W3P86-1578, Advises That Large Break LOCA ECCS Performance Analysis Will Be Repeated for Upcoming Cycle 2 Fuel Reload.Analysis Will Be Performed Using C-E Evaluation Model,Per Suppl 3 to CENPD-132,w/exception of Blowdown Hydraulics Calculation

Advises That Large Break LOCA ECCS Performance Analysis Will Be Repeated for Upcoming Cycle 2 Fuel Reload.Analysis Will Be Performed Using C-E Evaluation Model,Per Suppl 3 to CENPD-132,w/exception of Blowdown Hydraulics Calculation

ML20211N546
Person / Time
Site:	Waterford
Issue date:	07/01/1986
From:	Cook K LOUISIANA POWER & LIGHT CO.
To:	Knighton G Office of Nuclear Reactor Regulation
References
W3P86-1578, NUDOCS 8607030146
Download: ML20211N546 (2)

Text

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Louisinma / 317BARONNESTREET P O W E FI & L 1 G H T NEW ORLEANS, LOUISIANA 70160 * (504) 595-3100 P. O. BOX 60340

$u $dvsYIU July 1, 1986 W3P86-1578 3-A1.01.04 A4.05 QA Mr. George W. Knighton, Director PWR Project Directorate No. 7 Division of PWR Licensing - B Office of Nuclear Reactor Regulation Washington, D.C. 20555

SUBJECT:

Waterford SES Unit 3 Docket No. 50-382 Cycle 2 LBLOCA Analysis Method

REFERENCE:

1) CENPD-132, Supplement 3-P, " Calculative Methods for the CE Large Break LOCA Evaluation Model for the Analysis of CE and W Designed NSSS", June 1985

2) CE Letter LD-85-050, dated October 30, 1985

3) Enclosure 1-P to LD-81-095, Letter from A.E. Scherer (CE) to J.R. Miller (NRC), December 15, 1981

4) LP&L Letter W3P85-2177, dated July 19, 1985

5) NRC Letter /SER, "Large Break LOCA Reanalysis for Waterford 3", May 6, 1986

Dear Mr. Knighton:

For the upcoming Waterford 3 Cycle 2 fuel reload, the large break LOCA (LBLOCA) ECCS performance analysis will be repeated. This letter specifies the model and assumptions that will used for this analysis.

The LBLOCA analysis will be performed using the June 1985 version of the CE evaluation model as identified in CENPD-132, Supplement 3 (References 1 and

2) except that the blowdown hydraulics calculation (CEFLASH-4A) will not be repeated. Not repeating the blowdown hydraulics calculation is the typical approach for a reload analysis. Thus, the Waterford 3 Cycle 2 LBLOCA analysis will not incorporate the revisions to the CEFLASH-4A numerics and nodalization or the new CEFLASH-4A leak flow model. Reference 1 describes the effect of these model changes on the calculated peak clad temperature (PCT). The numerics and nodalization changes have a negligible impa.:t on the blowdown hydraulics, and therefore do not affect the PCT. The sew leak flow model as calculated in Reference 1 causes a reduction in the 7CT of /

13*F. Thus, if the blowdown hydraulics calculation was repented '.or the Waterford 3 Cycle 2 analysis, the PCT would be about 13*F lower '.han what would be calculated with the existing Waterford 3 blowdown calculation.

0 hh h0 DOh bhbO 382 EQUAL OPPORTUNITY EMPLOYER" b

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W3P86-1578-4 Page 2 July 1, 1986 Furthermore, the LBLOCA analysis will be done assuming the maximum low pressure safety injection (LPSI) flow as verbally requested by NRC. This assumption has a very small adverse effect on containment pressure and may result in a slightly higher PCT than if one LPSI pump were assumed to fail.

The Cycle 2 analysis will continue to use the NUREG 0630 model for clad I

swelling and flow blockage described in Reference 3 and the new axial power shape selection methodology described in Reference 2. Both of these .

methods are consistent with the current Cycle 1 LBLOCA ECCS performance analysis of record; the results of which were submitted in Reference 4 and

approved by the NRC in Reference 5.

j Please contact me or R.J. Murillo if you have any questions.

.t Sincerely,

. K.W. Cook 1

Nuclear Support & Licensing Manager KWC:JBH:ssf l cc: B.W. Churchill, W.M. Stevenson, R.D. Martin, J.H. Wilson, NRC Resident Inspector's Office (Site) i s

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