ML17348A321

LER 90-001-01:on 891222 & 900112,liquid Effluent Radiation Monitor R-18 Failed & Ratemeter Did Not Have Display Indication.Caused by Control Circuit Malfunction.Low Voltage Power Supply Processor & Timer Cards replaced.W/900615 Ltr

ML17348A321
Person / Time
Site:	Turkey Point
Issue date:	06/15/1990
From:	Harris K, Dawn Powell FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-90-218, LER-90-001, LER-90-1, NUDOCS 9006260064
Download: ML17348A321 (8)

Text

~, ACCELERATED 'DI TRJBUTION DEMONSTRATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9006260064 DOC.DATE: 90/06/15 NOTARIZED: NO DOCKET 1T

. FACIL:50-250 Turkey Point Plant, Unit 3, Florida Power and Light C 05000250 AUTH. NAME AUTHOR AFFILIATION POWELL,D.R. Florida Power & Light Co.

HARRIS,K.N. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 90-001-01:on 900112,liqiud effluent process radiation monitor R-18 inoperable during liquid release.

W/9 DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident pt, etc.

NOTES RECIPIENT COPIES 'ECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 PD2-2 PD 1 1 EDISON,G 1 r 1 INTERNAL: ACNW 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB9H3 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB11 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB SD 1 1 NRR/DST/SICB 7E 1 1 1 . 1 NRR/DST/SRXB SE 1 1 1 1 I

RES/DS R/EI B 1, 1 1 1 EXTERNAL: EG&G STUART,V.A 4 4 L ST LOBBY WARD 1 1 LPDR'SIC 1 ' 1 NRC PDR 1 1 MAYS,G 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

r PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 34 ENCL 34 r

1 I

PAL gUN i5 1990 L-90-218 10 CFR 50..73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: Turkey Point Units 3 and 4 Dockets No. 50-250 and 50-251 Reportable Event: 90-001 Revision 1 Date of Event: January 12, 1990, Liquid Effluent Process Radiation Monitor R-18 Inoperable Durin a Li uid Release Due to a Control Circuit Malfunction The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide supplemental information on the subject event.

Very, truly yours, A i",(

K. N.

~ ~ arris Vice resident Turkey Point Plant KNH/DRP/DWH/rat attachment cc: Stewart E. Ebneter, Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, Turkey Point Plant arr FPL Group cornpsng

NAC foiiil $55 U.S, HUCLEAII AEOULATOAYCOMMISSION (94$ l APPAOVEO OMS NO. $ 1500105 LICENSEE EVENT REPORT (LER) EXPIRES.'/$ 1(N PA fACILITYNAME Ill DOCKET NUMSEA (2)

Turkey Point Unit 3 o 5 o o o 250 >of04 Liauid Effluent Process Radiation Monitor R-18 Inoperab e During A Liquid ReTease Due To A Control Circuit Malfunction EVENT OATf (Sl LEA NUMSER (SI AEPOAT DATE (7I OTHER PACILITIES INVOLVKO Nl MONTH DAY YEAR YfAA 5 5 0 V 5 Ir 7 I*

irVM~ 5 A I ~ IEYAx)ir IcVMOER OAY YfAR PACILITY NAMES DOCKK'7 HUMSER(SI Ill Turkey Point Unit 4 0 5 0 0 0 2 5 0 1 12 90 9 0 0 1 0106 1 5 9 0 0 5 0 0 0 THIS AEPOA'7 IS SVSMITTEO PUASUAHT 7 0 THE AKDUIAEMKNTKof 10 cotl Ij; tchcce ose or isore ot the lotto sf( (11 OPEAATII(4 MODE ( ~ I I 20. 502 (5) 20.505(c) 50.7$ (clLT)lirl 7$ .71(III 20.505( ~ ) OI 50.$ 5(cl(1) 50.7$ (el (2)(el 7$ .71(cl

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LICENSEE CONTACT POA THIS LER (12)

NAME, TELEPHONE HLiMSER AREA CODE David R. Powell, Licensing Superintendent 305 246- 6 55 9 COMPLETE OHE LINE POII EACH COMPONENT PA(LURE DfSCAISED IN THIS AEPOAT (1$ l MA4UP AC. EPOATA@LE COMPONENT MAHVPAC. EPOATASL CAUSf SYSTf M COMPONENT CAVSE SYSTEM TURER TO NPAOS TURER TO HPRDS JIP X I L t ON X999 i>H V"

