ML20006B796

Forwards Summaries of Latest ECCS Evaluation Model Changes

ML20006B796
Person / Time
Site:	Mcguire, Catawba, McGuire, 05000000
Issue date:	01/29/1990
From:	Tucker H DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9002050362
Download: ML20006B796 (4)

Text

,

. Duke her Conrany flu & M a PO Bat 33998 lice hesident Charlotte, NC 2R 42 Nuclear Pwduction (Tl4)3t34531 DUKEPOWER January 29, 1990 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C.: 20555

~

Subject:

McGuire Nuclear Station Docket'Nos.. 50-369, 50-370 Catawba Nuclear Station.

Docket Nos. 50-413. 50-414 10CFR 50.46 (a)(3)(li)

ECCS Evaluation Model Changes

References:

1) DAP-89-661, " Duke Power Company McGuire Units 1 and 2 Reporting of ECCS Evaluation Model Revisions "

S. S. Kilborn (Westinghouse) to R. C. Futre11'(Duke) -

December 15, 1989

2) DCP-89-681, " Duke Power Company Catawba Units 1 and 2 Reporting of ECCS Evaluation Model. Revisions "'

S. S. Kilborn (Westinghouse) to R. C. Futrell (Duke),

December 15, 1989

3) NS-NRC-89-3463, "10 CFR 50.46 Annual Notification for 1989 of Modifications in the Westinghouse ECCS Evaluation.

Models," W. J. Johnson (Westinghouse) to T. E. Murley (NRC), September 5, 1989

4) NS-NRC-89-3464, " Correction of Errors and Modifications to the NOTRUMP code in the Westinghouse Small Break-LOCA ECCS Evaluation Model Which Are Potentially Significant "

W. J. Johnson-(Westinghouse) to T. E. Murley-(NRC),

September 5, 1989 Dear Sirst Attached are summaries of the latest ECCS-evaluation model changes for .

McGuire and Catawba which are submitted in accordance with the' requirements; of 10CFR 50.46 (a)(3)(ii). These summarize changes described by Westinghouse.in References 1 and 2. Further.information has been previously-

-provided to your office per' Reference 3 and 4..

1 1

s

, 9002050362 900129 m U

PDR ADOCK 05000369 f , pOh

?- 'I

., PDC .d h 3 g (_ ., , q

,h~

a e' ..

.U. S.-Nuclear R:gulctory Commic2irn e Jinuary 29,'1990 Page 2  ;

I FSAR updates for both stations will note the potentially increased peak clad temperatures resulting from these changes. ] +

Very truly yours, i f

C 44 / VM Hal B. Tucker  :!

j LTB28/lcs j Attachment I

cci Mr. S. D..Ebneter Regional Administrator, RII e U. S. Nuclear Regulatory Commission i 101 Marietta Street, NW, Suite 2900 i  ;

Atlanta, Georgia. 30323 l Mr. D. S. Hood r Office of Nuclear Reactor Regulation }

U. S. Nuclear Regulatory Commission l Washington, D.C. 20555 ,

r Dr. K. Jabbour i u

Office of Nuclear Reactor Regulation .

l U. S. Nuclear Regulatory Commission- .;

. Washington, D.C. 20555 .ir Mr. P. K. VanDoorn Sr. NRC Resident Inspector.  !

McGuire Nuclear Station- 1

.i Mr. W. 'i . Orders  !

Sr. NRC Resident Inspector Catawba Nuclear Station.

]

,,- j I

.i

,q 1 .

l  ;

i

,5' v . ., -

y q' t o

g s

(/j' '4.

7, Attachment 1 1989 McGuire ECCS Evaluation Model Change Summary I. ! s .1ARGE BREAK LOCA EVALUATION MODEL' t- . . .

A.. Several improvements were made to the BASH computer code to treat-special' analysis cases related to the tracking of fluid. Interfaces.

No,increaseinpeakcladgemperature.(PCT)isexpectedforthe majority of cases, but 30 F is' assumed as n' conservative estimate.

II. SMALL BREAK LOCA EVALUATION MODEL A. Modification'to preclude changing the region' designation.for a node 1 '

.:in a stack which does not contain the mixture-vapor interface (small PCT decrease).

B. Correction of typographical errors <in the equations which calculate. '

the heat transfer rate derivations for' natural convection conditions for ghe upper region of interior fluid nodes (PCT increase of uplto :

36.8 F).

C. Correction of-an error in t.he implementation of-the equation describing-the calculation of the flow link friction parameter for-single phase flow in a non-critical flow link-(PCT decrease).-

D. Implementation of new FORTRAN compiler which tregts numerical =

precision differently (PCT increase of up to 4.8 F).

E. Correction of errors in. implementing equations' describing the partial derivatives of an interpolation parameter.with respect to pressure and' specific enthalpy;(PCT decrease). <

r F. Modifications to the small break ECCS Evaluation.Model version'of; LOCTA-IV'(very small PCT decrease).4 III. CHANGES IN THE APPLICATION'OF EVALUATION MODELS A,

Increaseinassumedgteamgeneratortube' plugging...fromSito64(PCT increase of up to 10.Fffor11arge break lOCA).'-

g

, t.: , .

i , ,

l i g

g

'r i

. Y

g Al  ?

q ::;. ,,,

k I' I

• k _5^:5 , .. ,:. x t > .)L

• b j

. t g_:3 f { , 3

,'I~ g;.

j qUfa' M.

, . . , p ,

j ,

g- .e yl y- > s V (.; hk {p' J'3 % ;M. '

V,}g}[ L1 , n <' ,

.Q

-

3

I (Q,, 4 i-tr ,

n .,.. a, p* ..

j Attachment 2 --

1989 Catawba ECCS Evaluation Model Change Summary 'l i

l

-t I. -1ARGE BREAK LOCA EVALUATION MODEL ,

~

Several improvements were made to the BASH computer code to treat A.

, special analysis cases related to.the tracking of fluid interfaces. i

? Noincreaseinpeakcladgemperature.(PCT)isexpectedforthe majority of cases, but 10 F is assumed as a conservative estimate.

II. SMALL BREAK LOCA EVALUATION MODEL

~

' A. Modification to preclude changing the region. designation for a' node.

~

in a stack which.does not contain the mixture-vapor interface (small- t PCT decrease). .

B .' Correction of typographical errors'in the. equations which calculate the heat transfer rate derivations-for natural-convection conditions. ,

?

for ghe upper legion of interior fluid' nodes- (PCT, increase of up to  ;

36.0 F).  ;

C. Correction of an error in the implementation of the. equation' .

l; describing the calculation of the flow: link friction parameter for.  ;

single phase flow in a non-critical flow link (PCT decrease).- .i

.q D. Implementation of new FORTRAN compiler which tregts numerical  ;;

precision differently _(PCT increase of up to 4.8 F).

~

, 'j E. Modifications to the small break ECCS Evaluation'Model; version of LOCTA-IV (very small PCT decrease).-

'f a

s -

i

'?

I

[

s

'?

1 l' ,

-l S

' g '}

It

, g, , .