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:
and assessing qualification for safety-related I&C systems in nuclear power plants. The staff concludes that this alternative has the following values and impacts: • value < probable improvement in the likelihood of achieving safety goals as a consequence of consistent qualification practices in the nuclear power industry < consideration of consensus approaches to qualification < common understanding of good design, testing, and implementation practices tailored to the nuclear power industry, on the basis of established qualification approaches by the military and by commercial industries • impact < staff cost of evaluating qualification practices for specific relevance to the nuclear power industry < staff cost of endorsing tailored sets of practices from selected standards DG-1142, Page 14 4. Conclusions Evidence is available that the plant environment can adversely affect computer-based I&C systems differently than their analog counterparts. General Design Criterion 4 requires that SSCs important to safety shall be compatible with and accommodate the effects of conditions associated with nuclear power plant service. The primary focus of the current qualification standard is the reliable operation of safety-related equipment if design-basis accidents occur. With the inevitable use of computer-based I&C systems for safety-related applications, it is essential to address the full scope and intent of Federal regulations (i.e., assurance of reliable operation in case of design-basis events, specifically normal and abnormal operational occurrences and anticipated operational accident conditions throughout the life of the system). Toward that end, the NRC staff considered three approaches to providing qualification guidance. Taking no action might result in accumulating 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