ML17328A839

LER 90-008-01:on 900619,discovered That Isolation Relay Circuitry for Low Header Pressure Auto Start Switch for Essential Svc Water Pumps Installed Incorrectly.Caused by Design Errors.Plant Mod Packet initiated.W/910104 Ltr

ML17328A839
Person / Time
Site:	Cook
Issue date:	01/04/1991
From:	Blind A, Carteaux P INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-008, LER-90-8, NUDOCS 9101090528
Download: ML17328A839 (13)

Text

~, . '>> <<>> vv ACCELERATED: DIQ'RIBUTION DEMONSTTION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9101090528 DOC.DATE: 91/01/04 NOTARIZED: NO DOCKET FACIL:50-315 Donald C. Cook Nuclear Power Plant, Unit 1, Indiana & 05000315 AUTH. NAME AUTHOR AFFILIATION CARTEAUX,P.F. Indiana Michigan Power Co. (formerly Indiana & Michigan Ele BLIND,A.A. Indiana. Michigan Power Co. (formerly Indiana & Michigan Ele RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 90-008-01:on 900619,discovered that isolation relay circuit'ry for low header pressure auto start switch for essential svc water pumps installed incorrectly. Caused by ltr.

design errors. Plant mod packet initiated.W/910104 DISTRIBUTION CODE: ZE22T COPIES RECEIVED:LTR TITLE 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

ENCL + SIZE:

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-1 LA 1 1 PD3-1 PD 1 1 COLBURN,T. 1 1 INTERNAL: ACNW 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1

'NRR/DOEA/OEAB 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SICB 7E 1 1 NRR/DST/SELB 8D 1 1

1 1 NRR/DST/SRXB 8E "1 1 RGN3 PI'1 1 1

1 1

RES/DSIR/EIB 1 1 EXTERNAL EG &G BRYCE y J ~ H L ST. LOBBY WARD 1 1 NRC PDR NSIC MAYS,G 1 1 NSIC MURPHY,G.A NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

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 31 ENCL 31

1" Indiana Michigan Power Company Cook Nuclear Plant One Cook Place Bridgman, MI 49106 616 465 590I Z

INDMNA NICHIGAN POWER January 4, 1991 United States Nuclear Regulatory Commission Document Control Desk Rockville, Maryland 20852 Operating Licenses 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:

90-008-01 Sincerely, 4g A.A. Blind Plant Manager

~

AAB sb Attachment c'.H. Williams, Jr.

A.B. Davis, Region III M.P. Alexich P.A. Barrett J.E. Borggren R.F. Kroeger B. Walters Ft. Wayne NRC Resident Inspector T. Colburn NRC J.G. Keppler M.R. Padgett G. Charnoff, Esg.

Dottie Sherman, ANI Library D. Hahn INPO S.J. Brewer/B.P. Lauzau B.A. Svensson 9ioi09052S 5000315 PDR ADOCK PD~

V, NRC FORM 355 UW NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 31504)04

~ (569)

EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REGUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (F630), U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON. OC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (31500104). OFF ICE OF MANAGEMENTAND BUDGET, WASHINGTON,0020503.

FACILITY NAME (1) DOCKET NVMBEA (2) PA E D. C. Cook Nuclear Plant, Unit 1 o s o o o3 15>oF06 10 CFR Appendix R Deficiencies Resulting in Potential for Loss of Auto Start of Service Water Pumps Due to Incorrect Implementations of Design Change EVENT DATE (5) LE R NUMBER (5) REPORT DATE (7) OTHER FACILITIES INVOLVED (SI rp 'SSOUSNTIAL MONTH OAY YEAR YEAR M .

