ML20214S098
| ML20214S098 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 06/01/1987 |
| From: | Shelton D TOLEDO EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 1388, TAC-65105, NUDOCS 8706090132 | |
| Download: ML20214S098 (2) | |
Text
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TOLEDO
%sEDISON Docket No. 50-346 DONALD C. SHELTON w %. - ear w
[419] P49 2399 License No. NPF-3 Serial No. 1388 June 1, 1987 United States Nuclear Regulatory Commission Document Control Desk Washington, D. C.
20555 Gentlemen:
The System Review and Test Program at Davis-Besse has been satisfactorily completed. The results obtained during the program have demonstrated the function:1 adequacy of the 34 systems important for safe operation.
The specific results of the final testing in this program were obtained during a unit trip on March 13, 1987 as reported in our letter to you dated March 23, 1987 (Serial No. 1-716).
There is additional information that Toledo Edison will be obtaining during future testing to be used as part of the continuing effort to enhance plant reliability and further increase margins of safety. This additional information will be utilized in assessing or confirming plant response to transient conditions. The major areas of additional information can be summarized as follows:
1.
Evaluation of Plant Response for Loss of One Main Feedwater Pump This test will be performed to evaluate plant transient response to loss of a single main feedwater pump at high power. This information will be utilized in identifying any necessary equipment and system changes to facilitate continued plant operation following a feed pump trip at powers up to 100% without experiencing a reactor trip. Our analyses indicate that the current maximum power at which this could be achieved is between 85% and 90% power. We plan to perform this test from about 80% power.
2.
Confirmation of Rapid Feedwater Reduction (RFR) Operation and Integrated Plant Response on Reactor Trip Satisfactory testing of the RFR circuit, valve position and pump speed target responses has been completed.
The integrated plant response during a high power trip with the feedwater pump and feedwater control valves in automatic will be 8706090132 E70601 PDR ADOCK 05000346
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P PDR THE TOLEDO EDISON COMPANY EOISON PLAZA 300 MADISON AVENUE TOLEDO. OHIO 43652 l
Docket No. 50-346 License No. NPF-3 Serial.No. 1388 Page 2 1
evaluated during a future plant trip. This data will be analyzed to determine any necessary additional modifications, or if practical, elimination of potentially redundant circuitry.
3.
Evaluation of Pressure Pulsations During Main Turbine Trip On June 9, 1985, pressure pulsations due to closure of the main turbine stop valves were propagated to the steam generators where the pressure change was interpreted as a level change by the l
differential pressure transmitters, resulting in actuation of the Steam and Feedwater Rupture Control System. Data to evaluate the pressure pulsations and confirm the adequacy of the modifications previously installed will be obtained during a future plant trip.
Close management attention is being paid to these items and when obtained, the information from the above testing will be evaluated to determine any additional adjustments or modifications for the fifth refueling outage.
Instrumentation has been installed to collect data for these transient evaluations in the event an unplanned trip occurs.
J An additional area for which data may be obtained during a plant trip is associated with investigation of main steam line vibration as it affects main steam safety valve reliability.
It should be noted that if results from ongoing work determines its adequacy, further investigation will not be necessary All of the above was discussed in the April 22, 1987 telephone conference between Messrs. DeAgazio, Byron, Kosloff, VanDenburgh, and Hehl from the NRC and Messrs. Hildebrandt, Storz and Piccolo from Toledo Edison.
Very trul
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DCS:PCH:bjs cc: DB-1 NRC Resident Inspector A. B. Davis, Regional Adminiatrator (2 copies)
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