ML19261F289

Abnormal Occurrence 50-289/74-18:on 741010,1A Makeup Pump Tripped During Engineering Safeguards Actuation Sys Test. Caused by Wrong Lug Type Connecting Feeder Cable to a Phase Motor Winding Lead.Lead Repaired & Reconnected

ML19261F289
Person / Time
Site:	Three Mile Island
Issue date:	10/17/1974
From:	Arnold R METROPOLITAN EDISON CO.
To:
References
GQL-0408, GQL-408, NUDOCS 7910250737
Download: ML19261F289 (4)

Text

..

AEC DISTRIBUTION FOR PART 50 DOCKET MATERIAL (TEMPORARY FORM)

CON T RO L NO :_10251___ _

FILE:

F ROM: Metropolitan Edison Co. DATE OF DOC DATE REC'D LTR TWX RPT OTHER Reading a 10-18-74 10-24-74 xxx TO: 9treclorate of Licensing ORIG CC OTHER SENT AEC PDR xxxx m xx 1-signed SENT LOCAL PDR vvvvv- v CLASS UNCLASS PROPINFO INPUT NO CYS REC'D DOCKET NO:

m xx 1 50-289 DESCRIPTION: ENCLOSURES:

Ler Reporting Abnormal Occurrence on ^4("'my n - - ---, n" 10-10-74 concerning the tripping of the 1A Makeup Pump threatened to -

cause an Engineered Safeguard feature or system to be incapable of performint its intended function DO h,,,," ,- gy"n ~

THree Mile Island FOR ACTION /INFORMATION 10-Z9-74 JG3 BUTLER (L) SCHWENCER (L) ZIEMANN (L) REG AN (E)

W' Copies W/ Copies W/ Copies p' / Copies CLARK (L) STO LZ (L) DICKER (E) / LEAR (L)

W/ Copies W/ Copies W/ Copies W/VCopies PAR R (L) VASSALLO (L) KNIGHTON (E)

W/ Copies W/ Copies W/ Copies W/ Copies KNIEL (L) PURPLE (L) YOUNGBLOOD (E)

W/ Copies W/ Copies W/ Copies W/ Copies

, INTERNAL DISTRIBUTION

/ FG R FM r TECH REVIEW DENTON LIC ASST A/T IN D

/ C PDR GRIMES BRAlTMAN GC, ROOM P-506A ICHROEDER GAMMILL DIGGS (L) SALTZMAN 4UNTZING/ STAFF /MACCARY KASTN ER GEARIN (L) 8. HURT 4ASE vkNIGHT BALLARD GOULBOURNE (L)

GI AMBUSSO ./PAWLICKl SPANGLER KREUTZER (E) PLANS BOYD AHAO LEE (L) MCDONALD MOORE (L) (BWR) ELLO ENVIRO MAIGRET (L) CHAPMAN DEYOUNG (L) (PWR) OUSTON MULLER REED (E) DUBE w/ input SKOVHOLT (L) OVAK DICKER SERVICE (L) E. COUPE GOLLER (L) AOSS KNIGHTON SHEPPARD (L)

P. CO LLINS 4POLITO YOUNGBLOOD SLATER (E) . THOMPSON (2)

DENISE TEDESCO REGAN ITH (L) LECKER EG OPR 64 ONG PROJECT LDR EETS (L) ISENHUT FILE & REGION (3) d_AI N AS WILLI AMS (E)

• d1OR RIS -GENAROYA HAR LESS WILSON (L)

JTEELE A'O LIM E R gAQj I'"'

Q9

, EXTERNAL DISTRIBUTION f_ '

d f- LOCAL PDR _ Harrisburg, Pa

/if TIC (ABERNAl HY) (1)(2)(10) - N ATIONAL LABS 1 - PDR SAN /LA/NY v4 - NSIC (BUCH AN AN) 1 - ASLB>(E/W Bldg Rm 52G,. 1 - BROOKHAVEN NAT LAB 1 - AS L B 1 - W. PENNINGTON, Rm E 2t 1 GT 1 - G. ULRIKSON, ORN L 1 - Newton Anderson 1 - B&M Su!!NEBRO AD, Rm E..'ll GT 1 - AGMED (RUTH GUSSMAN)

