ML20217C024
| ML20217C024 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 09/25/1997 |
| From: | Dennis Morey SOUTHERN NUCLEAR OPERATING CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20217C031 | List: |
| References | |
| NUDOCS 9710010124 | |
| Download: ML20217C024 (5) | |
Text
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Dave Morey Southern Nuclear We hesident Operaung Company larley hoject P0.im t?95 Bimnngham. Atat:ama 35201 Tel 705 932 5131 i
t Septetaber 25, 199 SOUTHERN COMPANY Energy to Sers e )our World" Docket Nos:
50 341t 50 364 U. S Nuclear Regulatory Commission l
Attn:
Document Control Desk Washington, DC 20555 Joseph hl. Farley Nuclear Plant Credit for lletenfutJpent Fuel Storage.JMLEnpsnEc1 Ladies and C. utlemen:
1his letter is in : sponse to the Reqqcst for Additional Information (RAI) datal August ?'1,1997, cencerning our st amittat dated June 30,1997, titled " Joseph hl. Farley Nuclear Plant Technical Specifications Chtnge Request Credit for lloron for Spent Fus t Storage " Attachment I provides the Southern Nuclear Operating Company (SNC) responsu to the RAI. Attaclunent 2 contains revised Technical Specifications bases pages, if you have any questions, please advise.
Respectfully submitted, f ]h&
Dave htorey EWC:maf ra'ifbl0. doc Attachments I
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Sworn to and subscribed befor me thiso/ yo h 1997
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1 w /, M7 hty Commission thpires:/ du s
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htr. L. A. Rey s, Region 11 Administrator htr. J. l. Zimmerman, NRR Project hianager htr. T. hl. Ross, Plant Sr. Resident inspector Dr. D. E. Williamson, State Department of Public Ilealth 9710010124 970925 llllllll@ lill 11ll1111lll11 lll! 11 PDR ADOCK 05000348 iqim[im Illi, liglilil,till lui il e
ATTACilMENT I SNC RESPONSE TO NRC REOUEST FOR ADDITIONAL INFORMATION RELATED TO CREDIT FOR BORON FOR SfENT FUEL STORAGE IQSEPil M. FARLEY NUCLEAR PLANT. UNITS 1 AND 2 a
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$NC RESPONSE TO NRC AEOUEST FOR ADDITIONALINFORMATION BELATED TQ_ CREDIT FOR BORON FOR SPENT FUliL STORAGE JOSEPH M. FARLEY_ NUCLEAR PLANT. UNITS 1 AND 2 1.
Question:
The criticality analysis includes a 3 out of 4 checkerboard conGguration (Section 4.0). Why is this not included in the proposed new Technical Specifications (TS)?
Response
When the analysis was begun, it was thought that the "3-out of-4" configuration may be needed in addition to the other analyzed configurations to meet future FNP fuel storage requirements. It was determined that the oaer configurations that arc included in the TS change are sufficient to provide for anticipated fuel storage needs at Faricy Nuclear Plant (FNP). Since the "3-ou of-4" configuration was not needed, it was decided to leave it out of the TS for simplicity.
2.
Questiont The new fuel pit storage racks have been previously shown to meet the k n less than or equal to O 95 u.1 der fully nooded condillons. Why is this criterion not included in TS 5.6.1.27
Response
Technical issues involving the new fuel storage racks were not considered since the submitted TS amendment involves no change to the design or operation of the new fuel storage racks. The new fuel-pit storage racks have been shown to meet k,a less than or caual to 0.95 under fully flooded conditions, and to meet k.a less than or equal to 0 98 assuming aqueous foam moderation. Current FNP TS describe only the aqucous foam moderation criteria because it results in the higher km. To be consistent with improved Technict.1 Specifications (ITS), SNC plans to include the fully flooded criteria when the FNP ITS is submitted per SNC docketed letter dated July 1,1997.
3.
Question:
Since the revised criticality analysis did not take credit for the Boranes panels, should this fact be included in the Hases 3/4.7.13 and 3/4.7.14 discussion?
Response
SNC agrees that this fact should be added to the Bases. Attached are changes to Unit i Bases 3/4.7.13 & 3/4.7.14 and Unit 2 Dases 3/4.7.14 & 3/4.7.15 specifying that no credit is taken for the Doraficx panels.
4 his change does not result in a change to the conclusions of the r,igrdricant hazards evaluation submitted s ith the proposed amendment, therefore, no additional evaluation is included with this bases changs 4.
Question:
Section 6.3.2 of the criticality analysis states that the 50 ppm required for Integral Fuel Hurnable Absorber (IFBA) credit is bounded by the 150 ppm required for burnup credit in the burned / fresh checkerboard configuration and, therefore, the total boron credit required remains at 350 ppm. Ilowever,if both IFBA credit for the high enriched assembly and burnup credit for the low enriched assemblies are taken, the total required soluble ooron credit would be 400 ppm (200+150+50). Please esplain.
Response
Fifly ppm is added to the pool boron concentrat:on to compensate for unertainties in IFBA concentrations. Credit for IFBA is taken only for "high enrichment" assemblies of the burned / fresh configuration. One hundred fifty ppm is added for uncertainty for burnup in the burned / fresh configuration. Humup credit is applied only to the " low enrichment" assemblies. No assemblies are given both IFBA and burnup credit, therefore, the uncertainties are not summed and the most limiting of the two is the 150 ppm applied for burnup uncertainty. Ac total uncertainty is therefore 350 ppm (200+150).
5.
Question:
Since the most reactive point in life considers both IFHA and fuel depletion, please explain what is meant by the statement in Section 6.3.3 that the fuel assembly is modeled at its most reactive point in life and no credit is taken for any burnable absorbers in the assemb!y in developing the k model.
Response
%c k. is defined for an infinite array of assemblics without any IFBA rods and at the maximum enrichment of the fresh fuel that can be stored without any bumable absorbers (3.9 w/o). His analysis determines the maximum k. TS limit under cold reactot geometry needed to keep the fuel rack reactivity below the 0.95 design limit. For the purposes of the analysis the most reactive time in assembly life is zero bumup with no IFDA installed. His assumed condition results in the highest k.
that could actually occt.r at any time in the assembly life. %crefore, the assembly is modeled at conditions that are bounding since no credit is taken for burnable absorbers and the maximum enrichment is assumed.
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ATTACllMENT 2 FARLEY NUCLEAR PLANT TECilNICAL SPECIFICATIONS CilANGE REQUEST GEpjT FOR BORON FOR SPENT FUEL STORAGE RA RESPONSE FNP Unit i Technical Specifications Changed Prses Ust FNP Unit 1 Technical Specifications Typ<xt Pages FNP Unit i Technical Speci0 cations Marked-up Pages FNP Unit 2 Technical Specifications Changed Pages List FNP Unit 2 Techn.:al Specifications Typed Pages FNP Unit 2 Technical Specifications Marked-up Pages 4
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