Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by the China National Nuclear Corporation.
This standard is under the jurisdiction of the National Technical Committee on Nuclear Instruments of Standardization Administration of China (SAC/TC 30).
Qualification procedure of electrical equipment important to safety for nuclear power plant
1 Scope
This standard specifies the tasks, qualification categories and methods, qualification program elements and test implementation procedures for the initial qualification of electrical equipment important to safety for nuclear power plant and its interfaces.
This standard is applicable to the initial qualification of electrical equipment important to safety for nuclear power plant, as well as the re-qualification after the equipment qualification is changed. This standard may be used for reference to the equipment qualification requiring only stability or structural integrity under seismic load.
Note: This standard does not specify the test items, functionality to be monitored and acceptance criteria of specific equipment.
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.
GB/T 2421.1-2008 Environmental testing for electric and electronic products - General and guidance
GB/T 2423.1 Environmental testing for electric and electronic products - Part 2: Test methods - Tests A: Cold
GB/T 2423.2 Environmental testing for electric and electronic products - Part 2: Test methods - Tests B: Dry heat
GB/T 2423.3 Environmental testing - Part 2: Testing method - Test Cab: Damp heat, steady state
GB/T 2423.4 Environmental testing for electric and electronic products - Part 2: Test method - Test Db: Damp heat, cyclic (12h+12h cycle)
GB/T 2423.10 Environmental testing for electric and electronic products - Part 2: Tests methods - Test Fc: Vibration (sinusoidal)
GB/T 2423.22 Environmental testing - Part 2: Tests methods - Test N: Change of temperature
GB/T 11026.4 Electrical insulating materials - Thermal endurance properties - Part 4: Ageing ovens - Single-chamber ovens
GB/T 12727 Qualification of safety class electrical equipment for nuclear power plants
GB/T 13625 Seismic qualification of electrical equipment of the safety system for nuclear power plants
GB/T 22718 Thermal evaluation methods of insulation systems for high-voltage electrical machines
GB/T 26168.2 Electrical insulating materials - Determination of the effects of ionizing radiation - Part 2: Procedures for irradiation and test
NB/T 20040 Seismic qualification test rules of safety classified electrical equipment for nuclear power plants
NB/T 20086 Assessing, monitoring and mitigating aging effects on class 1E equipment used in nuclear power plants
NB/T 20218 Nuclear power plants instrumentation and control important to safety requirements for electromagnetic compatibility testing
NB/T 20283 Classification on environmental conditions for qualification of electrical equipment important to safety for nuclear power plant
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 12727 and the following apply.
3.1
natural aging
change of physical, chemical or electrical characteristics of components or equipment with time under the environmental conditions for normal operation, which may cause deterioration of important functionality
[NB/T 20063-2012, Definition 6.2.1]
3.2
accelerated aging
acceleration process of subjecting equipment or a component to stress conditions consistent with the known measurable physical or chemical degradation rules in order to render its physical and electrical characteristics similar to those it would have during the expected life when operating under normal operating conditions, which is used to simulate the expected life in a short time
Note: It is revised from Definition 6.2.2 in NB/T 20063-2012.
3.3
aging degradation
general process in which physical characteristics of structures, systems or components are gradually degraded with time or use under storage or operating conditions due to the aging mechanism, which may weaken the ability of structures, systems or components to perform their expected functions
[NB/T 20063-2012, Definition 6.2.3]
3.4
installed life
period from installation to removal of equipment or a component, during which the equipment or component can withstand the designed operating conditions
Note: When some components are replaced regularly, the installed life of components may be shorter than that of the equipment.
[NB/T 20063-2012, Definition 6.1.7]
3.5
type tests
compliance test conducted on one or more samples representing the equipment with same design, material (component) and manufacturing process in order to verify that the design and manufacturing process meet the use requirements
3.6
qualification test
test conducted to determine the functionality of an (or a certain class of) equipment under specific environmental conditions and prove that the equipment performance meets the requirements of the qualification specification
3.7
routine test
test conducted for each equipment during or at the end of manufacturing to verify that the equipment meets some provisions of the requirement specification
3.8
sample equipment
tested product equipment, which is used to obtain valid data within the scope of its technical specification
[NB/T 20063-2012, Definition 6.1.18]
3.9
influencing quantities
variables of environmental conditions and operating conditions (such as temperature, pressure, irradiation and electromagnetic interference) that may affect equipment performance
3.10
normal atmospheric conditions
standard atmospheric conditions for measurement and testing specified in GB/T 2421.1-2008:
a) temperature: 15~35℃;
b) relative humidity: 25%~75%;
c) atmospheric pressure: 86kPa~106kPa.
