ML19282A763
| ML19282A763 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 03/02/1979 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 061A, 61A, NUDOCS 7903060465 | |
| Download: ML19282A763 (2) | |
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1 N epCO VIRGINI A ELECTRIC AND POWER COMP ANY, RICHMOND, VIRGINI A 23261 March 2, 1979 Mr. -James P. O'Reilly. Director
Serial No. 061A
-.0ffice Inspection & Enforcement PSESC/JMD:adw:mc.
U. S. Nuclear Regulatory Comission
- Aegion II Docket No. 50-339.
'101 Marietta Street, Suite'3100 Atlanta, Georgia 30303
Dear,
Mr. 0'Reilly:
_Undertheprovisionsof10CFR50.55(e),NRCRegionIIwasnotifiedon
~
January 31. 1979 concerning the lack of seismic supports and missle pro-i tection for.the' Unit 2 diesel generator mufflers.
Following a field in-spection of the exhaust mufflers our personnel determined the mufflers-seismic support plates-had been omitted..
Following an engineering evaluation in conjunction with the diesel gen-erator manufacturers muffler loading recommendations, it has been detemined that subjecting the mufflers to seismic or tornado wind loadings may over-stress the roof support attachments.
In addition, should a failure of a muffler or the associated exhaust piping located on the roof, cause a block-i age of the exhaust gases, the diesels operation-could be adversely affected.
Corrective actions for cach diesel have been initiated to modify the j
current exhaust systems. Each exhaust line will be modified to provide a parallel exhaust path, originating within the service building structure.
3 Each diesel's exhaust will be aligned to discharge from a seismically supported unauffled exhaust line in addition' to the existing muffled exhaust arrangement.. - A flexible self-detaching fabric connector will be incorp-orated in the exposed portion of each muffled exhaust line, downstream of i
each exhaust line service building penetration. The flexible connectors will prevent potentially damaging muffled exhaust line movements, introduced from external sources, from being transmitted back to the associated unauffled ex-
. haust line within the building structure. Operating the diesels in this ven-dor approved manner presents no operational or reliability problems. Existing roof structures will be modified to provide the necessary seismic and missle
'i protection for the new unauffled exhaust piping.
In order to reduce the low-pitch operating drone of.the diesels during periodic operations, the unmuffled exhaust lines will be secured via manually operated high temperature valves.
. The modifications.to the' Unit 2 diesel exhaust lines will be completed prior to fuel load. Pending the receipt of the isolation vsives, the~ un-muffled branches will. be blanked off. Should delivery of the isolation valves l
be delayed beyond fuel load, portions of.the exposed muffled exhaust pipes, downstream of-the building penetrations, will be removed providing temporary
. unmuffled exhaust paths. Eliminating portions of the exhaust system, exposed to possible damage and/or occulsion, ensures the diesels availability for j
service..
i 79030604(of g
L- _ ---
v.
1
. Mr. James P. O'Reilly, Director
- 2-4 v
' This submitta1Lshall be considered'a final report under the provisions of 10CFR50.55(e).. Should you require further information, pleasa. contact this
-office.
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[ Sam C. Br)own, Jr.%#
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Senior Vice President Poymr Station Engineering ~and C nstruction j
- cc: ffr. -John G. Davis.. Acting Director Office of Inspection & Enforcement Mr. Harold R. Denton, Director-Office of Nuclear Reactor. Regulation 4
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