ML20039A610
| ML20039A610 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 12/08/1981 |
| 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, NUDOCS 8112180513 | |
| Download: ML20039A610 (2) | |
Text
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j TENNESSEE VALLEY AUTHORITY
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CH ATTANOOGA, TENNESSEE 374ot 400 Chestnut Street Tower II 3
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December 8, 1981 to Mr. James P. O'Reilly, Director CE !E
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DEC171981> q Office of Inspection and Enforcement U.S.' Nuclear Regulatory Commission a
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4 nmunut cus Region II - Suite 3100 101 Marietta Street U
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Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - MAIN STEAM LINE ANALYSIS TPIPE INPUT ERROR - NCR BLN CEB 8007 - FINAL REPORT' The subject deficiency was initially reported to NRC-0IE Inspector R. W. Wright on October 2, 1980 in accordance with 10 CFR 50.55(e).
This was followed by our interim reports dated October 31, 1980 and July 20 and September 17, 1981. Enclosed is our final report.
If you have any questions concerning this matter, please get in touch with R. H, Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mil 2s, Ma ager
, Nuclear Regulation and Safety Enclosure-cc:
Mr. Victor Stello, Jr., Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 Q$hO as 8112180513 G11208"
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PDR ADOCK 05000438 y
S pg An Equal Opportunity Employer
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 MAIN STEAM LINE ANALYSIS TPIPE INPUT ERROR
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NCR BLN CEB 8007 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency The calculated effects of a steam hammer occurrence in the Bellefonte Nuclear Plant ~.ain steam lines have been questioned because of an input error in the TPIPE computer program used in the analysis.
The input error occurred when several forcing functions with different arrival times were applied at individual node names. This procedure is incorrect (though the application of multiple forcing functions at a single node name is permissible provided all have the same arrival times).
In order to facilitate the analysis of the main steam lines, the computer is programmed to analyze only a portion of the total piping involved with each problem submittal. The problems affected by the subject input error are N4-1SM-A, -B, -C, ~K, and -L.
These represent main steam line piping in valve room A, piping transversing into the Turbine Building, valve room B, and main steam line piping which
- penetrates primary containment, respectively.
Safety Implications Other routing and equipment changes (e.g., valve weights, positions,
..etc.) required concurrent and subsequent reanalysis of these problems.
Because of these other changes in input for these particular problems, it.
is impracticable to assess the exact impact of the time history input error. Since the overall change to resulting support loads and locations was small, the effect of this error in this case is also judged to be small. However, had this error gone undetected, it is possible that supports would have been imprcperly designed and may have failed to perform.
their intended safety-function during a seismic event.
Corrective Action Problems N4-1SM-A, -B, -C,
-K, and -L have now been issued with the corrected time histories included. The affected drawings have been revised to document the completed reanalysis. To prevent recurrence, the analyst using this option of TPIPE has been instructed in its' proper use through discussions with PMB Systems Engineering, Incorporated, the developers of.
the program. TPIPE bulletin 8 has been issued to clarify the proper use of
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this TPIPE option for future users. TPIPE time history analyses have not been used in the design of pipe supports for any other TVA nuclear plant.
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