ML17265A268
| ML17265A268 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 05/08/1998 |
| From: | Mecredy R ROCHESTER GAS & ELECTRIC CORP. |
| To: | Vissing G NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-M95759, NUDOCS 9805150069 | |
| Download: ML17265A268 (7) | |
Text
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CATEGORY 1-REGULA'1 RY INFORMATION DISTRIBUTI A
SYSTEM (RIDS)
'h ACCESSION NBR:9805150069 DOC.DATE: 98/05/08 NOTARIZED: YES FACIL:50-244 Robert Emmet Ginna Nuclear Plant, Unit 1, Rochester G
AUTH.NAME AUTHOR AFFILIATION MECREDY,R~C.
Rochester Gas
&. Electric Corp.
REC IP. NAME RECIPIENT AFFILIATION VISSING,G.S.
SUBJECT:
Provides response to recpxest for addi info on cooling aspects of spent fuel pool storage rack mod at plant.
DISTRIBUTION CODE'OOID COPIES RECEIVED'LTRj ENCLi SIZE'ITLE:
OR Submittal: General Distribution NOTES:License Exp date in accordance with 10CFR2,2.109(9/19/72)
DOCKET ¹ 05000244 T
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RECIPIENT ID CODE/NAME PD1-1 LA VISSING, G.
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U NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD)
ON EXTENSION 415-2083 TOTAL NUMBER OF COPXES REQUIRED:
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4ND ROCHESTER GASANDE1ECTR1C CORR7RAT1ON
~ 89 FASTAVENUE, ROCHESTER, N. Y 14649-0001 ARFA CODE716 5'-270D ROBERT C. MECREDY Vice President Hvcteor Operotions May 8, 1998 U.S. Nuclear Regulatory Commission Document Control desk Attn:
Guy S. Vissing Project Directorate I-1 Washington, D.C. 20555
Subject:
Response
to Request for Additional Information (RAI) on the Cooling Aspects of the Spent Fuel Pool Storage Rack Modification (TACNo. M95759)
R. E. Ginna Nuclear Power Plant Docket No. 50-244 Ref. (1):
Letter from Guy S. Vissing (NRC) to Robert C. Mecredy (RG&E),
SUBJECT:
REQUEST FOR ADDITIONALINFORMATIONON THE COOLING ASPECTS OF THE SPENT FUEL POOL STORAGE RACK MODIFICATIONATR. E. GINNANUCLEARPOWER PLANT (TACNO. M95759), dated February, 3, 1998
Dear Mr. Vissing:
By Reference 1, the NRC staF requested additional information regarding the Cooling Aspects of the Spent Fuel Pool Storage Rack Modification at the R. E. Ginna Nuclear Power Plant. Attachment 1 ofthis letter provides the requested information.
Very truly yours,
'tt80M50069 980508 J
PDR ADOCK 05000244 P
PDR Attachment Robert C. Mecredy Subscribed and sworn to before me on this 8 day of May, 1998
$ (y~ gg d.u Notary Public MARIE C, VILLENEUVE Notary
- Public, State of New York Monroe County commission Expires october 3I, I9$ cr
XC:
Mr. Guy S. Vissing (Mail Stop 14B2)
Project Directorate I-1 Division ofReactor Projects IJII Office ofNuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King ofPrussia, PA 19406 U.S. NRC Ginna Senior Resident Inspector Mr. Paul D. Eddy State ofNew York Department ofPublic Service 3 Empire State Plaza, Tenth Floor Albany, NY 12223-1350 Mr. F. WilliamValentino, President New York State Energy, Research, and Development Authority Corporate Plaza West 286 Washington Ave. Extension Albany, NY 12203-6399 Res onse to Re uest for Additional Information on the Coolin As ects ofthe S ent Fuel Pool Stora e Rack Modification at R. E. Ginna Nuclear Power Plant NRC Question:
1.0 8%at are the design Seismic Categories for the spent fuel pool (SFP) cooling system Loops 1 and 27
Response
As discussed in the resolution ofSEP Topic IX-1, "Spent Fuel Pool Cooling", letter dated June 9, 1981, the seismic classification of the spent fuel pool cooling systems is as follows:
Spent Fuel Pool Cooling system loop 1 at Ginna Station (original plant design) is not designed to be a seismic system on the spent fuel pool cooling side (it is Seismic Category 1 in terms ofService Water System pressure boundary). It is designed such that any potential failures would not result in decreasing the SFP level below the top ofstored fuel assemblies.
