CNL-15-165, Submittal of Electromagnetic Interference (EMI) Survey Results
| ML15232A540 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 08/20/2015 |
| From: | James Shea Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CNL-15-165 | |
| Download: ML15232A540 (20) | |
Text
Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-15-165 August 20, 2015 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-001 Watts Bar Nuclear Plant, Unit 2 Construction Permit No. CPPR-92 NRC Docket No. 50-391
Subject:
WATTS BAR NUCLEAR PLANT UNIT 2 - SUBMITTAL OF ELECTROMAGNETIC INTERFERENCE (EMI) SURVEY RESULTS
References:
- 1. TVA Letter to NRC, Watts Bar Nuclear Plant (WBN) - Resistance Temperature Detector Bypass Elimination Audit Readiness, dated March 24, 1989
- 2. TVA Letter to NRC, Watts Bar Nuclear Plant (WBN) - Unit 2 - Westinghouse Eagle-21 Process Protection System (TAC No. MD6311), dated February 28, 2008
- 3. TVA Letter to NRC, Watts Bar Nuclear Plant (WBN) Unit 2 - Instrumentation and Controls Staff Information Requests, dated April 15, 2011
- 4. NUREG-0847, Supplement No. 23, Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant, Unit 2, dated July 2011 The purpose of this letter is to provide the electromagnetic interference (EMI) survey results as previously committed in References 2 and 3. This EMI survey of the main control room and the auxiliary instrument room was performed to show the field strength of radiated EMI around critical equipment.
U.S. Nuclear Regulatory Commission CNL-15-165 Page 2 August 20, 2015 The commitments from References 2 and 3 are listed below.
- 1) TVA will perform an electromagnetic interference/radio frequency interference (EMI/RFI) site survey of the Watts Bar Nuclear Plant (WBN) Unit 2 Eagle 21 system during hot functional testing. TVA will submit the results of this survey to the NRC. The submittal will include a description of the methodologies and test equipment that were used to perform the survey, a comparison between on-site and factory EMI/RFI test results, and an assessment of the margin between the measured EMI/RFI spectrum and a conservative threshold above which EMI/RFI problems could occur.
- 2) TVA will perform an EMI survey of the containment high range radiation monitors after they are installed in WBN Unit 2 and submit the results to the NRC within two weeks of the survey being completed.
WBN Unit 2 field strength of radiated EMI during hot functional testing was less than 0.5 volts/meter per the EMI Survey Results.
- 1) The Eagle 21 Process Protection System radiated immunity testing was satisfactorily completed at 10 volts/meter (Reference Westinghouse WCAP-11733 previously provided in Reference 1). Therefore, the margin between the components radiated EMI field strength tested and the measured WBN Unit 2 EMI survey radiated EMI field strength values provides assurance that these components will be able to perform their safety function.
- 2) The Containment High Range Radiation Monitors radiated immunity testing was satisfactorily completed at 10 volts/meter (Reference Sorrento Electronics RM-1000 EMC Test Reports 04509050 and 04038800 previously provided in Reference 3). Therefore, the margin between the components radiated EMI field strength tested and the measured WBN Unit 2 EMI survey radiated EMI field strength values provides assurance that these components will be able to perform their safety function. provides the survey results which were found to be acceptable.. Enclosure 2 provides an evaluation of the survey results.
The delay in submitting this report in accordance with Commitment No. 2 above has been discussed with the NRC staff and has been entered into TVAs corrective action program.
The completion of this survey for the Containment High Range Radiation Monitors is the subject of Supplemental Safety Evaluation Report (SSER) 23, Appendix HH, Open Item No. 79 as described in Reference 4. With the submittal of these survey results, TVA considers Open Item No. 79 and the associated commitments to be closed.
U.S. Nuclear Regulatory Commission CNL-15-165 Page 3 August 20, 2015 There are no new regulatory commitments made in this letter. Should you have questions regarding this submittal, please contact Gordon Arent at (423) 365-2004.
Respectfully, J. W. Shea Vice President, Nuclear Licensing
Enclosures:
- 1. Electromagnetic Interference (EMI) Survey Results
- 2. Analysis of Watts Bar Unit 2 EMI/RFI Survey Results for the Eagle 21 Process Protection System and Containment High Range Radiation Monitors cc (Enclosures):
U.S. Nuclear Regulatory Commission, Region II NRC Project Manager - Watts Bar Nuclear Plant, Unit 2 NRC Senior Resident Inspector - Watts Bar Nuclear Plant, Unit 2 J. W. Shea Digitally signed by J. W. Shea DN: cn=J. W. Shea, o=Tennessee Valley Authority, ou=Nuclear Licensing, email=jwshea@tva.gov, c=US Date: 2015.08.20 14:48:35 -04'00'
E1-1 Watts Bar Nuclear Plant, Unit 2 Electromagnetic Interference (EMI) Survey Results
B43150803001
ThespectrumsfortheMCRandtheAuxInstrumentRoomwere
comparedbeforeHFTandduringHFT.Thespectrumswerelargelythe
samebeforeandduring.Thefieldstrengthfortheseareasislow.The
resultsarecomparedtoexistingtestlimits.
