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:
r in the output circuit (e.g., surges) should also be considered. • The qualification should consider the levels and duration of the fault current on the nonsafety side of the device. For safety and nonsafety isolation, during and following the application of the MCF or surge test, there should be no degradation or distortion of the isolation device input that would have a detrimental effect on the performance of the safety system. For the isolation of redundant safety circuits, there should be no degradation or distortion of the redundant channel that would have a detrimental effect on the performance of the safety system. Applicable industry standards should be used as the basis for performing the qualification testing (e.g., IEEE Std C62.45-2002). Devices might be used either for isolation of safety circuits from nonsafety circuits or for isolation of redundant safety divisions. For qualification testing, the detailed device configuration depends on the objective of the isolation and the specific type and configuration of the isolation device (e.g., relay, isolation amplifier, optical-electronic device). BTP 7-11-7 Draft Revision 6 – August 2015 The MCF represents the application of the maximum credible AC and direct current (dc) voltages and currents that are applied to the device in common and differential modes (as defined by IEEE Std 100-2000, “The Authoritative Dictionary of IEEE Standards Terms Seventh Edition”) that exist based on the installation of the device. Common mode refers to faults between both signal terminals and a common reference plane (ground) and causes the potential of both sides of the transmission path to be changed simultaneously and by the same amount relative to the common reference plane (ground). Differential mode refers to faults between the signal terminals that cause the potential of one side of the signal transmission path to be changed relative to the other side. The mode of application should satisfy the following