1. Electromagnetic Compatibility (EMC) and
Nuclear Power Facilities
presented by Washington Laboratories, Ltd. Steven G. Ferguson

2. NRC Regulations
Part 50 of Title 10 of the Code of Federal Regulations (10CFR50): “Domestic Licensing of Production and Utilization Facilities”
Structures, systems, and components important to safety in a nuclear power plant be designed to accommodate the effects of environmental conditions (i.e., remain functional under all postulated service conditions)
design control measures such as testing be used to check the adequacy of design.

3. Safety Functions
IEEE Std IEEE Standard Application of the Single-Failure Criterion to Nuclear Power Generating Station Safety Systems – Description
Replaced IEEE Standard (Std) 279, "Criteria for Protection Systems for Nuclear Power Generating Stations,"
Incorporated in 10 CFR §50.55a(h) of the NRC regulations
provides more specific requirements for the design of instrumentation and control (I&C) systems performing safety functions

4. Safety Analysis Report
Must be sufficient to confirm that the I&C systems important to safety are identified with descriptions of how these systems meet the appropriate acceptance criteria and guidelines applicable to them.
SAR descriptions form the licensing design basis for the plant

5. NRC Regulatory Guide 1.180
Guidelines for Evaluating Electromagnetic and Radio-Frequency Interference in Safety-Related Instrumentation and Control Systems
Revision 1 issued October 2001
Adopted MIL-STD-461E and IEC series of test methods
Provides:
Regulatory position on EMC
Position on EMI/RFI limiting practices
Position on EMI/RFI emissions and susceptibility testing
Position on SWC testing

6. RG1.180 Emission testing MIL-STD-461E IEC 61000-6-4
CE101 Conducted emissions, low-frequency, 30 Hz to 10 kHz
CE102 Conducted emissions, high-frequency, 10 kHz to 2 MHz
RE101 Radiated emissions, magnetic field, 30 Hz to 100 kHz
RE102 Radiated emissions, electric field, 2 MHz to 1 GHz
IEC
(None) Conducted emissions, low-frequency, 30 Hz to 10 kHz
CISPR11 Conducted emissions, high-frequency, 150 kHz to 30 MHz
(None) Radiated emissions, magnetic field, 30 Hz to 100 kHz
CISPR11 Radiated emissions, electric field, 30 MHz to 1 GHz
RG1.180 calls for applying one or the other standard – no selective application
Selection of IEC method allowed if special exemption conditions are met for power quality and proximity to equipment sensitive to magnetic fields

7. RG1.180 Susceptibility testing
MIL-STD-461E
CS101 Conducted susceptibility, low frequency, 30 Hz to 150 kHz
CS114 Conducted susceptibility, high frequency, 10 kHz to 30 MHz
CS115 Conducted susceptibility, bulk cable injection, impulse excitation
CS116 Conducted susceptibility, damped sinusoidal transients, 10 kHz to 100 MHz
RS101 Radiated susceptibility, magnetic field, 30 Hz to 100 kHz
RS103 Radiated susceptibility, electric field, 30 MHz to 1 GHz
IEC
Conducted susceptibility, electrically fast transients/bursts
Conducted susceptibility, surges
Conducted susceptibility, disturbances induced by radio-frequency fields
Conducted susceptibility, 100 kHz ring wave
Conducted susceptibility, low frequency, 16 Hz to 2.4 kHz
Conducted susceptibility, low frequency, 15 Hz to 150 kHz
Radiated susceptibility, magnetic field, 50 Hz and 60 Hz
Radiated susceptibility, magnetic field, 50/60 Hz to 50 kHz
Radiated susceptibility, magnetic field, 100 kHz and 1 MHz
Radiated susceptibility, electric field, 26 MHz to 1 GHz
RG1.180 calls for applying one or the other standard – no selective application

8. RG 1.180 Surge Withstand Capability (SWC) testing
Ring wave
IEEE Std C
IEC
Combination wave
IEC
Electrically Fast Transients (EFT)
IEC
IEEE Std C provides test methods for C62.41

9. EPRI TR R3
Guidelines for Electromagnetic Interference Testing of Power Plant Equipment
Revision 3, issued November 2004
Revision issued to better conform to standard test methods, investigate CS114 test levels and provide technical rationale for variance to RG1.180
Provides:
Plant emissions data
Practices to ensure EMC
Equipment susceptibility and emissions testing guidance
Margin analysis of recommended testing limits