NUMSEII z+

REVISION NUMbER MONTH OAY YEAR FACILITYNAMES OOCKFT NUMBFAIS)

D. C. Cook, Unit 2 o 5 o o o 316 0 6 0 1 90 90 008 0 1 0 1 0 4 9 1 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T 0 THE RLQUIREMENTS OF 10 CFR (): /Cneck onc or morc of the loiiowinp/ (11 OPERATING MODE (9) 20.405(c) 50.73(el(2) Br) 73.71(b)

POWER 20AOS( ~ l(1)(I) 50M(c) (I) 50.73(eH2)(r) 73.71(cl LEVEL ~

0 20A05(el(1) (5) 50.35(c) (2) 50 73(e) (2) (rlt) OTHER /Specify In Abttrect below enrf In text, IY/IC Form 20.405(el(1)(III) 50.73(e) (2)(I) 50,73(e) (2) (r9 I) (A) 366AJ 20.405(e) (1) (Nl 50,73(e)(2)(S) 50.73(el(2)(rib) (Bl 20.405(e) (1) (rl 50.73(e)(2)(III) 50.73(e) (2) (xl LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE P. F. Carteaux Safety and Assessment Superintendent 61 646 5-5 01 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

S y MANUFAC EPOATABLE:k . MANVFAC. EPORTABL CAUSE SYSTEM COMPONENT TO NPADS SYSTEM COMPONENT TURER TO NPRDS TVAER cc Ie

.N . N 4i SUPPLEMENTAL REPORT EXPECTED (14) MONTH OAY YEAR EXPECTED SUBMISSION DATE (15)

YES llfyer, COmplrte EXPECTED SVBSIISSIOII D476/ NO ABSTRACT /Limit to /400 tprcct, I.o., epproxlmetrly filtern clnpiccprcc typerrritNn /Incr/ (15)

On June 19, 1990, for the it was discovered that the isolation relay circuitxy low header pressure auto start switch for the Essential Service Water (ESW) pumps had been installed incorrectly. Because of a fuse coordination problem between the pressure switch and the remainder of the control circuit, it was possible for a pressure switch wiring short to disable the ESW pumps'uto start circuit. On June 20, 1990, the same condition was found for the isolation relay circuit for the low header pressure auto start switch for the Camponent Cooling Water pm(ps.

However, it inoperable.

was determined that this condition would not render the CCW pumps Appendix R of 10 CFR 50 requires that when cables of redundant equipment necessary to achieve ard maintain hot shutdown conditions are located in the same area, steps must be taken to ensure that one of the redundant trains is free of fire damage. The installed configuration for the pressure switch isolation circuitxy did not meet this requirement.

The ir((mediate corrective action taken was to replace the isolation relay circuit fuses with smaller value fuses to provide proper fuse coordination. A plant modification packet has been initiated to modify the circuits to the correct configuration.

NRC Form 355 (589)

NRC FORM 355A LLS. NUCLEAR REGULATORY COMMISSION APPROVED OMS NO. 31504)04 1548)

EXPIRES: e/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT {LER) INFORMATION COLLECTION REQUEST: 500 HRS. FORWARD COMMENTS REGARDING SURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P430), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO 1HE PAPERWORK RFOUCTION PROJECT 131504)0i), OFFICE OF MANAGEMENTANO BUDGET,WASHINGTON,DC 20503.

FACILITY NAME 11) DOCKET NUMSER )2) I.ER NUMSER ISI ~ AGE IS)

YEARN5$ 5OVENTIAI <65 NVM SR ~ ~

HVMSSA D. C. Cook Nuclear Plant, Unit 1 TEXT ///more eoece JI mqvkw5 we ~ HRC Form 33542/ l17) o 6 o o o 3 1 5 9 0 0 0 8 0 1 02 OF 0 6 Condition Prior to Occurrence Unit One in Mode One at 83 percent pcarer.

Unit Two in Mode One at 90 percent pcarer.

Descri tion of Event On June 19, 1990, it was discovered that the isolation relay circuitry for the low header pressure auto start switch (EIIS/BI-PIS) for the Essential Service Water (ESW) pumps (EIIS/BI-P) had not been correctly modified and might nat meet the Appendix R separation criteria. Because of a fuse coordination problem between the pressure switch and the remainder of the control circuit, it was possible for a prie disable an ESW pump s auto start circuit. An engineering evaluation switch wiring short to ccmpleted August 1, 1990 verified that this condition was reportable.

The breaker control circuits for the ESW pumps on both Unit One and Two are not in ccmpliance with our 10 CFR 50 Appendix R commitments as described in our submittal documented in the "Safe Shutdown Capability Assessment, Proposed Modifications and Evaluations," Section 5, Figure

5. 14.2.

