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:
ed from the emergency zone by multiple barriers such as multiple door vestibules or their equivalent. 6. Radiation Shielding. Control room operators as well as other plant personnel are protected from radiation sources associated with normal plant operation by a 6.4-16 Revision 3 - March 2007 combination of shielding and distance. The review of the adequacy of this type of protection for normal operating conditions is coordinated with the organization responsible for the review of design bases accident radiological consequence analysis. To a large extent, the same radiation shielding (and missile barriers) also provides protection from DBA radiation sources. This is especially true with respect to the control room walls, which usually consist of at least 46 cm (18 in) of concrete. In most cases, the radiation from external DBA radiation sources is attenuated to negligible levels. The following items should be considered qualitatively in assessing the adequacy of control room radiation shielding and should be coordinated with the organization responsible for the review of design basis accident radiological consequence analyses, who will be requested to provide assistance as necessary. A. Control Room Structure Boundary. Wall, ceiling, and floor materials and thickness should be reviewed. Forty-six to 61 centimeters (Eighteen inches to 2 feet) of concrete or its equivalent will be adequate in most cases. B. Radiation Streaming. The control room structure boundary should be reviewed with respect to penetrations (e.g., doors, ducts, stairways). The potential for radiation streaming from accident sources should be identified, and if deemed necessary, quantitatively evaluated. C. Radiation Shielding from Internal Sources. If sources internal to the control room complex are identified, protective measures against them should be reviewed. Typical sources in this category include contaminated filter trains, or airborne radioactivity in enclosures adjacent to the control