ML20006C290
| ML20006C290 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 01/26/1990 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR C311-90-2009, GL-87-02, GL-87-2, NUDOCS 9002070287 | |
| Download: ML20006C290 (2) | |
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@M GPU Nucleet Corporation >
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TELEX 84 2386 fr Writer's Direct Dial Number:
I January 26, 1990 Z
C311-90-2009
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- 10. S. Nuclear Regulatory Commission JAttn: Document' Control Desk yf.g Washington; DC 20555-
' Gentl emen:'
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Three Mile' Island Nuclear Generating Station, Unit 1 (TMI-1)
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- Operating License No. DPR-50 Ls
- Docket No. 50-289
-Unresolved ~ Safety Issue:A-46 Resolution
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'NRCsletter dated December 4, 1989, regarding the TMI-1 Integrated Schedule y
Update, Lindicates that as-much of the-seismic verification walkdowns and t
associated analyses required by Generic Letter 87-02 as possible should be
. performed prior to the 10R. outage. This-letter provides additional information
_ supporting deferral: of the SQUG walkdowns to the 10R. outage.
OurEp1an is.not.to perform the walkdowns.and analyses on a-piecemeal basis.
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- The: e.ntire walkdown effort is scheduled.for a 2-3 week period during the 10R.
outag'e. Componc.nt work. packages will be, developed prior to the 10R: outage in preparation for the walkdowns.. The Seismic' Qualification. Utility Group (SQUG).
. pilot ' studies indicate that the seismic verification 'walkdown and analysis-t
- should be completed in one' effort,. utilizing the same.SQUG team' personnel and s
' technical experts to ensure consistency in approach and seismic evaluation.
. This.' consistency may be lost if the walkdown team personnel change. Additional
'SQUG training would be required for new personnel. Also,: performing walkdowns t
' during. plant operations may present an undue risk to ' safe plant operation as-3 some. components:will1 require erection of scaffolding or-ladders in. order to-yfvisually.inspectcomponentsupportsandmountingdetails,andmostelectrical equipment would' require some disassembly to allow inspection of mounting
-details.
- During'the initial development of the SQUG criteria and GpVN experience data
- and training-efforts,- walkdowns and evaluations were performed in selected areas of the TMI-1 Control and Auxilia'ry Buildings by a prime SQUG contractor.
The cable tray / conduit reviews were intended to benchmark the developing SQUG criteria.
However it is important to note that no significant problems were identified with respect to seismic qualification by use of experience data.
9002o70287 900126,
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GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation.
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c C311-90-2009 January.26, 1990.
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-TMI-l'was seismically designed in accordance with the appropriate design basis
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criteria at' the time of initial plant licensing.
Resolution of USI-A-46 is a seismic verification effort to reassess the existing margins of safety and.to confirm that acceptable safety margins exist for equipment designed and
-qualified'before. current criteria were developed. Therefore, we believe that performance of the SQUG walkdowns during the 10R outage, as indicated in our November 3, 1989 letter, provides the proper scheduling and priority for resolution of USI A-46 for TMI-1 when compared to other projects on the Integrated Schedule for 9R, and we-intend to proceed on this schedule.
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Sincerely,
- 1. D. Hokill Vice President.and Director, TMI-1 DJD/311-89d cc: J. Stolz, USNRC R. Hernan, USNRC W. Russell, USNRCi, Region I F. Young, USNRC TMI-1 Site l
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