ML17347B123

LER 89-003-00:on 890505,reactor Tripped During Performance of Steam Generator Protection Set III Channel Test.Cause Under Investigation.Leads Landed to Provide Signal to Reactor Protection Sys for Valve position.W/890605 Ltr

ML17347B123
Person / Time
Site:	Turkey Point
Issue date:	06/05/1989
From:	Day S, Woody C FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-89-196, LER-89-003-02, LER-89-3-2, NUDOCS 8906120258
Download: ML17347B123 (9)

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REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS) 1 ACCESSION NBR:8906120258 DOC.DATE: 89/06/05 NOTARIZED: NO DOCKET FACIL:50-251 Turkey Point Plant, Unit 4, Florida Power and Light C 05000251 AUTH. NAME AUTHOR AFFILIATION DAY,S.T. Florida Power & Light Co.

WOODY,C.O. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION R

SUBJECT:

LER 89-003-00:on 890505,reactor protection set tripchannel III during performance of test.

steam generator ~

W/8 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL Q SIZE:

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TITLE: ~50;73/50. 9 Licensees Event ~ Report (L'ER), Rpt, 'etc.

NOTES:

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I P.O. Box14000,~ Juno Beach, ~ FL 33408.0420 KSB 5 )989 L-89-196 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: Turkey Point Unit 4 Docket Nos. 50-251 Reportable Event: 89-03 Date of Event:- May 5, 1989 Reactor Trip During Performance of Steam II r

'Generator Protection Set III Channel Test The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.

Very truly yours, C. O. oody

< Acting

, Senior Vice President. Nuclear COW/JRH/cm Attachment cc: Stewart D. Ebneter, Reg'ional Administrator, Region II, .USNRC Senior Resident Inspector, USNRC, Turkey Point Plant 8906120258 890605 PDR ADOCK 05000251 S PDC an FPL Group company

NRC Form 300 V.S. NUCLEAR REGULATORY COMMISSION 194131 APPROVEO OMB NO. 31504104 LICENSEE EVENT REPORT (LER) EXPIRES! ~ /31/00 T k P tU't4 DOCKET NUMBER o 5 o o o It) 251 ioF PAGE 3

eactor r~p Unng er ormance o earn enera or Protection Set III Channel Test EVENT DATE (5I LER NUMBER ISI REPORT DATE (7) OTHER FACILITIES INVOLVED ISI

$ 0GUENVIAI. IIEVBION OAY YEAR FACILITYNAMES DOCKET NVMSEAISI MONTH OAY YEAA YEAR NUMSEII NUM00II MONTH 0 5 0 0 0 0 5 05 89 8 9 0 0 3 0 0 0 6 0 5 0 5 0 0 0 OPERATING THIS REPORT IS SUSMITTED PURSUANT T0 THE REGUIREMENTS OF 10 cFR g: /Choco ont or moie o/ tht follow np/ Ill)

MODE ISI 20.402(ol 20.405( ~ ) 50 73(e l(2) liv) 73.71(0)

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I.ICENSEE CONTACT FOA THIS LER (12I NAME 'TELEPHONE NUMBER AREA CODE Stanley T. Day, Jr., Compliance Engineer 305 246 -6590 COMPLETE ONE LINE FOA EACH COMPONENT FAILURE OESCAIBED IN THIS REPORT (13)

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On May 5, 19891 at 0152, with Unit 4 in Hot Standby, and during rod drop testing, a Reactor Protection System (RPS) actuation occurred while performing procedure 4-SMI-071.4. The reactor tr'ipped when Instrumentation and Control personnel (non-licensed utility personnel) placed bistable BS-4-446-1 in the Test position in accordance with procedure 4-SMI-071.4.

This simulated a reactor power greater than 10/".7 enabling the low power permissive s reactor trips. An investigation determined that the reactor trip logic was completed by a turbine trip signal generated by indication of closed turbine stop valves. Although the turbine stop valves (TSV) were in an open position, the RPS indicated they were closed due to the presence of lifted leads'n the TSVs position sensing circuitry. An investigation is being conducted to establish the root cause of the event and the corrective actions to prevent recurrence . Upon identification, the root cause and corrective actions to prevent reoccurrence will be issued in a Supplemental Licensee Event Report. As an immediate action the leads were landed to provide a signal to the RPS indicating the TSV s position.