10. EPRI R3 Emission testing
Low frequency conducted emissions
CE101
High frequency conducted emissions
CE102
IEC
FCC 47CFR Part 15
Low frequency radiated emissions
RE101
High frequency radiated emissions
RE102

11. EPRI R3 Susceptibility testing
Low frequency conducted
MIL-STD-461E CS101
IEC & IEC
High frequency conducted
CS114
IEC
Low frequency radiated
RS101
IEC , IEC and IEC
High frequency radiated
RS103
IEC
Surge
CS116
IEC and IEC or IEEE C
Electrically Fast Transient (EFT)
CS115
IEC or IEEE C62.41
Electrostatic Discharge (ESD)
IEC

12. Low frequency conducted emissions
CE101, 30 Hz – 10 kHz (AC start frequency = 2nd harmonic)
Exempt equipment from test if
Power quality requirements are consistent with existing power supply and design practices include power quality controls
New equipment will not impose additional harmonic distortion exceeding 5% THD or other power quality criteria with a valid technical basis
Measurement in current terms
Limit relaxation allowed for high current AC power
EPRI does not limit relaxation to AC
RG1.180 & EPRI R3 testing the same – limits are different

13. High frequency conducted emissions
RG1.180
CE102, 10 kHz to 2 MHz
CISPR 11, 150 kHz to 30 MHz (if CE101 is exempt)
Measurement in voltage terms
EPRI R3
CE102, 10 kHz to 10 MHz
CISPR 11, 150 kHz to 30 MHz
Measurement in current terms (voltage to current based on 50W)

14. Low frequency radiated emissions
RE101, 30 Hz – 100 kHz
Applicable to enclosures and interconnecting leads
Exempt equipment from test if
RG Equipment is not installed in areas with equipment sensitive to magnetic fields – distance not specified
EPRI R3 – Applicable to new equipment that is a source of large magnetic fields (>300A/m) installed <1m from sensitive equipment
EPRI R3 - Equipment and cable separation of EMI limiting requirements are not satisfied
Measurement in flux density terms
RG1.180 & EPRI R3 testing the same – limits are different
Testing performed with loop antenna moved over equipment face and cables maintaining 7cm separation
If non-compliant a determination of the distance for compliant should be accomplished

15. High frequency radiated emissions
RG1.180
RE102, 2 MHz to 1 GHz
CISPR 11, 30 MHz – 1 GHz
EPRI R3
RE102, 2 MHz to 10 GHz
CISPR 11, 30 MHz to 1 GHz
FCC 47 Part 15, 30 MHz to 1 GHz

16. High frequency radiated emission limits/testing
QP measurements for CISPR and FCC
EPRI calls for CIPSR/FCC testing to 5X highest frequency up to 10 GHz but no limit defined
Testing is accomplished with an appropriate antenna located at the specified distance – receiver parameters defined in the test standard

17. Low frequency conducted susceptibility
Purpose is to evaluate performance in the presence of low frequency interference conducted via the power or signal lines
MIL-STD-461E
CS101, Conducted susceptibility, low frequency, 30 Hz to 150 kHz
IEC
IEC , Conducted susceptibility, low frequency, 16 Hz to 2.4 kHz
IEC , Conducted susceptibility, low frequency, 15 Hz to 150 kHz

18. Low frequency conducted susceptibility limits/testing
CS101
Low frequency sinusoidal signals are used to modulate the power lines to simulate interference
Prior to test a maximum drive level is establish with a fixed load
The interfering signal is coupled to the power input and the amplitude increased to the test voltage without exceeding the maximum drive level
The test frequency range is swept at a defined rate
RG1.180 and EPRI have the same limit although EPRI is specified in current terms
IEC
Coupling is typically by use of a programmable power source that is programmed for the specific test frequencies and amplitude
RG1.180 provides a test limit table for harmonic frequencies correlated to Class 2 of the standard omitting the inter-harmonic testing
EPRI calls for Class 2 testing implying that the inter-harmonic testing of the test standard is applicable
The limit chart in EPRI R3 is inadequate to determine the test levels so the test standard is preferred
IEC
Low frequency sinusoidal signals are coupled to the power and signal lines (capacitively coupled or direct injection)
IEC , Conducted susceptibility, low frequency, 16 Hz to 2.4 kHz
Level 3 is called out by both RG1.180 and EPRI R3 – however the test level curves are not the same
EPRI R3 does not specify the short duration high level test.

