ML19256G135

Forwards LER 79-039/01T-0

ML19256G135
Person / Time
Site:	Peach Bottom
Issue date:	12/14/1979
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19256G136	List: ML19256G135 ML19256G140
References
NUDOCS 7912270497
Download: ML19256G135 (3)

Text

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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.O. BOX 8699 .

PHILADELPHIA. PA.19101 (215)841 4000 December 14, 1979 Mr. B oy c e H . Grier, Director Office of Inspection . tad Enf orcement Region I United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

SUBJECT:

Licensee Event Report Narrative Description The following occurrence was reported to Mr. Greenman, Region I, Office of Inspection and Enforcetnent on N ovembe r 30, 1979.

Reference:

Docket No. 50-276 Report No: LFR 3-79-39/1T Report Date: D e c e mb e r 14, 1979 Occurrence Date: N ove mb e r 30, 1979 Facility: Peach Bottom Atomic Power Scation RD 1, Delta, PA 17314 Technical Specification

Reference:

Technical Specification 6.9 2.a(9) requires reporting "perf ormance of structures, systems, or c o mp one n t s that requires remedial action or corrective measures t o p revent operation in a manner less cons.rvative than assumed in the accident analyses in the safety analysis report..."

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Mr. B oy ce H. Grier Page 2 LER 3-79-39/IT Description of the Event:

As a result of the inspection program which is being performed in response t o NRC Bulletin 79-02, an engineering review of vendor design revealed that a t ot al of 16 seismic supports associated with the Unit 3 1" Control Rod Drive (CRD) insert and withdrawal piping were not seismically qualified.

Four of the supports are outside p rima ry containment and twelve supports are inside primary containment.

Prompt notification 3-79-39/IP on N ove mbe r 30, 1979 and its update on December 4, 1979 identified 12 supports (f our outside primary containment and eight inside primary containment) that would have been overstressed in the case of a Design Basis Earthquake (DBE). In the case of the eight inside primary containment (the second and third supports off the pedestal on each of the f ou r bundles ), only one member of each support would have been overstressed.

Subsequent analysis had identified four additional supports inside primary containment (the first support of f the pedestal on each bundle) that would have been ove rs tressed du ring a DBE.

During a DBE each of the f our supports would have had excessive deflection of the 14 interior vertical members supporting the individual CRD pipes. However, they would not be overstressed during an Operating Basis Earthquake.

Consequences of Event:

A review of the CRD system design related t o seismic inadequacies for certain supports indicates that no drive insert or withdrawal line would break under a seismic event. Also, the p os tulat ed f ailure of the CRD lines involved would not result in exceeding the requirements established for CRD insertion or scram in the required time period.

Cause of the Event:

The csuse of the occurrence was inadequate initial support design.

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Mr. Boyce H. Grier Page 1 LER 3-79-35/IT Corrective Action On December 7, 1979 Unit 3 was placed in the cold shutdown condition t o complete modification of the supports. For the 16 supports identified in this report, appropriate structural members were reinf orced and s ome additional members installed to eliminate any overstressed condition during a s eis mic event. All modifications were completed by December 11, 1979 prior to the 7 nit 3 startup.

Very truly yours,

,ff}U

. . Cooney S erintend t Generation Division - Nuclear A t t a ch men t cc: Director, NRC -

Office of Inspection and Enforcement Mr. Norman M. Haller, NRC -

Office of Management &

Program Analysis 4

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