ML20207P875
| ML20207P875 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 01/13/1987 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF ADMINISTRATION (ADM) |
| References | |
| 5211-87-2008, NUDOCS 8701200359 | |
| Download: ML20207P875 (2) | |
Text
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a GPU Nuclear Corporation Nuclear
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a Middletown, Pennsylvania 17057-0191 717 944-7621 TELEX 84 2386 Writer's Direct Dial Number:
January 13, 1987 5211-87-2008 U.S. Nuclear Regulatory Commission l
Attention: Document Control Desk Washington, DC 20555
Dear Sir:
l Three Mile Island Nuclear Station Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 10 CFR 50 Appendix R Multiple High Impedance Faults GPUN letter to NRC dated October 22, 1986 (5211-86-2177), committed to establish emergency fire procedures to respond to electrical bus trips resulting from multiple high impedance faults. This letter provides additional information to clarify the scope of the actions required by the emergency fire procedures.
GPUN has reviewed the cable routings of the power circuits for Appendix R required buses and evaluated the circuits in each fire zone / area to determine which fires have the potential for causing a bus to trip due to a multiple high impedance fault. For those cases identified, where a bus trip could occur on a bus required for Appendix R safe shutdown, procedures to restore the bus are being developed.
Upon trip of the electrical bus, these procedures will instruct the operator to open the breakers for all circuits which have been determined to be capable of causing a bus trip due to multiple high impedance faults in the affected fire zone and then re-energize the bus, thereby restoring power to the protected Appendix R loads.
These actions, r.dequately address the multiple high impedance fault scenario and limits the required operator action to opening only those breakers which have been determined to be capable of causing the bus trip.
If any additional information is required, please contact us.
Sincerely, 8701200359 870113 i
PDR ADOCK 05000289
/
F PDR
. D. Hukill Vice President & Directer, TMI-1 b
HDK:DJD:nk/0752A Io GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation
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5211-87-2008 January 13, 1987 cc:
J. F. Stolz, USNRC T. Murley, USNRC Region I J. Thoma, USNRC F.' Young, USNRC TNI Site D. Kubicki, USNRC PEISCB A. Krasopoulos, USNRC Region I l
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