ML19323J158

Final Rept of Significant Const Deficiency 7 Re Loose Control Element Drive Mechanism Guide cones.C-E Completed Corrective Repairs During Wk Ending 800315.Guide Cones Were Firmly Locked in Place,Torqued & Spot Welded

ML19323J158
Person / Time
Site:	Waterford
Issue date:	06/10/1980
From:	Crnich J, Hart J, Milhiser R LOUISIANA POWER & LIGHT CO.
To:
References
NUDOCS 8006190313
Download: ML19323J158 (3)

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LOUISIANA POWER AND LIGHT COM?M;Y WATERFORD SES UNIT NO. 3 FINAL REPORT OF SIG'i1FICANT CONSTRUCTION DEFICIENCY NO. 7 LOOSE CONTROL ELEME'iT DRIVE MECHANISM GUIDE CONES Reviewed By ( J. Crnich - Site Manager '

0 Reviewed By f 2 - _- 6 >h R/ M111niser - Project Superintendent Reviewed By , M M /d [d

/J. Han - Project / Licensing Engineer Reviewed-By d#-- S R. A. Hartnett - QA Site Supervisor l

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FINAL REPORT SIGNIFICANT CONSTRUCTICS DEFICIENCY NO. 7 LOOSE CEDM GUIDE CONES Introduction-This report _is submitted pursuant to 10CFR50.55e (3). It describes a deficiency in the CEDM' Guide Cones for use in Waterford Unit No. 3.

Background

Ly telephone conversation August 14, 1978, Louisiana Power and Light Company con-firmed notification to the NRC concerning a deficiency that had been identified during preoperational testing at Arkansas Power & Light Co:pany's Arkansas Nuclear One - Unit 2. The deficiency involved the CEDM Guide Cones in the reactor vessel head.

Descriotion of Deficiency During inspection of the reactor closure head (at ANO-2) following hot functional testing a number of CEDM nozzle cones were found to be loose. The set screws that hold the cones fast were also loose in some of the housings. This allows the loose cones to be-rotated and/or rocked back and forth.

i Safety I=olications The deficiency could possibly cause binding of the CEA extension shaf ts, increasing insertion time on reactor trip. There also exists the possibility that over a long period of time, the set screws would wear and the cones, because of vibratory loads, ,

could possibly rotate and fall free. If this should happen, the cones would be held) loosely around the control rod shaf ts. The possibility exists, if this were to occu that the loose' cone (s) could prevent CEDM insertion.

, Corrective Action

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. Combustion Engineering completed corrective repairs during the week ending 3/15/80 l under the surveillance of a National Board Authorized Nuclear Irspector and issued a Manufacturer's Report of Walded Repairs or Alterations dated 3/13/80.

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Corrective Action was accomplished in accordance with CE Precedure No.-00000-1

" General Procedure For Tack k'elding Guide Cones To The CEDM F.ousings Fcr Ni-Cr-Fe Guide Cones".

The Guide Cones were firmly locked in place and secured by tightening each guide cone to a torque valve of 60 ft. 1bs. + 2 ft. Ibs. - Tightening the set scree in each CEDM housing until seated on the guide-cenes or as far as possible if the screw; heads were damaged from staking . Tack welding each guidefcone to the CEDM housings by depositing two velds located 180 1 20 apart at the CEDM and guide cone shoulder. interface and subsequently spot welding over each set screw.

The cenpleted spot welds and tack welds were visually inspected and verified as having met the requirements as delineated in Procedure No.-00000-1.~

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