05000219/LER-1981-015, Forwards LER 81-015/03L-0.Detailed Event Analysis Encl

Forwards LER 81-015/03L-0.Detailed Event Analysis Encl

ML20003G180
Person / Time
Site:	Oyster Creek
Issue date:	04/21/1981
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20003G181	List: 05000219/LER-1981-015, Forwards LER 81-015/03L-0.Detailed Event Analysis Encl 05000219/LER-1981-015-03, /03L-0:on 810324,main Steam Line High Flow Sensors Tripped at Values Greater than Tech Specs Limit.Caused by Instrument Repeatability.Both Sensors Reset
References
NUDOCS 8104280438
Download: ML20003G180 (2)

LER-1981-015, Forwards LER 81-015/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191981015R00 - NRC Website

text

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t OYSTER CREEK NUCLEAR GENERATING STATION JCP&t.~

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"J'E& uta.s s,vorn (609)693-6000 P.O. BOX 388

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• NEW JERSEY

• 08731 c#

cer April 21, 1981 d

Mr. Boyce H. Grier, Director Office of Inspection and Enforcenent 4

7 Region I o

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United States Nuclear Regulatory Ccmnission y

A 631 Park Avenue G.

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King of Prussia, Pennsylvania 19406 s

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Dear Mr. Grier:

SUR7ECT: Oyster Creek Nuclear Generating Station Docket No. 50-219 License Event Report Reportable Occurrence No. 50-219/81-15/3L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/81-15/3L in empliance with paragral i 6.9.2.b.1 of the 'nrhnical Specifications.

d Very truly yours, l

Ivan R. Finf r.

l Vice President -

&L l

Director - Oyster Creek IRF:dh Enclosures cc: Director (40 copies)

Office of Inspection and Enforcenent United States Nuclear Regulatory Ccanission Washington, D.C.

20555 Director (3)

Office of Management Information and Program Control l

United States Nuclear hgulatory Ccmnission Washington, D. C. 20555 NBC Resident Inspector (1)

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

8104280 N s

i OYSTER CREEK hTX1 EAR GENERATING STATICN Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/81-15/3L Report Date April 21, 1981 Occurrence Date i

l March 24, 1981 Identification of Occurrence During surveillance testing, the Main Steam Line high flow sensors RE-22F and RE-22G tripped at values greater than the desired setpoint as given in the Technical Specification, Table 3.1.1 sections B.2 and B.3.

This event is considered to be a reportable occurrence as defined in the Technical Specifications, paragraph 6.9.2.b.1.

Conditions Prior to Occurrence The plant was operating at steady state power.

Major Plant Parameters Power:

Reactor 1910 Mit Generator 646 bHe 4

Flow:

Recirculation 14.9 x 10 p Feedwater 7.03 x 106 lb/hr Description of Occurrence l

During perfornance of the High Flow in the Main Steam Line Test and ralibration (Procedure 619.3.005),- high flow sensors RE-22F and RE-22G tripped at values greater than the Ibchnical Specification limit of <97.5 psid. The testing yielded the following data:

Sensor Designation Desired Setpoint(psid)

As Found(psid)

As Inft(psid)

RE-22A

<97.5 95 92.5 RE-22B 797.5 97 93.5 RE-22C 797.5 96 92 RE-22D 797.5 91.5 91.5 RE-22E 797.5 97.5 93 RE-22F 797.5 101.5 92.5 RE-22G 797.5 99 92.5 RE-22H [97.5 96 92.5

O Reportable Occurrence Page 2 Report No. 50-219/81-15/3L Apparent Cause of Occurrence The cause is attributed to instrument repeatability. % e total design accuracy is

+7.25 psid (6.0 due to instrument accuracy and 1.25 psid due to ealibration

- accuracy). Sensor RE-22F was last reset at 91.5 and tripped at 101.5, so it was, therefore, operating outside of the daign criteria. Sensor RE-22G was last reset at 92.0 and tripped at 99.0, therefore, it was operatiry within the design criteria of the instrunent.

Analysis of Occurrence Either of the Main Steam Lines will isolate due to a line break as sensed by either a high tenpe.rature or a high flow condition. Each line contains 4 high flow sensors, which are part of the logic system which will initiate closure of the Main Steam isolation valves (MSIV). he logic systen contains 2 channels, and initiation of MSIV closure requires a signal frcun both channels. Additionally, each channel containing 4 sensors is further divided into 2 circuits.

With the existing logic systen, the event is limited to only a tanporary loss of redundancy in 2 circuits of different trip channels. In the case of RE-22F, sensor RE-22B is located in the same trip circuit and would have actuated within the required limit. In the case of RE-22G, senscr RE-22C is located in the same trip circuit and it also would have actuated within the desired limit. Based on the above discussion, the safety significance of the occurrence is considered minimal.

Corrective Action

Both of the sensors were reset to trip within the procedural limits of 92.5 +1 psid (note the "As Left" values in the Description of Occurrence). The problems Involved with these snap-action type switches are currently being evaluated, as are possible setpoint changes to account for instrument design error. Also, the PORC has re_,1.+r@d replacanent of the sensors with a more suitable qualified nodel.

1 i

Failure Data l

Manufacturer - ITr Barton Model - #228A Indicating Pressure Switch l

Range 200 psig l

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