ML20041A128
| ML20041A128 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 02/10/1982 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| 775, GL-81-14, NUDOCS 8202190140 | |
| Download: ML20041A128 (3) | |
Text
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e TOLEDO
%se EDISON RCHAre P. CROUSE
$w 141912SS5221 Docket No. 50-346 License No. NPF-3 t-Serial No. 775 cb February 10, 1982 8
HSCEIVED s
2 FEBI 879826 h Director of Nuclear Reactor Regulation Wasumm 7 '
mc Attention:
Mr. Darrell G. Eisenhut, Director Division of Licensing ru United States Nuclear Regulatory Commission to
/
Washington, D.C.
20555
Dear Mr. Eisenhut:
NRC Generic Letter 81-14 requested that we review the seismic qualification of the Auxiliary Feedwater System for the Davis-Besse Nuclear Po.ar Station, Unit No. 1.
In our July 15, 1981 letter to you, Serial No. 729, we responded to Generic Letter 81-14.
On January 11, 1982 we received a request, from the Staff, for additional information concerning the seismic qualification of the Auxiliary Feedwater System. Attached is our response to the Staff's request.
t Yours very truly, RPC:CLM cc: NRC Davis-Besse Resident Inspector db b/5 M
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THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO. OHIO 43652 8202190140 820210 PDR ADOCK 05000346 P
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Docket No.'50-346-License No. NPF-3 Serial No.' 775 February 10, 1982 Response to NRC Generic Letter 81-14 Seismic Qualification of the Auxiliary 'Feedwater System Additional Information Request In response to your January 6,1982 request for additional information regarding the seismic qualification of the Auxiliary Feedwater.(AFW)-
. System, we are providing the following answers:
Question 1:
Clarify whether a walkdown was performed for the condensate storage tank (CST) and the portion of the suction side piping from the CST to the
- entrance of the auxiliary. building.
Response 1:
A walkdown was not performed for the CST and the suction piping from the
. CST to the auxiliary building. -The rational behind not walking down this non-seismic portion of the AFW system is that it is not required to supply water to the AFW pump following a seismic event. As explained in our previous response (Serial No. 729) the seismic category I source of water-for the AFW pumps is provided by the service water system (SWS).
If the non-seismic portion of the AFW system should.be damaged during a seismic event, its loss of function will be detecte'd by: low pressure switches located in the seismic category I portion of the piping from the CST (i.e.; inside the auxiliary building). These switches, upon low pressure, will automatically transfer. the suction of L the auxiliary feedwater pumps -
(AFPs) to the SWS. All equipment required to effect the switchover from the CST to the SWS is seismic category I.
We have-not taken credit for the non-seismic portion of the AFW system in our Final Safety Analysis-Report.
Question 2:
Provide information on your scheduled completion date for:
a.
Modifications to the auxiliary feedwater (AFW) pump turbine (AFPT) pipe support.
b.
Reevaluation and any resultant modifications for compliance with IE Bulletin 80-11 for the 29 concrete masonry unit block walls.
Reference'to your. response to IE Bulletin No. 80-11 dated September 29, 1981 where applicable is appropriate. Please indicate walls /subwalls affecting the AFW system.
l' l:
c.
Proposed redesign and rerouting of the AFPT exhaust piping.
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Response 2a:
The design of the modifications to the AFPT pipe supports has been completed and is oeing implemented under facility change request (FCR)79-421. The modifications consist of adding one lateral support, replacing each of two sway struts with a snubber, changing out a spring on each of two supports, resetting a spring on each of two supports, and relocating a stanchion for one support. We presently plan to have these modifications completed by the end of the 1982 refueling outage, scheduled to begin February 26, 1982.
Response 2b:
i The concrete masonry unit (CMU) walls /subwalls which support or are penetrated by AFW system piping and electrical circuits which passed the acceptance criteria established for IE Bulletin No. 80-11 are listed below:
CMU Walls Passing Acceptance Criteria 304D 2317 4607 2
307D 2347 4617 1147 2357 4627 2227*
2367 4687 2237 4587 4757 2247 4597 4816
- Wall 2227 has been added to the list since our previous submittal.
i The wall is penetrated by the AFW pump exhaust piping discussed in response 2c.
r The walls /subwalls which did not meet the acceptance criteria and require modification are listed below:
4 CMU Walls Requiring Modifications 2297 3187 4796 3036 3447 4826 3167 4016 4886 3177 4647 4896 The modifications to walls /subwalls 3447, 4647 and 4826 have been completed.
i The modification to the remaining nine walls /subwalls will be completed in January 1983.or sooner as indicated in our September 29, 1981 letter, Serial No. 1-217.
l Response 2c:
The AFW pump turbine exhaust piping has been redesigned and rerouted to provide separate exhausts from each of the turbines. The new piping is seismic category I and missile protected. This modification was installed i
under FCR 79-421 and is completed.
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