ML20213D520
| ML20213D520 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/05/1986 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8611120130 | |
| Download: ML20213D520 (3) | |
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.. TEN'NESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 37401 SN 157B Lookout Place NOV 051986 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 Conunission Washington, D.C. 20555
Dear Mr. Youngblood:
In the Matter of
)
Docket Mos. 50-327 Tennessee Valley Authority
)
50-328 SEQUOYAH NUCLEAR PLANT - INTERIM ACCEPTANCE CRITERIA - CABLR TRAY SUPPORT TVA had previously supplied NRC with interim acceptance criteria for cable tray supports at Sequoyah Nuclear Plant (SQN) units 1 and 2.
Presentation of' this criteria occurred at the NRC offices in Bethesda, Maryland, 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:
1.
August 18, 1986, from R. L. Gridley to B. Youngblood on Interim Acceptance Criteria.
I 2.
September 4, 1986, from R. L. Gridley to B. Youngblood on Additional Technical Information Requests for SQN Interim Acceptance Criteria.
3.
September 24, 1986, from R. L. Gridley to B. Youngblood on Generic Technical Information Requests for SQN Cable Tray Supports.
During the recent NRC audit (Dr. Hans Ashar, NRC Audit Team Leader) conducted at SQN from September 29, 1986 through October 3, 1986, discussions were held on all proposed cable tray support interim acceptance criteria. As a result of these discussions, the following revisions or actions are being implemented j
by TVA.
4 1.
Interim operation Factors of Safety (F.S.) on anchor bolts will be revised to 2.5 (wedge bolts) and 2.8 (self-drilling anchor bolts).
I i
The designs for the supports on the shield wall and the control, j
Auxiliary, Reactor, and Diesel Cenet eor Buildings are being examined to i
j these F.S. (TVA comnitment date is November 15, 1986).
Indications are that no supports will require modification as a result of this criteria revision.
goo i
P
' D An Equal Opportunity Employer l
. Director of Nuclear Reactor Regulation ~
NOV05ENMS Limit allowable shear stresses in structural steel members and bolts to 2.
1.4 x AISC allowables.
A technical evaluation is presently being conducted to assess the need for the usage of this limitation on chear stresses.
TVA will complete this evaluation by December 1, 1986.
Support NK-31 (Auxiliary Building) was observed to be in close proximity
}
3.
to an electrical conduit.
Clearance between the conduit and cable tray support NK-31 will be provided. This field modification will be completed by November 15, 1986.
Support NK-11D at Elevation 764 and Azimuth 2280 in the Reactor 4.
Building Annulus was observed to have a hole in the tube steel member.
l A further walkdown and evaluation of this condition will be completed by i
November 15, 1986. At that time, it will be determined whether modification will be required.
In addition to the above, the following items were discussed during the audit but were not addressed during the exit interview.
One-eighth-inch fillet welds not meeting the requirements of AWS D1.1, 1.
section 10.
A test program is being conducted to define acceptability. A copy of this test program was given to NRC during the audit. The test program and its subsequent evaluation will be completed by November 15, 1986.
Errors discovered in calculations for NK-11D on shield wall.
2.
Spring constants for self-drilling anchor bolts were used instead of 3.
spring constants for wedge bolts for the cable tray supports on the shield wall.
The calculations for the supports on the shield wall are being revised to I
correct these identified conditions. Completion dato is November 15, 1986. No modifications are anticipated as a result of these corrections.
Remaining interim acceptance criteria for SQN cable tray supports systems, which were not discussed in this letter, remain unchanged and will be utilized as prosented originally.
l
, Director of Nuclear Reactor Regulation NOV 0 o EMMS 615/870-6422.
If any additional questions exist, please call M. R. Harding at Very truly yours, TENNESSEE VALLEY AUTHORITY R.
ridley, Director Nuclear Safety and Licensing U.S. Nuclear Regulatory Commission cc:
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 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