Document: NRC Regulatory Guide
Document ID: d35b20dd-1c15-4bc0-ab12-86d3766156f4
Document Type: regulatory_guide
Title: Withdrawing RG 1.41 because its guidance has been incorporated into RG 1.32, Revision 4
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1427/ML14272A332.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.41
CFR Part: 
CFR Title: 

Content:
Regulatory Guide Periodic Review Regulatory Guide Number: 1.41 Title: Preoperational Testing of Redundant On-Site Electric Power Systems to Verify Proper Load Group Assignments Office/division/branch; NRO/DCIP/QVIB Technical Lead: Thomas Kendzia Recommended Staff Action: Revise 1. What are the known technical or regulatory issues with the current version of the Regulatory Guide (RG)? Regulatory guide (RG) 1.41, “Preoperational Testing of Redundant On-Site Electric Power Systems To Verify Proper Load Group Assignments,” published March 1973 is used with RG 1.6, “Independence Between Redundant Standby (Onsite) Power Sources and Between Their Distribution Systems (Safety Guide 6)” and RG 1.32, “Criteria for Power Systems for Nuclear Power Plants” to verify proper load group assignments and electrical independence between redundant load groups. RG 1.41 expands on Section 5.2.2.5 of the Institute of Electrical and Electronics Engineers (IEEE) Standard 308- 1971, “IEEE Standard Criteria for Class 1E Electric Systems for Nuclear Power Generating Stations” which states … “Auxiliary devices that are required to operate dependent equipment shall be supplied from a related bus section to prevent loss of electric power in one load group from causing the loss of equipment in another group.” The IEEE standard has been revised and updated to IEEE Std. 308-2012, and the applicable section (5.2.2.5 Auxiliary Systems) has been renumbered to Section 5.2.2.4, Auxiliary Systems, but the recommendation is unchanged. The references do not include the correct version of IEEE 308, do not reference Part 52 requirements, and do not include references to RG 1.68, 1.70, and 1.206, which would be appropriate. RG 1.41 was initially developed to provide guidance on preoperational testing of on-site electrical power systems important to safety, for load group assignments, electrical separation, and redundancy. Since that time, the Commission has amended its regulations for