ML20213F320
| ML20213F320 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/10/1986 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8611140152 | |
| Download: ML20213F320 (4) | |
Text
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e TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 374o1 SN 157B Lookout Place NOV 101986 Director of Nuclear Reactor Regulation Attention:
Mr. B. Youngblood, Project Director PWR Project Directorate No. 4 Division of Pressurized Water Reactors (PWR)
Licensing A U.S. Nuclear Regulatory Comnission Washington, D.C. 20555
Dear Mr. Youngblood:
In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 SEQUOYAH NUCLEAR PLANT - INTERIM ACCEPTANCE CRITERIA FOR ALTERNATELY ANALYZED PIPINC AND SUPPORTS TVA had previously supplied NRC with interim acceptance criteria for alternately analyzed piping and supports at Sequoyah Nuclear Plant (SQN) units 1 and 2.
Presentation of this criteria occurred at the NRC offices in Bethesda, Maryland, on July 17-18, 1986 as part of the SQN restart program orientation.
Further information was submitted by TVA in response to several technical information requests (TIRs). Reference our transmittals dated August 18, 1986, from me to you on Interim Acceptance Criteria and September 4, 1986 from me to you an Additional Technical Information Requests for SQN Interim Acceptance Criteria.
The Phase I alternately analyzed piping and supports evaluation for SQN unit 2 is essentially complete from an engineering and design standpoint.
Based upon our efforts to date, TVA has determined that it is no longer necessary to utilize several of the original criteria.
Additionally, during the recent NRC audit (Dr. Shou-Nien Hou, NRC Audit Team Leader) conducted at SQN from October 6, to October 10, 1986, it was determined that several criteria were no longer required. Also, one of the remaining criteria required clarification.
The criteria has now been revised to reflect these findings. The enclosed documents interim acceptanco criteria for alternately analyzed piping and supports.
8611140152 861110 DR ADOCK 05000327 PDR
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. Director of Nuclear Reactor Regulation NOV 10 086 Note that these changes were not caused by deficiencies in the original criteria. They are based rather on infrequent or nonusage of the criteria during Phase I and the desire to facilitate a more expeditious NRC review.
Very truly yours, TENNESSEE VALLEY AUTHORITY R. Gridley, Director Nuclear Safety and Licensing Enclosure cc (Enclosure):
U.S. Nuclear Regulatory Commission Region II Attn:
Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. James Taylor, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Carl Stahle Sequoyah Project Manager U.S. Nuclear Regulatory Commission 7920 Norfolk Avenuo Bethesda, Maryland 20814 Mr. G. G. Zech Director, TVA Projects U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 1
o SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 REVISED INTERIM ACCEPTANCE CRITERIA ALTERNATELY ANALYZED PIPING AND SUPPORTS PROGRAM I.
Piping A.
Criteria 1 - Separate evaluation of SAM and Th + TAM to equation (10) limits.
TVA Action: Piping criteria 1 will be modified such that:
- 1. Secondary stresses due to OBE seismic anchor movements (SAM) plus thermal anchor movements (TAM) will be evaluated to long-term allowable or to 1.5 times equation (10) limits for piping with a maximum operating temperature of 2000F or less.
- 2. Secondary stresses due to OBE seismic anchor movements (SAM), plus thermal anchor-movements (TAM),
plus thermal (Th) will be evaluated to long-torn allowable or to 1.5 times equation (10) Limits for piping with a maximum operating temperature exceeding 2000F.
B.
Criteria 2 - Exclusion of OBE loads.
TVA Action:
- 1. Piping criteria 2 is hereby withdrawn.
C.
Criteria 3 - Use of current code allowables with stress intensification factor (1).
t TVA Action:
- 1. Piping criteria 3 is hereby withdrawn.
II. Pipe Supports A.
Criteria 1 - Use allowable stress of 1.7 x AISC allowables for SSE load case only.
TVA Action:
- 1. Pipe support criteria 1 is hereby modifled such that the existing faulted design basis factor (1.6) will be applied to eitner the larger of the upset or faulted support loads. Except as noted, OBE loads will not be considered.
B.
Criteria 2 - Rigidity requirements apply only to first two supports in either direction from rotating equipment.
1 TVA Action:
- 1. Pipo support criteria 2 is hereby withdrawn.
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Criteria 3 - Neglect effect of frictional loads due to thermal expansion.
j TVA Action:
- 1. None required. Pipe support criteria 3 is unchanged.
D.
Criceria 4 - No check on spring force variability and use of 1.7 times normal load rating or NF faulted load rating for faulted evaluations for compo.tont standard supports.
TVA Action:
- 1. The 1.7 times normal load rating in pipe support criteria 4 is hereby withdrawn.
NF load ratings are considered acceptable design practice for SQN although it is not the code of record.
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