Document: NRC Regulatory Guide
Document ID: 4b34bbdf-f837-4227-9a0d-3f0ad3778b30
Document Type: regulatory_guide
Title: Protection of Nuclear Power Plant Control Room Operators Against an Accidental Chlorine Release (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1229/ML12298A134.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.95
CFR Part: 
CFR Title: 

Content:
Postulated Hazardous Chemical Release," identifies chlorine as a hazardous chemical which, if present in the control room at- mosphere in sufficient quantity, could result in the control room becoming uninhabitable. It is the pur- pose of this guide to describe specific design features and procedures that are acceptable to mitigate hazards to control room operators from an acciden- tal chlorine release. Although this guide was developed to provide protection from an onsite chlorine release, the protection provisions described here are also expected to be sufficient for an offsite chlorine release. The positions stated in this guide are based on the specific physical properties and physiological effects of chlorine. Two basic accident types can be postulated: a long- term, low-leakage-rate release and a short-term puff release. The majority of chlorine releases experienced to date have been of the first type, involving leakage from valves or fittings and resulting in a long-term release with a leakage rate from near zero to less than one pound of chlorine per second. Given warning, only breathing apparatus is necessary to protect the control room operator from this kind of release. However, because such a release might continue un- abated for many hours, self-contained breathing ap- paratus, a t sourc a.. :i.. mafo- outlets, or equivalent protection capable of operation for an ex- tended period of time should be available. A less probable but more severe accident would be the failure of a manhole cover on the chlorine con- tainer or the outright failure of the container itself. USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, U.S. Nuclear Regulatory Guides are issued to describe and make available to the public Regulatory Commission. Washington, DC. 20555, Attention: Docketing and methods acceptable to the NRC staff of implementing specific parts of the Service Section. Commission's regulations, to delineate techniques used by the