ML20212J263
| ML20212J263 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/14/1987 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Youngblood B NRC OFFICE OF ADMINISTRATION (ADM) |
| Shared Package | |
| ML19292G642 | List: |
| References | |
| NUDOCS 8701280120 | |
| Download: ML20212J263 (7) | |
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e TENNESSEE VALLEY AUTHORITY CHATTANOOGA, TENNESSEE 374ot SN 157B Lookout Place JAN 141987 U.S. Nuclear Regulatory Conunission Attn: Document Control Desk Office of Nuclear Reactor Regulation Washington, D.C.
20555 Attention:
Mr. B. J. Youngblood 1
In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 SEQUOYAH NUCLEAR PLANT - DRAFT SAFETY EVALUATION - INTERIM ACCEPTANCE CRITERIA FOR CABLE TRAY SUPPORTS The draft safety evaluation report on the Sequoyah Nuclear Plant interim acceptance criteria for cable tray supports transmitted by your letter to S. A. White dated December 5,1986 has been reviewed by TVA. is conunents in clarlfication of several items. TVA recommends inclusion of these amendments with the final issuance of this NRC report. is responses to the 10 confirmatory items identified on pages 16 and 17 of the NRC transmittal. As discussed in our telephone conference of December 17, 1986, nine of these issues were identified previously to TVA and have subsequently been resolved. One of the 10 (item 8) was only recently addressed and requires additional confirmatory calculations for closeout. TVA efforts are currently in progress; scheduled completion of this study is January 30, 1987.
Additionally, an open item was identified within the body of this safety evaluation report that did not formally get recorded as a confirmatory item.
TVA acknowledges this concern and will evaluate by January 30, 1987. provides the details of this additional item.
If you have any questions, please call M. R. Harding at 615/870-6422.
Very truly yours, TENNELSEE VALLEY AUTHORITY 8701280120 870114 ADOCK050g7 PDR P
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idley, D rector p,M Nuclear Safe and Licensing oF i
Enclosures I
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Qh pC' An Equal Opportunity Employer
. U.S. Nuclear Regulatory Commission JAN 14 MMil cc (Enclosures):
U.S. Nuclear Regulatory Commission 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 Commission 7920 Norfolk Avenue 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 Sequoyah Resident Inspector Sequoyah Nuclear Plant P.O. Box 2000 Soddy Daisy, Tennessee 37319
ENCLOSURE 1 Comments on " Transmittal o} Draft Safety Evaluation on the Interim Acceptance Criteria for Cable Tray Supports."
The following comments are provided as clarification for the subject transmittal:
1.
Page 3, first paragraph. The last sentence in the paragraph should be revised as follows:
"The following are typical stress ratios (defined as actual stress / normal stress allowable) for cable tray supports in the Auxiliary Building.
These stress ratios are less than the allowable for the SSE loading condition of 1.6 x normal stress allowables."
2.
Page 7, paragraph 3.
The second sentence should be revised as follows:
"If the criteria were met with the reduced weight, the load rating of the tray was reduced and controls were established to prevent addition of weight beyond the reduced capacity." ;
3.
Page 14. Section 5, Baseplate Analysis. The fourth sentence should be revised as follows:
" Trays that were less than full were considered to be full with the exception that some of the supports located on the Steel Containment Vessel were evaluated for actual tray loading."
4.
Page 14, Section 5, Baseplate Analysis. The eighth sentence should be revised as follows:
"The deviation between the center of cable tray's mass points and brace connection points had not been considered by TVA for all supports at the time of staff audit. The supports on the Steel containment Vessel had considered the effects of this eccentricity."
ENCLOSURE 2 The following comments are provided for the " Confirmatory Items" on pages 16 and 17 and are with respect to the numbered items.
NRC item 1:
An unused bolt hole was observed in the main tube member of support MK 11d in the annulus.
It should be verified that this support is adequate.
TVA response Calculations have been developed and documented that demonstrate this support meets design requirements considering the effects of the hole.
NRC item 2:
The1/8-inchfilletweldsuskdthroughoutthesupportstothe shield wall do not satisfy the requirement of AWS Dl.1-85
'Section 10.5.31.
The adequacy of these welds is to:be investigated based on data to be obtained in a scheduled TVA test program.
TVA response Testing and subsequent calculations have been completed and documented that demonstrate the adequacy of the 1/8-inch fillet welds to meet design requirements.
NRC item 3:
The spring constant for self-drilling bolts was used for the BASEPLT II analyses. Most of the bolts are wedge bolts. The BASEPLT II analyses must be revised to reflect the proper bolt type.
TVA response The Baseplate II analysis for the supports on the shield wall has been revised and documented utilizing spring constants for the inplace wedge bolts. These analyses demonstrate that the baseplates and anchor bolts meet design requirements.
NRC item 4:
An error in one of the moment components for support NK lid in the annulus was found.
The evaluation of this support should be revised.
TVA response The Mk lid support on the shield wall has been reanalyzed and documented i
utilizing the correct loads. The reanalysis demonstrates that this support meets all design requirements.
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. l NRC item 5:
An interfac2 between a conduit and support MK 31 in the Auxiliary Building was observed during the audit. TVA must evaluate the significance of this condition.
TVA response TVA evaluated the closeness of a conduit and a Mk 31 support in the Auxiliary Building. As a result of this evaluation, the conduit has been moved such that it will not be in contact with the cable tray support during a seismic event.
NRC item 6:
The evaluation of all " worst / case" supports in the Auxiliary Building must be completed and documented.
TVA response The evaluation of all " worst / case" supports in the Auxiliary Building has been completed and documented.
(A calculation package was developed and issued and is in TVA's records system for each " worst / case" support.)
NRC item 7:
The Interim Acceptance Criteria for anchor bolts should be based on safety factors of 2.5 and 2.8 for the wedge bolts and self-drilling bolts respectively.
TVA should fully document its implementation of these safety factor related criteria.
TVA response The design calculations for the supports that utilized anchor bolts have been evaluated for factors of safety of 2.5 for wedge bolts and 2.8 for self-drilling anchor bolts. The design calculations reflect that all supports meet these factors of safety. These factors of safety have been documented in TVA's anchor bolt Design Standard (DS-C1.7.1).
NRC item 8:
TVA is to develop and submit for staff acceptance calculations which demonstrate that the eccentricity of the cable tray mass will not adversely affect the qualification of supports.
TVA response TVA is developing a study to demonstrate that its support desisns meet design requirements when the effects of the eccentricity of the cable tray mass and I
the center of the support are considered. This study will be completed by January 30, 1987.
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NRC item 9:
TVA is to pro' vide their final evaluation report addressing the design adequacy of cascading cables tested at the Wyle Labs for staff review and acceptance.
TVA response TVA has completed testing and evaluation which demonstrates the adequacy of the cascading cables. The TVA Summary Test Report, TR CEB N-1010, is enclosed for NRC review (enclosure 4).
NRC item 10: TVA will complete all required cable tray supports modifications, as determined by the TVA evaluations against the staff approved Interim Acceptance criteria, prior to restart.
TVA response l'VA will complete all cable tray support modifications as required by evaluation to the Interim Acceptance Criteria before restart of the units.
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ENCLOSURE 3
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s-NONCONFIRMATORY OPEN ISSUE
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In addition, it was noted on page 11 of the Draft Safety Evaluation that cracked concrete was found beneath a baseplate. There was evidence of spalling beneath the Mk 1 baseplate shown as Detail A of Drawing 48W952, Sheets 1 and 2.
This support is being evaluated for this condition and TVA will complete this evaluation by January 30, 1987.
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