ML19318A051

Final Deficiency Re Loose Control Element Drive Mechanism Guide cones.C-E Secured & Tightened Each Guide Cone to 60 Ft Lb Torque Value.Completed Spot & Tack Welds Visually Inspected & Approved

ML19318A051
Person / Time
Site:	Waterford
Issue date:	06/10/1980
From:	Crnich J, Hart J, Milhieser R LOUISIANA POWER & LIGHT CO.
To:
Shared Package
ML19318A045	List: ML19318A044 ML19318A051
References
NUDOCS 8006180391
Download: ML19318A051 (3)

Text

_ _ _ _ - _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

. ~.

O .

LOUISIANA POWER AND LIGHT CCMPANY WATERFCRD SES LTIT No. 3 FINAL REPORT OF SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 7 LOOSE CONTROL ELD 1E'iT DRIVE MECHANISM GUIDE CONES Reviewed By ( J. Cruich - Site Manager 0 Reviewed By [ / _ _- 6 o /A:7 s

F/ W111hiser - Projecr Superintendent Reviewed By . ,- /d [d gf(/J. Har7- Proj ect/ Licensing Engineer Reviewed By d '^' '

R. A. Hartnett - QA Site Supervisor 8006180 39;

W 3- -.

FINAL REPORT

' SIGNIFICANT' CONSTRUCTION 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 Waterf ord Unit No. 3.

Background

By 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 testin3 at Arkansas Power & Light Co=pany's Arkansas Nuclear Ona - Unit 2. The deficiency involved the CEDM Guide Cones in the reactor vessel head.

Description 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 thel cones fast were also loose in some of the housings. This allows the icose cones co be rotated and/or rocked back and forth.

~

Safetv Implications Thedeficien\cy. could possibly cause binding of the CEA extension shaf ts, increasing irsertion time on r'eactor trip. There also exists the possibility that over a long C . 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 hele loosely around the control rod shaf ts. The possibility exists, if. this were to ocet-that the loose cone (s) could prevent CEDM insertion.

Corrective Action

. - Combustion Engineering completed corrective. repairs-during the week ending 3/15/80 under the. surveillance of a National' Board Authorized Nuclear In=pector and issued-a Manufacturer's Report of_Walded Repairs or Alterations dated 3113/80.

l Corrective Action was acccm'lished p in ac:ordance with CE Precedure No.-00000-1

" General Procedure For Tack 'n'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 f t. -lbs. i 2 f t. lbs. - Tightening the set screw 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 guide cone to the CE"M housings by depositing two welds located 180 i 20 apart at the CEDM and guide cone shoulder interface and subsequently spot welding over each set screw.

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

.