Document: NUREG-0800
Document ID: c81bfd3b-114e-4701-a558-e08d57d14fd5
Document Type: srp
Title: D provides additional guidance.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1515/ML15159A769.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.1
CFR Part: 
CFR Title: 

Content:
hen credit is taken for surge protection in these types of circuits. American National Standards Institute (ANSI) Std C84.1-1989, “American National Standard for Electric Power Systems and Equipment Voltage-Ratings (60 hertz),” discusses nominal voltages and guidelines for steady-state tolerances. RG 1.204, “Guidelines for Lightning Protection of Nuclear Power Plants,” provides guidance for the design and installation of lightning protection systems to ensure that electrical transients resulting from lightning phenomena do not render safety-related systems inoperable or cause the spurious operation of such systems. 3. Purpose The purpose of this BTP is to provide guidance to address the application and qualification of isolation devices through the application of maximum credible fault1 (MCF) voltages and currents. This BTP has three objectives: • Confirm that the design and implementation of isolation devices conforms to the guidance of RG 1.75. • Confirm that the qualification basis for isolation devices is consistent with accepted industry standards and use in the plant. • Confirm that qualification testing demonstrates that the isolation devices meet the acceptance criteria of IEEE Std 603-1991 or IEEE Std 279-1971. B. BRANCH TECHNICAL POSITION 1. Introduction This BTP addresses the electrical qualification and application of isolation devices. Other qualification requirements (such as those that pertain to environmental conditions, EMI/RFI, and seismic events) are addressed in SRP Section 7.1. The following types of isolation devices are examples of devices that have been found to be acceptable, provided the guidelines of this BTP are satisfied: • Isolation amplifiers • Isolation transformers • Fiber-optic couplers • Fiber-optic cable2 • Photo-optic couplers • Relays (coil to contact isolation) 1IEEE Std 384 defines a maximum credible voltage or current transient as voltage or current transient that may exist in circuits, as determined