ML20086K955

Telecopy AO 74-26:on 740513,incorrect Calibr Noted in Recirculation Loop Flow Transmitters FT-2-110A Through D. Caused by Use of Inappropriate Range for Flow Transmitters. Average Power Range Monitor & Rod Block Monitor Adjusted

ML20086K955
Person / Time
Site:	Peach Bottom
Issue date:	05/14/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086K944	List: ML20086K942 ML20086K955
References
AO-74-26, NUDOCS 8402070089
Download: ML20086K955 (2)

Text

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Mr. James P. O'Reilly, Director United States Atomic Energy Co:r.sission yp 337 77g Directorate of Regulatory Operations 631 Park Avenue _

King of Pruscia, Penncylvania 19406

[1 2h

Subject:

Abnorm 1 Decurrence 24-Hour Notifict< tion Confirming Mr. Fleischrann's conversation with Mr. R. A.' Feil, A.E.C.

Region I Regulatory Operations Office on May 14, 1974.

Reference:

License Number DPR-44, A=endment Number 1 Technical Specification Reference 2.1.A.1; 2.1.B. and Table 3 2.C Report No.: 30-277-74-26 Report Date: May 14, 1974 Occurrence Date: May 13, 1974

. Facility: Peach Bottom Atomic Power Station R. D. 1, Delta, Pennsylvania 17314 Identification of Occurrence:

Incorrect calibration of recirculation loop flow transmitters FT-2-Il0A thru D.

Conditions Prior to Occurrence:-

Plant Operating at about 60% power.

Description of Occurrence: -

During plant etartup testing, an investigrittion into the dicogreement in now indication between the recirculation loop instru=entation and the core flow instrumentation disclosed that the-recirculation flow tranc .itters were not calibrated to the proper range. .

Designation of Apparent Cause of Occurrence:

Use of inappropriate range for the flow transmitters.

Analysis of Occurrence:

Investigation into the disagreement between indicated core now as derived frc=

jet pucp flow censurement, calculated core now as derived from pump curves and spacured pu=p head, and indicated recirculation loop flow diceleced than the rceirculation loop flow indication was hi Cher than actual flow. This was determined to be due to calibration of the flow trenceittern to the wrong range. This higher flow signal

• is supplied to the APRP.'s and REM's. Thus the APRM flow biaced serca and rod blocks.ond the RBM flow bineed rod biceks, vere higher than the liciting cafety cyctem cettingc given in the Tecnnical Specificationc.

The error wa:r about 75 abave ce: point. However, a ceram would h,sve occurred at about 100% power due to a " scram clamp" which hnd been placed in service for the startup period to encure t mt scram settingo were concervative. '

8402070089 740523

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DR ADOCK 05000 ( y' '

I Analynic of Occurrence: ((continueO Although thia han resulted in exceeding a cafety a stem setting, there e ic no nafety cicTrO =ce dece ee **e reactor vo=1 ve ==r ==ea -

/

. at about 100,4power. The banco to th.e Tec al Specifications.

d s which refera to Section 14 of the FSAR, states that "with a 120 percent ceram trip setting, none of the ahnerm1 operational transients analyzed viointo the fuel asfety limit and there is a substr.ntial margin from fuel dan,sge. Therefore, use of a flow-binced scram provides even additional margiR".

Corrective Action:

Because of the work involved in repairing the flow tranmitters, the gains in the APRM and RbM flow convertero were readjusted to provide a flow signal of the proper value thus resulting in flow biased ceram and rod blocks of the correct value. Recalibration of the flow trancnitterc will be done when feacibic; they provide only indication otherwise. .

Failure Data:

None previous.

I gg,y -

W. T. Ullrich, Superintendent Peach Bottom Ato:ie Power Station ,.

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