ML20064E876

Forwards Safety Rept for Instru Control Rod Drive & Orifice Assemblies

ML20064E876
Person / Time
Site:	Fort Saint Vrain
Issue date:	11/17/1978
From:	Millen C PUBLIC SERVICE CO. OF COLORADO
To:	Kuzmycz G Office of Nuclear Reactor Regulation
Shared Package
ML20064E880	List: ML20064E876 ML20064E881
References
NUDOCS 7811240226
Download: ML20064E876 (3)

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PUBLIC SERVICE COMPANY OF COLORADO P- O. B0x 840 0ENVER, C 0,L O R A D O e02Of r

c. n & i s c~,oa v.c c . c.,o c~, November 17, 1978 Ft. St. Vrain Unit No. 1 P-78184 Mr. George Kuzmycz Prc,. ject Tianager U. S . Nuclear Regula tory Commission f' h Division Project Management N/

, Special Projects i Washington, D.C. 20555

SUBJECT:

Modified Control and Orificing Assemblies

Dear Sir:

In previous meetings and discussions with your staff, we addressed our plan to install two modified control rod drives and orificing assemblies which contain instrumentation to further study and evaluate the power, flux, and temperature fluctuations we have experienced. In support of these plans we are submitting a _ Safety Eval.uation Report for the instrumental control rod drive and orifice assemblies which'we intend' to install during the refueling outage in January, 1979, and which will remain in the core until the second refueling.

Even though the Safety Evaluaticn clearly shows that the modified CRD's will not have an adverse impact en the physical plant or on the requirements stated in the L

FSAR and the Technical Specifications, the following discussion of the Technical Specifications related to control rod drives is included for your review:

LCO 4.1.2 " Operable Control Rods" Whenever the term of " control rod pair" is referred to in the Technical Specifications, it shall be construed that the modified control rods meet tMs definition. ,

LCO 4.1.3 " Rod Sequence" Since the modified control rod drives will have no impact on the rod seq ue nces , this LCO will be adhered to as written. "h LCO 4.1.4 " Partially Inserted Rods" Whenever the term of " control rod pair" is referred to in the Technical Speci fica tions , it shall be construed that the modified control rods meet this definition.

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i November 17, 1978 Mr. George Kuzmycz Page 2 LCO 4.1.6 " Reserve Shutdown" Reserve shutdown hoppers in the modified control rod drives will be operable and this LCO will be adhered to in its entirety.

LCO 4.2.9 "PCRV Closure Leakage" This LCO will be adhered to in its entirety.

SR 5.1.lb " Control Rod Operability" (a) Scram time for the modified CRD's may exceed 160 seconds, but will be scrammable.

1 (b) The slack cable alarms will be operable on the modified control rod drives and will be verified as stated in this surveillance.

SR 5.1.2 " Reserve Shutdown System" This surveillance will be adhered to in its entirety.

SR 5.1.5 " Withdrawn Rod Reactivity" Rod worths of the modified control rod drives will be checked initially as the rods are withdrawn in their normal sequence.

SR 5.2.16 "PCRV Closure Leakage" The modified primary and secondary closures for the two regions where modified CRD's will be installed will be leak checked upon the initial repressurization of the PCRV after the refueling outage.

SOP 12-02 " Reactivity Calculations" New rod worth curves for the two modified assemblies will be incorporated

, in SOP 12-02.

Any abnormalities affecting shutdown margin, which result directly from the in- .

stallation of the modified control rod drives, will result in an orderly reactor shutdown. Under these conditions the reactor shall remain shutdown pending nec-essary evaluation and approval to restart.

t i Based on the Safety Evaluation Report and the Technical Specification analysis,

( we request your concurrence for installing the instrumented control and orific-

ing assemblies.

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November 17, 1978 Page 3 Mr. George Kuzmycz .-

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r Mr. Don Warembourg.If you have any questions concerning s, please contact these modifica Very truly yours, Public Service

- - Company of Colorado

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i . -.c C. K. Millen Senior Vice President CKM/dme i

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