ML052920822

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Presentation for 09/15/2005 Meeting with R. E. Ginna SBLOCA EPU Results Summary
ML052920822
Person / Time
Site: Ginna Constellation icon.png
Issue date: 09/15/2005
From:
Westinghouse
To:
Office of Nuclear Reactor Regulation
References
TAC MC7382
Download: ML052920822 (11)
v • d • e


Text

Westinghouse A BNFL Group company R. E. Ginna SBLOCA EPU Results Summary Overview

  • Present Overview Of SBLOCA EPU Analysis Results
  • BNFL Side 2 AM W)WOOVMM Side?

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R. E. Ginna SBLOCA EPU Results Summary SBLOCA EPU Analyses Performed With NOTRUMP EM

  • EM Model Consists Of Two Main Codes

+NOTRUMP V39.0

+SBLOCTAV23.0

  • EPU Analysis Results Demonstrate Considerable Margin To 10 CFR 50.46 Criteria

+PCT << 22000F

+Maximum Local Oxidation << 17%

SER Application WCAP-10054-P-A Letter from C 0. Thomas (NRC) to E. P. Rahe Generic Over-all model application (W), 'Acceptance For Referencing Of Licensing Topical Report WCAP 10079(P) "NOTRUMP, A Nodal Transfer Small Break and General Network Code", May, 1985.

WCAP-10079-P-A Letter from C 0. Thomas (NRC) to E. P. Rahe Generic Code proper (W), "Acceptance For Referencing Of Licensing Topical Report WCAP 10054(P) VWestinghouse Small Break ECCS Evaluation Model Using the NOTRUMP Code", May, 1985.

AftF Slide 4 2

NOTRUMP EM WCAPs WCAP #

SER Application WCAP-1 1145-P-A Letter from C. E Rossi (NRC) to L D. Butterfield Generic Forward-fit applicability (WOG), 'Acceptance for Referencing of Licensing Topical Report WCAP-1 1145".

October 1986.

WCAP-10054-P-A, NRC Letter fron R. C Jones (NRC) to N. J.

Generic Addendum. 2, Uparulo (W),"WCAP-10054-P, Addendum 2, Revision 1 Revision 1, 'NOTRUMP SBLOCA Using the COSI COSI Steam Condensation Model, " (TAC NO.

M90784), August 1996.

  • BNFL Side S

SER Application WCAP-1471 0-P-A Letter from T. E. Collins (NRC) to N. J. Liparulo Generic (W), "Acceptance For Referencing Of The Topical Report WCAP-1 471 0(P) "1-D Heat Conduction Model For Annular Pellets" (TAC NO. M96746), March 1998.

  • BNFL 9de 6
  • WKWu=

3

R. E. Ginna SBLOCA EPU Results Summary Analysis Features

  • Only Broken Loop RCP Loop Seal Clearing Allowed For Breaks < 6-inches
  • 10 Minute HHSI Interruption Modeled In Switchover To Recirculation Phase

+Limiting PCT Occurs During RWST Injection Phase

  • PBNFL srkde 7

% Max ZrO2 0.02 0.07 0.02

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R. E. Ginna SBLOCA EPU Results Summary SBLOCA Analysis Results Overview

  • Supplemental Calculations Performed Indicate No Core Uncovery For4-and 6-Inch Breaks
  • BNFL Swie 9

s we R. E. Ginna SBLOCA EPU Results Summary NRC Review Acceptance Issues

  • Only Limited Plots Provided For The 2-Inch Case

+Additional Information Transmitted To NRC

  • No Information Provided Supporting No Core Uncovery Statement For 4-and 6-Inch Breaks

+Additional Details To Be Provided

  • Integer Break Spectrum Approach Is Too Coarse

+Currently Being Evaluated As a Generic Issue

-Westinghouse Letter Being Generated For 9/1 5/05 Transmittal GBNFL Wed1o eWesauie 5

R. E. Ginna SBLOCA EPU Results Summary NRC Acceptance Issues (Continued)

  • Provide An Analysis Of Break Sizes Up To and Including 1.0-ft2

+These Breaks Are Typically Non-Limiting Due To Rapid Depressurization Characteristics

-This is planned to be addressed on a generic basis

  • BNR Sr-deo II W8e"1s6 6

Ginna Station Extended Power Uprate Long-Term Cooling I Boric Acid Precipitation -

Overview Summary

  • Break size and break location scenarios were evaluated with respect to operator actions to prevent boric acid precipitation
  • Boric acid precipitation EOP action times reduced considerably for EPU (from 19 hours2.199074e-4 days <br />0.00528 hours <br />3.141534e-5 weeks <br />7.2295e-6 months <br /> to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />)

BENFL Side I GWet1nuse Ginna Station Extended Power Uprate Post-LOCA Evaluation Methodology Ginna EPU Post-LOCA Methodology

  • Post-LOCA Subcriticality (Sump Boron Concentration)

