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:
and toxic gases. Specific criteria as to radiation and toxic gas sources are as follows: A. Radiation sources. As a general rule the control room ventilation inlets should be separated from the major potential release points by at least 31 meters (100 feet) laterally and by 16 meters (50 feet) vertically. However, the actual minimum distances should be based on the dose analyses (Ref. 9). (1) The whole-body gamma, thyroid, and beta skin doses are consistent with the recommendations of International Committee on Radiation Protection (ICRP) 26, which were used in the May 21, 1991, revision of 10 CFR Part 20. 10 CFR 20.1201 limits organ dose to 50 rem annually. 6.4-6 Revision 3 - March 2007 B. Toxic gases. The minimum distance between the toxic gas source and the control room is dependent upon the amount and type of the gas in question, the container size, and the available control room protection provisions. The acceptance criteria for the control room habitability system are provided in the regulatory positions of Regulatory Guide 1.78 with respect to postulated hazardous chemical releases in general. 6. Radiation Hazards A. For current operating reactors that do not implement an alternative source term under 10 CFR 50.67, 10 CFR Part 50, Appendix A, General Design Criterion 19 (GDC 19) “Control room,” requires that “Adequate radiation protection shall be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposures in excess of 5 rem whole body, or its equivalent to any part of the body, for the duration of the accident.” In accordance with GDC 19, these doses to an individual in the control room should not be exceeded for any postulated design basis accident. The whole body gamma dose consists of contributions from airborne radioactivity inside and outside the control room, as well as direct shine from all radiation sources. i. For current operating reactors the dose guidelines for