Document: NUREG-0800
Document ID: 4f097781-0d4c-4b5b-be06-a3cd19ae9fe8
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0706/ML070660430.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
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at contains it, nor will power failure erase it; some computers may contain embedded software stored in electrically erasable programmable read-only memory (EEPROM), but changing this memory typically requires a special sequence of actions by maintenance personnel. Engineered safety features (ESF) - Safety equipment which removes heat or otherwise assists in maintaining the integrity of the three physical barriers to radioactive release, which are cladding, reactor coolant pressure boundary, and containment. Engineered safety features actuation systems (ESFAS) - Those I&C systems which initiate and control safety equipment which removes heat or otherwise assists in maintaining the integrity of the three physical barriers to radioactive release (cladding, reactor coolant pressure boundary, and containment). Formal methods - Mathematically based methods for the specification, design, and production of software. Also includes a logical inference system for formal proofs of correctness, and a methodological framework for software development in a formally verifiable way [MOD-00-55]. Function - Specific purpose of an entity or its characteristic action. [IEEE Std 610.12-1990] Functional characteristic - A trait or property of a design output that implements a functional requirement, a portion of a functional requirement, or a combination of functional requirements. For software, functional characteristics include accuracy, functionality, reliability, robustness, safety, security, and timing. Appendix 7-B-7 Revision 5 - March 2007 Functional requirement - A requirement that specifies a function that a system or system component must be capable of performing [IEEE Std 610.12]. In the SRP, the term functional requirement includes design requirements, interface requirements, performance requirements, and physical requirements. Functionality (as a software functional characteristic) - Those operations which must be carried out by the software. Functions generally transform