Document: NUREG-0800
Document ID: 1877a6e5-f5a2-4394-bd63-c323831e96d0
Document Type: srp
Title: INTRODUCTION - TRANSIENT AND ACCIDENT ANALYSES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML2231/ML22319A149.pdf
Revision Date: 2023-07
Chapter: 15
Section ID: 15.0
CFR Part: 
CFR Title: 

Content:
. 6. Event Evaluation A. Identification of Causes and Frequency Classification. For each initiating event evaluated, the reviewer ensures that the application includes a description of the occurrences that can lead to the event and a categorization of the event as either an AOO or postulated accident. The reviewer also checks for clear definitions of the analysis acceptance criteria appropriate to the specific nature of the initiating event, as well as the event’s categorization. B. Sequence of Events and Systems Operation. The reviewer verifies that the application addresses the following considerations for each event: i. Step-by-step sequence of events, from event initiation to the final stabilized condition (i.e., identification on a time scale of each significant occurrence, including flux monitor trips, insertion of control rods, attainment of primary coolant safety valve setpoints, opening and closing of safety valves, generation of containment isolation signals, and containment isolation) and identification of all operator actions credited in the transient and accident analyses for consequence mitigation ii. Extent to which normally operating plant instrumentation and controls are assumed to function iii. Extent to which plant and reactor protection systems are required to function iv. Credit taken for the functioning of normally operating plant systems v. Credited operation of engineered safety systems 15.0-9 Draft Revision 4 – July 2023 vi. If applicable and available,6 consistency between the safety analyses and the emergency response guidelines/emergency procedure guidelines or emergency operating procedures with respect to the operator response (including action time) and available instrumentation The reviewer verifies that the applicant has specified only safety-related systems or components for use in mitigating AOO and postulated accident conditions and has included the effects of single failures in those systems and components. In the event that