ML20093B646
| ML20093B646 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 10/02/1984 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| 5211-84-2245, NUDOCS 8410100167 | |
| Download: ML20093B646 (2) | |
Text
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Nuclear
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Route 441 South Middletown, Pennsylvania 17057 0191 717 944 7621 TELEX 84-2386 Writer's Direct Dial Number:
October 2, 1984 5211-84-2245 Office of Nuclear Reactor Regulation Attn: John F. Stolz, Chief Operating Reactors Branch No. 4 U. S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Sir:
Three Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Response to the NRR Safety Evaluation on the Seismic Capability of the Backup Incore Thermocouple Display System Upon review of the Safety Evaluation by the Office of Nuclear Reactor Regulation of August 23, 1984 on the seismic capability of the backup incore thermocouple display system, GPUN has identified two points where further clarification appears to be needed.
- 1) The voltmeter readings taken as part of the alternate method of obtaining backup incore thermocouple readings are read at Signal Conditioning Cabinet B2 located two floors below the Control Room in the Control Building. The thermocouple voltages are then converted to temperature and the information is relayed to the control room operator.
- 2) The test to compare the primary and backup readings described in the GPUN letter of May 31, 1984 will not allow verification and adjustment of the voltage to temperature conversion equation at temperatures ranging from 2000F to 23000F.
GPUN committed to perform a test comparing the computer readings with the results of the portable voltmeter at various power ranges during the Start-up 8410100167 841002 DR ADOCK 05000
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V GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation 0
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y Mr. John F. Stolz 5211-84-2244 and Test Programs. Temperature will vary from approximately 5250F to 6100F. Any change to the conversion equation over this range
. would be insignificant. The non-linear thermocouple behavior at high temperatures is a generic problem and cannot be demonstrated during any Start-up and Test Program and is unrelated to the seismic capability of the display.
Installation of the qualified voltmeter prior to plant startup will result in cancellation of the test.
Sincerely,
. D.
kill Director, TMI-1 HDH:SMO:vjf cc:
R. Conte J. Van Vliet A
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