Document: NUREG-0800
Document ID: 1c401e6c-8c2d-47df-b05f-2978939cbd15
Document Type: srp
Title: CONTROL ROOM HABITABILITY SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550069.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.4
CFR Part: 
CFR Title: 

Content:
ir supply for a limited time. In some plant designs, the containment pressure is reduced below atmospheric within 1 hour after a DBA. This generally ensures that, after 1 hour, significant radioactive material will not be released from the containment. Such a design makes it feasible to maintain the control room above atmospheric pressure by use of bottled air. Periodic pressurization tests are necessary to determine that the rated flow, normally about 150 to 300 L/s (300 to 600 cfm), is sufficient to pressurize the control room emergency zone. The system should also be composed of several separate circuits, one of which is assumed to be inoperative to account for a possible single failure. At least one nonredundant, once through filter system for pressurization as a standby for accidents of long duration should be provided. Compressed air bottles should be protected from tornado missiles or internally generated missiles and should be placed so as not to cause damage to vital equipment or interference with operation if they fail. 4. Atmosphere Filtration Systems. The primary organization responsible for ventilation and air filtration evaluates the iodine removal efficiency of the atmosphere filtration systems under SRP Section 6.5.1, determines the appropriate credit to be given, and advises the organization responsible for emergency preparedness and radiation protection. The review by the primary organization responsible for ventilation and air filtration should include evaluation of the testing proposed for the filtration system and should use applicable positions of Regulatory Guide 1.52 for guidance. 5. Relative Location of Source and Control Room. SRP Sections 2.2.1 and 2.2.2 provide guidance on identifying potential sources of toxic or otherwise potentially hazardous gases. The organization responsible for the review of SRP Sections 2.2.1 and 2.2.2 will provide its findings to the organization responsible for ventilation and air filtration for its toxic gas