Document: NRC Regulatory Guide
Document ID: 82021804-a487-471b-a76c-095315525b53
Document Type: regulatory_guide
Title: Guidelines for Evaluating Electromagnetic and Radio-Frequency Interference in Safety-Related Instrumentation and Control Systems (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1628/ML16281A531.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.180
CFR Part: 
CFR Title: 

Content:
ischarge, and accounts for the evolution of the operational environment at nuclear power plants arising from the increased use of digital technology, including wireless communication for both personal (laptops, tablets, and smartphones) and industrial (remote I&C) applications. Background Existing I&C equipment in nuclear power plants is currently being replaced with digital I&C systems or advanced analog systems. However, the electronic architecture used with these technologies may be more sensitive to the nuclear power plant EMI/RFI environment than existing I&C systems. This RG provides an acceptable method for qualifying digital and advanced analog systems for the projected electromagnetic environment in nuclear power plants. The typical environment in a nuclear power plant includes many sources of electrical noise. Examples include hand-held two-way radios, smartphones, industrial wireless devices, arc welders, switching of large inductive loads, high fault currents, and high-energy fast transients associated with switching at the generator or transmission voltage levels. The increasing use of advanced analog- and digital-based I&C systems in reactor protection and other safety-related plant systems has introduced concerns with respect to the creation of additional noise sources and the susceptibility of this equipment to the electrical noise already present in the nuclear power plant environment. Manufacturers of digital systems are continually incorporating increasingly higher clock frequencies and lower logic level voltages into their designs. However, these performance advancements can have an adverse impact on the operation of digital systems because of the increased likelihood of extraneous electromagnetic noise being misinterpreted as legitimate logic signals. With recent advances in analog electronics, many of the functions currently being performed by several analog circuit boards could be combined into a single analog circuit board operating at