Document: NUREG-0800
Document ID: 06884384-e650-488f-bf96-f48afd211643
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550075.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
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Content:
ic exceptions discussed in Regulatory Guide 1.118). IEEE Std. 338-1987 provides design and operational criteria for the performance of periodic and automatic testing; its criteria are supplementary to IEEE Std. 603-1991. Regulatory Guide 1.152, "Criteria for Digital Computers in Safety Systems of Nuclear Power Plants," endorses IEEE Std. 7-4.3.2-2003, "IEEE Standard Criteria for Digital Computers in Safety Systems of Nuclear Power Generating Stations," systems. The Regulatory Guide and endorsed standard provide guidance applicable to the development of self-test software and to making safety functions independent from self-test functions. 3. Definitions Periodic tests are tests performed at scheduled intervals to detect failures and verify operability (IEEE Std. 338-1987). Periodic tests include surveillance tests. A self-test is a test or series of tests performed by a device upon itself. Self-tests include on-line continuous self-diagnostics, equipment-initiated self-diagnostics, and operator-initiated self-diagnostics. Surveillance tests are conducted specifically to confirm compliance with technical specification surveillance requirements. A watchdog timer is a form of interval timer that is used to detect a possible malfunction (IEEE Std. C37.1-1994, "IEEE Standard Definition, Specification, and Analysis of Systems Used for Supervisory Control, Data Acquisition, and Automatic Control"). 4. Purpose The purpose of this BTP is to provide guidance for NRC staff to verify that the previously cited regulatory basis and standards are met by an applicant/licensee's submittal. The objectives of this BTP are to confirm that: • The safety system (including self-test) is designed for in-service testability commensurate with the safety functions to be performed through all modes of plant operation. • The positive aspects of self-test features are not compromised by the additional complexity that may be added to the safety system by the self-test features. • Hardware