ML17325A198

LER 87-010-00:on 870605,inadvertent Opening of Reactor Trip Breakers Occurred Due to High Turbine Exhaust Pressure. Caused by Excessive Leakage of Low Pressure Steam Supply Isolation Valve AMO-12.Procedures implemented.W/870707 Ltr

ML17325A198
Person / Time
Site:	Cook
Issue date:	07/07/1987
From:	Blind A, Will Smith INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
LER-87-010, LER-87-10, NUDOCS 8707150290
Download: ML17325A198 (7)

Text

REGULA% Y INFORMATION DISTRIBUTIO YSTEM (RIDS)

ACCESSION NB R: 87071 50290 DOC. DATE: 87/07/07 NOTARIZED: NO DOCKET FACIL: 50-315 Donald C. Cook Nuclear Poeer Planti Unit 1I Indiana Rc 05000315 AUTH. NAME AUTHOR AFFILIATION BLINDI A. A. Indiana 8~ Michigan Electric Co.

SMITHS'. G. Indiana 8< Michigan Electric Co.

REC IP. NAME, RECIPIENT *FF II IATIQN

SUBJECT:

LER 87-010-00: on 870605I inadvertent opening of reactor tr ip breakers occurred due to high turbine exhaust pressure.

Caused bg excessive leakage of low pressure steam supply isolation valve AMO-12. Procedures implemented. W/870707 ltr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR ( ENCL TITLE: 50. 73 Licensee Event Report (LER) Incident ~

J Rpti'tc.

SIZE:

NOTES:

REC IP 1 ENT COP I ES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-3 L* 1 1 PD3-3 PD 1 WIGQINGTONP D 1 INTERhlAL: ACRS MICHELSON 1 1 ACRS MQELLER 2 2 AEQD/DQA 1 1 AEOD/DSP/ROAB 2 2 AEQD/DSP/TPAB 1 1 DEDRO 1 1 NRR/DEST/ADE 1 0 NRR/DEST/ADS 0 NRR/DEST/CEB NRR/DEST/ELB 1 NRR/DEST/ ICSB 1 NRR/DEST/MEB NRR/DEST/MTB 1 NRR/DEBT/PSB NRR/DEST/RSB 1 NRR/DEST/SGB 1 NRR/DLPG/HFB 1 NRR/DLPG/GAB 1 NRR/DOEA/EAB 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 2 NRR/PMA NLRB NRR/PMAS/PTSB 1 1 E 02 1 1 RES DEP Y G I 1 1 S ORDI J 1 1 RES/DE/EIB 1 1 RGN3 FILE 01 1 1 EXTERNAL: EQ~DQ GRQHI M 5 5 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 NSIC HARB ISI J 1 NSIC MAYST G 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 44 ENCL 42

NAC Form 388 U.S, NUCLEAR AEOULATORY COMMISSION (9-83)

APPROVED OMB NO. 31600101 EXPIRES; 8/31/88 LICENSEE EVENT REPORT (LER)

FACILITYNAME (I) DOCKET NUMBER (2) PA E 3 D.C. Cook Nuclear Plant, Unit 1 ,o 5 o o o 31510F04

"'"'"'SF Actuation (Inadvertent Opening of Reactor Trip Breakers) Due to High Turbine Exhaust Pressure as a Result of Excessive Isolation Valve Leaka e EVENT DATE(5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR :PS SEQUENTIAL OAY YEAR FACILITYNAMES DOCKET NUMBER(S)

NVMBFR NUMBER MONTH 0 5 0 0 0 0 6 0 5 8 7 8 7 0 1 0 0 0 0 7 0 7 8 7 0 5 0 0 0 OPERATINO THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 cFA ('I; ICheck one or more of thr follovffnfl(I'l MODE (9) 3 20A02(b) 20AOBI ~ ) 50.73(s)(2)(lr) 73.7 1(b)

POWER 20AOS( ~ I(1)(l) 50.35(c) (1) 50.73(s)(2)(v) 73.71(c)

LEYEL 0 0 20AOS(s)(1) (8) 50.38(c) (2) 50.73(s)(2)lvil) OTHER ISprclfy In Ahstrrct helovrrrxf ln Text, HRC Form 20AOS(s)(1)(BII 50.73(s)(2)(l) 50.73(s) (2) (rill)(A) 3SSAI 20AOS( ~ I(1) Ilv) 50.73(s)(2)(B) 50.73(sH2)(rill) (BI

~&~~i:>> .,>Ak&kN 20AOS(s) II)(v) 50.73(s) (2) (III) 50.73(s)(2)lx)

LICENSEE CONTACT FOA THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE A. A. Blind Assistant Plant Mana er 6 1 64 6 5 90 1 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC.