Our submittal stated that the pressure switches that provide the lear header pressure auto start signal for each ESW pump will be isolated fram the remainder of the pump s control circuit. %his isolation was to be provided to prevent any common mode elctrical open, short or graund fault/

due to a fire, fram disabling the control circuits of all four ESW pumps.

This comnnn mode failure was considered possible because the pressure switches for all four ESW pumps (both units) are in the same fire zone.

'%his deters)ination was made during the Appendix R evaluation of Safe Shutdown ccm)ponents.

Isolation of the lear header pressure switches was to be accamplished through the use of an isolation relay and by inserting fuses to isolate the relay coil and pressure switch contacts circuit from the rest of the

'ump's control circuit. The design drawings issued for the design changes (RFC-1-2668 and RFC-2-2685) that were to implement this isolation were incorrectly revised resulting in this isolation not being appropriately prove.ded.

'Ibis condition was the result of design errors implemented under RFC-1-2668 and RFC-2-2685. It was found that while the engineering documents for the design changes had been properly prepared, the changes were not-properly implemented on the design drawing. The Design DepaMent's check of the drawings did not find the error, nor did the NRC Form 35SA ($ 40)

NRC FORM 355A UA. NUCLEAR REGULATORY COIhMISSION APPROVED OMB NO. 3)500104 (889)

E X PI A ES: h/30/92 ESTIMATED BURDEN PEA RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REOUEST: 50A) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPOATS MANAGEMENT BRANCH (P430), U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON. DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3)504)05), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITYNAME (11 DOCKET NUMBER (2) I.EA NUMBER (8) PAGE (3)

YEAR 5EOUtNTIAL X><. RSVrSION D. C. Cook Nuclear Plant, Unit 1 NUM 54 1?P. NUMSTR o s o o o 3 1 5 9 0 0 0 8 010 3 OF 0 6 TEXT //F more 5/reoe /5 Ter/rrkerL rree 5/1/orro/NRC Form 35543/ (I7) engineering review. Ihe drawings were then issued and the changes implemented at the Plant. RFC-1-2668 was completed on November 13, 1985.

RFC-2-2685 was campleted on June 23, 1984.

To get a better understardiLng of the problem, please refer to the attached sketch. 'Ihis sketch is typical for all ESW pumps. The circuit labeled "Proposed CKPI shows how the isolation was supposed to be provided. In the "Proposed Circuit," the pressure switch contact and the isolation relay would be isolated from the rest of the control circuit. by 10 amp fuses. A fault at pressure switch NPS-701 would result in one of the isolation relay fuses being blown. 'Ihe 10 amp control circuit fuse would be left unaffected.

The circuit labeled "Actual CZPI shows what was actually installed. As shown on the sketch, the 10 amp isolation relay fuses were placed in series with the 10 amp control circuit fuse.

Since the fuses have the same rating and characteristics, there is a chance that the control circuit fuse would blow before the isolation relay fuse in the event of a fault at WPS-701. If this happened, the pump's closed circuit would become inoperable. If the pump was already running, it would continue to run, but if it was not running or was subsequently shut down, the pump could not be restarted without manual action by the operators at the pump's electrical breaker.

Appendix R requires that the cables be separated or an alternate shutdown capability be provided. HcFhrever, the procedures that the operator would have used had a fire occurred that affected all four ESW pumps coincident I with a loss of offsite poorer, would have instructed the operator to replace the fuses. Replacing fuses is considered a repair in Appendix R and is not allowed to reach hot shutdown. Therefore, that this condition is outside our Appendix it has been design basis.

detern)ined R Cause of Event

'Ihis condition was the result of design errors implemented under RFC-1-2668 and RFC-2-2685. It was found that, while the engineering documents for the design ~es were not properly implemented'on the design drawings. Ihe Design had been properly prepared, the changes ~

Department's check of the drawings did not find the error, nor did the engineering review. At this time, no reason can be found as to why this mistake was made nor why design checks.

it was not detected during the engineering and NRC Form 355A (889)

NRC FORM 35SA (LS. NUCLEAR REGULATORY COMMISSION APPROVEO OMB NO. 31500104 (669) EXPIRES: O/30/B2 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION REQUEST: 503) HAS, FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BAANCH (F430). U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON. OC 20555, AND TO THE PAPERWORK REDUCTION PAOJECT (3150010(), OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503 FACILITYNAME (I) DOCKET NUMBER (2) LER NUMBER FS) PAGE (3)

