Document: NUREG-0800
Document ID: 010ad62f-cd7b-4f06-9f81-a781faf5701b
Document Type: srp
Title: ENGINEERED SAFETY FEATURE VENTILATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070560.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.4.5
CFR Part: 
CFR Title: 

Content:
the ESFVS are correctly identified and are isolatable from nonessential portions of the system. The P&IDs are reviewed to verify that they clearly indicate the physical divisions between such portions and indicate design classification changes. System drawings are also reviewed to see that they show the means for accomplishing isolation, and the system description is reviewed to identify minimum performance requirements for the isolation dampers. For the typical system, the drawings and description are reviewed 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 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 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 testing 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 environmental 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 nonseismic systems, components, or structures located close to essential portions of the system will not preclude operation of the essential portions of the ESFVS. Reference