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:
he 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 mobile sources of hazardous chemicals in the vicinity of their plant sites. The periodicity should be based on the number, size, and type of industrial and transportation activities in the vicinity of the plant and regional and local changes in uses of land. The staff recommends conducting a survey of the location, types, and quantities of the mobile and stationary hazardous chemical sources at least once every 3 years, or more frequently as applicable. The staff also recommends annual performance of an onsite survey of hazardous chemical sources. For CREs under construction, the hazardous chemical analysis should be based on the expected performance values. When the envelope and associated ventilation systems are operational, the calculation should be based on an inleakage value determined according to guidance being developed in Draft Regulatory Guide DG-1115 (Ref. 9). 2.6 Reactor Control This Regulatory Position provides guidance to address potential consequences to the environment in the control room and the alternate shutdown panel room. This Regulatory Position does not address the performance of the reactor controls and instrumentation systems that are affected by environmental conditions caused by a radiological, toxic gas, or fire event. Demonstrating a facility's CRH includes ensuring that an accident arising from a radiological event, hazardous chemicals, or a fire would not prevent the control room operators from controlling the reactor. Facilities should demonstrate that they meet the 9 reactor control aspects of their design basis (typically GDC-19). The specific acceptance criteria for radiological events are provided in 10 CFR 50.67, "Accident Source Term," and guidance being developed in Regulatory Position 4.5 of Draft Regulatory Guide DG-1113 (Ref.