NAC Form 300 i903i

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NRC Form 3CCA U.S. NUCLEAR REGULATORY COMM)$$ /ON (943)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATI APPROVED OMS NO. 3)EOMIOC EXPIA ES: 8/31/88 FACILITY NAME (Il DOCKET NUMBER (3) I.ER NUMSER (8) PACE (3l Turkey Point Unit 4 YEAR I~

Ir?N SEQUENTIAL @/I NVMSCR RCVICION

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EVENT On May 5, 1989, at 0152, with Unit 4 ip Mode 3 (Hot Standby), a Reactor Protection System (RPS) (EIISEJC) actuation occurred while performing procedure 4-SMI-071.4, "Steam Generator Protection Set III Analog Channel Test." At the time of occurrence, control banks C and D were withdrawn for rod drop testing in accordance with procedure 4-PMI-028.3, "RPI Hot Calibration, CRDM Stepping Test, and Rod Drop Test." The reactor tripped when Instrumentation and Control personnel (non-licensed utility personnel) placed bistable BS-4-446-1 in the Test position in accordance with step 6.2.3.1 of procedure 4-SMI-071.4: All systems functioned as designed, and Unit 4 remained stable in Mode 3 throughout the event. An investigation is being conducted to determine the root cause(s) of the incident,and establish the corrective actions to prevent recurrence.

Placing BS-4-446-1 in the Test position simulated a reactor power greater than 10X, enabling the RPS low power permissive s (P-7) reactor trips; thus, one-half of the reactor trip logic was provided . A subsequent investigation determined that the coinCident half of the reactor trip logic was provided by a turbine trip signal due to the presence of lifted leads in the turbine stop valve- position sensing circuitry. The lifted leads prevented the RPS from receiving a signal indicating the turbine stop valves (EIIS:TA) were open. The turbine stop valves were verified to be in an open position.

CAUSE OF EVENT Our investigation into the event has not established the root cause of the event as of issuance of this report. A Supplemental Licensee Event Report will be issued to document the root cause(s) and corrective actions to prevent recurrence .

ANALYSIS OF EVENT A post-trip review was conducted to assess the proper operation of safety-related equipment. The review established that no thermodynamic response to the trip occurred and that plant parameters responded as expected. Other than the automatic initiation of the, reactor trip, there were no manual or automatic reactor protection system or engineered safety features actuations. Although the lifted leads prevented the RPS from receiving a true indication of the turbine stop valves position, the RPS was in the fail safe position indicating the turbine stop valves were closed.

Based on the above, the health and safety of the public were not affected.

CORRECTIVE ACTIONS

1) The lifted leads for the turbine stop valves position sensing circuitry NRC FORM 3CCA *U.S.OPO:(9884.83O 538/455 (943)

()RC Form 398A U.S. NUCLEAR REGULATORY COMMISSION (943)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATI APPROVED OM8 NO. 3150-0)04 EXPIRES: 8/31/88 I'ACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (8) PACE 13)

YEAR SEOUENTIAL REVISION NvMeeR NVMeeA Turkey Point Unit 4 o s o o o 251 8 9 0 3 00 03 OF 0 3 TEXT ///core oPece /e ooRRrorL ~ oAI5mo/H/IC /rorrrr 33559/ (17) were landed on May 5, 1989.

2) An investigation is being conducted'o, establish the root cause(s) of the event and the corrective actions to prevent reoccurence. A Supplemental Licensee Event Report will be issued to document the root cause(s) of the event and the corrective actions to prevent reoccurrence.

l ADDITIONAL INPORMATION Similar occurrences: LER 250-89-004 describes a reactor trip due to a defective procedure during performance of OP 14004 1 (the old procedure F including the Steam Generator Protection Set III Analog Channel Test),

LER 251-88-010 delineates a reactor trip due to personnel error during the performance of OP 14004 1, and I'LERI250-86-030 describes a reactor trip F

and safety in)ection due to inadequate planning of post~aintenance testing associated with OP 14004 .1. l NRC FORM 3lseA *U.S.GPO:1985 0.524 538/455 (9831

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