ML20126H320

RO 2-81-19/1P:on 810320,re-evaluation of Concrete Block Walls Identified Four Walls Which Were Unstable Under Effects of Obe.Caused by Const or Design Error.Addl Restraints Will Be Designed & Implemented

ML20126H320
Person / Time
Site:	Peach Bottom
Issue date:	03/23/1981
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
RO-2-81-19-1P, NUDOCS 8104090215
Download: ML20126H320 (2)

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PitILADELPHI A ELECTRIC COMPANY l[

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Peach Bottcan Atomic Power Station 1- O .

Delta, Pennsylvania k, "

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14: . Boyce H. Grier Office of Inspection and Enforcement Region I ,

United States Nuclear Regu14 tory Cmunission j 631 Park hvenue l King of Prussia, PA 19406 j

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SUBJECT:

REPORTABLE OCCURREleCE -PROMPT N(yf!FICATION Confirming W. T. U11 rich's conversation with Mr. C. Cowgill, Region I, ihacicar Regulatory Comrnission, Office of Inspection and Enforcement on g March 20, 1991. 3 Rcierencet Docket No. 50-277/278 Pench Sotton Units 2 and 3 Technical Specification

Reference:

3.8.C.8 Report No.: 2-81-19/IP Occurrence Date 3/20/81 Identification of Occurrenco_:

Re-evaluation of concrete block walls identified four walls which were f unctable under the offects of an Operating tesis Earthquake. (

conditions Prior to occurrence:

Unit 2 shut down for an unrelated forced omtape. Unit 3 shut down for a refueling outage. C s-Apparent Cause of Occurrences Construction or design error.

Analysis of Occurrences During the re-evaluation of con'crote block walls, walls number 102.8 and 102.9 (Unit 2), and wall 418.30 and 419.11 (Unit 3), were found to be unstable under '

the ef fects of an Operating Basis Earthquake. These walls are located on the 4 tefueling floor adjacent to the reactor building vent monitors and the conduit associated with these monitors. The vent monitors could becoene inoperable should the wal) co)3apre during a ocinmic event. The referenced Technical Speciffrationf, indiente that the reactor buildinq exhaust vent monitors snist be operable for pinnt operation. If they become luoperable, a shutdown must be initiated within one hour and n hot r;hutdown condition achieved within 10 days. f;ince thene nonituiu have no safety system logic, Jous of there monitors has minimal safety r.19 nificance. This is particularly true since the plant would be shutdown for other reasons in the event of an Operating Basis Earthquake.

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