llcl MOHTir OAY VKAA SVPPLKMfNTAL AEPOIIT EXPECTED EXPECTED SU 5 M I $$ ION DATE (15I YES (tt yn, cosiotcte EXPECTED SVSM(SS(OIY OA TEl X No ASSTAACT ILIIstt to tc00 tenn i t eooroei etety a(tees Iihpie Ioece tpoewstres hhnt (lsl At 1043, on January 12, 1990, with Unit 3 in Mode 1 at 100 percent power and Unit 4 in Mode 4 (Hot Shutdown), a Reactor Control Operator (RCO) noted at the end of a release that the liquid effluent Process Radiation Monitor (PRM R-18) channel had failed. The ratemeter did not have display indication, the associated chart recorder was off scale high, no alarm conditions existed, and automatic closure of con-trol valve RCV-018 had not occurred . A similar event occurred on fail-December 22, 1989. The PRM R-18 vendor believes an intermittent ure of the + 5 volt low voltage power supply within the radiation mon-itor cabinet caused these events. Failure of the + 5ofvolt power supply liquid efflu-would affect the ability to cause automatic closure the ent release path control valve upon reaching the predetermined alarm setpoint. Cognitive error by licensed utility personnel contributed to these events. Failure to frequently monitor the PRM R-18 channel during how-a release is not in accordance with Operating Procedure OP 5163.2; ever, FPL believes that the PRM R-18 channel alarm setpoint was not reached during the releases. A review of Technical Specification Table 3.9-2, Item 1.a concluded that both events are reportable. The lowcard voltage power supply, processor card, timer card, and limit switch were replaced.

Nt(C fotis $ 55

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4AC raid SASA U 5 4UCLCAA ACQULATOAV COMMI$QOss 9 AT LICENSEE E T REPORT ILER) TEXT CONTINUA ArraOvTO OUS 4O JISO~IOs f s ~ IAES b 3I gy SACILITY SIAMT III OOCKTT SIUMIEII ITI LRII SIUMIIII III rAQC Iil 5CQVA4T'AL aTV'5i04 4UM sa Turkey Point Unit 3 o 5 o o o 2 5 0 9 0 0 0 1 0 102 oF0 4 TExT <<v irvs4 asrsr isnevred, vsr rudisrsars srssc srrsa J554'ss IITI DESCRIPTION OF'HE. EVENT At 1043, on January 12, 1990, with Unit 3 in Mode 1 (Power Operation) at 100 per-cent power and Unit 4 in Mode 4 (Hot Shutdown: average reactor coolant tempera-ture between 200 degrees F and 350 degrees F), a release of the B Monitor Tank to the environment was completed. Upon termination, a Reactor Control Operator (RCO) noticed the following: the liquid effluent Process Radiation Monitor (PRM R-18)

(EIIS:IL, Component:MON) channel did not have ratemeter display indication, the associated chart recorder was off scale high, no alarm conditions existed and automatic closure of liquid effluent release path control valve RCV-018 had not occurred. A review of the PRM R-18 channel r'atemeter signal output to the chart recorder indicated that display functions failed at approximately 0957. The PRM R-18 channel was demonstrated to be operable prior to initiation of the release at 0905, as required by Operating Procedui e OP 5163.2, "Waste Disposal System-Controlled Liquid Release to the Circulating Water System."

At 1433, on January 12, 1990, the NRC was notified of the above .event pursuant to 10CFR50.72(b)(2)(iii)(C).

The PRM R-18 channel continuously monitors liquid effluent releases from Turkey Point Units 3 and 4. Automatic valve closure is initiated by this monitoring channel to stop the release after exceeding a predetermined alarm setpoint or upon loss of power.

Technical Specification (TS) Table 3.9-2, Item l.a, requires the liquid radwaste effluent line gross radioactivity monitor providing automatic termination of re-lease (PRM R-18) to be operable during effluent releases. With PRM R'-18 inoper-able, liquid effluent releases may continue provided that, prior to initiating a release:

1. At least two independent samples are analyzed and;

2. At least two technically qualified members of the Facility Staff inde-pendently verify the release rate calculations and discharge valving (one performs, one verifies);

Otherwise, suspend release of radioactive effluents via this pathway.

An earlier failure of the PRM R-18 channel was noticed at 1350, on December 22, 1989, during release of the A Waste Monitor Tank. The symptoms noticed at the end of this earlier release were identical to those noticed during the January 12, 1990 event. The PRM R-18 channel had been demonstrated to be operable pr ior to initiation of the release at 1304, as required by Operating Procedure OP 5163.2. A review of the PRM R-18 channel ratemeter signal output to the chart recorder indicates that the display functions failed at approximately 1305. Ver-ification that the release'had been terminated was interpreted as meeting the conditions of TS 3.9-2, Item 1.a. The ribbon cable connector to the PRM R-18 channel ratemeter was cleaned and tightened. No further investigation into the cause of the noticed symptoms was performed.

