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:
tion to ensure that the control room operators can remain in the control room and take actions to operate the plant under normal and accident conditions. The personnel protection features incorporated into the design of a particular plant's CRHSs depend on the nature and scope of the plant-specific challenges to maintaining habitability of the CRE. In the majority of the CRHS designs, isolation of the CRE atmosphere from that of adjacent areas is fundamental to ensuring a habitable control room. The primary design function of CRHSs is to protect the public and the control room operator. If the response of the operator is impaired during an accident, there could be increased consequences to public health and safety. It is important for the operators to be confident of their safety in the control room to minimize errors of omission and commission. The NRC identified CRE integrity as one of the control room habitability problems during a series of plant visits conducted between 1985-1987 as a part of the staff response to concerns and recommendations of the Advisory Committee on Reactor Safeguards (ACRS). NUREG/CR-4960, “Control Room Habitability Survey of Licensed Commercial Nuclear Power Generating Stations” (Ref. RA-2), presents the results of this survey. The major conclusion of the report is that the numerous observed discrepancies may be indicative of similar discrepancies throughout the industry. The issue of CRE integrity was identified by the NRC in Information Notice 86-76, “Problems Noted In Control Room Emergency Ventilation Systems” (Ref. RA-3), at various DOE/NRC Air Cleaning Conferences and at industry engineering society and engineering organizational meetings (e.g., American Society of Mechanical Engineers or Nuclear Heating, Ventilation, and Air Conditioning Users Group). In 1992, Zion became the first nuclear power plant to rigorously test its CRE for integrity. Since then, approximately 30 percent of the licensed facilities have performed