Purpose
TheEMIsurveyoftheMCRandtheAuxInstrumentRoomweredonetoshowthefieldstrengthof
radiatedEMIaroundcriticalequipment.ThetestresultswillbesenttotheNRC.Thistestingwaspartof
theWBNU2startup.
TestEquipment
1.
EMCWareSoftwareV3.1
2.
AgilentE7404SpectrumAnalyzer
3.
LabFerriteCable
4.
LabRedBNCJumper
5.
USBtoGPIBadapter
6.
SAS2/DWideBandAntenna
Configuration
Thespectrumanalyzer,theantennaandthecomputerwereconnected.Theantennawasmovedto
eachlocationforthetest.
Thesoftwarewouldscanfrom10kHzto1GHzin2steps.Theantennaoutputswouldbechangedfrom
lowtohighasappropriate.
Data
Thedatawastakenonatwoseparatedays.Thefirstdaywasbeforehotfunctionaltesting(HFT)had
begunandtheseconddayafterHFThadstarted.
Themaincontrolroom(MCR)infrontofthehighrangeradiationmonitorsandtheauxiliaryinstrument
roominlocationsbycontrolpanels.
Thespectrumgraphshavearedlineat0.5V/mforareferencepoint.
MainControlRoom
HerearethespectrumsfromtheMCRbeforeandafterHFT.
MCR:BeforeHFT
MCR:AfterHFT
AuxiliaryInstrumentRoom
HerearethespectrumsfromtheAuxInstrumentRoombeforeandafterHFT.Thebeforespectrumsare
shownonseparategraphs.Theafterspectrumsarecombinedononegraph.Thisdifferenceisdueto
softwareissues.
AuxInstrumentRoom:BeforeHFT
AuxInstrumentRoom:BeforeHFT
AuxInstrumentRoom:BeforeHFT
AuxInstrumentRoom:BeforeHFT
AuxInstrumentRoom:BeforeHFT
AuxInstrumentRoom:BeforeHFT
AuxInstrumentRoom:AfterHFT
Results
ThespectrumsshowthatthefieldstrengthsinbothbeforeandafterHFTintheMCRare:
1.
Before-
a.
Allbutthecellphonesignalislessthan80dBuV/m.
b.
Thecellphonesignalislessthan90dBuV/m.
2.
After-
a.
Whilethespectrumisslightlydifferentthemagnitudesarethesame.
ThespectrumsshowthatthefieldstrengthsinbothbeforeandafterHFTintheAuxInstrumentRoom
are:
1.
Before-
a.
Belowabout120kHzthefieldstrengthpeaksat100dBuV/m
b.
Above120kHzthefieldstrengthisbelow80dBuV/mforallbutthecellphone
frequencies.
c.
Thecellphonefrequenciesarebelow100dBuV/m
2.
After-
a.
Belowabout120kHzthefieldstrengthpeaksat100dBuV/m
b.
Above120kHzthefieldstrengthisbelow85dBuV/m
c.
Thecellphonefrequencyisbelow80dBuV/m.
Conclusion
ThespectrumsshowthatthefieldstrengthsinboththeMCRandAuxInstrumentRoomareverylow.
Themaximumfieldstrengthof100dBuV/mtranslatesto0.1V/mat1meter.
x ExtensivetestingwasdonewhentheNextelphoneswereintroducedtotheplants.Hereare
someoftheresults.
o ThefieldstrengthoftheNextelphoneswas~5V/mat1meter
o SQNwasmonitoredviaICSduringtestingwiththeNextelphonetransmittingon
maximumpower
Therewerenoanomalies
Eagle21-Theantennaofthecellphonewasplacedbetweenthecards-in
nearfieldcoupling.
Thephoneswereplacednexttoprocesscontrolequipment.
ThephoneswereplacednexttoRodPositionequipment.
Otherequipmentwastestedwithoutanomaly.
o ThephoneswereinstalledatBFN,SQN,andWBNfor~9yearswithoutanEMIincident.
x ThepresentEMIenvironmentisprotected.
o Allelectronic/electricalequipmentintroducedtotheplantmusthavetheemissions
evaluatedbyengineeringbeforeinstallation.
o TVASSE18.14.01usesEPRITR102323/RG1.180asabasis.
o Allnew1Eandeconomicinstrumentshaveimmunitytestingperformedat10V/m
TherewasenoughequipmentoperatingbeforeHFTthatthespectrumswereessentiallythesameafter
HFTwasbegun.
E2-1 Watts Bar Nuclear Plant, Unit 2 Analysis of Watts Bar Unit 2 EMI/RFI Survey Results for the Eagle 21 Process Protection System and Containment High Range Radiation Monitors
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