Document: NRC Regulatory Guide
Document ID: 26c3e31f-c018-4aee-b926-6db849b72a5a
Document Type: regulatory_guide
Title: Guidelines for Environmental Qualification of Safety-Related Computer-Based Instrumentation and Control Systems in Nuclear Power Plants
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0630/ML063040591.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.209
CFR Part: 
CFR Title: 

Content:
ting regulatory expenses, as applicants or licensees submit proposed methods to assure the staff that safety-related systems are compatible with the proposed environment for computer-based I&C systems and, thus, meet the requirements of NRC regulations. By itself, the identification of enhancements to current qualification approaches on the basis of unique features of computer-based I&C systems does not guarantee that the full scope and intent of 10 CFR 50.55a(h) have been addressed. Therefore, this alternative alone also leaves the potential for regulatory uncertainty that could result in greater costs for both the NRC staff and the applicant or licensee during the safety evaluation process. On the basis of the greatest value and most reasonable impacts of the problem solution (especially regulatory burden), the staff chose the third alternative. This alternative, tailored endorsement of the current qualification standard (i.e., IEEE Std 323-2003), would be sufficient when clarifications to address the unique characteristics of computer-based I&C systems are adequately addressed. This approach can contribute to establishing uniformity and consistency in environmental qualification practices for safety-related computer-based I&C systems in mild environments and can provide a roadmap to address the unique characteristics of microprocessor-based technology. BACKFIT ANALYSIS This regulatory guide does not require a backfit analysis, as described in 10 CFR 50.109, “Backfitting,” because it is intended for new nuclear power plants. The use of this regulatory guide by current operating licensees is entirely voluntary. 2 EPRI publications may be purchased from the EPRI Distribution Center, 207 Coggins Drive, P.O. Box 23205, Pleasant Hill, CA 94523; telephone (510) 934-4212. 3 IEEE publications may be purchased from the IEEE Service Center, 445 Hoes Lane, Piscataway, NJ 08855; online at http://www.ieee.org; telephone (800) 678-4333. 4 Copies are available at current