Calculation of Sump Mixed Mean Boron Concentration Confirmed for each reload as part of Reload Safety Evaluation

  • Boric Acid Precipitation Evaluation Methodology basis In 1975 W/NRC Letter EOP actions to preclude boric acid precipitation Boric calculations similar to CENP-254-P-A (SKBOR code versus BORON code)

All core boiloff calculations use Appendix K decay heat Confirmed that for a large hot leg or cold leg break, UPI flow provides sufficient core cooling flow at early entry Into sump recirculation (24 minutes)

Confirmed that for a large cold leg break, UPI flow provides sufficient core dilution flow to prevent boric acid buildup (hot leg breaks are addressed by re-establishing CL flow at EOP action time)

Confirmed that for a large hot leg break, the re-established cold leg flow rrovides sufficient core dilution flow prior to reaching the boric acid solubility sirnit VEINR Slide 2

L~tesaItinfiie 1

Ginna Station Extended Power Uprate Boric Acid Precipitation Ginna Current Boric Acid Precipitation Methodology

  • High head Si to cold legs, RHR to Upper Plenum Injection (UPI)
  • Boric acid precipitation for 2-loop UPI plants originally addressed in 1975 WINRC letter
  • Ginna Station currently based on 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> boric acid precipitation action time
  • High head SI must be re-established at 19 hours2.199074e-4 days <br />0.00528 hours <br />3.141534e-5 weeks <br />7.2295e-6 months <br /> after event to address hot leg break
  • BM Sie 3 eotsI Ginna Station Extended Power Uprate Boric Acid Precipitation Ginna EPU - LAR Boric Acid Precipitation Methodology Evaluated 3 classes of break sizes for breaks in either hot leg or cold leg
  • Large Breaks RCS quickly depressurizes to UPI cut-in pressure
  • Intermediate Breaks RCS initially stabilizes above UPI cut-in pressure. EOP ES-1.2 is entered to depressurize the system to initiate UPI flow.
  • Small Breaks RCS remains pressurized with high head SI.
  • BNFL Meid
  • Wetotfuse 2

Ginna Station Extended Power Uprate Boric Acid Precipitation Ginna EPU - LAR Boric Acid Precipitation Methodology (cont'd)

Large Breaks Cold leg breaks - UPI provides flushing flow to prevent boric acid buildup Hot leg breaks - boric acid buildup begins with termination of cold leg Si.

Cold leg SI will be re-established before boric acid solubility limit is reached.

Intermediate Breaks Cold leg breaks - boric acid buildup occurs untl UPI flow is established.

UPI provides flushing flow to reverse the rate of boric acid buildup.

Hot leg breaks - boric acid buildup occurs onl after cold leg Sl is terminated. Cold leg Si will be reestablished before boric acid solubility limit Is reached.

Small Breaks EOP ES 1.2 will depressurize and cooldown the reactor under controlled conditions Natural circulation or RHR normal shutdown cooling will prevent boric acid buildup In the core

  • Used 1975 W/NRC Letter methodology as a basis No SI subcooling No Lower plenum mixing No core voiding 1971 ANS finite decay heat
  • Showed that BA concentration is < 23.53 wt. % at 6.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />
  • Boric acid precipitation will not occur f UPI is established within 6.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />
  • If Si to the cold legs is terminated, boric acid precipitation will not occur if Si to cold legs is re-established by 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> BNFL Slide 6

3

Ginna Station Extended Power Uprate Boric Acid Precipitation Ginna EPU NRC Review Acceptance Issues - Boric Acid Precipitation

  • Does the mixing volume vary with time?
  • What constitutes the mixing volume?
  • Was the loop resistance taken into account in calculating the mixing volume?
  • BNFL SUo 7 GWWWM=

Ginna Station Extended Power Uprate Boric Acid Precipitation Ginna EPU NRC Review Acceptance Issues - Boric Acid Precipitation Evaluation - RAls

  • Does the mixing volume vary with time?

No (consistent with 1975 WINRC letter)

  • What constitutes the mixing volume?

Volume inside the core barrel from the top of the lower core plate to the to the bottom of the hot leg...

not including the former regions, displaced volume due to fuel and internal structures, and volume inside the RCCA thimble tubes Lower plenum volume not Included, nor volume in the hot leg piping

  • BNFL AsaeSide 4

Ginna Station Extended Power Uprate Boric Acid Precipitation Ginna EPU NRC Review Acceptance Issues - Boric Acid Precipitation Evaluation - RAls Was the loop resistance taken into account in calculating the mixing volume?

No (consistent with 1975 W/NRC letter)

AlR calculations used atmospheric conditions to maximize boiloff and minimize boric acid solubility limit Effects of increased vessel pressure include;

  • Reduced boiloff (benefit)
  • Reduced voiding (benefit)
  • Higher solubility imrit (benefit)
  • Lower core region liquid density (penalty)
  • Effect on core mbiture level (penalty)

GBNFL S1C9e 5

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