ML20087M502

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Final Deficiency Rept Re Incorrect Modeling of Problems in Tpipe Program.Initially Reported on 830801.Item Not Considered Reportable Under 10CFR50.55(e).Records Amended to Delete Subj Nonconformance
ML20087M502
Person / Time
Site: Bellefonte  Tennessee Valley Authority icon.png
Issue date: 03/22/1984
From: Mills L
TENNESSEE VALLEY AUTHORITY
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 8403300004
Download: ML20087M502 (2)


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TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 374ot 400 Ches ut reet Tower II 34 M March 22,1984 BLRD-50-438/83-47 BLRD-50-439/83-39 U.S. Nuclear Regulatory Commission Region II Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

BELLEFONTE NUCLEAR PLANT UNITS -1 AND 2 - INCORRECT MODELING OF PROBLEMS IN TPIPE - BLRD-50-438/83-47, BLRD-50-439/83 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector Linda Watson on August 1, 1983 in accordance with 10 CFR 50.55(e) as NCR BLN CEB 8304. This was followed by our interim report dated August 26, 1983 Enclosed is our final report.

TVA does not now consider the subject nonconforming condition adverse to the safe operation of the plant. Therefore, we will amend our records to delete tins subject nonconformance as a 10 CFR 50.55(e) item.

If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.

Very truly yours, TENNESSEE VALLEY' AUTHORITY I .

L. M. Mills, nager Nuclear Licensing Enclosure cc: Mr. Richard C. DeYoung, Director (Enclosure)

Office 'of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Records Center (Enclosure).

' Institute of Nuclear Power Operations 1100 Circle 75 Perkway, Suite 1500 Atlanta, Georgia 30339-8403300004 840322 PDR ADOCK 05000438 OFFICIAL COPY S PDR -

T/27 1983-TVA SOTH ANNIVERSARY pg An Equal Opportunity Employer r

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. ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 INCORRECT MODELING OF PROBLEMS IN TPIPE NCR BLN CEB 8304 BLRD-50-43 8/ 83-47, BLRD-50-43 9/ 83-3 9 10 CFR 50.55(e)

FINAL REPORT Descrintion of Deficiency Isometric drawings for the reactor coolant (RC) drains, vents, and miscellaneous piping systems show that snubbers at nodal points 67 and 75 are to be 90' or perpendicular to the RC drain piping. The directions of supports at nodal points 67 and 75 or problem N4-INK-C (unit 1) (N4-2NK-C)

(unit 2) were not modeled in the TPIPE program consistent with the analysis isometric. Incorrect data using the snubbers skewed at 30' was input into TPIPE program which would af fect the support design loads, the piping system movements and piping stresses.

Safety Implications

. After revising the computer model to correctly represent the supports normal to the pipe (90 degrees off the axis of the pipe) and subsequent reanalysis, it was discovered that the loads actually decreased. The deficiency described above is considered to be an isolated event, no support design changes are needed and no conditions associated with this deficiency exist that would adversely affect the safety of the plant.

Thus, we no longer consider 10 CFR 50.55(e) applicable.

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