19. High frequency conducted susceptibility
Purpose is to evaluate performance in the presence of RF signals inducing currents into the equipment via the cables
MIL-STD-461E
CS114, Conducted susceptibility, high frequency, 10 kHz to 30 MHz
IEC
IEC , Conducted susceptibility, 150 kHz to 80 MHz, disturbances induced by radio-frequency fields

20. RG1.180, High frequency conducted susceptibility limits
Two IEC limits are provided
140dBmV (10Vrms) for power and medium exposure signal lines (96.5dBmA)
130dBmV (3Vrms) for low exposure signal lines (86.5dBmA)
Frequency range is not defined so the 150 kHz to 80 MHz range from the test standard is normally assumed
A pre-calibrated forward power limit (drive level) is applicable if the current is not attained

21. EPRI R3, High frequency conducted susceptibility limits
CS114 testing between 30 MHz and 200 MHz may be exempted if RS103 is accomplished
EPRI states that use of the Army Ground Applications test level is acceptable but the limit is shown incorrectly – which applies
A pre-calibrated forward power limit (drive level) is applicable if the current is not attained

22. Electrically Fast Transients/Bursts (EFT)
RG1.180
CS115, Conducted susceptibility, bulk cable injection, impulse excitation
IEC , Electrically Fast Transient/Bursts
Applicability to signal lines
Applicable to power lines under the SWC testing – allows use of C
EPRI R3
Same tests as RG1.180 but different levels and applicable to power and signal
CS115 is listed but the limit is not stated – 5A is implied under the listing of differences between ERPI R3 and RG1.180

23. EFT limits/testing
CS115 uses a pre-calibrated test current using a fixed load test fixture then interference is applied that drive level
RG1.180 – 2A
EPRI R3 – 5A
Interference is coupled inductively – current injection
IEC uses an open circuit voltage that is applied to the circuit
RG1.180 – 1kV (low exposure), 2kV (medium exposure) for signal lines
RG1,180 – 2kV (low exposure), 4kV (medium exposure) for power lines (SWC)
EPRI R3 – 2kV power lines; 1kV signal lines (2kV for lines that connect to unsuppressed inductive loads)
Interference is coupled capacitively – voltage injection
Common mode and differential mode testing is not discussed although both test standards have provisions for testing

24. Surge RG1.180 EPRI R3 Test duration
CS116, Conducted susceptibility, damped sinusoidal transients, 10 kHz to 100 MHz or
IEC , Surge immunity test (combination wave) and
IEC , Oscillatory waves immunity test
Applicability to signal lines
Applicable to power lines under the SWC testing – allows use of C
EPRI R3
Same tests as RG1.180 but different levels and applicable to power and signal
RG1.180 defines 4-12 test as ring wave and EPRI R3 provides for a repetition frequency for the oscillating wave
CS116 is listed but the not recommended
Oscillating wave specified rise time; \ Damped Oscillatory vs. Ring Wave
Test duration
CS116 calls for duration and pulse repetition rate
4-5 combination wave test uses a number of repetitions
4-12 ring wave test uses a number of repetitions
4-12 oscillating wave uses a repetition frequency and duration

25. Surge limits/testing
CS116 uses a pre-calibrated test current using a fixed load test fixture then interference is applied as lesser of test current or drive level
RG1.180 – 5A
EPRI R3 – no limit stated (allows but does not recommend CS116)
Interference is coupled inductively – current injection
IEC uses an open circuit voltage that is applied to the circuit (current limiting is applicable)
RG1.180 – 1kV (low exposure), 2kV (medium exposure) for signal lines
RG1,180 – 2kV (low exposure), 4kV (medium exposure), 6kV (external) for power lines (SWC)
EPRI R3 – 2kV secondary power lines; 4kV primary power lines; 2kV signal line shields and remote grounds
Interference is coupled capacitively – voltage injection
IEC uses an open circuit voltage that is applied to the circuit (current limiting is applicable)
RG1,180 – 2kV (low exposure), 4kV (medium exposure) for power lines (SWC)
Common mode and differential mode testing is not discussed although both test standards have provisions for testing

