ML20147H692

Advises That Info Received from GE Re Transient Analysis Methods.Odyn Code Prepared by GE & Will Be Reviewed by Dec 1978

ML20147H692
Person / Time
Site:	Black Fox
Issue date:	10/17/1978
From:	Davis L NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD)
To:	Purdom P, Shon F, Wolfe S Atomic Safety and Licensing Board Panel
References
NUDOCS 7810270087
Download: ML20147H692 (2)

Text

b UNITED STATES e g 'id NUCLEAR REGULATORY. COMMISSION WASHINGTON, D. C. 20555 g g e

October 17, 1978

• sa,*

NRC PUBLIC DOCUMENT ROOM Sheldon J. Wo1fe, Esq.

Mr. Frederick J. Shon, Member Atomic Safety and Licensing Board Atomic Safety and Licensing Board i

U.S. Nuclear Regulatory Coninission U.S. Nuclear Regulatory Commission Washington, D. C.

20555 Washington, D. C.

20555 Dr. Paul W. Purdom Di rector, Environmental Studies Group Drexel University p

4 32nd and Chestnut Street 8

Philadelphia, Pennsylvania 19104 eg g

OgD g Jgo N r

In the Matter of D[

-4 PUBLIC SERVICE COMPANY OF OKLAHOMA ;

.i /$s 5'

ASSOCIATED ELECTRIC COOPERATIVE, int -

AND WESTERN FARMERS ELECTRIC COOPERATIVE, (Black Fox Station, Units 1 and 2) cr y

Docket'Nos. STN 50-556 and STN 50-557 Gentlemen:

This letter is to infonn the Board and parties of infonnation received by the Staff # rom General Electric in the area of transient analysis methods.

As 7dicated in the enclosures to this letter, tests at a domestic an? toreign BWR for the purpose of transient model verification showed the artain portions of the REDY Code (which is used for calculat.: s of certain transients including turbine trip) under predicts the decrease in critical power ratio (CPR) limits.

For this reason, a new code named ODYN has been prepared by General Electric and is currently under review by the Staff.

The review of the ODYN Code is expected to be conpleted in December 1978.

This will provide sufficient time for the Applicant to evaluate the consequences of anticipated operational occurrances with the appmved method and initiate appmpriate design changes if such changes are needed or deemed beneficial.

The Staff anticipates that these changes, if needed, can be accommodated by minor modifications of

~~

design details, such as the specification of faster rod insertion rates.

I am also informed that while the REDY and ODYN Codes are used for the calculation of certain transients, including turbine trip, the new code OUY%.

m changes do not affect the Energency Core Cooling System and consequently will have no effect on B1ack Fox Contention Number Two.

Sin cerely,

k kj sD.

[o, C ^Sua )c% Cu_t u b

1 c

L. Dow Davis Counsel for NRC Staff Enclosures :

1.

GE October 25, 1977 letter to NRC 2.

Rosztoczy November 23, 1977 letter to Ross 3.

GE January 9,1978 letter to NRC 4.

GE June 46, 1978 letter to NRC cc (w/ encl s. ):

Joseph Gallo, Esq.

Michael I. Miller, Esq.

Mrs. Carrie Dickerson Mr. Clyde Wisner Andrew T. Dalton, Jr. Esq.

Mrs. Ilene H. Younghein Paul M. Murphy Lawrence Burrell Mr. Geral d F. Diddle Mr. Vaughn L. Conrad Joseph R. Faris, Esq.

Robert Franden, Esq.

Mr. Maynard Human Mr. T. N. Ewing Dr. M. J. Robinson Atomic Safety and Licensing Appeal Board Atomic Safety and Licensing Board Panel Docketing and Service Section l

l

'l ' '