Document: NUREG-0800
Document ID: 44d6a58e-60c4-48dc-ac30-11a77c1b190a
Document Type: srp
Title: B-4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550087.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.1
CFR Part: 
CFR Title: 

Content:
the timing margins for changeover from injection to recirculation mode are sufficient to allow manual initiation of the transition. Clause 3(7) of IEEE Std. 279-1971 requires in part that the range of transient and steady-state conditions be identified for both the energy supply and the environment during normal, abnormal, and accident conditions under which the system must perform. This information is used in subsequent evaluations. Clause 3(8) of IEEE Std. 279-1971 requires in part the identification of malfunctions, accidents, or other unusual events that could physically damage protective system components or could cause environmental changes leading to functional degradation of system performance, and for which provisions must be incorporated to retain necessary protective action. This information is used in subsequent evaluations, with special attention given to Clause 4.4 of the standard, "Equipment Qualification." Clause 3(9) of IEEE Std. 279-1971 requires in part the identification of the performance requirements — including system response times, system accuracies, ranges, and rates of change of sensed variables — to be accommodated until conclusion of the protective action. The applicant/licensee's analysis, including the applicable portion provided in Chapter 15, should confirm that the system performance requirements are adequate to ensure completion of protective actions.