TURER REPORTABLE TO NPRDS SYSTEM COMPONENT MANUFAC.

TURER EPORTABLE TO NPADS m(Mki X S B I S R 3 0 4 5>)SI~%Ã F~m k7~!

SUPPLEMENTAL REPORT EXPECTED (1C)

EXPECTED MONTH KM4(DAY YEAR SU 8 M I SS ION DATE (15)

YES Ilf yrs, complrtr EXPECTED SVShfISSION DATEI NO ABSTRAGT ILlmlt to IeOO sprees, i.e., rpproxlmrtely fifteen slnofe swee typrrvrlttrn llnml (18)

On June 5, 1987, at 0538 hours0.00623 days <br />0.149 hours <br />8.895503e-4 weeks <br />2.04709e-4 months <br />, while preparing for Unit startup, an Engineered Safety Features Actuation (inadvertent opening of the reactor trip breakers) occurred due to first stage turbine pressure reaching the 10 percent setpoint which de-energized the P-7 permissive enabling the "four of four turbine stop valves closed" reactor trip signal. The pressurization of the high pressure turbine first stage was the result of isolation valve AMO-12 (low pressure steam from left Moisture Separator Reheater) leakage which in turn pressurized the high pressure turbine. t The cause of this event has been determined to be the excessive leakage of the low pressure steam supply isolation valve AM0-12.

Contributing to the event was Moisture Separator Reheater tube leakage.

The repair of both the subject isolation valve and the MSR tube leakage will be completed before the conclusion of the current refeuling outage (tentatively scheduled for August 24, 1987).

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P,DOCK 70707 05o0000315

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NRC Fotm 388 1983)

NRC Form 38SA U rL NUCLEAR REGULATORY COMMISSION (583)

LICENSEE E T REPORT (LER) TEXT CONTINUAT APPROVED OMB NO. 3150M)04 EXPIRES: 8/31/BB FACILITY NAME (I I OOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

.'O'A SEQUENTIAL 1~o+" REVISION i%./ NUMBER 'PRE NUMBER D.C. Cook Nuclear Plant, Unit. 1 o 5 o o o 3 1 5 8 7 0 1 0 0 0 0 2 OF 0 4 TEKT /3'14olo +ect /r Er)ckEIL ooo //E/OEM/ NRC %%drm 35EA'E/ (IT)

Conditions Prior to Occurrence Unit, 1 in Mode 3 (Hot Standby) preparing for Unit startup, reactor sub-critical, reactor trip breakers closed, all reactor control rod shutdown banks fully withdrawn.

Descri tion of Event, On June 5, 1987, at 0538 hours0.00623 days <br />0.149 hours <br />8.895503e-4 weeks <br />2.04709e-4 months <br />, an Engineered Safety Features Actuation (inadvertent opening of the reactor trip breakers) occurred due to one of two first stage turbine pressure instruments (EIIS/TP) reaching the 10 percent setpoint which de-ener'gized the P-7 permissive enabling the "four of four turbine stop valves closed" reactor trip signal. The pressurization of the high pressure turbine first stage (EIIS/TA) was the result of isolation valve AMO-12 [low pressure steam supply from left Moisture Separator Reheater (MSR)

(EIIS/ISV)] leakage which in turn pressurized the high pressure turbine.

The pressurization began when an auxiliary steam flow control valve (ARV-60) (EIIS/FCV) was opened to supply the main feedwater pumps (EIIS/P) to facilitate low flow operation.

cluded that this is when leakage through AMO-12 began. The leakage of It has been con-AMO-12 allowed the auxiliary steam (125 psig) to enter the left MSR.

The normal drain from the left MSR to the 5B high pressure feedwater heater (EIIS/HX) was closed due to high levels within the heater.

The MSR alternate drains to the main condenser (EIIS/COND) were also closed which is the normal system alignment at this point in the startup sequence.

With the MSR drains closed the only flowpath available for the auxiliary steam was into the high pressure turbine via the cross under piping. The cross under piping contains four, 2 inch drain lines to the condenser. It appears, however, that the mass from steam leaking through AMO-12 combined with existing MSR tube leakage [as had been identified earlier (see LER 50-315/87-009-00)]

exceeded the capacity of these drains and resulted in the pressurization of the high pressure turbine. This in turn actuated the reactor trip sequence [opening of the reactor trip breakers (EIIS/BKR), insertion of the reactor control rod shutdown banks (EIIS/ROD)]. There was no automatic or manual actuation of the intermediate head safety injection system (EIIS/BQ).

