ML17177A478
| ML17177A478 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/11/1992 |
| From: | Siegel B Office of Nuclear Reactor Regulation |
| To: | Kovach T COMMONWEALTH EDISON CO. |
| References | |
| TAC-M82169, TAC-M82895, NUDOCS 9206170303 | |
| Download: ML17177A478 (4) | |
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Docket Nos. 50-237 and 50-249 Mr. Thomas J. Kovach Nuclear Licensing Manager Commonwealth Edison Company-Suite 300 OPUS West I II 1400 OPUS *Pl ace Downers Grove, Illinois 60515
Dear Mr. Kovach:
June* 11, 1992
- DISTRIBUTION:
Co.o.cke.t.:...tLLEiJ NRC & Local PDRs B. Boger R. Barrett B. Siegel ACRS ( 10)."'.
R. Jenkins PDIII-2 r/f PDIII-2 p/f J. Zwolinski C. Moore*
OGC B. Clayton f; Rosa A}
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,i REQUEST FOR ADDITIONAL INFORMATION RELATED, To* THE SECOND:LEVEL
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UNDERVOLTAGE SETPOINTS FOR DRESDEN, UNIT;S,_.'2 *AND J, (TAC NO_S ~ M8216~ -'. *..
SUBJECT:
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The staff is currently *evaluating your March 3, 1992. subrjlittal,.-and * *'. *.
- OFC supplemental. informat.ion provided, to determine the "adequacy.of your.r.e'v.i~ed second-level undervoltage setpoints.
As a result of thfs ~valuatioh..the, staff
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has determined that the enclosed request for addition al' information~ (RAI) *.is needed to complete its review.
It is requested that you respond'~to..thi,s.. RAI within 30 days of receipt of this letter.
~ *.,: *
- The reporting and/or recordkeeping requirements contained in this letter*
affect fewer than ten respondents: the~efore, OMB clearance is ndt ~~quired under P. L.96-511.
If you have any qu.estions regarding this request, please contact me.
Enclosure*:
Request for Additional.
Information cc w/enclosure:
See next page 9206170303 920611.
PDR. ADOCK 05000237;
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PDR Sincerely, Original ~igned by:
Byron L. Siegel, Project Manager Project Directorate IlI-2 Division of Reactor Projects - III/IV/V Office of Nuclear Reactor Regulation
- ,t /JI /92
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Mr. Thomas J. Kovach Commonwealth Edison Company cc:
Michael I. Miller, Esquire Sidley and Austin One First National Plaza Chicago, Illinois 60690 Mr. C. Schroeder Plant Manager Dresden Nuclear Power Station Rural Route #1 Morris, Illinois 60450 U. S. Nuclear Regulatory Commission Resident Inspectors Office Dresden Station Rural Route #1 Morris, Illinois 60450 Chairman Board of Supervisors of Grundy County Grundy County Courthouse Morris, Illinois 60450 Regional Administrator Nuclear Regulatory Commission, Region Ill 799 Roosevelt Road, Bldg. #4 Glen Ellyn, Illinois 60137 Illinois Department of Nuclear Safety Office of Nuclear Facility Safety 1035 Outer Park Drive Springfield, Illinois 62704 Robert Neumann Office of Public Counsel State of Illinois Center 100 W. Randolph Suite 11-300 Chicago, Illinois 60601 Dresden Nuclear Power Station Unit Nos. 2 and 3
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REQUEST FOR ADDITIONAL INFORMATION RELATED TO SECOND LEVEL UNDERVOLTAGE SETPOINTS FOR DRESDEN STATION. UNIT 2 & 3 ENCLOSURE The Sargent and Lundy engineering calculations used to develop the new second level undervoltage setpoints cite assumptions requiring verification. Provide a status on the disposition of the subject assumptions.
Verify that surveillance procedures have been changed to incorporate periodic testing of the load shed modifications installed to establish and maintain the new second level undervoltage setpoints.
Discuss what analyses have been performed to evaluate the effects of operation at the new second level undervoltage setpoints for protective devices, control circuits, and other components required to operate below the 480 volts level.
Discuss what quality assurance verification and validation testing has been performed on the "Hathcalc" software program utilized by the Digital Fault Recorder to provide computed values for safety related applications. We.note that Calculation 8982-13-19-5, "Comparison of DGCWP Test Oscillogram with Hathcalc," checked the oscillogram output with the Hathcalc computed values for reasonableness using 1 to 4 test points.
Given the estimates for the slip at maximum torque, stator impedances, and rotor impedances as well as the use of test data to determine the moment of inertia in the development of the analytical model for the DGCWP motor, explain what motor characteristics are independently verified by the model.
For those safety related 120 volt starter contactors which do not meet the vendor minimum voltage requirement of 75 percent of the contactor rating at the new second level undervoltage setpoints, the licensee provided the following rationale for proper operation:
a)
The qualified GE series contactor design assures 75 percent voltage pickup at the end of its 40 year life.
b)
A test on a new series 300 contactor resulted in a pickup voltage of 58 percent of rated voltage.
c)
The installation of the new series 300 contactors in all of the safety related size two starters.
d)
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- The minimum expected voltages during the Spring 1992 time period will assure contactor operation.
Describe the permissible margin for aging and what testing has been conducted to ensure that the remaining margin will be adequate for the new second level undervoltage setpoints. Discuss what acceptance tests and surveillance testing will ensure that the subject contactors will continue to function outside of the manufacturer's specified ranges over the life of the component..