Document: NUREG-0800
Document ID: b4dc2da5-bdfa-4120-9cf3-b2918a366a3e
Document Type: srp
Title: CONTROL ROOM AREA VENTILATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350557.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.4.1
CFR Part: 
CFR Title: 

Content:
es and systems. Statements in the SAR that verify that the above conditions will be met are acceptable at the CP stage. b. The essential portions of the CRAVS are protected from the effects of floods, hurricanes, tornadoes, and internally or externally gen- erated missiles. Flood protection and missile protection criteria are discussed and evaluated in detail under the Section 3 series of the SRP. The location and the design of the system, structures, and pump rooms (cubicles) are reviewed to determine that the degree of pro- tection is adequate. A statement to the effect that the system is located in a seismic Category I structure that is tornado missile and flood protected, or that components of the system will be located in individual seismic Category I cubicles or rooms that will withstand the effects of both flooding and missiles is acceptable. c. The total system has the capability to detect and control leakage of airborne contamination into the system. It is acceptable if the following conditions are met: (1) The system P&IDs show monitors located in the system intakes that are capable of detecting radiation, smoke, and toxic chemicals. The monitors should actuate alarms in the control room. 9.4.1-5 Rev. 2 - July 1981 (2) The capability for isolation of nonessential portions of the CRAVS by two automatically actuated dampers in series is shown on the P&IDs. (3) The CRAVS has provisions for an internal recirculation filtering mode of operation or can discharge airborne contaminants from the control room area using a once-through ventilation mode, as applicable. (4) Provisions for isolation of the control room upon smoke detec- tion at the air intakes are shown on the P&IDs. The isolation may be actuated manually for most cases. Automatic isolation may be required in special cases such as for fires resulting from aircraft crashes. d. Essential components and subsystems can function as required in the event of loss of offsite power. The system design will be