ML20236D789

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Advises of Actions Taken in Response to Inoperability of Remote Shutdown Instrument NI-9.NI-9 to Be Repaired During Hot Shutdown in Excess of 48 H.Roving Firewatch & Continuous Control Room Manning Serve as Compensatory Measures
ML20236D789
Person / Time
Site: Crane 
Issue date: 07/27/1987
From: Hukill H
GENERAL PUBLIC UTILITIES CORP.
To:
NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
5211-87-2124, NUDOCS 8707310064
Download: ML20236D789 (1)


Text

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GPU Nuclear Corporation G U Nuclear

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Middletown, Pennsylvania 17057 0191 717 944 7621 TELEX 84 2386 Writer's Dhect Dial Nurnber:

July 27,1987 5211-87-2124 U.S. Nuclear Regulatory Cormnission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:

Three Mile Island Nuclear Station Unit 1 (TMI-1)

Operating License No. DPR-50 Docket No. 50-289 Inoperability of Remote Shutdown Instrument NI-9 I

During testing performed prior to startup from the recent outage to replace the letdown coolers, NI-9, the source range neutron flux instrument located on the Remote Shutdown Panel, was found to be inoperable.

Best effort was exerted to return NI-9 to operable status prior to startup. We were unable to repair NI-9, therefore, a compensatory measure was taken. The compensatory measure consists of the existing roving firewatch through the Relay Room and the continuous manning of the Control Room.

This assures the early detection and suppression of a fire prior to significant damage which would result in the need to rely on the Remote Shutdown Panel to achieve safe shutdown.

In addition, there are alternate means available to the operator to assess subcriticality, which would be the function of NI-9.

We plan to repair NI-9 during the first available opportunity when TMI-1 is in a hot shutdown condition in excess of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

The NRC Senior Resident was informed of the instrument inoperability and the compensatory measures planned prior to startup.

cincerely, 8707310064 070727 EUR ADOCK 05000289 PDR D. 'likill Vice President & Director, TMI-l HDH/SM0/spb:0941 A cc:

R. Conte, USNRC

- 0 G. Edison, USNRC

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GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation J