Document: NUREG-0800
Document ID: ef1386f3-1e51-490d-9646-d1018f39b2c8
Document Type: srp
Title: TURBINE AREA VENTILATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350572.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.4.4
CFR Part: 
CFR Title: 

Content:
e changes in design classification. System drawings are also reviewed to verify that the means provided for accomplishing isolation and to identify minimum performance require- ments for the isolation dampers. For the typical system, the drawings and descriptions are reviewed to verify that two automatically operated isolation dampers in series separate nonessential portions and compo- nents from the essential portions. b. Essential portions of the TAVS, including the isolation dampers separating essential from nonessential portions, are classified seismic Category I. Component and system descriptions in the SAR that identify mechanical and-performance characteristics are reviewed to verify that the above seismic classifications have been included, and that the P&IDs indicate any points of change in design classification. 3. The reviewer verifies that the safety-related portion of the system has been designed so that system function will be maintained as required, in the event of an earthquake or loss of offsite power. The reviewer evaluates the system, using engineering judgment and the results of failure modes and effects analyses to determine that: a. The failure of nonessential portions of the system or of other systems not designed to seismic Category I standards and located close to essential portions of the system, or of nonseismic Category I structures that house, support, or are close to essential portions of the TAVS, will not preclude operation of the essential portions of the TAVS. Reference to SAR sections describing site features and the general arrangement and layout drawings will be necessary, as well as the SAR tabulation of seismic design classifications for structures and systems. A commitment in the SAR confirming that the above conditions are met is acceptable. (CP) 9.4.4-4 Rev. 2 - July 1981 b. Components and subsystems necessary for preventing unacceptable releases of radioactive contaminants can function as required in the event of loss of