NIIC FORM 3SEA rO U.S.GPO:1088.<&24.538/E55 (BB3)

NRC Form 366A UA. NUCLEAR REOULATORY COMMISSION (883 l

(

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3150M)04 EXPIRES: 8/31/BB FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PACE (3)

YEAR 9+hj SEQUENTIAL M< REVISION NUMBER ~?'.3 NUMBER D.C. Cook Nuclear Plant, Unit 1 '0 g 0 0 0 3 1 5 8 7 0 1 0 0 0 0 3 oF0 4 TEXT //moro SPooo /4 re/O//or/ Irro or//Oono/HRC Form 3I)/MS/ ()2)

Operations personnel immediately implemented special Emergency Operating Procedure 1-0HP-4023.E-O to verify proper response of the automatic protection system (EIIS/JC) and to assess plant conditions for initiating appropriate recovery action.

The NRC was notified of the event via the ENS at 0752 hours0.0087 days <br />0.209 hours <br />0.00124 weeks <br />2.86136e-4 months <br />, June 6, 1987.

With the exception of the leakage of both'he low pressure steam supply isolation valve and the MSR tubes there were no inoperative structures, components, or systems that contributed to this event.

Cause of Event The cause of this event has been determined to be the excessive leakage of the low pressure steam supply isolation valve (AM0-12).

Contributing to the event was MSR tube leakage.

Anal sis of Event This Engineered Safety Features Actuation, which resulted in a reactor trip, is reportable pursuant to 10 CFR 50.73 (a)(2)(iv)-.

The Engineered Safety Features Actuation signal was generated as a result of one of two first stage shell pressure instruments reaching the 10 percent setpoint, which de-energized the P-7 permissive enabling the "four of four turbine stop valve closed" reactor trip signal.

The automatic protection system responses were verified to have functioned properly as a result of the Engineered Safety Features actuation. The Reactor Trip Breakers actuated in less than 100 ms which is consistent previous data. All reactor shutdown control rod banks fully inserted as a result, of the reactor trip signal. Based on the above, it does not constitute an unreviewed safety question as defined by has been concluded that this event 10 CFR 50.59. The health and safety of the public were not affected.

Corrective Actions Operations personnel immediately implemented plant procedures to verify proper response of the automatic protection system and to assess plant conditions for initiating appropriate recovery actions. The repair of both the subject isolation valve and the MSR tube leakage will be completed before the conclusion of the current refueling outage (tentatively scheduled for August 24, 1987) .

'NRC FORM 366A oU.S.GPO)1088O4)24 538/455 (64L))

NRC Form 35EA U.S. NUCLEAR REOULATORY COMMISSION

($ 53)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEO OMB NO. 3150-0104 EXPIR ES: 5/31/(I FACILITYNAME (1) OOCKET NUMBER (2) LER NUMBER (5) PACE (3)

SEQUENTIAL REVISION YEAR NUMBER NUMBER D.C. Cook Nuclear Plant Unit 1 0 ~ 0 0 0 3 1 5 8 7 0 1 OF TENT /g mCEB REBCB /E nqulaf. INB //I/BRE/HRC Form 3//M3/ (17)

Failed Com onent Identification Isolation Valve Left Moisture Separator Reheater reheat steam to West main feedwater pump turbine Plant Designation: 1-AMO-12 Manufacturer: Rockwell Edward Model: 606MY, 10 inch EIIS Code: ISV Previous Similar Events LER 50-315/87-009-00 NRC FORM BBBA +U.S.GPO:10554.52E 538/E55 (943)

arteen 1

g+leprric INDIANA & NICHIGAN ELECTRIC CONPANY DONALD C. COOK NUCLEAR PLANT P.O. Box 458, Brldgeman, Ml 49106 Telephone (616) 465.5901 July 7, 1987 United States Nuclear Regulatory Commission Document control Desk Washington, D.C. 20555 Operating License DPR-58 Docket No. 50-315 Document. Control Manager:

In accordance with the criteria established by 10 CFR 50.73 entitled Licensee Event Re ortin S stem, the following report is being submitted:

87-010-00 Sincerely, v3 J W. G. Smith, Jr.

WGS:afh Attachment CC A. B. Davis, Region J. E. Dolan III D. L. Wigginton, NRC R. C. Callen, MPSC D. Hahn, MDPH G. Charnoff, Esp.

Dottie Sherman, ANI Library INPO M. P. Alexich R. F. Kroeger H. B. Brugger R. W. Jurgensen NRC Resident Inspector PNSRC J. G. Feinstein/B. P. Lauzau A. A. Blind File