Document: NUREG-0800
Document ID: 409035a3-eae4-4524-8ae0-ca7775f4072a
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550073.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
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Content:
irements for a PLC. Generic qualification is the first of a two-step process; further qualification for a plant-specific application is required. Examples of generic qualifications can be found in the SERs for the Triconix Tricon PLC system dated December 11, 2001, and the Westinghouse Common Qualified (Common Q) platform that includes an AC 160 PLC dated August 11, 2000. NUREG/CR-6421, “A Proposed Acceptance Process for Commercial Off-the-Shelf (COTS) Software in Reactor Applications,” discusses graded acceptance processes for commercial off-the-shelf software used in reactor applications. The guidance in this NUREG will aid the reviewer in the evaluation of acceptance processes that are part of commercial dedication of PLC embedded, operating system software, and programming tools. 3. Purpose The purpose of this BTP is to provide guidance for NRC staff to verify conformance with the previously cited regulatory bases and standards in the design of digital computer systems using PLCs. This BTP has two objectives: BTP 7-18-3 Revision 5 - March 2007 • To assure that embedded and operating systems software, programming tools, and peripheral components are reviewed, and the appropriate acceptance criteria are applied. • To assure that the PLC application software (e.g., ladder-logic software) are developed using an appropriate software development process. B. BRANCH TECHNICAL POSITION 1. Introduction PLCs are often used to monitor and control industrial processes. They are typically commercial-grade computer systems that include simplified operating systems and standard service functions such as self-testing and communications, Most PLCs are configured for their specific application using a high-level language, such as ladder logic. The software for PLCs should be designed and implemented using a process that conforms with the guidance in SRP BTP 7-14. Software design and implementation for specific applications may be easier to implement for PLCs due to the use