3.11
service condition
generic term for environmental, loading, power, and signal conditions during normal/abnormal operation or design basis events of a nuclear power plant
3.12
functionality
functional attribute for transforming input information into identified output information
3.13
(equipment) identification file
traceable file representing equipment characteristics (including model, manufacturer, manufacturing documents, adopted standards, routine test result report, etc.) generated during equipment procurement
3.14
mission time
duration from the start of design basis event to the completion of safety function test of equipment withstanding accident environmental conditions
3.15
same equipment
equipment manufactured by the same manufacturer using the same design, material and manufacturing process under the supervision of the approved quality assurance program
3.16
similar equipment
equipment manufactured by the same manufacturer using the similar design and manufacturing process of a certain equipment under the supervision of the approved quality assurance program
3.17
equipment important to safety
equipment that is part of a safety group and/or whose malfunction or failure could lead to undue radiation exposure of the site personnel or members of the public
Note: It is revised from Definition 3.12 in IEC/IEEE 60780-323:2016.
3.18
condition-based qualification
qualification based on observation and measurement of one or more condition indicators of equipment or component, demonstrating whether the equipment or component remains in qualified condition
Note: It is revised from Definition 6.1.17 in NB/T 20063-2012.
3.19
severe accident
accident conditions more severe than a design basis event and involving significant core degradation
3.20
qualified condition
condition of equipment, prior to the start of a design basis event, for which the equipment has been demonstrated to meet the design requirements for the specified operating conditions
Note: The qualified condition is related to the characteristic quantities (condition indicators) characterizing the equipment condition, and these condition indicators are obtained at the end of age conditioning.
3.21
condition indicator
characteristic of equipment or a component that can be observed, measured and trended to infer or directly indicate the current and future ability of the equipment or component to function in all specified service conditions (including DBE conditions)
[NB/T 20063-2012, Definition 6.1.14]
3.22
end condition
value(s) of equipment condition indicator(s) at the conclusion of age conditioning
[GB/T 12727-2017, Definition 3.6]
4 General
In order to ensure that the electrical equipment important to safety for nuclear power plant and its interfaces can perform their predetermined safety functions under the specified operating conditions and environmental conditions, sufficient valid evidence shall be obtained in initial qualification to prove that the functionality of the equipment and its interfaces meets or exceeds the requirements of the equipment technical specifications during the whole installed life under the environmental conditions of normal/abnormal operation and accident conditions of the power plant, and establish the correlation between the initial qualification of equipment and equipment design, manufacturing, installation, maintenance, periodic test and condition-based qualification. The following missions shall be completed in initial qualification:
a) prepare the initial qualification program for equipment;
b) conduct functional simulation test under the environmental conditions of normal/abnormal operation and selected design basis events of the power plant;
c) determine the condition indicator and change trend of qualified life and qualified condition for equipment with significant aging mechanisms;
d) determine the configuration, installation and connection mode of qualification test, so as to provide basis for on-site installation and maintenance of qualified condition of equipment;
e) determine the components needing regular maintenance (replacement of vulnerable parts) during the operation of equipment as well as the maintenance interval;
f) document the qualification evidence.
5 Qualification categories and methods
5.1 Qualification categories of environment
The qualification of electrical equipment shall be based on the comprehensive analysis of its installation location, possible operation mode and functional requirements to determine the qualification environmental conditions and qualification categories.
If the sample equipment represents the type qualification (or prototype test) of a class of products, the equipment may undergo multiple different design basis events or be installed in different locations of the power plant. Considering the cumulative effect of environmental conditions, in order to make the qualification results applicable to all cases, the test conditions shall cover the environmental conditions of various design basis events, environmental conditions in different regions and different functional requirements.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General
5 Qualification categories and methods
5.1 Qualification categories of environment
5.2 Qualification methods
6 Qualification program
6.1 General
6.2 Technical specification of equipment
6.3 Qualification plan
7 Initial qualification test
7.1 General
7.2 Reference test
7.3 Extreme value test of influencing quantities
7.4 Age conditioning
7.5 Tests simulating the conditions of the design basis event
8 Qualification change
9 Qualification documentation
9.1 General
9.2 Qualification documents
Annex A (Informative) Time-dependent changes of pressure and temperature in containment during a typical nuclear power plant design basis event
Annex B (Informative) Items and sequence of qualification tests for electrical equipment important to safety
Annex C (Informative) Cable qualification test sample and test item configuration in harsh environment
Bibliography
