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

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.

Safety Functions IEEE Std 379-2000 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

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 http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0800/

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 61000 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

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 61000-6-4 (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

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 61000-4 61000-4-4 Conducted susceptibility, electrically fast transients/bursts 61000-4-5 Conducted susceptibility, surges 61000-4-6 Conducted susceptibility, disturbances induced by radio-frequency fields 61000-4-12 Conducted susceptibility, 100 kHz ring wave 61000-4-13 Conducted susceptibility, low frequency, 16 Hz to 2.4 kHz 61000-4-16 Conducted susceptibility, low frequency, 15 Hz to 150 kHz 61000-4-8 Radiated susceptibility, magnetic field, 50 Hz and 60 Hz 61000-4-9 Radiated susceptibility, magnetic field, 50/60 Hz to 50 kHz 61000-4-10 Radiated susceptibility, magnetic field, 100 kHz and 1 MHz 61000-4-3 Radiated susceptibility, electric field, 26 MHz to 1 GHz RG1.180 calls for applying one or the other standard – no selective application

RG 1.180 Surge Withstand Capability (SWC) testing Ring wave IEEE Std C62.41-1991 IEC 61000-4-12 Combination wave IEC 61000-4-5 Electrically Fast Transients (EFT) IEC 61000-4-4 IEEE Std C62.45-1992 provides test methods for C62.41

EPRI TR-102323 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

EPRI R3 Emission testing Low frequency conducted emissions CE101 High frequency conducted emissions CE102 IEC 61000-6-4 FCC 47CFR Part 15 Low frequency radiated emissions RE101 High frequency radiated emissions RE102

EPRI R3 Susceptibility testing Low frequency conducted MIL-STD-461E CS101 IEC 61000-4-13 & IEC 61000-4-16 High frequency conducted CS114 IEC 61000-4-6 Low frequency radiated RS101 IEC 61000-4-8, IEC 61000-4-9 and IEC 61000-4-10 High frequency radiated RS103 IEC 61000-4-3 Surge CS116 IEC 61000-4-5 and IEC 61000-4-12 or IEEE C62.41-1991 Electrically Fast Transient (EFT) CS115 IEC 61000-4-4 or IEEE C62.41 Electrostatic Discharge (ESD) IEC 61000-4-2

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

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)

Low frequency radiated emissions RE101, 30 Hz – 100 kHz Applicable to enclosures and interconnecting leads Exempt equipment from test if RG1.180 - 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

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

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

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 61000-4 IEC 61000-4-13, Conducted susceptibility, low frequency, 16 Hz to 2.4 kHz IEC 61000-4-16, Conducted susceptibility, low frequency, 15 Hz to 150 kHz

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 61000-4-13 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 61000-4-16 Low frequency sinusoidal signals are coupled to the power and signal lines (capacitively coupled or direct injection) IEC 61000-4-13, 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.

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 61000-4 IEC 61000-4-6, Conducted susceptibility, 150 kHz to 80 MHz, disturbances induced by radio-frequency fields

RG1.180, High frequency conducted susceptibility limits Two IEC 61000-4-6 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

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

Electrically Fast Transients/Bursts (EFT) RG1.180 CS115, Conducted susceptibility, bulk cable injection, impulse excitation IEC 61000-4-4, Electrically Fast Transient/Bursts Applicability to signal lines Applicable to power lines under the SWC testing – allows use of C62.41-1991 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

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 61000-4-4 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

Surge RG1.180 EPRI R3 Test duration CS116, Conducted susceptibility, damped sinusoidal transients, 10 kHz to 100 MHz or IEC 61000-4-5, Surge immunity test (combination wave) and IEC 61000-4-12, Oscillatory waves immunity test Applicability to signal lines Applicable to power lines under the SWC testing – allows use of C62.41-1991 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

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 61000-4-5 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 61000-4-12 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

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 61000-4-8, Radiated susceptibility, magnetic field, 50 Hz and 60 Hz IEC 61000-4-9, Radiated susceptibility, magnetic field, 50/60 Hz to 50 kHz IEC 61000-4-10, Radiated susceptibility, magnetic field, 100 kHz and 1 MHz IEC 61000-4-10 has additional limiting applicability to high current switching sources (bus bar switching) in EPRI R3

Low frequency radiated susceptibility limits/testing RS101 MIL-STD-461E Army limit (flux density terms) IEC 61000-4-8 50 or 60 Hz sine wave, 30 A/m (152dBpT) continuous (300 A/m (172dBpT) short duration) IEC 61000-4-9 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 61000-4-10 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

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 61000-4-3, 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 61000-4-6 testing is performed EPRI calls for testing above 1 GHz for evaluation of wireless device interference

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 61000-4-3 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

Electrostatic Discharge (ESD) Not specified in RG1.180 Optional in EPRI R3 IEC 61000-4-2 is the test standard Level 4 testing (8kV contact; 15kV air) Test points selected based on accessibility

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

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

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

Steve Ferguson: stevef@wll.com Washington Laboratories, Ltd. Contact Contact: Steve Ferguson: stevef@wll.com Washington Laboratories, Ltd. 7560 Lindbergh Drive Gaithersburg, MD 20879 301/216-1500: fax: 301/216-1590 www.wll.com