Overview
IEC 62671:2013 is an international standard established by the International Electrotechnical Commission (IEC) focusing on nuclear power plants' instrumentation and control systems that are important to safety. This standard specifically addresses the selection and use of industrial digital devices of limited functionality within nuclear power plants. These devices may feature embedded software or digitally-configured circuits and are typically developed in accordance with non-nuclear industry standards but are candidates for nuclear safety applications. The standard provides a comprehensive framework for evaluating such devices when they have dedicated, specific, and limited functionality with restricted configurability.
Updated to include the corrigendum from September 2016, IEC 62671:2013 supports designers, operators, system evaluators, and licensors in safely integrating industrial digital devices not originally designed for nuclear applications into nuclear instrumentation and control (I&C) systems.
Key Topics
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Scope and Background: Outlines the use of pre-developed limited-function devices containing embedded software or digital circuits not produced under nuclear-specific standards but considered for nuclear safety applications.
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Applicability Criteria: Defines when and how IEC 62671 applies, focusing on devices with limited configurability and functionality.
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Evaluation Process: Details the structured approach including an Evaluation and Application Plan (EAP) and Evaluation and Application Report (EAR) to assess the suitability of devices.
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Functional Suitability: Criteria to assess:
- Primary and ancillary functions of the device.
- Degree of configurability and superfluous functions.
- Hardware robustness, reliability, maintainability, testability.
- Cyber security considerations.
- Adequacy of user documentation for safety purposes.
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Dependability Evidence: Emphasizes the need for evidence supporting the correctness of device operation through:
- Previous certifications.
- Avoidance of systematic faults.
- Quality assurance in design and manufacturing.
- Product stability and operational experience.
- Complementary testing and verification measures.
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Integration Limits and Conditions: Guidance on integration challenges such as:
- Restrictions on use in safety systems.
- Required modifications for the device or system.
- Commissioning procedures and conditions to ensure safety compliance.
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Preservation of Acceptability: Addresses lifecycle support including:
- Notifications from manufacturers.
- Maintenance of documentation and tools.
- Support lifetime considerations for existing product versions.
Applications
IEC 62671:2013 is highly valuable in practical scenarios where nuclear power plant designers and operators must incorporate industrial digital devices that were not originally engineered for nuclear safety contexts but are attractive due to market availability or obsolescence issues in nuclear-grade equipment. Specific applications include:
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Instrumentation and Control Systems: Use and integration of limited-function embedded digital devices in monitoring, protection, or control systems important to safety.
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System Upgrades and Modernizations: Guiding utilities seeking to replace obsolete safety-related equipment with commercially available industrial devices conscious of safety requirements.
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Evaluation and Licensing: Assisting system evaluators and regulatory bodies in assessing compliance and reliability criteria to ensure safety standards are met even with non-nuclear-origin devices.
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Cybersecurity in Nuclear Plant I&C: Incorporating cybersecurity requirements to mitigate threats and maintain system integrity when adding digital devices to safety-related systems.
Related Standards
IEC 62671:2013 complements and provides guidance distinct from, yet related to other key IEC standards for nuclear I&C, including:
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IEC 60880: Focuses on software for computer-based systems performing safety functions in nuclear power plants.
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IEC 62138: Covers programmable logic controllers (PLCs) for nuclear applications.
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IEC 62566: Addresses software tools used for nuclear instrumentation and control.
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IEC 61508: A general safety standard for electrical/electronic/programmable electronic safety-related systems, often the basis for many industrial digital devices.
By addressing the selection and evaluation of devices not designed to nuclear-specific standards, IEC 62671 fills an essential gap and enables safe adoption of commercially developed digital components in nuclear safety instrumentation and control systems.
Keywords: IEC 62671, nuclear power plants, safety instrumentation and control, industrial digital devices, limited functionality, device evaluation, nuclear I&C systems, embedded software, digital circuits, functional suitability, device dependability, cybersecurity, nuclear safety standards, IEC nuclear standards.