ML19210D617

Forwards LER 79-049/01T-0

ML19210D617
Person / Time
Site:	Peach Bottom
Issue date:	11/16/1979
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19210D618	List: ML19210D617 ML19210D625
References
NUDOCS 7911270398
Download: ML19210D617 (2)

Text

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PHILAD ELP.il A ELECTRIC CO M PANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 12151 841 40o0 November 16, 1979 Mr. Boyce H. Grier, Director Office of Inspection and Enforcement Region I United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406

SUBJECT:

Licensee Event Report Narrative Description The following occurrence was reported to Mr. Greenman, Region I, Office of Inspection and Enf orcement on N ove mb e r 2, 1979.

Reference:

Docket Number 50-277 Report No: LER 2-79-49/lT Report Date: November 16, 1979 Occurrence Date: October 5, 1979 Facility: Peach Bottom Atomic P ow e r Station R .D . 1, Delta, PA 17-314 Technical Specification

Reference:

Technical Specification 6.9.a(9) requires reporting

" performance of structures, systems, or c omp onent s that require remedial action or remedial action or corrective measures to prevent operation in a manner less conservative than assumed in the accident analysis in the safety analysis report ..."

Description of the Event:

As part of the inspection p rogram which is being perf ormed in response to IE Bulletin 79-02, an engineering review of vendor

, design revealed a non-conservative condition existing with four seismic supports associated with one inch Control Rod Drive piping. The affected piping runs from the Control Rod Drive Hydraulic Control Units in the Reactor Building to the gg 3x39 oso 7 9112 7 0 3 9 E

m r Mr. Boyce H. Grier P a g e. 2 November 16, 1979 LER 2-79-49/IT containment boundary. Four of the six anch or bolts on each support were f ound to have a design safety factor less than 2.

Consequences of Event:

Postulating the design basis earthquake, f ailu re of these seismic supports and subsequent failure of the supported piping would not prevent the Control Rods f rom s cramming.

Cause of Event:

The cause of this event is an engineering design deficiency.

Corrective Action:

Redesign of the above seismic supports and corrective actions were imp lemented within the seven day requirement (reference letter from B. H. Grier, Director, NRC, Region I to S.

L. Daltroff, Vice President, Electric Production, PECo. dated October 24, 1979). The anchor bolt safety factors of the above supports are now greater than 2. Future redesign modificaticn work is planned to raise the safety factors above 5.

Previous Similar Occurrences:

2-79-33/1T, 2-79-35/1T, 3-79-19/1T, 3-79-23/1T, 3-79-25/1T, 3-79-26/lT, 3-79-29/1T, 2-79-43/1T, 2-79-44/lT, 3-79-30/lT, 3 31/1T, 3-79-32/1T.

Yours truly,

/

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• A. J. Coong Superinten'ent Generation Division-Nuclear Attachment cc: Director, NRC - Office of Inspectiot and Enforcement Mr. Norman M. Haller, NRC - Office of Management &

Program Analysis ,

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