26. Low frequency radiated susceptibility (magnetic field)
Exempt test if equipment is not near sources of large magnetic fields and limiting practices are used
RG1.180 indicates CRTs, motors, high current cables as large sources
EPRI R3 indicates <1-m from >300A/m sources
Test methods:
RS101, Radiated susceptibility, magnetic field, 30 Hz to 100 kHz
IEC , Radiated susceptibility, magnetic field, 50 Hz and 60 Hz
IEC , Radiated susceptibility, magnetic field, 50/60 Hz to 50 kHz
IEC , Radiated susceptibility, magnetic field, 100 kHz and 1 MHz
IEC has additional limiting applicability to high current switching sources (bus bar switching) in EPRI R3

27. Low frequency radiated susceptibility limits/testing
RS101
MIL-STD-461E Army limit (flux density terms)
IEC
50 or 60 Hz sine wave, 30 A/m (152dBpT) continuous (300 A/m (172dBpT) short duration)
IEC
RG1.180 and EPRI R3 indicate a frequency range for the test but standard is based on a pulse
Pulse 6.4/16mS, 300A/m (172dBpT)
IEC
Damped oscillatory wave 100 kHz (40 Hz repetition) and 1 MHz (400 Hz repetition)
Test level is 30A/m (152dBpT)
Testing is performed with an induction coil adjacent to test article or coil surrounding the test article depending on test

28. High frequency radiated susceptibility (electric field)
MIL-STD-461E, Radiated susceptibility, electric field, 30 MHz to 1 GHz (10 GHz EPRI)
Modulation with a 1 kHz square wave
IEC , Radiated susceptibility, electric field, 26 MHz to 1 GHz
Modulation with a 1 kHz sine wave
RG1.180 and EPRI R3 call for the same tests and levels
EPRI adds testing for RS103 in the 10 kHz to 30 MHz frequency range if CS114 is not performed
EPRI supports deletion of 30 MHz to 80 MHz if IEC testing is performed
EPRI calls for testing above 1 GHz for evaluation of wireless device interference

29. High frequency radiated susceptibility limits/testing
RG1.180 and EPRI specify 10V/m test levels
Test frequency range based on test method and other testing as stated previously
Modulation is not consistent between standards
Testing at frequencies between 1 GHz and 10 GHz is becoming the normal
Testing is accomplished with a radiating antenna producing the test field
MIL-STD-461E testing calls for use of field probe to measure test level during test
IEC testing supports testing with a uniform field calibrated prior to test
Use of an anechoic shielded enclosure is standard
Antenna placement may be varied to broaden the beamwidth coverage but test article must see exposure

30. Electrostatic Discharge (ESD)
Not specified in RG1.180
Optional in EPRI R3
IEC is the test standard
Level 4 testing (8kV contact; 15kV air)
Test points selected based on accessibility

31. Tailoring testing
Understand the test article use and installation to assess applicable tests
Items not exposed to high magnetic fields are exempt for the associated susceptibility tests
Look as the applicability tables in the standards
Required – indicates test is always applicable
Evaluate – determine applicability based on use and criticality
Optional – used when impact is minimal or control measure negate the need
Why tailor?
Cost and schedule drivers
Testing cost is somewhat elevated by performing unnecessary tests
Recurring cost to add unnecessary control measures may be significant
Installation practices may be a significant cost driver to provide unnecessary control measures
Not advocate of deleting tests – operational down-time from EMI is an on-going cost that specifying control measures can mitigate
Test planning should consider the application instead of blindly calling for doing all potential tests
Wide usage equipment may elect to do all testing for all standards

32. Acceptance criteria
Acceptance criteria provided earlier is not supported by RG1.180 or EPRI R3
SWC testing of RG1.180 specifies that performance criteria be established in the test plan
Open door testing is frequently called on for equipment that must operate during maintenance – test planning should consider acceptance with closed doors if reasonable

33. Threshold measurements
Threshold measurements provide data on the amplitude and frequency of interference that produces susceptibility
This is the lowest level that produces unacceptable results
Frequency ranges of susceptibility need to be identified
Test procedure needs to identify measurements of susceptibility
Threshold measurements
Reduce interference level for test article recovery
Reduce an additional 6dB
Increase amplitude to point of susceptibility
Record that measurement
Why?
Absence of information makes acceptance of a deviation nearly impossible
Solutions need the data to support design

34. Steve Ferguson: stevef@wll.com Washington Laboratories, Ltd.
Contact
Contact:
Steve Ferguson:
Washington Laboratories, Ltd.
7560 Lindbergh Drive
Gaithersburg, MD 20879
301/ : fax: 301/