ML20204J352

Requests That Encl Document Be Entered in NRC Pdr.Documents Consists of Composite of Attachments to NSP Ltrs, & 990308 & Should Be Linked to Both Ltr

ML20204J352
Person / Time
Site:	Prairie Island
Issue date:	03/26/1999
From:	Kim T NRC (Affiliation Not Assigned)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9903300071
Download: ML20204J352 (5)

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March 26,1999 l.

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l MEMORANDUM TO: Documerf Control Desk FROM: Tae Kim, Senior Project Manager Project Directorate ill-1.

Division of Licensing Project Management Office of Nuclear Reactor Regulation

SUBJECT:

RELEASE OF DOCUMENT TO NRC PUBLIC DOCUMENT ROOM Please enter the attached document irito the NRC PDR. The attached document is a

composite of the attachments to Northern States Power Company (NSP) letters dated September 8,1998 (ACN 9809140199) and March 8,1999 (ACN 9903180338) and should be linked to both letters. The document was initially withheld from public disciosure because it was inadvertently marked " Westinghouse Proprietary." The March 8,1999, letter from NSP removed the proprietary marking.

If you have any questions, please call Carole Jamerson on 415-1337.

Attachment:

As stated Distribution:

Docket File (50-282,50-306)

PUBLIC PD31 r/f

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Attachment:

As stated DOCUMENT NAME: G:\PD3-1\WPDOCS\ PRAIRIE \PR990308.WPD h

To rece6ve a copr of this document. bdicate h me bor C= Copy Wo attachment / enclosure E= Copy weih attachment / enclosure N = No copy OFFICE LA:PD31 15 PM:PD31 E NAME CJamersorOkTJKimk DATE 3/ d(e /99[ 3/24[99 OFFICIAL RECORD COPY l '

9903300071 990326 PDR ADOCK 05000282 P ppR l

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Northern states Power company Docket Nos. 50-282, 50-306

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Prairie Island Nuclear Generating Plant i Sept 8, 1998 & March 8, 1999 l l

Report of Corrections to ECCS-Evaluation Models (Attachment) {

l PLANT-SPECIFIC ASSESSMENT TO REBASELINE LIMITING CASE l

A plant-specific calculation was performed on the Prairie Island plant to rebaseline the limiting break size calculation. The combined effects of all of the code changes since the analysis of record are contained in this calculation. The effect of code modifications were originally generically determined using a method consistent with the 10 CFR 50.46 requirements. The effect of the plant-specific I calculation is included on the Margin Utilization Sheets for Prairie Island Units 1 and 2. This is an  :

assessment made to comply with NSP's request, and could change pending Westinghouse's ongoing ]

investigations.  !

I EFFECT OF SIIN BROKEN LOOP The effect of modeling safety injection in the broken loop is discussed in detail in NSAL-93-018. The effect was generically determined to be a 150'F penalty, which was included in the 1993 Annua! 10 CFR 50.46 Notification and Reporting Information. A plant-specific assessment of modeling safety injection in the broken loop was performed on Prairie Island, and the revised effect is reflected on the Margin Utilization Sheets for Prairie Island Units 1 and 2. Note that in order to quan;ify the effects of SI in the broken loop, the break was also moved to a less conservative location, from the bottom of the cold leg to the cold leg centerline in order to establish ECCS spill to containment, consistent with WCAP-10054, Addendum 2, Revision 1. The SI line actually penetrates the cold leg above the centerline, so the revised break location does remain conservative.

EFFECT OF IMPROVED CONDENSATION MODEL The effect of the COSI condensation model is discussed in detail in NSAL-93-018. The effect was generically determined to be a 150 F benefit, which was included in the 1993 Annual 10 CFR 50.46 Notification and Reporting Information. A plant-specific assessment of modeling the COSI condensation model was performed on Prairie Island, and the revised effect is reflected on the Margin Utilization Sheets for Prairie Island Units 1 and 2.

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. Small 'dreak Peak Clad Tempe:3hne Margin Utillatian Revision Date: 09/08/98 Plant Name: Prairie Island Units 1 and 2 Eval. Model: NOTRUMP Utility Name: Northern States Fower Fuel: 14x14 OPA ZIlUJD(TM)

FQ=2.80 FaH=2.00 SGTP=25%

Reference

• Clad Temperature Notes A. ANALYSIS OF RECORD C//93) 1 PCr= 1195 'F 1 B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS 2 APCT= -19 *F C.10 CPR 50.59 SAFETY EVALUATIONS Table A APCr= 3 *F D.1998 to CPR 50.46 MODEL ASSESSMENTS (Permanent .t " of PCT Mardn)

1. Effect of SIin Broka Loop APCT= 21 *F 2,3

2. Effect ofImproved ConA== Hon Modd . APCT= 4 'F 2

3. Plant-Specific h-r to R-6.1m-Ilmiting Case APCT= 259 'F 4,5 E. TEMPORARY ECCS MODELISSUES**

1. None APCr= 0 *F F. OTHER MARGIN ALLOCA*IIONS

1. None APCT= 0 *F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 1463 'F

• References for the Peak Clad Temperature Margin Utilization summary can be found in Tab:e B.

