ML19225B842

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Responds to IE Bulletin 79-04.One 6-inch Velan Check Valve Found in Emergency Condensate Line to Loop 1 Steam Generators.Conservative Seismic Analysis Rate Provides Adequate Safety Margin
ML19225B842
Person / Time
Site: Fort Saint Vrain Xcel Energy icon.png
Issue date: 05/04/1979
From: Justin Fuller
PUBLIC SERVICE CO. OF COLORADO
To: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
P-79098, NUDOCS 7907260166
Download: ML19225B842 (2)


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May 4,1979 Fort St. Vrain Unit No. 1 P-79098 Nuclear Regulatory Commission Region IV .

611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 ATTN: Mr. Karl V. Seyfrit, Director Docket #50-267 REF: IE Bulletin No. 79-04 Gentlemen :

In response to IE Bulletin 79-04, we have conducted an audit of all 3 to 6 inch diameter check valves at Fort St. Vrain. We did find one 6 inch Velan swing check valve in safety related service. Our responses to the action items to be taken by licensees is as follows:

1. One 6" Velan check valve (V2268) was found in 6" L22253-09 which is the Emergency Condensate line to the Loop 1 Steam Generators. This vclve is not in high pressure (>l500 lb) service.
2. The seismic evaluation of this line was accomplished by Atlanta Engineering Company in July of 1976. Atlanta used a valve weight of 800 lbs as compared to the 525 lb. weight listed in the I&E Bulletin. PSC does not know why the higher weight was used, but we believe it to be for conservatism.
3. Not applicable.
4. V2268 is installed in the Emergency Condensate line to the Loop 1 Steam Generators. The weight used for seismic analysis purposes was 800 lbs which makes the analysis more conservative than required in that 450 lbs could have been used for this case. No modifications were or are required to piping systems due to the change in weicht as specified by the manufacturer because Atlanta Engineering used a conservative number (800 lbs) in their original analysis.

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5. The analytical technique used for all 21/2" to 8" piping at Fort St. Vrain is a simplified dynamic analysis method based upon a simph 7 ported beam utilizing computer-based building response spectr. ves.

The conservative weight used for V2268 provides adequate margin for seismic purposes. We consider this response adequate to answer the concerns set forth in IE Bulletin 79-04. If you have any further questions, please contact this office. -

Very truly yours,

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J. K. Full er Vice President Engineering and Planning JrsF/LMM/sch 1

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