ML20084U123

Ao:On 750418,during ECCS Simulated Automatic Test,Hpci Sys Turbine Stop Valve Failed to Open.Caused by Failure of Auxiliary Oil Pump.Work Request 1385-75 Issued to Investigate & Make Necessary Repairs

ML20084U123
Person / Time
Site:	Quad Cities
Issue date:	04/21/1975
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20084U089	List: ML20084U087 ML20084U123
References
NJK-75-212, NUDOCS 8306270058
Download: ML20084U123 (1)

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Quad-CM Generating Station -

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April 21, 1975 0'X t -s Y 97 j

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J. Keppler, Regional Director Directorate of Regulatory Operations Region til

• U. S. NUCLEAR REGULATORY COMMISS1011 799 RooseveIt Road .

Gicn Ellyn, IL 60137

REFERENCE:

Quad-Cities Nuc1 car Power Station, Unit 2 Docket No. 50-265, DPR-30 ~

Appendix A, Sections 1.0.A.4, 6.6.B.1.2.

Dear Hr. Keppler:

The purpose of this letter'Is to provide you with notification of an Abnormal Occurrence as required by Technical Specification 6.6.B.I.a. within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the occurrence.

At 8:00 p.m. on April 18, 1975, during the emergency core cooling system simu-lated automatic initiation surveillance test, the high pressure coolant in.lec-tion system turbine stop valve failed to open upon receipt of the int tlation signal. The stop valve did not open because the auxiliary tube oil pump failed to remain running, thus insufficient oil flow was supplied to open the valve.

The auxiliary lube oil pump sta,rted, but stopped again due to a failure of the scal-in circuit. Work Request 1385-75 was issued to investigate and make re-

. pairs as necessary.

This occurrence was discussed by telephone with Mr. Feierabend of your office on April 21, 1975 Further information will be provided by Abnormai Occurrence Report A0 50-265/75-14 which will be submitted within 10 days of the date of this occurrence.

Very truly yours, COMMOUWEALTil EDISON COMPANY QUAD-CITIES NUCLEAR POWER STATION

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N. J. Kalivianakis Station Superintendent NJK:SRH/dkp .

cc: Directorate of Lic:nsing )

J. S. Abel ,

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April 2c, 1975 Mr. John F. O' Leary. Di recto r Directorate of Licensing Regulation U. S. Nuclear Pegulatory Co mission Washington, D. C. 20545 Re f e ren ce : Quad-Ci ti es Nuclear Powe r S ta ti on Occket No. 50-265, OPR-30 .

Appendix A, Sections 1.0.A.4, 6.6.B.l.a

Dear Mr. O' Leary:

Enclosed please find Abnorr al Occurrence Report No. 50-265/75-14 for Quad-Cities Nuclear Power Station. This occurrence was previously reported to Region Ill, Directorate of Regulatory Operations by telephone on April 21, 1975 and to you and Region Ill, Di rectorate of Regulatory Operations by telecopy on April 21, 1975 This report is submitted to you in accordance with the requi rements of Tech-nical Specification 6.6.8.1.a.

Very truly yours, COMMONWEALTH EDIS0'4 COMPANY '

QUAD-CITIES NUCLEAR POWER STATION s- '~! . /..

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N. J. Kalivianakis Station Superintendent NJK/S RH/lk cc: Region lil, Directorate of Regulatory Operations J. S. Abel

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L REPORT NUMBER: A0-50-265/75-14 REPORT DATE: April 28. 1975 OCCURRENCE DATE: April 18, 1975 FACILITY:

Quad-Ci ties Nuclear Power Station Cordova, Illinois 61242 IDENTI FICATION OF OCCURRENCE:

Failure of Uni t 2 High Pressure Coolant injection (HPCI) system control valve to open during the Emergency Core Cooling System (ECCS) simulated automatic actuation test. ,

CONDITIONS PRIOR TO OCCURRENCE:

Uni t 2 was in the refuel mode at zero poser. An ECCS simulated automatic actuation test was being performed at the time of the occurrence.

DESCRIPTION OF OCCURRENCE:

During the ECCS testing on April 18, 1975 at 8:00 p.m., the HPCI system failed to start. It was noted by the operator that the HPCI auxiliary oil pump was cycling on and off and the emergency pump started. The aux-liiary oil pump supplied both lubrication for the HPCI turbine and hydr'au-lic pressure to open the turbine steam stop valve. The emergency tube oil pump supplies only lubrication for bearings.

The operator manually started the auxiliary oil pump and the HPCI system started successfully.

DESIGNATION OF APPARENT CAUSE:

. The auxiliary oil pump starts automatically on a loss of coolant accident initiation signal when the control switch is in the auto posi tion. The auxiliary oil pump supplies both the high pressure hydraulic system and a lower pressure hydraulic control system. A portion of the control system oil is also used to supply the bearing lubrication header.

The emergency oil pump is used to supply the bearing lubrication header only in the event the shaf t driven and/or the auxiliary oil pumps become unavail-able. The signal required to auto start the emergency oil pump is normal

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O A0 50-265/75-14 April 28,1975 l

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pressure on the high pressure header and low pressure on the bearing lub-rication neader. ,

i i During an auto initiation of the high pressure coolant injection system the auxiliary oil purp auto starts and runs until the shaft driven pumps

are capable of supplying the required hydraulic pressure at which time the auxiliary oil pump will auto trip. .

t Due to the pressure switch settings however, the emergency oil pump would sense nornal pressure on the high pressure hydraulic system while it was .

still sensing low pressure on the bearing lubrication header and would there- l fore auto start. As soon as the emergency oil punp started, the pressure would increase on the hydraulic control systen header which would auto trip i the auxiliary oil pump. The energency oil pump cannot supply the control ,

system header so the auxiliary oil pump would again auto start on a low pressure signal. During this cycling, there was not enough control oil pressure available to open the stop valve,.

I ANALYSIS OF OCCURRENCE:

Had an actual initiation signal for the HPCI systen been received during plant operation, the operator would have had to manually start the auxiliary lube oil pump in order to open the turbine stop valve. He would have re-cognized this when he saw the pump cycling. -

Wh'en such an initiation signal is received, the core spray'and residual heat j renoval (RHR) pumps also start but do not inject water into the core until the pressure is reduced. If the HPCI system is not started fast enough or the leak size is greater than its capacity, the automatic blowdown system

} will open the electric relief valves to reduce pressure and allow both core spray pumps and four RHR pumps to add water to the core. Therefore;. in spite of the HPCI sy. stem delayed start or failure to start, the core would have been adequately cooled to prevent any health h'azard to plant personnel or the public.

CORRECTIVE ACTION: .

The 'immediate action taken in response to this occurrence was to manually

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start the HPCI auxiliary pump. Follow-up corrective action was to raise the auxiliary oil pump pressure switch set point to eliminate the automatic trip. During an automatic initiation signal the auxiliary oil pump will auto

- start and remain running until manually tripped.

FAILURE DATA:

This is the first such event to occur at Quad-Cities Station; therefore, there are no safety -implications based. on cumulative experience.  !

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