NB/T 20003 specifies the non-destructive testing method, quality classification of testing results and recommendatory acceptance criteria of mechanical components in nuclear island of nuclear power plants.
This part of NB/T 20003 specifies technical requirements and acceptance criteria with mechanical components in nuclear island of nuclear power plants tested by X-ray and γ-ray.
This part is applicable to radiographic testing of castings and welded joints in mechanical components in nuclear island of nuclear power plants when in manufacture and assembly processes.
2 Normative References
The following referenced documents are indispensable for the application 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.
GBZ 117 Radiological Protection Standards for Industrial X-ray Detection
GBZ 132 Radiological Protection Standards for Industrial Ganna-radiography
GB 11533 Standard for Logarithmic Visual Acuity Charts
GB/T 12604.2 Terminology for Nondestructive Testing Radiographic Testing
GB 18871 Basic Standards for Protection against Lonizing Radiation and for the Safety of Radiation Sources
JB/T 7902 Non-destructive Testing-Image Quality Indicators (Wire Type) for Radiographic Testing
JB/T 7903 Industrial Radiographic Illuminators
NB/T 20003.1 Non-destructive Testing for Mechanical Components in Nuclear Island of Nuclear Power Plants - Part 1: General Requirements
ASTM E186 Standard Reference Radiographs for Heavy-walled (2 to 41/2-in.[51 to 114-m m]) Steel Castings
ASTM E192 Standard Reference Radiographs for Investment Steel Castings for Aerospace Applications
ASTM E280 Standard Reference Radiographs for Heavy-walled (41/2 to 12-in.[114 to 305-mm]) Steel Castings
ASTM E446 Standard Reference Radiographs for Steel Casting up to 2 in.[51mm] in Thickness
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 12604.2 and NB/T 20003.1 and the following apply.
3.1
penetrated thickness
T
the nominal thickness of material in the direction of radiography, or the sum of nominal thicknesses of each layer of materials in case of multiple-wall radiography
3.2
object-to-film distance
b
the distance between the surface of tested workpiece at the radiographic source side and the film measured along the central axis of the radiation beam
3.3
source-to-object distance
f
the distance between the radiographic source and the surface of tested workpiece at the radiographic source side measured along the central axis of the radiation beam
3.4
source-to-film distance
F
the distance between the radiographic source and the film measured along the central axis of the radiation beam
3.5
source size
d
the effective focal spot size of radioactive isotope source or X-ray tube
3.6
rounded defect
NB/T 20003.3-2010 The following standards are cited：
NB/T 20003.3-2010 Cited by the following standards：
