Document: NUREG-0800
Document ID: 2cde5121-7267-482f-82a5-b36a0b9fc741
Document Type: srp
Title: ENGINEERED SAFETY FEATURE VENTILATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350029.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.4.5
CFR Part: 
CFR Title: 

Content:
iewed to verify that two automatically operated isolation dampers in series separate nonessential portions and components from the essential portions. b. Essential portions of the ESFVS, including the isolation dampers sepa- rating essential from nonessential portions, are classified seismic Category I. Component and system descriptions in the SAR that iden- tify mechanical and performance characteristics are reviewed to verify that the above classifications have been included, and that the P&IDs indicate points of change in design classification. c. Design provisions have been made that permit appropriate inservice inspection and functional testing of system components important to safety. It is acceptable if the SAR information delineates a test- ing and inspection program and if the system drawings show the necessary test recirculation loops around fans or isolation dampers that would be required by this program. 3. The reviewer verifies that the system has been designed so that system function will be maintained as required in the event of adverse environ- mental phenomena 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 non- seismic systems, components, or structures located close to essential portions of the system will not preclude operation of the essential portions of the ESFVS. Reference to SAR sections describing site features and the general arrangement and layout drawings will be neces- sary, as well as the SAR tabulation of seismic design classifications for structures and systems. b. The essential portions of the ESFVS are protected from the effects of floods, hurricanes, tornadoes, and internally and externally generated missiles. Flood protection and missile protection criteria are discussed and evaluated in detail under the Section 3 series of the SRP. The location and