ML20236E166

Requests That Util Address Listed Items as Part of Response to Generic Ltr 87-02,per Nov 1988 Equipment Walkdown at Plant.Floor Response Spectra Needs to Be Reviewed & Approved Since Rest of Work Dependent on Spectra

ML20236E166
Person / Time
Site:	Hatch
Issue date:	03/16/1989
From:	Crocker L Office of Nuclear Reactor Regulation
To:	Hairston W GEORGIA POWER CO.
References
REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR GL-87-02, GL-87-2, TAC-69259, TAC-69260, TAC-71145, TAC-71146, NUDOCS 8903230478
Download: ML20236E166 (3)

Text

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March 16, 1989 Docket'Nos.: 50-321 50-366 Mr. W. G. Hairston, III Senior Vice President -

Nuclear Operations Georgia Power Company P.O. Box 1295 Birmingham, Alabama 35201

SUBJECT:

SEISMIC QUALIFICATION OF EQUIPMENT, GENERIC LETTER 87-02 (USI A-46) (TACS 69259/69260)

In November 1988, an NRC team participated as observers during an equipment walkdown at Plant Hatch by GPC personnel involved in implementing the Seismic Margins Program. The walkdown served also as partial fulfillment of GPC's response to Generic Letter 87-02 pertaining to seismic qualification of equipment USI A-46.

Several of the NRC observers have responsibilities both for the seismic margins effort and for the Generic Letter 87-02 issues.

Based upon staff observations during the walkdown and information provided by GPC personnel during the walkdown, our reviewers have identified several matters that need to be addressed as part of the effort in response to Generic Letter 87-02. These are as follows:

(1) Two sets of floor response spectra were available for use in the implementation of USI A-46, namely, the licensing Final Safety Analysis Report (FSAR) floor response spectra and the Seismic Margin Earthquake (SME) floor response spectra.

GPC representatives stated that where floor response spectra were required for the seismic verification, the SME floor resaonse spectra would be used for the Seismic Margins Assessment (SMA) and would N conservatively used for the initial screening for the A-46 verification. The staff requested that the floor response spectra / input motion to the equipment be submitted for staff review and approval before conduct of the final implementation of USI A-46.

(2) The approach of judging whether the natural frequency of a piece of equipment is greater or less than 8 H by visual or hand-felt observation is highly subjective and can be grossiy in error depending on the experience of the Seismic Review Team members.

It was suggested that a better method be investigated for use in the final implementation.

(3) Many electrical cabinets had doors which would rattle vigorously during a postulated earthquake.

This can cause relay chatter similar to that resulting (Cl

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l Mr. W. G. Hairston, III from impact of cabinets.

This effect should be considered in the Generic l

Implementation Procedure (GIP) developed by the Seismic Qualification Utility Group.

(4) The effect of edge distance and spacing distance of anchor bolts should be evalu'ted carefully.

(5) RHR and plant service water vertical pumps were identified by the Seismic a

Review Teams as cutliers due to the pump casings being supported at intervals greater than 20 feet.

The staff observed that one of the pump shafts laid in the yard was sheared near the bottom impeller.

Seismic capacity of the pumps should be carefully determined considering the existing environmental i

degradation effects.

j (6) The analysis of the condensate storage tank had not been performed, but the procedures to be used were discussed. The final staff position regarding i

GPC's approach to the analysis and the use of damping values will be reflected

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in the evaluation of the approach and criteria described in the GIP.

In l

addition, the staff observed that several of the tank hold down anchor bolts j

were not tight. They should either be tightened, or credit for capacity of the loose bolts should not be allowed.

Likewise, several radial cracks on the tank foundation mat were observed. The cracks running through the anchor bolts should be investigated and the potential tensile strength reduction of a l

bolt in cracked concrete should be considered.

(7) The staff noted that a few areas within the scope of A-46 'were not discussed such as the assumptions and criteria used in the selection of the success path, the relay functionality evaluation, the cable trays and conduit systems.

These areas will be discussed in the future.

It is requested that you consider these matters during the further work on the response to Generic Letter 87-02.

In particular, the floor response spectra (item 1 above) needs to be reviewed and approved by the staff at an early date since the rest of the work is de)endent upon use of acceptable response spectra.

I urge you to submit t1e proposed floor response spectra as soon as is convenient.

Please call me if you have any questions.

Sinceely,

Original Signed By:

i Lawrence P. Crocker, Project Manager Project Directorate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation cc:

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Mr. W. G. Hairston, III Edwin I. Hatch Nuclear Plant, Georgia Power Company Units Nos. I and 2 1

CC:

G. f. Trowbridge, Esq.

Mr. R. P. Mcdonald Shaw, Pittman, Potts and Trowbridge Executive Vice President -

2300 N Street, N. W.

Nuclear Operations Washington, D.C.

20037 Georgia Power Company P.O. Box 1295 Mr. L. T. Gucwa Birmingham, Alabama 35201 Engineering Department Georgia Power Company Mr. Alan R. Herdt, Chief P. 0. Box 1295 Project Branch #3 Birmingham, Alabama 35201 U.S. Nuclear Regulatory Comission 101 Marietta Street, NW, Suite 2900 Nuclear Safety and Compliance Manager Atlanta, Georgia 30323 a

Edwin I. Hatch Nuclear Plant j

Georgia Power Company P. O. Box 442 Baxley, Georgia 31513 Mr. Louis B. Long

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Scathern Company Services, Inc.

d P. O. Box 1295 Birmingham, Alabama 35201 1

Resident Inspector U.S. Nuclear Regulatory Commission Route 1, Box 725 l

Baxley, Georgia 31513 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta Street, Suite 2900 Atlanta, Georgia 30323 Mr. Charles H. Badger Office of Planning and Budget Room 610 270 Washington Street, S.W.

Atlanta, Georgia 30334 Mr. J. Leonard Ledbetter, Commissioner Department of Natural Resources 270 Washington Street, N.W.

Atlanta, Georgia 30334 Chairman Appling County Commissioners County Courthouse Baxley, Georgia 31513

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