ML20154P826
| ML20154P826 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 03/05/1986 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8603200424 | |
| Download: ML20154P826 (3) | |
Text
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l a-TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 37401 SN 157B Lookout Placo Harch 5, 1986 c:
BLRD-50-438/84-45
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BLRD-50-439/84-41
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U.S. Nuclear Regulatory Commission Region II
~0 Attn:
Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 G
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Dear Dr. Grace:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - SUPPORTS MAY BE IMPROPERLY ATTACHED l
TO INTENSIFIED COMPONENTS - BLRD-50-438/84-45, BLRD-50-439/84 FINAL REPORT a
1 The subject deficiency was initially reported to NRC-0IE Inspector I
P. E. Fredrickson on August 9, 1984 in accordance with 10 ClR SO.55(e) as NCR BLN CEB 8411.
Our first interim report was submitted on September 11, 1984.
Enclosed is our final report.
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If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY R.
L. Gridir Manager of Licensing i
Enclosure j
ec:
Mr. James Taylor, Director (Enclosure) j office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 f
Records Center (Enclosure)
Institute of Nuclear Power Operations 1100 circle /5 Parkway, Suite 1500 Atlanta, Georgia 30339 8603200424 860305 PDR ADOCK 05000438 1
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An Equal Opportunity Employer -
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 SUPPORTS MAY BE IMPROPERLY ATTACHED TO INTENSlFIED COMPONENTS BLRD-50-438/84-45 AND BLHD-50 -439/84-41 NCR BLN CEB 8411 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency, Some pipe supports designed by ITT Grinnell, providence, Rhode Island, and located on alternately analyzed safc1y-related systems have incorporated welded pipe attachments on intensified componetits. These components are typically piping elements such as elbows, tees, etc., that are subject to stress intensification. This arrangement violates TVA's alternate analysis criteria and is an unacceptable design configuration.
TVA's Civil Engineering Branch evaluated the generic implications of the identified deficiency and determined that tne scope of the deficiency was limited to the type of Bellefonte supports identified above.
The root cause of this deficiency was TVA's failure to instruct 1TT-Grinnell on the limitations of lug stress allowables for alternate lug designs.
Safe Q_1mplications The use of welded attachments on intensified components could raise the stress intensification f actor of the attached components above acceptable levels.
This could result in failure of the attached components and a loss of function or degradation of performance of affected systems, thus adversely affecting the safe operation of the plant.
Corrective Actions TVA performed a review to identify all ITT Grinnoll supports containing integral pipe attachments made to intensified piping components on alternately analyzed piping systems. The review identified three supporta under the scope of the non-conformance report (NCR),
Supports 1Nd-MPHG-06/3 SH 1 and INB-MPHG-061/ SH 1 were redesigned per engineering change notice (ECU) 3322 to remove the integral attachments (stanchions) from the itensified components (elbows).
Rework of the eupports will be completed no later than six monLhn before unit 1 fuel load.
Support OVK-MPHG-0304 was requalified, using new procedures, to remain as designed.
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t Design criteria N4-50-D717 was modified to incorporate the new procedures used to qualify support OVK-HPHG-0304, per exception request EX-N4 ',0-D/17-1, to allow the use of integral attachments on intensified components in some cases.
To prevent recurrence of this deficiency, the support vendor (ITT Grinnell) was notified to stop designing these types of integral attachments on alternately analyzed piping.
ITT Grinnell's design services contract was substantially complete by the time the disposition was determined. Therefore, TVA determined that there was no reason to allow ITT-Grinnel to incorporate integral attachments to intensified components on their remaining work.
- Also, I
the Bellefonte pipo Support Declgn Manual Section 7.4 was issued (Rev 2) containing the necessary equations to evaluate these specific integral attachments.
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