ML20209B428
| ML20209B428 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/28/1987 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Youngblood B NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8702040041 | |
| Download: ML20209B428 (5) | |
Text
e o
TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 37401 SN 157B Lookout Place WAN 28 E87 U.S. Nuclear Regulatory Connaission Attn: Document Control Desk Office of Nuclear Reactor Regulation Washington, D.C.
20555 Attention:
Mr. B. J. Youngblood In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 SEQUOYAH NUCLEAR PLANT - DRAFT SAFETY EVALUATION REPORT - INTERIM ACCEPTANCE CRITERIA FOR SMALL BORE PIPINC The draft safety evaluation report on the Sequoyah Nuclear Plant interim acceptance criteria for small bore piping transmitted by B. J. Youngblood to S. A. White on December 19, 1986 has been reviewed by TVA. provides coments in clarification of several items. TVA recomends inclusion of these amendments with the final issuance of this NRC report. responds to the five confirmatory items identified on page 1 of the NRC transmittal.
If you have any questions, please get in touch with M. R. Harding at (615) 870-6422.
Very truly yours, TENNESSEE VALLEY AUTHORITY
(/PrtM
. Cridley, Director Nuclear Safety and Licensing Enclosures cc: See page 2 kf040E00 o*?8sg,
\\
bi I
I An Equal Opportunity Employer
. CAN28 m i
U.S. Nuclear Regulatory Comission cc (Enclosures):
U.S. Nuclear Regulatory Comission Region II Attn:
Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. J. J. Holonich Sequoyah Project Manager U.S. Nuclear Regulatory Comission 7920 Norfolk Avenue Bethesda, Maryland 20814 Mr. G. G. Zech,. Director TVA Projects U.S. Nuclear Regulatory Comission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Sequoyah Resident Inspector Sequoyah Nuclear Plant P.O. Box 2000 Soddy Daisy Tennessee 37319 4
4
ENCLOSURE 1 COMMENTS ON " TRANSMITTAL OF DRAFT SAFETY EVALUATION ON THE INTERIM ACCEPTANCE CRITERIA FOR SMALL BORE PIPING" The following comments are provided as clarification for the subject transmittal:
1.
Section 3.3.1.2.3, fourth paragraph, should be revised as follows to be consistent with SQN-AA-001:
Unit I and unit 2 hanger location isometrics will be collected for piping identified as being required for restart to obtain existing documentation. These hanger location isometrics were developed for 2-inch and smaller piping and included position retention piping.
2.
Section 3.3.1.2.2, " Exception 3 - Evaluation" should be revised as follows to be consistent with program requirements and FSAR commitments:
Evaluation:
In the program implementation, TVA was able to meet ANSI B31.1, 1967 or ASME III. Winter 1972 code allowables with corresponding stress intensification factors (1).
This satisfies the FSAR commitment and this criteria exception was withdrawn. This was acceptable to the staff.
ENCLOSURE 2 The following comments are provided for the " Confirmatory Items" as specified in the NRC SER transmittal letter dated December 19, 1986.
NRC Item No. 1:
TVA will perform a study during the long-term portion of the pipe support reanalysis program to verify that friction loads on supports due to thermal growth of piping at Sequoyah are not significant.
TVA Response:
As part of the Phase II Alternate Analysis Review Program, TVA will show by either unique support evaluation or by a generic study that friction loads on supports due to thermal growth of the pipe are not significant.
NRC Item No. 2:
TVA will also perform during the long-term portion of the program an evaluation which will justify the pipe support deflection criteria used to verify rigidity.
TVA Response:
During the Phase II portion of the Alternate Analysis Review Program, TVA will perform an evaluation to show that the pipe support deflection criteria used to verify support rigidity is adequate to ensure that support flexibility has an insignificant effect on the dynamic response of the piping.
NRC Item No. 3:
TVA will review the results of the Employee Concern Program and the Category I(L) Piping Program to assess any potential impact on the Alternately Analyzed Piping Program.
TVA Response:
TVA personnel involved in the Employee Concern Program have coordinated the items potentially impacting alternate analysis. TVA personnel have reviewed and will continue to review substantiated employee concerns for program impact.
The AA Review Progrs and the Category I(L) Piping Program have been coordinated and discussed between the implementing parties for potential impact during the normal course of performing the respective studies.
In addition, the Category I(L) final report will be reviewed by AA personnel.
I
. 1 l
l NRC Item No. 4:
TVA should confirm that the deadweight effects of line mounted valves with extended operators were properly accounted for in the original analysis and that the walkdown program instituted for the Phase I activity did not identify any lack of support for concentrated deadweights.
TVA Response:
All valves with extended operators that were not supported in both the in-plane and out-of-plane directions were evaluated in Phase I for combined seismic and deadweight loads. Valves that were supported in both the in-plane and out-of-plane directions were identified, walked down, and photographed but were not specifically analyzed for adequate deadweight support. However, it was determined that these valves are acceptably supported for deadweight, usually with supports very close to the valve. No cases of inadequate deadweight support were identified in either the Phase I walkdowns or evaluations.
NRC Item No. 5:
TVA's generic guidelines for assuring adequate seismic supports for pipe mounted valves with extended structures should be revised and made unambiguous regarding the requirement of both vertical and lateral supports (as opposed to requiring supports in two orthogonal planes); also, additional training of inspectors to assure proper consideration of vertical supports should be discussed.
TVA Response:
The influence of supports adjacent to valves will be analytically evaluated simultaneously when the torsional effect requires analytical evaluation.
Even if the valve operator is supported in both the in-plane and out-of-plane directions and an analytical evaluation of torsion is not required, the support configuration of the pipe is still reviewed for specific discrepancies (including support of the total valve weight) which could adversely affect the operability of the system.
If, based on the analysts' judgment, this type of discrepancy is identified, it will be evaluated and documented in the calculation package as part of the l
Phase I program.
(It was expected that this type of discrepancy would be unlikely.
It is noted that the Phase I walkdowns and analyses to date have not identified this specific type of discrepancy related to lack of doadweight support for the concentrated weight of the valve, and none are expected in the future.)
Additional documented training of piping analysts i
reviewing piping configurations has been provided to ensure and reconfirm proper consideration of vertical supports.
l 1
-