05000287/LER-1982-008, Forwards LER 82-008/01T-0.Detailed Event Analysis Encl

Forwards LER 82-008/01T-0.Detailed Event Analysis Encl

ML20054L881
Person / Time
Site:	Oconee
Issue date:	07/02/1982
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20054L882	List: 05000287/LER-1982-008, Forwards LER 82-008/01T-0.Detailed Event Analysis Encl
References
NUDOCS 8207090032
Download: ML20054L881 (3)

LER-2082-008, Forwards LER 82-008/01T-0.Detailed Event Analysis Encl

Event date:
Report date:
2872082008R00 - NRC Website

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DUKE POWER COMPANY 'A [ kp PowEn Buttonxo . Cj ,

422 SouTn Cucacu STREET, CImaISTTE, N. C. asa4a Y; ,O '

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4 WILLI AM O. PAR K ER, J R. 9, Ver Pers DENT TCLtPMONC: ARE A 704 sn. p=oouctio,. July 2, 1982 273-ace 3 f Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 Re: Oconee Nuclear Station Docket No. 50-287

Dear Mr. O'Reilly:

Please find attacheu Reportable Occurrence Report R0-287/82-08. This report is submitted pursuant to Oconee Nuclear Station Technical Specification 6.6.2.1.a(9),

and describes an incident which is considered to be of no significance with respect to its effect on the health and safety of the public.

This incident is essentially the same as Reportable Occurrence Reports R0-269/

81-11 and R0-270/82-02 for which detailed descriptions and evaluations were pro-vided by W. O. Parker, Jr. to James P. O'Reilly in letters dated July 24, 1981, August 5, 1981, October 5, 1981, January 8, 1982, and February 5, 1982. The results of the efforts conducted for the Oconee 1 incident are considered to be applicable to this incident at Oconee 3.

Ver truly yours,

(.) . . . \

(O . 3 William O. Parker, Jr JKF/php Attachment cc: B&W Regulatory Response Group:

Mr. J. J. Mattimoe, SMUD, Chairman Mr. J. H. Taylor, B&W Mr. W. C. Rowles, TECO Mr. D. C. Trimble, AP&L Mr. G. Beatty, FPC Mr. R. J. Wilson, GPU Mr. W. T. Orders W Ei .g g()g NRC Resident Inspector #

Oconee Nuclear Station ~

b 8207090032 820702 PDR ADOCK 05000287 S PDR

l E L Mr. James P. O'Reilly, Regional Administrator ,

July 2, 1982 Page 2 i ,

J cc: Document Control Desk U. S. Nuclear Regulatory Commission Washington, D. C. 20555 .

Mr. T. M. Novak Office of Nuclear Reactor Reg u:Oton

' U. S. Nuclear Regulatory Commic .en i Washington, D. C. 20555 ,

I Mr. P. C. Wagner  ;

i Office of Nuclear Reactor Regulation [

U. S. Nuclear Regulatory Commission i Washington, D. C. 20555 9

! Records Center Institute of Nuclear Power Operations l

1820 Water Place i Atlanta, Georgia 30339 ,

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Duke Power Company Oconee Nuclear Station Unit 3 Report Number: R0-287/82-08 Report Date: July 2, 1982 Occurrence Date: June 9, 1982 Facility: Oconee Unit 3, Seneca, South Carolina Identification of Occurrence: Core Barrel Assembly Thermal Shield Bolts Broken Conditions Prior to Occurrence: Cold Shutdown Description of Occurrence: On June 9, 1932, during removal of the locking clips on the thermal shield bolts, 19 of 27 bolts had the bolt heads broken off. Upon completion of the locking clip removal 46 of 96 thermal shield bolts had the bolt heads broken.

Previous visual inspection showed no abnormal conditions, and ultrasonic testing showed indication ranging from 15 percent to 50 percent through-wall cracking on 51 of the 96 thermal shield bolts. Bolts that showed no indication by ultra-sonic testing were found to be intact when removed, but for those bolts with indication, the percent through-wall indication was not indicative of their condition.

Apparent Cause of Occurrence: The apparent cause of the thermal shield bolt failures is intergranular stress corrosion cracking as described in the letter of W. O. Parker, Jr. to James P. O'Reilly dated January 8, 1982.

Analysis of Occurrence: A detailed evaluation has been made of the safety implications of the thermal shield bolt failures for a similar incident on l

' Oconee 1 (RO-269/81-11). Results of this evaluation are reported in letters of

(

W. O. Parker, Jr. to James P. O'Reilly dated July 24, 1981, August 5, 1981, October 5, 1981, and January 8, 1982. Approximately 25 percent of the bolts from all other major joints which utilize the A286 material have been examined and no indications of deterioration were found. The evaluation performed for i Oconee 1 is considered applicable to this incident on Oconee 3; thus, it is considered that the health and safety of the public were not affected by this event.

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' Corrective Action: The 96 bolts and locking clips will be replaced with stud j

and nut assemblies as described in the letter of W. O. Parker, Jr. to James P.

0'Reilly dated October 5, 1981. All repairs to affected reactor vessel internals I will be completed prior to startup.

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