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:
of in- dividuals either outside the control room or within the control room but not directly involved in reactor operations. Breathing apparatus should be provided and be readily accessible throughout the plant in order to eliminate the need for personnel to seek shelter in the control room during a chlorine release. The features and procedures described in this guide apply to plants having conventional ventilation systems. Any different methods of protection proposed will be evaluated on a case-by-case basis. C. REGULATORY POSITION Control room operators should be protected against the effects of an accidental chlorine release as described below. 1. Liquified chlorine should not be stored within 100 meters of a control room2 or its fresh air inlets. (Small quantities for laboratory use, 20 lbs or less, are exempt.) 2. If a chlorine container having an inventory of 150 lbs or less is stored more than 100 meters from the control room or its fresh air inlets, the capability for manual isolation of the control room should be provided. 3. For single container quantities exceeding 150 lb, the maximum allowable chlorine inventory in a single container stored at specified distances from the con- trol room or its fresh air inlet is given in Table 1 for control room Types I through VI (described below). For each control room type, the maximum allowable chlorine inventory in a single container is given as a function of distance from the control room. If there are several chlorine containers, only the failure of the largest container is normally considered unless the 2 Control room is defined to include all zones serviced by the emergency ventilation system. 1 I 1.95-2 ,lo w w TABLE 1 MAXIMUM ALLOWABLE CHLORINE INVENTORY IN A SINGLE CONTAINER Control Room Type Control Room Characteristics Isolation Air Exchange Local Remote Time Rate - Normal Detectors Detectors (sec) (hrI Air Exchange Rate - Isolated (hr 4 ) 0.06 Maximum Weight (1000 Ib) of Chlorine as a Function of Distance