The Spent Fuel Pool Cooling system loop 2 is a complete 100%
capacity system, which is Seismic Category 1.
This system utilizes portions of the existing system piping, which were evaluated and re-supported as necessary to upgrade them to Seismic Category 1.
The Seismic Category 1 spent fuel pool cooling system is a one train system, i.e., one pump and one heat exchanger.
The original (non-seismic) system serves as an installed backup for all situations except a full-core discharge.
In addition to the original system there is a skid mounted heat exchanger capable of removing the decay heat associated with a normal refueling discharge and portable pump capable of replacing the existing spent fuel pool cooling system pump.
The portable system is connected with flexible hoses.
This system (loop 3) is also not Seismic Category 1. Together, loops 1 and 3 are a fullyredundant system in terms ofheat removal capacity to loop 2.
NRC Question:
2.0 The SFP cooling system Loop 2 is designed to operate at Lake Ontario temperature of80'F to maintain the SFP ~ater temperature at or below 150'F with a SFP heat load of 16.0x10 BTUlhr during a planned or unplanned full core offload Loops 1 and 3 are each designed to remove 7.93xl0 B?Vlhrwith a pool temperature of 150'F and Lake Ontario ~ater temperature of 80'F.
Discuss how Loops 1 and 3 can provide 100% backup cooling to Loop 2 during a planned or unplanned fullcore ojf-load
Response
Reference:
Letter, Maier (RGB') to Crutchfield (NRC), dated June 9, 1981, re: Spent Fuel Pool Cooling System; SEP Topic IX-1.
The quoted Loop 1 and 3 heat removal capability of 7.93 MBTU/hr is based on an environmental criterion that the intake to discharge temperature increase not exceed 20'F.
This is an artificial limitsince it incorrectly assumes no other service water is available to reduce the overall intake to discharge temperature rise by dilution.
Ultimately, any concern regarding the ability to cool the SFP would take precedence over this environmental limit.
According to information in Enclosure 2 of the reference above, the true capability of Loops 1 and 3 is 9.3 MBTU/hr each when the SFP cooling water temperature is 150'F, the service water temperature is 80'F, and no limit is placed on the service water discharge temperature.
In this case, the combined heat removal ofLoop 1 and Loop 3 exceeds the requirement of 16.0 MBTU/hr.
Athermal performance test ofthe Loop 1 heat exchanger has been performed.
Results of the test have been used to verify that Loop 1 would be capable ofremoving 9.3 MBTU/hr at the design spent fuel pool temperature of 150'F with 80'F service water.
NRC Question:
3.0 In the event ofafullcore offload, Loop 2 willbe operated alone withLoop I and 3 available for backup cooling GINNA stated that to ensure 100% cooling system backup prior to a full core offload, the skid-mounted loop is placed in position, hoses connected, and leak checked, to operate in parallel with Loop I.
Have these requirements been included in the plant operating procedures or 7RM?
Response
As stated in the November 11, 1997 letter, the requirements for 100% backup will be placed into the TRM and the plant operating procedures.
This change willoccur prior to the next fullcore ofF-load with the new racks installed.
NRC Question:
4.0 In the November II, 1997submittal, GINNAstated that the TRMwillbe modified to ensure 100% backup for all SFP cooling scenarios along with the Lake Ontario water temperature, in-reactor decay time, and associated SFP. heat loads.
However, GINNA only performed analyses to demonstrate the SFP heat loads with various core shutdown times and their corresponding SFP cooling system Loop 2 (primary loop) heat removal capabilityfor three lake temperature, 40
'F, 60'F, and 80
'F. If the lake temperature is in between the above temperatures (i.e. 55 'F), discuss the provisions establishedin the 7RMto require which core decay time, the one corresponding to the higher lake temperature (i.e.
60 'F) or a core decay time based on a new calculation for the lake temperature of55 F.
Response
The expected interpretation for this section of the TRM would be to chose the most conservative lake temperature (i.e. the next higher one) for the applicable scenario.
Since the TRM can be enhanced under 10CFR50.59 RG&E reserves the right to modify the table (i.e. to run a new case) should the need arise.