Document: NUREG-0800
Document ID: 8c2fce42-281a-4a50-9de7-513df024f27c
Document Type: srp
Title: CONTROL ROOM HABITABILITY SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340712.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.4
CFR Part: 
CFR Title: 

Content:
ystems having pressurization rates of less than 0.25 volume changes per hour should meet all the requirements for (2), above, except that periodic verification of control room pressurization (every 18 months) should be specified. 4. Emergency Standby Atmosphere Filtration System The atmosphere filtration system is reviewed by ETSB under SRP Section 6.5.1. The ETSB will determine the credit for iodine removal for this system in accordance with the guidelines of Regulatory Guide 1.52 (Ref. 5) and will advise the AEB accordingly. Efficiencies for systems not covered by Regulatory Guide 1.52 will be determined on a case-by-case basis by ETSB. 5. Relative Location of Source and Control Room The control room inlets should be located considering the potential release points of radioactive material 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 100 feet laterally and by 50 feet vertically. However, the actual minimum distances must be based on the dose analyses (Ref. 6). 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 protec- tion provisions. The acceptance criteria for the control room habitability system are provided in the regulatory positions of Regulatory Guide 1.78 (Ref. 7) with respect to postulated hazardous chemical releases in general and in Regulatory Guide 1.95 (Ref. 8) with respect to accidental chlorine releases in particular. 6. Radiation Hazards The dose guidelines for evaluating the emergency zone radiation protection provisions are as follows: 6.4-4 Rev. 2 - July 1981 whole body gamma: 5 rem thyroid: 30 rem beta skin dose: 30 rem* In accordance with GOC 19 (Ref. 3), these doses to an individual in the control room