Document: NRC Regulatory Guide
Document ID: ceaeb6d7-d85a-46d3-a1b6-70059a498965
Document Type: regulatory_guide
Title: 12/2001 (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0131/ML013100014.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.78
CFR Part: 
CFR Title: 

Content:
2000.2 5. L.B. Sasser et al., “Recommendations for Revision of Regulatory Guide 1.78,” NUREG/CR-6624, USNRC, July 1999.3 6. USNRC, Framework for Risk-Informed Changes to the Technical Requirements of 10 CFR Part 50, an attachment to “Status Report on Study of Risk-Informed Changes to the Technical Requirements of 10 CFR Part 50 (Option 3) and Recommendations on Risk- Informed Changes to 10 CFR 50.44 (Combustible Gas Control),” SECY-00-0198, September 14, 2000.2 7. NIOSH, “NIOSH Pocket Guide to Chemical Hazards,” National Institute for Occupational Safety and Health, 1997. 8. J.V. Ramsdell, Jr., and S.A. Stage, “Computer Codes for Evaluation of Control Room Habitability (HABIT V1.1),” NUREG/CR-6210, Supplement 1 (Prepared for the NRC by Pacific Northwest National Laboratory), USNRC, October 1998.3 4 Copies may be obtained from IEEE Service Center, 445 Hoes Lane, Piscataway, New Jersey 08855-1331. 1.78-14 9. ASTM, “Standard Test Method for Determining Air Change in a Single Zone by Means of a Tracer Gas Dilution, ASTM Standard E741-95, American Society for Testing and Materials, 1995. 10. IEEE, “Criteria for Safety Systems for Nuclear Power Generating Stations, “ IEEE Std 603-1991, Institute of Electrical and Electronics Engineers, 1991.4 1.78-15 APPENDIX A A SIMPLIFIED PROCEDURE FOR CALCULATING WEIGHTS OF HAZARDOUS CHEMICALS FOR CONTROL ROOM EVALUATIONS The weights presented in the following table are based on a toxicity limit of 50 mg/m3; air exchange rates of 0.015, 0.06, and 1.2 per hour, respectively; and a Pasquill stability category F representing the worst 5% of meteorological conditions observed at a majority of nuclear plant sites.  WEIGHTS OF HAZARDOUS CHEMICALS THAT REQUIRE CONSIDERATION IN CONTROL ROOM EVALUATIONS (FOR A 50 mg/m3 TOXICITY LIMIT AND STABLE METEOROLOGICAL CONDITIONS) Distance From Control Room (miles)a Weight (1000 lb) Air