Document: NUREG-0800
Document ID: 117c3e07-68b8-4bd8-b2f6-f2bcf4de73b9
Document Type: srp
Title: Draft Revision 6 – August 2015
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1515/ML15159A982.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
oftware, programming tools, and peripheral components should be qualified to a level commensurate with the system they are designed to support. EPRI TR-106439 and EPRI TR-107330 describe an acceptable process for qualifying commercial systems. NUREG/CR-6421 provides additional information on the characteristics of an acceptable process for qualifying existing software, and discusses the use of engineering judgment and compensating factors for purchased PLC software. See the discussion of the commercial dedication of pre-developed software (PDS) in SRP Appendix 7.0-A. PLC hardware, embedded and operating system software, and peripheral components built specifically for nuclear power plant applications should meet the appropriate quality criteria. The embedded and operating system software should meet the acceptance criteria contained in SRP BTP 7-14, appropriately graded for the application in which the PLC will be used. The application software (ladder logic or other) should meet the acceptance criteria contained in SRP BTP 7-14 commensurate with the system it is designed to support. Application software should conform to the recommended practices of NUREG/CR-6463. Tools for developing application software or loading it into the PLC should be qualified to a level commensurate with the system they are designed to support. PLC-based functions should conform to the guidance regarding real-time performance and testing outlined in SRP BTP 7-21 and SRP BTP 7-17. Administrative or hardware lockout controls that prevent unauthorized modification of the PLC software should be in place. This is particularly important because many PLCs are designed so that their software is easy to modify. All software changes should be under configuration management control. In particular, administrative procedures for maintaining control of the software implemented in the PLC should be detailed in the configuration management plan. 4. Review Procedures PLC applications should be reviewed in