ML20153H252
| ML20153H252 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 05/05/1988 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8805120190 | |
| Download: ML20153H252 (4) | |
Text
TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 37401 5N 1578 Lookout Place MAY 051988 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Hashington, D.C.
20555 Gentlemen:
In the Matter of
)
Docket Nos. 50-259 Tennessee Valley Authority
)
50-260
)
50-296 BROHNS FERRY NUCLEAR PLANT UNITS 1, 2, AND 3 - NRC INSPECTION REPORT NOS. 50-259/87-20, 50-260/87-20, AND 50-296/87 SUPPLEMENTAL RESPONSE TO DEVIATION This letter provides TVA's supplemental response to the letter from G. G. Zech to S. A. White dated July 8, 1987, which transmitted the subject report.
This report cited TVA with one deviation on the seismic mounting of the main control room panels being inconsistent with the mounting configuration as described in the Final Safety Analysis Report (FSAR) section 7.2.5.2.
The modification work on the panels as elscussed in our most recent letter has been delayed.
TVA has since issued a revision design change to the field and modifications efforts are now underway. provides TVA's original response with a new completion date. A
'ist of commitments is provided in enclosure 2.
If you have any questions, please telephone Clark Madden at (205) 729-2049.
Very truly yours.
TENNESSEE VALLEY AUTHORITY
/
R.
ridley, D rector Nuclear Licensing and Regulatory Affairs Enclosures cc:
See page 2 l l G805120190 880505 PDR ADOCK 05000259 g
DCD An Equal Opportunity Employer
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\\ U.S. Nuclear Regulatory Commission EY 05 W88.
cc (Enclosures):
Mr. K. P. Barr, Acting Assistant Director for Inspection Programs TVA Projects Division U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NH, Suite 2900 Atlanta, Georgia 30323 Mr. G. G. Zech, Assistant Director for Projects TVA Projects Division U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Browns Ferry Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 Athens, Alabama 35611
ENCLOSURE 1 RESPONSE TO NRC INSPECTION REPORT NOS. 50-259/87-20, 50-260/87-20 AND 50-296/87-20 DATED JULY 8, 1987 ITEM Section 7.2.5.2 of the Browns Ferry Plant Final Safety Analysis Report (FSAR) states that the seismic capability of certain safety systems, including control room panels, were demonstrated by vibration testing of the representative assemblies.
The FSAR further states that during testing, the panels were mounted on the shaker table in a manner similar to the service mounting.
Contrary to the above, main control room vertical bench board type control panels and freestanding vertical control panels were found to be mounted in a manner not consistent with the seismic qualification with no similarity analysis to justify the differences.
NEDO-10678, "Seismic Qualification of Class 1 Electric Equipment," documents that the panels were to be floor mounted using 5/8 inch bolts in all mounting holes.
Mechanical layout drawing 47W605-3 shows the as-constructed mounting details of these panels to be "tack welded at intervals to fasten in place."
1.
Corrective Steps Which Have Been Taken and Results Achieved The anchorage details for the control room panels specified on the mechanical layout drawing 47W605-3 issued on May 1, 1968, did not adequately specify the anchorage details to ensure installation similar to that required by the qualification test.
TVA's engineering procedures now require engineering drawings to clearly specify the anchorage requirements which are documented by appropriate engineering evaluations. Also, TVA has since improved the quality inspection program to require a more rigid inspection of the anchorage installation and to provide the proper documentation certifying the proper installation.
TVA has performed a seismic review of the main control room vertical bench board panels and freestanding control panels to determine the appropriate mounting arrangement.
Following this analysis, a design change was issued to reflect the correct anchorage requirements.
2.
Corrective Steps Which Will 8e Taken to Avoid Further Deviation The subject panels will be modified to meet the design requirements.
The design change, together with the modification, will bring the seismic qualification of the subject panels into compliance with FSAR section 7.2.5.2.
i 3.
Date of Full Compliance June 15, 1988 i
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ENCLOSURE 2 RESPONSE TO NRC INSPECTION REPORT NOS. 50-259/87-20, 50-260/87-20 AND 50-296/87-20 DATED JULY 8, 1987 LIST OF COMMITMENTS l
l 1.
A design change has been issued to reflect the correct anchorage requirements.
(complete) i 2.
The modifications of the main control room panels will be complete by June 15, 1988.
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