Document: NUREG-0800
Document ID: 7916b088-fb90-4163-84fe-027bd315bcc5
Document Type: srp
Title: REVIEW OF RISK INFORMATION USED TO SUPPORT PERMANENT PLANT-
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0717/ML071700658.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.2
CFR Part: 
CFR Title: 

Content:
ould be cognizant with regard to the following types of dependencies that could exist and could affect the results of the change analysis: Functional Dependencies: These dependencies occur because the function of one system or component depends on that of another system or component. Functional dependencies include interactions that can occur when the change in the function of a system or component causes a physical change in the environment that results in the failure of another system or component. Functional dependencies include the following examples: • Shared component dependencies (e.g., systems or system trains that depend on a common intake or discharge valve), • Actuation requirement dependencies (e.g., systems that depend on common actuation signals, common actuation circuitry, or common support systems like AC or DC power or instrument air for initiation or actuation) and conditions needed for actuation (e.g., low RPV water level), • Isolation requirement dependencies (e.g., conditions that could cause more than one system to isolate, trip, or fail), including environmental conditions (temperature, pressure, and/or humidity), temperature and pressure of fluids being processed, water level status, and radiation levels, • Power requirement dependencies (e.g., systems that depend on the same power sources for motive power), • Cooling requirement dependencies (e.g., systems that depend on the same room cooling subsystem, or the same lube oil cooling subsystem, or systems that depend on the same service water or component cooling water train for cooling), • Indication requirement dependencies (e.g., systems that depend on the same pressure, temperature, or level instrumentation for operation), 19.2-48 June 2007 • Phenomenological effect dependencies (e.g., conditions generated during an accident sequence that influence the operability of more than one system), including generation of harsh environments that result in protective trips of systems,