• • It is recommended that those temporary PCT allocations which address currect IDCA model issues not be considered with respect to 10 CFR 50.46 reporting requircraents.

Notes:

1. Includes ancular pc.h.cvaluation.

2. Plant-specific assessments for the effects that wem originally estimated for these two items in Reference 6.

3. Also includes the effect of relocation of the break location to the midplane of the cold leg (see WCAP-10054-P-A,

. Addendum 2, Revidon 1). 'Ite original estimatt did not include this effect.

4. Val'as requested by customer pending completion of Westinghouse investigation.

5. At the request of N3P. this line item was included under Seedon D, and represents a deviation from Westinghouac's normal approach, a

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. j-Large Break Peak Clad Temperature Margin Utilizamen Raision Date: 09/08/95 Plant Name: PralrieIsland Units 1 and 2 Eval. Model: SECY UPI Udlity Name: Northern States Power Fuel: 14x14 OPA ZIRLO(TM) l FQ =2.40 PAH = 1.77 SGl?-15%

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l Refwenoc Clad Temaperstne Notes l

A. ANALYSIS OF RECORD (3/95) 3,4 PCT = 2180 *F 1 I

3. PRIOR PERMANENT ECCS MODEL ASSESSMEN'I5 2 APCr= -196 *P C.10 CPR 50.59 SAFETY EVALUATIONS - Table A APCT= 0 *F D.199810 CPR 50. 4 MODEL ASSESSMPRIE l 9 " A-aat of PCT Margin) 1

1. Nome APCT= 0 *P E. TEMPORARY ECCS MODELISSUES**

1. None APCT= 0 *F P. OTHERMARGIN ALLOCATIONS '

1. None APCT= 0 *F LICENSING BASIS PCT + MARGIN ALI4 CATIONS PCT = 1984 *F

• References for the Peak Clad Temperature Margin Utilizadon summaries can be found in Table B.

• • It is recommended that thcee tamporary PCT allocations wnich addnas current IDCA model Issues not be considered with respect to 10 CFR 50.46 reporting requirements.

Notes:

1. P-bar-HA increased from 1.57 to 1.59 l

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4 Table A - 10 CFR 50.59 Safety Evaluations ]

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. Revimen rw 09ms/9s  !

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Plaat Name: PrairieIsland Units 1 and 2 Udlity Neins: Northern Semise Power I Rdarence Clad Tempersturu Notes

. L SMALL BREAK ECCS SAFETY EVALUA110NS A. MFWTemperature 5 APCT= 3 *F TOTAL le CFR 50.59 SMALL BREAK ANMENTS PCT = 3 *F .!

i U LARGE BREAK ECCS SAP 1iTY EVALUNt10NS j A. None ' APCT= 0 *F I

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TOTAL 10 CFR 50.59 LARGE BREAK ASSESSMENTS PCT = 0 *F j Notes: '

None ,

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l Table B - References

1. NSP-93 521, ' Northern Power Company Prairi. Island Units 1 and 2 Small Bnsk Lons-of-coolant Accident Final Engineering keport for the ZIRIJXIM) Puel Upgrade,' July 30,1993. {!

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2. NSP-97 201, ' Northern Power Compmy Prairie Island Units 1 and 210 CPR 50.46 Annual Notification and '!

I Reposting,' April 17, 1997.

3. 95NS40021, " Updated UPI LBLOCA," March 24,1995.

4. WCAP-13919, Addendum 1, ' Prairie Island Units 1 and 2 WCO'JRAflRAC Best Estimate UPI Large Break LOCA Analysis Engineerms Report Addendum 1: Updated Results,' December 1996.

5. NSP-97-504, ' Northern States Power Company Prairie Islant Units 1 and 2 Pecdwater Temperaturw Increase /

Nd RCS Heat Input Addition Program, Transmittal of Final Safety Evaluasion," September 23,1997.

6. NSAlc93 018N, " Safety injection (SI) la the Broken imp,' September 21,1993.

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• • TOTAL PAGE.08 **