ML20010D240

Final Deficiency Rept Re Expansion Anchors Not Passing Qualification Tests,Initially Reported on 780710.Random Survey Initiated to Determine Actual Capacity of Inplace Supports & Revision 6 to G-32 Const Spec Made

ML20010D240
Person / Time
Site:	Bellefonte
Issue date:	08/14/1981
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, NCR-871, NCR-898, NUDOCS 8108240126
Download: ML20010D240 (3)

Text

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TENNESSEE VALLEY AUTHORITYO Nf ?C PE CHATTANOOGA. TENNESSEE 37401 N 'g ;

y 400 Chestnut Street Tower II il m ig all . gg August 14, 1981 ap \ $1 !k, 9 ,

Mr. James P. O'Reilly, Director Office of Inspection and Enforcement  ;

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U.S. Nuclear Regulatory Commission G Region II - Suite 3100 t inic 2a J 79OI A 101 Marietta Street ,

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'8 Atlanta, Georgia 30303 8 d h,_. '

Dear Mr. O'Reilly:

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BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - EXPANSION ANCHORS NOT PASSING QUALIFICATION TESTS - NCR'S 871 AND 898 - FINAL REPORT NCR 871 was initially reported on July 10, 1978 to R. W. Wright, NRC-0IE Region II, in accordance with 10 CFR 50.55(e). This was followed by our first interim report dated August 9, 1978. After that time, related NCR 898 was determined to be reportable in accordance with 10 CFR 50.55(e) and .

was reported in our second interim report dated January 26, 1979. This was followed by our combined interim reports dated April 9. June 7, and July 20, 1979, January 7, March 25, and July 8, 1980, January 14, March 18, and May 19, 1981. As discussed with R. V. Celenjak on August 7, 1981, enclosed is our final report.

If you have any questions concerning this matter, please get in touch with D. L. Lambert at FTS 857-2581.

Very truly yours, TENNESSEE VALLEY AUTHORITY t

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a L. M. Mills, Ma ger Nuclear Regulation and Safety Enclosures cc: Mr. Victor Stello, Jr., Director (Enclosures)

Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 TEF 3 l

0108240126 810814 DR ADOCK 05 h. An Equal Opportunity Employer

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ENCLOSURE 1 BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 EXPANSION SHELL ANCHORS INSTALLED BEFORE QUALIFICATION i

10 CFR 50.55(e)

FINAL REPORT

Description of Deficiency Self-drilling expansion shell anchors were installed in the plant before their qualification as required by TVA General Construction Specification G-32. Initial qualification testing failed to qualify all sizes of expansion shell anchors that had been installed in the plant.

f Safety Implication i

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Because the testing and analysis for the anchors was found acceptable, had l the subject condition remained uncorrected, it could not have affected adversely the safety of operation of the plant.

Corrective Action For the configuration of anchors without cutting rebar, each size of

! self-drilling anchor being used on the project has been qualified according to the requirements of TVA General Construction Specification G-32. The

, qualification test reports have been reviewed by the Division.of Engineering Design and found to be acceptable. Revision 5, dated July 21, 1977, was made to General Construction Specification G-32 which required j qualification tests for all anchorages set in hardened concrete before i installation at the plant site. The plant site was admonished to more l closely follow the requirements of the G-32 specification.

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ENCLOSURE 2

'BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 EXPANSION SHELL ANCHORS INSTALLED IN H0LES WITH CUT REINFORCING STEEL 10 CFR 50.55(e)

NONCONFORMANCE REPORT 898 FINAL REPORT Description of Peficiency Supports for safety-related cable trays and heating and ventilation ducts were installed using expansion shell anchors in core-drilled holes when rebar had been cut as allowed by the design drawings. The installed attachments were thought to have a reduced load-carrying capacity. This type of installation was not covered by TVA General Construction Specification G-32. An evaluation was initiated to determine if this type of installation is equivalent to that covered in G-32 specification. The results indicated a reduction in tensile values for expansion anchors installed through rebar.

Safety Imolication Because the testing and analysis for the anchors was found acceptable, had the subject condition remained uncorrected, it could not have affected adversely the safety of operation of the plant.

Corrective Action In order to determine the actual capacity of inplace supports, a random survey was initiated in accordance with the OIE Bulletin 79-02 inspection guidelines. The survey was performed on those attachments which were installed before issuance of revision 6 to G-32. For the survey, plate loads were obtained through analysis and worst case loadings were chosen for anchor load determination.

A total of 363 anchors were evaluated representing 78 supports. Of these supports, only one was found to be incapable of supporting its load; however, failure of this support would nct have jeopardized the safe operation o. the plant during a seismic event. The remaining supports were found to be adequate with actual anchor loadings well below the design values.

In addition to performing analysis on the attachments, revision 6 to the G-32 construction specification dated February 17, 1981 was made to prevent use of expansion shell type anchors in holes with cut rebar. This was made to ensure against recurrences and similar deficiencies at Bellefonte Nuclear Plant and other TVA nuclear plants.

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