Document: NUREG-0800
Document ID: a2598df1-7ec6-43a6-9d2a-d8210d1f944f
Document Type: srp
Title: through 7.9. Additional information relevant to the review process can be found in the references in
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500461.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.1
CFR Part: 
CFR Title: 

Content:
esses"). The software life cycle typically includes a planning phase, requirements phase, design phase, implementation phase, integration phase, validation phase, installation phase, and operation and maintenance phase. The purpose of such a mapping is to permit concurrent execution of related activities, and to provide staged checkpoints at which product and process characteristics are verified during the development process. B. Background The fundamental acceptance criteria for I&C systems are described in 10 CFR 50.55a; ANSI/IEEE Std 279, "Criteria for Protection Systems for Nuclear Power Generating Stations;" Reg. Guide 1.153, "Criteria for Power, Instrumentation, and Control Portions of Safety Systems," which endorses IEEE Std 603, "IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations;" and Appendix A of 10 CFR 50 (General Design Criteria). Appendix B of 10 CFR 50 (Quality Assurance Criteria) provides criteria for quality assurance programs to be applied to the design, fabrication, construction, and testing of I&C safety systems. The criteria of 10 CFR 50 apply to digital I&C systems and are sufficient to support licensing of such systems. For applications under 10 CFR 52, the technical acceptance criteria of 10 CFR 50 apply. Certain characteristics of digital I&C systems necessitate that augmented review approaches and different review perspectives be used in assessing compliance with the fundamental acceptance criteria of 10 CFR 50. These characteristics are important to the evaluation of (1) design qualification of digital systems, (2) protection against common-mode failure, and (3) selected functional requirements of IEEE Std 603 and the General Design Criteria that pose new assurance challenges when implemented using computers. These topics are discussed in more detail below. B.1. Qualification of Digital Instrumentation and Control Systems and Components Digital I&C systems require additional design and qualification approaches