ML20080M129

Final Significant Const Deficiency Rept 33 Re Chilled Water Piping Supports.Caused by Overstressed Welds & Structures & Seismic Span Criteria Being Exceeded.Designs Modified

ML20080M129
Person / Time
Site:	Waterford
Issue date:	09/15/1983
From:	Drummond F ARKANSAS POWER & LIGHT CO.
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
10CFR-050.55E, 10CFR-50.55E, 33, W3I83-0311, W3I83-311, W3I883-311, NUDOCS 8310030482
Download: ML20080M129 (3)

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9 I OURSIANA / 142 DELARONDE STREET POWER & LIGHT / P O BOX 6008

• NEW ORLEANS, LOUISlANA 70174 . (504) 366-2345

$S0N5YS September 15, 1983 W3I83-0311 I

hh Mr. John T. Collins SEP 2 31983 Regional Administrator, Region IV .

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U. S. Nuclear Regulatory Commission i. l - -

611 Ryan Plaza Drive, Suite 1000 +

Arlington, Texas 76012

SUBJECT:

Waterford SES Unit No. 3 Docket No. 50-382 Significant Construction Deficiency No. 33

" Chilled Water Piping Supports" Final Report

REFERENCE:

LP&L Letter W3I83-0256 dated July 29, 1983

Dear Mr. Collins:

In accordance with the requirements of 10 CFR 50.55(e), we are hereby providing two copies of the Final Report of Significant Construction Deficiency No. 33, " Chilled Water Piping Supports."

If you have any questions, please advise.

Very truly urs, I

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F. J. Drummond Nuclear Services Manager cc: 1) Director 3) Mr. E. L. Blake Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555

2) Director 4) Mr. W. M. Stevenson Office of Management Information and Program Control U. S. Nuclear Regulatory Commission Washington, D.C. 20555 F310030482 830915 PDR ADOCK 05000382 lb' S PDR

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FINAL REPORT OF SIGNIFICANT CONSTRUCTION DEFICIENCY No. 33

" CHILLED WATER PIPING SUPPORTS"-

INTRODUCTION This report is submitted pursuant to 10 CFR 50.55(e). It describes deficiencies in the design of the chilled water piping supports resulting in welds and structures being overstressed and seismic span criteria being exceeded. To the best of our knowledge, this problem has not been identified to the Nuclear Regulatory Commission pursuant to 10 CFR 21.

DESCRIPTION In the review and verification of the original design of the chilled water piping system, the following deficiencies were found:

1. Seismic span criteria were exceeded in some areas of the system.

2. The only seismic load considered was Operating Base Earthquake (OBE).

The horizontal "g" factor at elevation 46'-0 was used at support points above and below said elevation. Whea the appropriate Design Base Earthquake (DBE) load at specific elevations was applied to the supporting structures, it resulted in:

a) Welds that were overstressed.

b) Structures that were overstressed.

SAFETY IMPLICATIONS If welds and structures become overstressed, supports may be deformed. This deformation may lead to degradation or loss of the chilled water system.

Since the chilled water system provides cooling for the safety-related HVAC systems, the cooling capability of the HVAC systems may be degraded or lost under seismic loading conditions.

There are many safety-related systems and components that rely on HVAC for cooling. Thus, loss or degradation of cooling to these systems or components may cause them to be unable to carry out their required safety function.

Therefore, deformation of supports may adversely affect the safety of the plant if the supports are not modified to comply with design criteria.

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. FINAL REPORT OF

-SIGNIFICANT CONSTRUCTION DEFICIENCY NO.-33

" CHILLED WATER PIPING SUPPORTS"'

Page 2 CORRECTIVE ACTION-

1. The S/R design-modifications to correct this Significant Construction Deficiency were. incorporated.via DCN-MP-459 and new revisions / designs.

.This is to ensure the stress levels and loading criteria were correct.

- 2. All corrective action is complete and all the supporting documentation has been reviewed and accepted.

This: report is submitted as the Final Report.

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