05000219/LER-1981-050, Forwards LER 81-050/03L-0.Detailed Event Analysis Encl

Forwards LER 81-050/03L-0.Detailed Event Analysis Encl

ML20033C851
Person / Time
Site:	Oyster Creek
Issue date:	11/17/1981
From:	Carroll J JERSEY CENTRAL POWER & LIGHT CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20033C852	List: 05000219/LER-1981-050, Forwards LER 81-050/03L-0.Detailed Event Analysis Encl 05000219/LER-1981-050-03, /03L-0:on 811015,core Spray Pressure Switch Closed Alarm Failed to Clear When Reactor Pressure Increased Above RE18 Pressure Switch Setpoint.Caused by Low Reset Point on Core Spray Pump Discharge Pressure Switch RV29C
References
NUDOCS 8112040415
Download: ML20033C851 (3)

LER-1981-050, Forwards LER 81-050/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191981050R00 - NRC Website

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NUCLEAR GENERATING STATION mmse g;;;fe;ll y;;

j' (609) 693-1951 P.O. BOX 368

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Novenber 17, 1981 Mr. Ronald Haynes, Director Office of Inspection and Enforcenent

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United States Nuclear Regulatory Conmission

.9 6'31 Park Avenue Z

DEC3 198P King of Prussia, Pennsylvania 19406 i

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Dear Mr. Haynes:

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SUBJECT: Oyster Creek Nuclear Generating Station d 'Dt j lic/ \\

Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219/81-50/3L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/81-50/3L in empliance with para-graph 6.9.2.b.2 of the Technical Specifications.

Very truly yours, b

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. T. Carroll, J.

cting Director ter Creek JIC:dh Enclosures cc: Director (40 copies)

Office of Inspection and Enforement United States Nuclear Regulatory Ca mission Washington, D.C.

20555 Director (3)

Office of Managment Infornation and Program Control United States Nuclear Regulatory Ca mission Washington, D. C. 20555 NRC Resident Inspector (1)

Oyster Creek Nuclear Generating Station Forked River, N. J.

8112040415 811117 jb gDRADOCK 05000219 J

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OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/81-50/3L Report Date Novmber 17, 1981 Occurrence Date October 15, 1981 Identification of Occurrence Operation in a condition allowed under Section 3.4.A.4 in that operation of the Core Spray Systs was degraded due to a failure of core spray pinup pressure switch RV29C to reset at the proper value. Cbnsequently, loop redundancy within the (bre Spray Systs was impaired.

This event is considered to be a reportable occurrence as defined in the Technical Specifications, paragraph 6.9.2.b.2.

Conditions Prior to Occurrence The following plant conditions existed at the time of the occurrence:

Startup Mode Reactor Tmperature 375 F 4

Reactor Recirculation Flow 6.6 x 10 gpn Description of Occurrence On Thursday, October 15, 1931, while perfoming a plant startup, the " Core Spray Pressure Switch Closed" alarms failed to clear as expected when reactor pressure was increased. This alam is actuated by the RE18 or the RV29 pressure switches. Investigation revealed that pressure switch RV29C failed to reset. As a result of subsequent testing it was found that the trip point of RV29C was 25 psig rather than the 55 + 15 - 0 psig specified in plant procedures.

Cause of the Occurrence The apparent cause of this occurrence is instrument failure; lowever, no failure mechanism has been identified, as yet. An investigation is continuing and will be the subject of a revised report if additional info;mation becmes ava.lable.

Reportable Occurrence Page 2 Report No. 50-219/81-50/3L Analysis of Occurrence The intended function of the Core Spray Syst m is to provide cooling water to the core in the event of a loss of Coolant Accident (IOCA). The Core Spray Syst s is redundant with Syst m I identical to Syst m II.

Additionally, each.

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rcxlundant systm has redundant core spray and core spray booster pumps. Con-sidering the failure of pressure switch RV29C in conjunction with a IOCA, the exhaum net effect would be a loss of one (1) of the redundant pumps in each systm.

Each Core Spray Systm logic is established to provide for the starting of the redundant pump should the primary pump fail to start. This logic, with the failure of pressure switch RV29C, would allow simultaneous starting of one (1) core spray punp and one (1) oore spray booster pump which might have caused a diesel generator overload trip thereby incapacitating redundant emponents in Core Spray Syst s I and II.

Should this have occurred, Core Sproy Syst m I and II ope *able cmponents would have been available to perform the intended function of the Core Spray Systm.

Since operable cxxnponents in Core Spray Systm I and II were available had a IOCA occc red, there would be no adverse effect on the health and safety of the public.

Corrective Action

Pressure switch RV29C was replaced by a new switch preadjusted at the required setpoint.

Investigation into the cause of failure is continuing to determine additional

corrective action

The switch will be returned to the manufacturer to further attspt to deternune the failure mechanism.

During the investigation of this event, it was noted that the setpoint screw adjustment cover may, when installed, chamge the switc< setpoint, requiring a check of the setpoint following cover installation. Procedures will be revised, as required, to prevent this type of setpoint change.

Failure udta Manufacturer: Mercoid Model:

9-51 Range:

0-400 psig