Document: NUREG-0800
Document ID: 896f0b4b-b27c-462b-aed0-872a58b455c8
Document Type: srp
Title: Revision 6 – August 2016
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1601/ML16019A327.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
e shown to be applicable to the safety system application, it is of limited use. SRP Appendix 7.0-A, “Review Process for Digital Instrumentation and Control Systems,” Subsection C.3, describes the advantages of using high-level languages such as ladder logic and function charts. It also describes precautions that should be observed when reviewing systems specified or designed using such languages. Many vendors of PLCs allow programming languages other than ladder-logic to be used (e.g., C). The reviewer should take this possibility into account and assess the impact of using programming languages on the design of the PLC and the application. BTP 7-18-4 Revision 6 – August 2016 An I&C system built using PLCs contains a number of purchased components: hardware, including the processor, memory, I/O equipment, communications equipment, terminals, etc., and software, consisting of one or more operating systems, interpreters, compilers, libraries, configuration software, tools, and variations thereof. This purchased equipment should be of a quality appropriate to the proposed application. Other issues associated with the application of digital computers to I&C systems, such as maintenance, verification and validation, electromagnetic interference, and calibration, apply and should be reviewed. The staff should not accept an argument that the PLC is somehow simpler or different from a computer and hence does not require the rigorous review that a computer system would receive. 2. Information to be Reviewed Information to be reviewed is contained in the safety analysis report (SAR), revisions to the SAR, license amendment requests, topical reports, or other applicant or licensee documentation. Inspections, tests, analyses, and acceptance criteria (ITAAC) or detailed design documents describe designs, tests, analyses, or other methods of demonstrating that design commitments have been satisfied. Information that is not contained in the licensee’s or applicant’s