ML19345C485

Significant Deficiency Repts SD 369/80-20 & SD 370/80-15 Re Improper Loads for Design of Pipe Support/Restraints Initially Reported 801028.Comprehensive Program Initiated to Correct Problems

ML19345C485
Person / Time
Site:	Mcguire, McGuire
Issue date:	11/26/1980
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19345C484	List: ML19345C483 ML19345C485 ML19345C486
References
10CFR-050.55E, 10CFR-50.55E, SD-369-80-20, SD-370-80-15, SD-370-80-16, NUDOCS 8012050302
Download: ML19345C485 (4)

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JUKE POWER COMPMY Powen Dununua 422 Sot:Tu Cnunen STur.nT, Cl!AHIDTTx N. C. ::aa.m WI L LI AM O. PAR K E R J R.

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Noverier 26, 1980 3

Mr. Jatics P. O'Reilly, Director U. S. Nuclear Fagulatory CaTtission Pagion II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 Re: McGuire Nuclear Station Units 1 and 2 Docket Nos. 50-369 and 50-370 Daar Mr. O'Feilly:

Pursuant t.,10CFR 50.55e,please find attached Significant Deficiency Report SD 369/80-20, 370-80-15.

Very truly yours, k , h,,.y <be ! v , i s <

William O. Parker, Jr. Yd GIC:vr Attaclrcent cc: Director T. J. Donat Office of Inspection & Enforcanent ImC Resident Inspech -

U. S. Nuclear Pegulatory Comtission McGuire Nuclear Stat. 7 Washirgton, D. C. 20555 i

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FCGUIRE NUCIEAR STATION LNITS 1 & 2 REPORT NO: st>-369/80-20, 370/80-15 ,i REPORP DATE: Novmber 26, 1980 INITIAL !X7PIFICATION DATE: Octcber 28, 1980 FACILITY: ",Glire 11uclear Station, Units 1 & 2 IDmTIFICATION OF DEFICIF2LT: Inproper loads Used for Support /Pestraint Design (LOCA, Valve Discharge, Misantch) b DESCRIPTION OF DEFICIENCY:

This report describes a deficiency in use of design loadings for design of pipe support / restraints. Three separate problems contribute to the total deficiency as follws:

1) IOCA (Inss of Cbolant Accident) piping analysis rnethcds ware not sufficiently defined to permit accurate definition of suppcrt/ restraint loads at the tinu of initial design. After loadings became available, a review of the adequacy of affected support / restraints was performed and any inadeauacies dis-covered in that review were corrected. Original support /

restra!* design and this later review / resolution procedure were cerrls" out by EDS Nuclear, Inc under contract to Duke Pom r prior to turnover of design responsibility to Duke in mid 1979. Fecent revision activity on this scope of supp3rt/

restraints try Duke engineers at the site led to question tM adecuacy of the support / restraints for IOCA loads. A sub-sequent detailed review of the proccdure used by FDS Nuclear, Inc to review for IOCA adequacy revealed that the review pro-cedure was not sufficiently ccuprehensive to ensure adequacy of all parts of a suoport/ restraint. Hence the review was not ccuplete, and scen of the affected support / restraints may not be adequate for IOCA loads as required for consideration in design.

2) The above described problem concernire IOCA loads led to a revicw of methods used to include special dynamic and static

-loads in support / restraint design. Pesults of this revies showed that an inadequacy existed in use of ms Nuclear-supplied design loadings for support / restraints on the Pressurizer Safety / Relief piping due to valve discharge. Due to misocrmunication, valve disciarge loads given for Faulted Cordition were factored dowrraard for the Upset Condition, as is acceptable for earthauake loadings for McGuire due to the 8/15 ratio that exists for OBE/SSE carthouakes. Since valve discharge loads do not factor and are the same for Upset and for Faulted Conditions, Upset allcwable loadings and stresses

. O Noventer 26, 1980 Page 2 l

for support / restraints may be e>rcedcd when 100-percent of valve discharge loads are considered. Generally this defigipncy is limited to those support / restraints which have carponents' which are load or stress ratcd for the Upset Condition.

3) During initial stages of review to correct IOCA and valve dis-charge load deficiencies, reference to current piping analysis results on file rwealed that support / restraint loads shwn on design drawings (sketches) did not match the on-file results, regardless of IOCA or valve discharge consideration. Investiga-tion through EDS Nuclear, Inc (who produced both the sketches and the piping analysis under contract to Duke Power) slmed that increases in support / restraint design loads recuired by recent revised piping analyses were not placed on design sketches unless the sketch requircd revisicn to sh m a structural change to the design. It was recuired that all such increases in load be can-sidered in support / restraint desicn calculations and that adequacy of the support / restraints be proven for load increases. The problem occurredafter future update. responsibility for these sketches was transferred from EDS Nuclear to Duke Power in mid 1979. Duke engineers at the site have performd revisions to designs or made engineering judganents on installations based on sketch loads. Since sketch loads maynot represent current (higher) requircznents, revised ard/or installed configurations in this scope may not be adequate. This recp2 is limited to support /

restraint designs initially developcd and maintained by EDS Nuclear ard for which piping analyses have not been revised since sketch responsibility turnover in mid 1979.

'Ita total nuTber of support / restraints requiring analytical review an3 cossible revision is 1591. 'Ibe estincted nunber that rray require sonn hardware change is 450. A majority of this scope of support / restraints is located in the Reactor Building.

ANALYSIS OF SAFETl Il@LICATIQ4S:

vbrst case safety cenacquence is that certain pipe support / restraints may not be capable of withstanding loads as large as predicted by as-built piping analysis.

Although failure of these support / restraints is considered to be a reTote possibility, absence of failure cannot be confinrod without further reviw. In the event of wressive defonnations or failure of these support / restraints, loadings on adjacent support / restraints would change such that adeauate support of the piping systcm and loadings en components to which it connects can rot be confinred as adequate. This, in turn, means that ability of the piping systan to perform design functions cannot be assurcd.

CDRPJCTIVE ACTIO4:

A conprehensive program has been initiated to carplete the follcwing:

Novanber 26,198t Page 3 (1) Identify all support / restraints affected in a nonconservative manner by each of tic three cited problems.

(2) Perform engineering review of designs identified in (1) pgd, if necessary, revise the designs to stru required structural changes.

(3) Pavise all affected design sketches to show any higher loads required by current piping analyses.

(4) Make hankare changes to affected support / restraints as required by revised designs.

(5) Pcview piping analysis and support / restraint interface methods and procedures and take actions necessary to prevent future problems in this area.

Schedules' for acrpletion of the above corrective action iters for Units 1 eJd 2 are as follows:

Ca'pletion Date

, Corrective Action Itan Unit 1 Unit 2 (1)- Identification Co:pletc 6/1/81 (2) Engr. Review 12/19/80 Per Unit 2 Construction Schedule (3) Sketch Revision 12/19/80 Per Unit 2 Construction Schedule 3 (4) Hardwure Changes 1/28/81 Per Unit 2 Ccnstruction Schedule (5) Prccedure Confinration -

3/1/81 All of the above itens are wall underway for Unit 1 and results to date confirm the expected minimum number and type of structural changes.

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