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>P~ SASA E T REPORT (LER) TEXT CONTINUA U 5 NUCLE*A AECULATOAY COMMISEION AoaaOvEO OM4 vO lISO~IOA ExaiaES 4 SI ES NAME III OOCKET NUMSEII IEI LEN NUMEEII III

'ACILI'TY AACE ISI SSOVSVT<AL aTV'S>OV 4gV 4VM Ta satrap Turkey Point Unit 3 o s o o o 250 90 0 1 0 0 0F 04 TEXT NI mom N ~wnd. ant East~ WIC Arm J55A'T I IITI CAUSE OP THE EVENT The only fault identified during troubleshooting the PRM R-18 channel failure was a slight loss of regulation on the - 15 volt low voltage power supply. A total loss of the - 15 volt low voltage power supply would produce alarms on the monitor; therefore, this condition was not responsible for the PRM R-18 channel failure. The low voltage power supply was removed and discarded. A new low voltage power supply was installed.

Additional troubleshooting was performed on the Central Processing Unit (CPU) and the watchdogtimer, which re-programs the CPU in the event the CPU locks-up. The PRM R-18 channel failure could not be duplicated. The three removable cards that compr ise the radiation monitor channel logic and contr ol circuitry were replaced. The removable cards (processor, timer/alarm and limit switch) were sent to the vendor (Nuclear Research Corp.) for further analysis.

The vendor was unable to produce a failure in the three removable cards that

.comprise the radiation monitor channel logic and control circuitry. However,-

the vendor did duplicate the symptoms of the failure experienced in the PRM R-18 channel by removing the + 5 volt low voltage power supply to the cards. The vendor believes that an intermittent failure of the + 5 volt low voltage power supply was the cause for the PRM'R-18 channel failure. Because this low voltage power supply was discarded after being replaced during earlier troubleshooting, further analysis of the PRM R-18 channel failure to the component level can not be perfor med.

Cognitive errors by licensed utility personnel contributed to these events.

Operating Procedure OP 5163.2, Step 4.2, Precautions and Limits, requires the PRM R-18 channel to be frequently observed during a release to be assured that countrate is not approaching the setpoint stated on the liquid release permit.

Section 8.0, Instructions, contains requirements for the Auxiliary Building operator to request the RCO to periodically monitor the PRM R-18 channel and notify him if the indication approaches the alarm setpoint. An unmonitored release condition lasted for approximately 46 minutes on January 12, 1990 and for approximately 45 minutes on December 22, 1989. In both events, the failed PRM R-18 channel condition was not discovered until the end of the release.

ANALISIS OP THE EVENT A sample of the remaining tank contents determined that radioactivity concentra-tions were lower than at initiation of the release for both events. Because of

.this, FPL believes the PRM R-18 channel alarm setpoints were not reached. Addi-tionally, the radioactivity concentrations released were within the limiting com-bined Maximum Permissible Concentrations (MPC) allowed by 10CFR20, Appendix B, at the release point when averaged over a time period of one hour.

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LICENSEE Ei T REPORT {LER) TEXT CONTINUA J>>AOVEO OU4 'iO SIS0-OIOJ ET ~ IIIES 4 SI 45 TACILITYIIAME III, OOCKET IIUM4EII l2I LEII IIUMCEII IEI ~ AGE ISI YE J J 5 5 C V5 iiT I J I. JEV'5i04 4VV J hVM 5~

Turkey Point Unit 3 0 5 0 0 0 2 5 0 9 0 001 0 104 OF 0 4 TEXT illmd'dddd U iddv>>d. vM ddditNIJJl ITIIC SOrm 244A'Jl lltl CORRECTIVE ACTIONS

1. An On The Spot Change (OTSC) has been generated against Operating Proce-dure OP 5163.2, "Waste Disposal System Controlled Liquid Release to the Circulating Water System," which requires the RCO to record PRM R-18 chan-nel readings on the Liquid Release Permit every 15 minutes during a liquid effluent release.

2. An On The Spot Change (OTSC) has been generated against Nuclear Chemistry procedure NC-44, "Preparation of a Liquid Release Permit," which revises the Liquid Release Permit form to require the recording of PRM R-18 chan-nel readings at 15 minute intervals.

3. The low voltage power supply, processor card, timer card and limit switch card were replaced. The PRM R-18 channel tested satisfactorily and was re-turned to service.

4. The replaced cards were returned to the vendor (Nuclear Research Corp.) for evaluation. The vendor was unable to produce a failure in the replaced cards. However, the vendor did duplicate the symptoms of the failure ex-perienced in the PRM R-18 channel by removing the + 5 volt low voltage power supply to the cards.

ADDITIONAL INFORMATION The PRM R-18 microprocessor based ratemeter/controller is a Model DRM-200 RemRad monitoring system manufactured by Nuclear Research Corporation (NRC) Industries.

No similar Licensee Event Reports have been submitted for Turkey Point Unit 3 or 4 ~

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