05000289/LER-1978-016-01, T-0:on 780503,B&W Identified That for Cycle 4, Peak RCS Pressure Following Accident Exceeds Max Allowable Pressure by 4.4 Psig.Caused by Assuming Larger Instrument Error Associated W/Pressure Sensor.Tech Spec to Be Changed

T-0:on 780503,B&W Identified That for Cycle 4, Peak RCS Pressure Following Accident Exceeds Max Allowable Pressure by 4.4 Psig.Caused by Assuming Larger Instrument Error Associated W/Pressure Sensor.Tech Spec to Be Changed

ML19261F205
Person / Time
Site:	Crane
Issue date:	05/17/1978
From:	METROPOLITAN EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19261F203	List: 05000289/LER-1978-016, Forwards LER 78-016/01T-0 05000289/LER-1978-016-01, T-0:on 780503,B&W Identified That for Cycle 4, Peak RCS Pressure Following Accident Exceeds Max Allowable Pressure by 4.4 Psig.Caused by Assuming Larger Instrument Error Associated W/Pressure Sensor.Tech Spec to Be Changed
References
LER-78-016-01T-01, LER-78-16-1T-1, NUDOCS 7910250624
Download: ML19261F205 (2)

LER-1978-016, T-0:on 780503,B&W Identified That for Cycle 4, Peak RCS Pressure Following Accident Exceeds Max Allowable Pressure by 4.4 Psig.Caused by Assuming Larger Instrument Error Associated W/Pressure Sensor.Tech Spec to Be Changed

Event date:
Report date:
2891978016R01 - NRC Website

text

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8 6G 61 COCK ET NUMB E R 68 69 EVENT DATE 74 75 REPORT C ATE 80 EVENT CEf 0RIPTION AND PROB ABLE CCNSEQUENCES h

] IUrcn ecmtletien of the boundine analysis for determinine reak RCS tressure (folleving al l

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] pervative doppler ccefficient, and varying mcderator ccefficients, BW identified that l

] Ifor the Cycle h parameters, the peak RCS pressure folleving the accident exceeds the

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] paxi=m allowable pressure of 2750 psig by about h.h usic. This is reportable per l

] pech. Spec. 6.9.2.A(8).

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DESCRIPTION

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Event Descrintien and Probable Consecuences the peak RCS pressure of 275h.h psig, although exceeding the 2750 psig (1105 cf design) safety limit by only h.h psig, is still well below the 3125 psig at which RCS integrity has been verified. Further=cre, since the reacter had only reached h0% FP during the Cycle h startup, the expected peak RCS pressure as a rdsult of the accident occurring at h0% FP is considerably less than 2750 psig.

Cause Descrintion and Corrective Actions reduced to 2390 psig to prevent RCS peak pressure frc= exceeding 2750 psig.

A Technical Specification Change Request will be submitted as a pcrtion of the Cycle h refined Technical Specificatien submittal, to be submitted es soon as possible.

l481 147

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