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:
result of a chlorine release. The instal- lation of the detectors should ensure that they are protected from adverse temperature effects. (6) Maintenance, Testing, and Calibration. The manufacturer's maintenance recommendations are acceptable provided they follow sound engineering practice and are compatible with the proposed ap- plication. A routine operational check should be con- ducted at one-week intervals. Verification testing and calibration of the chlorine detectors and verification testing of the system response time should be conducted at six- month intervals. 5. The gross leakage characteristic of the control room should be determined by pressurizing the con- trol room to 1/8-inch water gage and determining the pressurization flow rate. (The use of a higher pressure differential is acceptable provided the flow rate is conservatively adjusted to correspond to 1/8-inch water gage.) For air exchange rates of less than 0.06 hr -', periodic verification testing should be per- formed. An acceptable method for periodic testing would be the use of a permanently installed calibrated pressurization fan. The system would have a known pressure-versus-flow characteristic so that the leak rate could be determined by measuring the control room pressure differential. Testing should be conducted at least every six months and after any ma- jor alteration that may affect the control room leakage. 6. Emergency procedures to be initiated in the event of a chlorine release should be provided. Methods of detecting the event by station personnel, both during normal workday operation and during minimum staffing periods (late night and weekend shift staffing), should be discussed. Instrumentation that has been provided for the detection of chlorine should be described including sensitivity; action in- itiated by detecting instrument and level at which this action is initiated; technical specification limitations on instrument availability; and instructions for maintenance,