Document: NRC Regulatory Guide
Document ID: 8291b9eb-e4a7-4806-8b5b-1deca2ff1fe2
Document Type: regulatory_guide
Title: Control Room Habitability at Light-Water Nuclear Power Reactors
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0207/ML020790125.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.196
CFR Part: 
CFR Title: 

Content:
ces of each potential radiological accident to ensure that they have identified the limiting accident. Unless a facility relies on a common control room isolation process for all types of radiological accidents, the limiting accident may not be obvious. There are several reasons for this. The inleakage characteristics of the envelope may vary with the CRE's response to an accident. The mitigative equipment used to reduce the radioactivity 8 released to the environment may vary with the accident. The location of the release points for the various accidents relative to the control room intakes may result in less favorable atmospheric dispersion and higher magnitude intake concentrations. Licensees should factor all the potential differences in accidents and CRE performance in order to determine the limiting condition. For hazardous chemicals, a logic process similar to that employed for radiological accidents should be used to determine the limiting condition. 2.4 Radiological Consequence Analysis Licensees should calculate control room operator doses for the accidents identified in Regulatory Position 1.2 using guidance that is being developed in Draft Regulatory Guide DG-1113 (Ref. 5) or Regulatory Guide 1.183, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors" (Ref. 10). For CREs under construction, the control room operators' doses should be based on expected CRHS performance values. When the envelope is operational, the inleakage value should be determined by guidance being developed in Draft Regulatory Guide DG-1115 (Ref. 9). 2.5 Hazardous Chemical Analysis Licensees should perform analyses of the impact of hazardous chemicals on control room operators using the methodology of Regulatory Guide 1.78, "Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release" (Ref. 1). Regulatory Guide 1.78 encourages licensees to conduct periodic surveys of stationary and