ML20235C736

Informs That NRC Completed Review of Three Changes to GE Analytical Model for LOCA (NEDE-20566-P) & Determined That Changes Acceptable.Three Changes Listed.Safety Evaluation Encl

ML20235C736
Person / Time
Issue date:	04/12/1977
From:	Goller K Office of Nuclear Reactor Regulation
To:	Sherwood G GENERAL ELECTRIC CO.
Shared Package
ML20234E460	List: ML20234E457 ML20234E570 ML20234E632 ML20234E685 ML20234E736 ML20234E798 ML20235B143 ML20235C320 ML20235C384 ML20235C401 ML20235C457 ML20235C519 ML20235C563 ML20235C636 ML20235C736 ML20235C753 ML20235C830 ML20235C896 ML20235C907 ML20235C912 ML20235C926 ML20235C931 ML20235C941 ML20235C944 ML20235D492 ML20235D516 ML20235D643 ML20235D684 ML20235D736 ML20235D963 ML20235E005 ML20235E021 ML20235E056 ML20235E199 ML20235E244 ML20235E571 ML20235E583 ML20235E615 ML20235E659 ML20235E682 ML20235E732 ML20235E841 ML20235E873 ML20235E912 ML20235E949 ML20235E964 ML20235F083 ML20235F117 ML20235F637 ML20244B882 ... further results
References
FOIA-87-40 NUDOCS 8707090521
Download: ML20235C736 (2)

Text

.

b .r W Q[f M  % UNITED STATES

$g y

3

=

g a

NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20665 v j -

h]

g***l*j/

April 12, 1977 RECEIVED

/h E MSJO ACRS MEMBERS General Electric Company " -

• t ATTN: Mr. Glen C. Sherwood - ' 4 .

Manager, Safety and - -

Licensing 175 Curtner Avenue San Jose, California 95114 Gentlemen:

The NRC staff has completed its review of three changes to the General Electric Company Analytical Model for Loss-of-Coolant Analyses (NEDE-20566-P) and has determined that the changes are acceptable. The changes are as follows:

1. The CHASTE computer code, used to calculate fuel rod thermal behavior during a loss-of-coolant accident, has been modified by improving the conduction equation and the method of nodaliza-tion, and by determining the radiation grey body factors more accurately. The modified version of the code approved by the staff is identified as CHASTE 05.

2. The REFLOOD computer code, used to calculate vessel refilling and core reflooding during the ECCS injection phase of.a LOCA, has been modified to account for the fuel bundle pressure drop that occurs during counter current flow. The modified version of the code approved by the staff is identified as REFLOOD 05.

Earlier versions of the REFLOOD code are no longer approved for licensing calculations.

3. The method for performing reflood calculations on cores that contain fuel assemblies with holes drilled in the lower tie plates has been modified to accomodate the special case of partially drilled cores. The method of reflood calculations approved by the staff is contained in NEDE-21156 " Supplemental Information for Plant Modification to Eliminate In-Core Vibration" dated January 1976 and Supplements thereto dated y September 1976 and January 1977. hg

?

y @ I V, j' ACRSOFFICECDPY J Jo No: Remove rom ACRS? ice 8707090521 870623 PDR FOIA THOMAS 87-40 PDR l

i

.,g.

. i l

General Electric Company April 12,1977 We have conclude'd that the abovd changes to the General Eldctric Evaluation model are acceptable and that the revised model may be '

used by licensees in carrying out the ECCS performance re-evaluations ordered by the Commission on March 11, 1977. Copies of this letter are being forwarded to affected licensees for their information.

Sincerely, ,

1 S

Karl R. Goller, Assistant Director for Operating Reactors Division of Operating Reactors

Enclosure:

Safety Evaluation Report i O

i q

1 1

1 l

)

f i

1

.1 l-i l

1 l

J