ML20062E442

Presents Revised Schedule to 781104 Reactor Refueling Region Outlet Temp Fluctuations, & Reflecting 781116 Discussions W/Nrc.Region Restraint Device Installation Delay.Sar Should Be Ready by Jan 1979

ML20062E442
Person / Time
Site:	Fort Saint Vrain
Issue date:	11/27/1978
From:	Justin Fuller PUBLIC SERVICE CO. OF COLORADO
To:	Gammill W Office of Nuclear Reactor Regulation
References
NUDOCS 7812070186
Download: ML20062E442 (3)

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PUBLIC SERVICE COMPANY OF COLORADO P. O. BCX 84O OCNVER, COLORADO 802Ot J. K. FULLER _

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November 27, 1978 Fort St. Vrain Unit No. 1 P-78189 Mr. William P. Gammill .

Assistant Director for Standardization and Advanced Reactors s

, Division of Project Management U.S. Nuclear Regulatory Commission Washington, D.C. 20555 --

Docket '50-267

Subject:

Immediate & Future Operating Plans -- Fort St. Vrain Unit No. 1

Reference:

NRC/PSC/GAC Meetings of November 3-4 and November 16, 1978 Gentlemen:

In the referenced meetings PSC discussed both near term and long term operating plans for Fort St. Vrain Unit No.1 relative to the reactor refuel-

• ing region outlet temperature fluctuations presently- under investigation. At the meeting of November 3 and 4,1978 a strategy was presented that included current and future plans for data gathering, evaluation, reactor refueling, and the proposed installation of reactor refueling region restraint devices. In view of the fluctuations observed on the morning of November 4 and discussed with the NRC on November 16, a revised schedule for operation of the reactor is presented: ,

1. Discontinue fluctuation testing and continue to operate reactor in the 60-70 percent power range. Concurrently --

a. Continue to evaluate data from the fluctuations of November 4, 1978.

b. Review test RT-500 for possible revision based on infor-mation gained during the November 4 fluctuations.

c. Review present monitoring instrumentation based on infor-mation gained during November 4 fluctuations.

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wa o, snur 2 Pusuc S cRvice Comeauv or COLORADO Om 11/27/78 P-78189 2'. On or about December 12 present the results of items la, lb, and Ic above to the NRC and request permission to reinstitute fluctuation testing below 70 percent reactor power.

3. Anticipate that continued fluctuation testing will be authorized on or about December 19, 1978.

4. Complete "less than 70 percent" fluctuation testing by January 5, 1979.

5. Present a summary of "less than 70 percent" fluctuation testing to the NRC on or about February 5,1979 and request permission to proceed to power levels "above 70 percent" reactor power.

6. Anticipate that testing "above 70 percent" reactor power will be authorized on or about February 12, 1979.

7. Continue reactor operation "above 70 percent" reactor power per SUT B-0 Series and RT-502, Fluctuation Testing at Greater Than 70 Percent Reactor Power. (Goal is to achieve 100 percent reactor power prior to shutdown for refueling.)

8. Shut down reactor about March 1,1979 for an eight to ten week reactor refueling operation. Concurrently complete the following tasks:

a. Reactor Refueling.

b. Inspection of Region No. 35.

c. Installation of Instrumented Control Rod Drives (ICRDs).

d. Installation of Relative Movement Indicating Upper Plenum Elements (Scratchers).

9. Return reactor to power operation on or about May 15, 1979.

10. Repeat tests RT-500 and RT-502.

a. Evaluate RT-500 and RT-502 data.

b. Evaluate and correlate information from ICRDs. '

c. Present the results of items a and b above to the NRC.

11. Continue to evaluate the installation of the Region Restraint Devices on the basis of continuing test results and evaluations, system load demand and unit availability, and NRC approval of installation.

12. Continue to operate reactor at as high a power level as is possible without incurring fluctuations (based upon RT-500 and RT-502 results) until the second refueling.

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13. Shut down for reactor refueling on or about January,1980. Con-currently complete the following:

a. Refuel Reactor.

b. Remove "Scratchers".

c. Remove ICRDs.

d. Install Region Restraint Dcvices if not previously installed depending on continuing evaluation of need.

14. Return reactor to power operation.

15. Repeat tests RT-500*and RT-502 and evaluate effect of Region Restraint Devices.

(~ 16. Continue to operate reactor normally with presumption that restraint devices will have resolved fluctuation problem.

Region Restraint Device installation had been considered for the first refueling and it had been decided to delay their installation for a number of reasons. One concern that was considered during the discussion of first refueling installation was the NRC " turnaround time" required to evaluate the Safety Analysis Report for the restraint devices and whether NRC approval to install the devices can be received in time for the first refueling. The SAR should be ready for sub-mittal to the NRC for review and approval by early January,1979.

As PSC has indicated numerous times in past meetings, initial reactor operations at power levels above 70 percent of rated thermal power would take place in accordance with the defined rise-to-power test program contained in Test Procedure SUT B-0. Flectuation testing would be performed in accordance with test RT-502.

PSC intends to abide by the same rules that governed continued operation of the reactor at up to 70 percent reactor power; i.e., (1) The reactor will not be operated in the fluctuating mode above 70 percent of rated thermal power except when specifically collecting data concerning fluctuation o'peration, and (2) In the event the reactor refueling region outlet temperatures should begin to fluctuate during " normal" operation above 70 percent power, the operators will initiate the necessary corrective action to terminate the fluctuations.

Please let us know if you have any questions.

Very truly yours,

. K. Fuller, Vice President Engineering and Planning JKF:ers 1

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