ML20044G476
| ML20044G476 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/26/1993 |
| From: | Broughton T GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| C311-93-2083, NUDOCS 9306030175 | |
| Download: ML20044G476 (3) | |
Text
_ _ _ - _.
9 GPU Nuclear Corporation G
Nuclear "nmir*
Middletown, Pennsylvania 17057-0480 (717) 944-7621 Writer's Direct Dial Number:
(717) 948-8005 May 26, 1993 C311-93-2083 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C.
20555 Gentlemen:
Subject:
Three Mile Island Nuclear Station, Unit I (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Response to Inspection Report 93-07 Request for Information on the Unresolved Issue of Makeup Pump Motor Performance This letter transmits the GPU Nuclear response to the request for information pertinent to the unresolved issue involving the Makeup Pump motor performance i
identified in Inspection Report 93-07. Attachment 1 provides the basis for the acceptability of the Westinghouse calculations reviewed by the Inspectors I
during the follow-up Electrical Distribution System Functional Inspection.
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Sincerely, T
1 Vice President and Director, THI-l WGH Attachment cc: Administrator, Region I THI-l Senior Project Manager TMI Senior Resident Inspector 9306030175 930526 PDR ADOCK'05000289
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G PDR GPU Nuclear Corporation is a subsidiary of General Public Utilities Corporation
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C31I-92-2083 Page 1 of 2 j
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Response to Unresolved Issue The 3ssue involving the Makeup Pump motor performance was first identified during the Electrical Distribution System Functional Inspection (IR 90-81) and l
was carried as an Open Item until the follow-up inspection was performed. ' A Westinghouse supplied calculation was made available to the NRC for review during the follow-up inspection.
It provided results justifying the increased horsepower operation of the Makeup Pump motors. The Unresolved Issue resulted when questions arose during the follow-up inspection because of variations between nameplate and input data used'as the basis foi the study.
The input data variations gave the appearance that the data was incorrect for the motors 4
i installed.
l The calculation was reviewed with Westinghouse and each item was resolved.
l The individual issues are discussed below:
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- 1) The variation in Motor Shop Order Numbers (68F20835 vs. 84F44578)
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resulted from the method by which Shop Order Numbers are assigned by Westinghouse. The numbers are assigned based on the date that the work is received in-house..The study was ordered in 1984 and the motor order was placed in 1968. Therefore, the two Shop Order Numbers will not match. The calculation was performed for the TMI-1 motor.
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is inconsequential to the calculation result since the Westinghouse computational program description manual (a proprietary Westinghouse i
document) designates that "CF" be input in the motor type field for all a
motor types " CSP" or "LLA".
Both " CSP" and "LLA" motors are of the i
i Buffalo design from the 1960's. The "CF" designation ensures that the correct data is used in the study.
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- 3) The variation in enclosure types between the installed motor and the study motor ("TEWC" vs. "DP") is appropriate since the Westinghouse computational program will not accept input of a_ "TEWC" designation in the field. The purpose of the program is to calculate the motor temperature rise based on the horsepower loading and the voltage when design parameters and ambient temperature are considered. The calculated temperature rise is used as input for the heat exchanger design of a " totally enclosed water cooled" motor. Therefore, this field has no bearing on the result calculated for the installed motors and is acceptable as shown.
- 4) The variation in temperature rise between the installed motors and the study motor (60"C vs. 80*C) is appropriate since the 60*C temperature i
rise specified on the motor nameplate is the design temperature rise based on motor operation at nominal parameters. The 80*C temperature rise is the NEMA maximum allowable temperature rise for Class B insulation. Both temperature rises are based upon a 40*C ambient temperature. The calculated temperature rise based on motor operation t
'C311-92-2083 Page 2 of 2 at a higher horsepower loading (837 Hp) and lower voltage (3600V) has been calculated to satisfy the NEMA allowable temperature rise for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
- 5) The variation in the specified time duration (18 vs. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) is extraneous in that the original GPUN contract requested verification that the Makeup Pump motor could operate at 837 Hp and 3600 volts for a period of 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br />. The Westinghouse calculation determined that the motor can operate at the designated load for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> before the NEMA allowable temperature rise is reached. This is adequate verification that operation for 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> is acceptable.
Based on these clarifications, the Westinghouse calculation is considered adequate supporting analysis for temporary operation of the Makeup Pump motors to 837 Hp.
It should be noted that when Westinghouse was tasked with performing this analysis, our calculation showed the Makeup Pump motor runout requirement was 837 Hp. This calculation has recently been updated and shows the requirement to be 750 Hp. This provides additional margin for operation in excess of 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br />.
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