[M- ACRS m 1 - CONSU LTANTS Rm B 127 GT Ssuf a ge, @4, NEWMARK/BLUME/A GBABI AN 1- D. MUELLER, Rm E 201 u /.S 7910e5g y 3 y g

mWN,f.7 2 7 c y, - . .. .,,,

METROPOLITAN EDISOM COMPANY 8C37 CFOCE BCX 542 REACl* G, PEN *4SYLV ANI A 19600 TEl.EPHONE 215 - 929-:C01 OCT 17.1974

?l l w'/

GQL 0408 .

f, ,

56.atrv .-- +,

<7[ /

3 'C

~U -

UQp#EI9ff G Director Directorate of Licensing , if g

• Qf k-U.S . Atomic Energy Com:aission s- 'e ' '% . ('s '-

Washington, D.C. 20545 N b-d' ' #

Dear Sir:

Docket No. 50-289 Operating License DPR-50 In accordance with the Technical Specifications for our Three Mile Island Nuclear Station, Unit 1, we are reporting the following A up.

Occurrence : ygO (1) Report Number: A0 50-289/74-13 $ {3 (2a) Report Date: October 18, 1974 007NL4n,,I.f (2b) Occurrence Date: October 10, 1974 4 k-73.,

(3)

Q "

.z..t g Facility : Three Mile Island Nuclear Station, Unit 1

/4 N e y q '.

(4) Identification of Occurrence:

Title:

IA Makeup Pump Trip during an ESAS Test Type: An abnormal occurrence as defined by the Technical Specifications, paragraph 1.8d, in that the tripping of the 1A Makeup Pump threatened to cause an Engineered Safeguard feature or system to be incapable of performing its intended function.

(5) Conditions Prior to Occurrence: The reactor was at steady state power with mr.jor plant parameters as follows :

Power: Core: 10 0%

Elec.: 866 W (Gross) -

RC Flow: 137 x 106 lbs /hr jhk -

RC Pressure: 2155 psig 102[1

RC Te=p . : 579 F PRZR Level: 240 in.

PRZR Temp . : 655 F (6) Description of Occurrence:

At 1404 hours0.0163 days <br />0.39 hours <br />0.00232 weeks <br />5.34222e-4 months <br /> on October 10, 1974, during performance of the High Pressure and Low Pressure Injection Logic Channel and Component Test on the Engineered Safeguards Actuation System (ESAS), Makeup Pump 1A tripped. The pump motor had started properly on three

" auto" actuation attempts , but tripped on " manual" actuation.

(7) Designation of Apparent Cause of Occurrence:

The apparent cause of the occurrence has been determined to be installation [ construction in that the wrong type of lug was used to connect .a feeder cable to a lead of the A phase motor winding.

Use of the arong type of lug did not provide for an adequate connection, which led to over-heating and burning of the connection area, and to severing of the lead from the lug. When the lead separated, an arc flashed to ground causing an A phase overcurrent and a grr,und overcurrent. As a consequence of this , the 1A Makeup Pump tripped. The fact that the pump tripped on a manual actuation signal rather than on one of the three previous auto actuation signals is believed to be entirely fortuitous.

(8) Analysis of Occurrence:

Ic is believed that the tripping of the LA Makeup Pump did not endanger either the health or safety of the public in that only one Makeup Pump is needed to supply emergency coolant to the reactor following a Loss of Coolant Accident. In the present case, the IB Makeup Pump was already operating and the IC Makeup Pump was selected for ESAS actuation.

(9) Corrective Action:

Immediate corrective actions were taken to first verify operability of the LB and 1C Makeup Pumps, then to r> pair the damaged lead, and to reconnect it to the feeder cable with .:he proper type of lug.

In addition, the connection lugs on the other two phases of the 1A Makeup Pump were checked and found to be of the proper type. The pump then tested satisfactorily.

At a meeting held af ter the incident, the Plant Operations Review Committee (PORC) reviewed and approved these actions , and recommended as a long term corrective action that checks be made of the Makeup Pump 1B and 1C connecting lugs to ensure that the proper type of lugs are installed.

The Station Superintendent concurred with PORC's findings , and it is presently anticipated that the IB and 1C Makeup Pump connecting lugs will be checked during the next outage period.

kb\

(10) Failure Data:

Not applicable.

Sincerely,

~

) 's '1 1 R. C . Ahold Vice President RCA/JFV/cas File: 7 7.3 5.1 20.1.1 cc: Mr . J . P . O ' Reilly Directorate of Regulatory Operations , Region i U.S . Atomic Energy Cornission 631 Park Avenue King of Prussia, PA 19406

&\ -