C5x(. SEQUENTIAL IIEVOI ION NUMOEII D. C. Cook Nuclear Plant, Unit 1 o s o o o 315 9 0 0 0 8 0 1 0 4 OF 0 6 TEXT ///IooIP opoco/J nqokaL ooo Atti'onal /VRC Form 3SSAS/()7)

Anal sis of Event

'this event is considered reportable per the requirements of 10 CFR 50.73 (a) (2) (B) for Units One ard Two ard 10 CFR 50.72 (b) (1) (ii) (B) for Unit One as a cordition that was outside the design basis of the Plant.

ApI~iix R of 10 CFR 50 requires .that when cables of redundant equips)ent necessary to achieve and maintain'hot shutdown conditions are located in the same area, steps must be taken to ensure that one of the redundant trains is free of fire damage. Ihe installed configuration of the pressure switches did not meet this requirement. All four ESW pressure switches for low header pressure are located in the same fire area. I Because of the lack of fuse coordination in the pump control circuitry, a short in the pressure switch wiring of a pump had the potential for disabling the auto start feature of that pump. 'ibis created a potential for a fire in the area causing a short in all ESW pressure switch cables

-.and disabling the auto start capability. This would not have affected any operating pun)ps, but following a loss of offsite pcver as stipulated in Appendix R for assessing fire consequences, the pun(ps could not have been restarted electrically. Restarting the pumps would have required identifying and repairing the faulted circuit.

During the period that this cordition existed, no fire occurred in this fire area. Had a fire occurred, would have been disabled. For this to happen, a short it is highly unlikely that all pur()ps would have to occur in a specific location in the cables of all pumps, ard a loss of offsite power would have to occur concurrent with the fire.

'lhe fire zones where the ESW and CCW pumps are located are equipped with fire protection systems, as required by Appendix R III G. Fire Zones 29 A, B, C and D, which include the ESW pump area, have an ionization smoke detection system. An exemption has been granted for these zones waiving the requirement for a suppression system. Dry pilot preaction sprinklers are provided throughout the normally accessible portions of Fire Zone 44S which includes the CCW pumps and a closed space perimeter of the open stairway to form a water curtain between fire areas, above ard belier. In addition, to increase sprinkler density over the CCW pumps, directional water spray sprinklers are provided for the pump bearings.

Based on the above, this event is not considered to have created a significant safety concern, nor did it create a significant hazard to the health and safety of the general public.

NAC Form 35SA (SBS)

0 NRC FORM 355A UN. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3)500104 (649) EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION REOUESTE 50A) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH IP630). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON. OC 20555, AND TO THE PAPERWORK REDUCTION PROJECT )31504)104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITYNAME O) DOCKET NUMBER I2) LER NUMBER LB) PAGE )3)

SEQUENTIAL REVISION YEAR @@ NVM 'EA NVM EA D. C. Cook Nuclear Plant, Unit 1 o s o o o 315 9 0 '0 0, 8 01 05 >>0 6 TEXT /I/more epeoe /4 redo/rerL eoe R/4/OON//VRC lrorm 35Ql3/ l)T)

Corrective Actions The +mediate corrective action was to replace the 10 amp isolation relay fuses with 5 amp fuses to provide proper fuse coordination with the 10 amp control circuit, fuse. %his action was ccjmpleted in both units on June 22, 1990.

The breaker control circuits for Unit Two ESW pumps will be mxiified duz'ing the current Unit Two refueling outage (Plant Munication Nunber 12~-110). The breaker control circuits for Unit One ESW pump>> will be modified during the next Unit One refueling outage (Plant Modification Number 12-MM-110).

The Electrical Plant Section Procedure 1'I-5 Design Verification was revised and issued in January 1985 to include the Electric Plant Section checklist. This checklist is used by the design checker to verify the correct completion of a design change. This checklist has given the checker an invaluable tool in assuring design completeness. RFC)s 01-2668 and 02-32685 were completed in 1984 before the checklist became part of the design check procedure. The checking procedu're is such today that this mistake would have been caught and corrected before any drawings had been issued.

Failed nent Identification None.

Previous Similar Events None.

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