3 Inspection
11.4 Rework
12 Surface treatment
12.1 Chrome plating
12.2 Galvanizing
12.3 Nickel plating
12.4 Electrolytic tin plating
12.5 Cadmium plating treatment
12.6 Phosphating treatment
12.7 Electropolishing
12.8 Zinc spraying
12.9 Painting
12.10 Nitriding treatment
12.11 Other metallic coatings or surface treatments
13 Cleaning
13.1 General requirements
13.2 Cleanliness classes, work areas and work zones in nuclear power plant site
13.3 Cleanliness inspection
13.4 Contamination prevention
13.5 Cleaning methods
13.6 Cleanliness maintenance
14 Bolt
14.1 General
14.2 Procedure or process
14.3 Assembly requirements
14.4 Requirements for lubricants
14.5 Requirements for threads
14.6 Requirements for sealing surfaces
14.7 Requirements for assembly tools
14.8 Surface pretreatment of fasteners
15 Heat treatment
15.1 General requirements
15.2 Heat treatment after forming
15.3 Post-weld heat treatment
15.4 Dimensional stabilization treatment
15.5 Bright annealing of austenitic stainless steel parts
15.6 Anti-dent control requirements for heat transfer tube of steam generator
16 Test and inspection
16.1 Application scope
16.2 Hydrostatic test of vessel (cavity)
16.3 Air pressure test of vessel (cavity)
16.4 Special circumstances of vessel (cavity) pressure test
16.5 Valve test
16.6 Pump tests
16.7 Steam generator wanding testing and rodding testing
16.8 Nondestructive testing
16.9 Dimension and geometric tolerance testing
17 Packaging, storage and transportation
18 Product welding witness parts and archived materials
18.1 Product welding witness parts
18.2 Archived materials
Annex A (Normative) Evaluation of forming process
A.1 Evaluation of bending process for heat transfer tubes of Stage 2 and 3 heat exchangers
A.2 Evaluation of forming processes other than bending process for heat transfer tubes of heat exchangers
Annex B (Normative) Process evaluation for expansion joint of heat exchanger tube and tube plate
B.1 Preliminary test
B.2 Process evaluation
Annex C (Normative) Cleanliness inspection
C.1 Description
C.2 Visible surface
C.3 Invisible surface
Annex D (Normative) Water quality
