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:
a specific location is called the “withstand level” at that location. Most locations in the interior of a facility, which are typical for signal leads, correspond to the Category B surge withstand classification described in IEEE Std C62.41.2-2002 and discussed in Regulatory Position C.5. The vast majority of signal leads are expected to be located in limited surge activity environments that correspond to low withstand levels (see Regulatory Position C.5). However, for those few I&C systems that may be implemented in plant areas characterized by surge environments with significant switching transients and lightning activity (e.g., in very close proximity to the service entrance from the switchyard), elevated withstand levels would be necessary (see Regulatory Position C.5) and, in those special cases, the operating envelopes given in Table 15 for CS115 and CS116 should be doubled. For the IEC tests, the operating envelopes in Table 17 should be used as a special case for those few I&C systems that may be implemented in plant areas that are characterized by the elevated surge environments. Table 15 MIL-STD-461G Conducted Susceptibility Operating Envelopes—Signal Leads Method Description CS114 Apply Figure 4.2 CS115 5 A CS116 5 A DG-1333, Page 22 Table 16 IEC 61000-4 Conducted Susceptibility Operating Envelopes- Low Withstand-Signal Leads Method Description 61000-4-4 Level 3: 1 kV test voltage 61000-4-5 Level 3: 2 kV open circuit test voltage and 1 kA short circuit current 61000-4-6 Level 3: 140 dBµV test voltage 61000-4-12 Level 2: 1 kV test voltage 61000-4-16 Level 3: see Table 12 Table 17 IEC 61000-4 Conducted Susceptibility Operating Envelopes- Moderate Withstand-Signal Leads Method Description 61000-4-4 Level 4: 2 kV test voltage 61000-4-5 Level 4: 4 kV open circuit test voltage and 2 kA short circuit current 61000-4-6 Level 3: 140 dBµV test voltage 61000-4-12 Level 3: 4 kV test voltage 61000-4-16 Level 3: see Table 12 4.3 EMI/RFI Radiated Susceptibility