ML20247A692
| ML20247A692 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/06/1989 |
| From: | Michael Ray TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-011, IEB-88-11, NUDOCS 8909120190 | |
| Download: ML20247A692 (2) | |
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' TENNESSEE VALLEY ' AUTHORITY-
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P SEP 061988 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk
- Washington, D.C.
20555
' Gentlemen:
In the Matter of
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Docket Nos. 50-327 Tennessee Valley Authority
.)
50-328 SEQUOYAH. NUCLEAR PLANT (SQN) - NRC BULLETIN 88-11, PRESSURIZER SURGE LINE THERMAL STRATIFICATION'
References:
1.
TVA. letter to NRC dated May 26, 1989, "Sequoyah Nuclear Plant (SQN) Units 1 and 2 - NRC Bulletin 88-11, Pressurizer Surge Line Thermal. Stratification"
-2.
Westinghouse Owners Group (HOG) letter to NRC dated June 15, 1989, " Westinghouse Owners Group Transmittal of Topical Report: HCAP-12277 [ Proprietary] and WCAP-12278
[Non-Proprietary], entitled ' Westinghouse Owners Group Bounding Evaluation for Pressurizer Surge Line Thermal Stratification'"
As required by the reporting requirements section of the subject bulletin, this submittal confirms the completion of Action 1.b for SQN.
Reference 1 provided the justification for continued operation of SQN Units 1 and 2 until all actions required by Bulletin 88-11 are complete.. Reference 2 provided a generic bounding' evaluation for H0G.
Before. concluding that SQN's surge lines are bounded by the generic evaluation, two~ stipulations in the report were addressed. 'First, SQN's surge line slope falls outside HOG's current monitoring data base range. The slope at SQN is greater than 1.4 degrees. Since it is greater, however, the effects of stratification will be reduced.
Second, intensified operational basis earthquake (OBE) seismic stresses should be less than 25,000 pounds per square inch (psi). A review of the existing SQN pipe stress calculation indicated that the intensified OBE seismic: stresses are much less than 25,000 psi.
In addition, Table 4-2 of WCAP-12277 was reviewed and is considered correct with respect to SQN Units 1 and 2.
Therefore, it can be concluded that the H0G generic bounding evaluation is applicable to the SON pressurizer surge lines.
Based on the submittal of SQN's justification for continued operation, the submittal of the EJG generic bounding evaluation, and the determination that the generic evaluation is applicable to SQN, TVA considers Action 1.b completed for SQN.
8909120190 890906 PDR ADOCK 05000327 O
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- th An Equal opportunity Employer
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U.S; Nuclear" Regulatory Commission:-
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- No commitments are contained in this sub.iitttal. -Please direct questions U
.concernir.g this issue to' K. S. Whitaker at (615)'843-7748.
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Very truly'yours, TENNESSEE VALLEY AUTHORITY
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\\ f-Manage, Nucle relicensing y
- and Regulatory Affairs
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s._ S. C.'Bleck, Assistant Director M
.for Projects TVA Projects Division-U.S. Nuclear Regulatory Commission One White Flint,-North 11555 Rockville Pike Rockville,' Maryland 20852 Mr. B. A. Wilson, Assistant Director for1 Inspection Programs TVA' Projects Division U.S. Nuclear Regulatory Commission Region-II
-101,Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323
~NRC Resident Inspector-
-Sequoyah Nuclear Plant 7.600 Igou Ferry Road Soddy Daisy, Tennessee 37379
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