Description
This publication defines a framework that represents the state of the art of assessment methodologies for safety and instrumentation and control software used at nuclear power plants. It describes an approach for developing and communicating assessments based on claims, arguments and evidence. The assessment of software dependability, which encompasses properties such as safety, reliability, availability, maintainability and security, is an essential and challenging aspect of the safety justification. Information is given on guiding principles to provide the basis for defining an assessment strategy and implementing the assessment process. Sources of evidence for the assessment are provided and lessons learned from past digital instrumentation and control system implementation in areas such as software development, operational usage, regulatory review and platform certification are also described.
Keywords
IAEA Nuclear Energy, Quality Assurance, Nuclear Power Plants, Instruments, Nuclear Reactors, Control, Digital Control Systems, Dependability Assessment, Assessment Methodology, Instrumentation and Control Systems, Safety Instrumentation, Communication, Safety Systems, Reliability, Availability, Maintainability, Integrity, Security, Lessons Learned, Software Development, Operational Usage, Regulatory Review, Platform Certification, Concepts, System Context, Dependability Properties, Standards, Codes, Functional Validation, Modelling, Software Analysis Techniques, Verification, Testing, Inspections, Reviews, Fault Tree Analysis, FTA, Member States, Research, Design, Regulatory Regimes, Common Cause Failure, CCF, Commercial of the Shelf, COTS, Strategies, Vulnerabilities, Claims, Arguments, Evidence, CAE, Software Evaluation, Guidance, Framework, System Behaviour, Interactions, Compliance, Fault Injection
