ML20024F541
| ML20024F541 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/12/1983 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20024F536 | List: |
| References | |
| 2NRC-3-041, 2NRC-3-41, NUDOCS 8309090463 | |
| Download: ML20024F541 (3) | |
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$VL 2NRC-3-041 (412)787 - 5141 Telecopy 4 Nuclear Construction Division Robinson Plaza, Building 2, Suite 210 July 12, 1983 Pittsburgh, PA 15205 United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 ATTENTION:
Mr. Richard W. Starostecki Division of Project and Resident Programs
SUBJECT:
Beaver Valley Porar Station - Unit No. 2 Docket No. 50-412 USNRC IE Inspection Report No. 50-412/83-07 Gentlemen:
This is in res pons e to the Item of Vio la t ion ci t ed in Ins pect ion No. 50-412/ 83-07 and listed in Appendix A (Not ice of Vio la t ion) a t t ached to your le t t er to Mr.
E.
J. Woolever, dated June 10, 1983.
NOTICE OF VIOLATION:
10 CFR 50, Appendix B, Criterion III requires that me asur es shall be es t ab li shed to as sur e that the de s ign ba s is is c o r-rectly trans la t ed into spe ci fica t ions, dr awi ng s, pr oced ur es,
and direct ions.
Chapter 17 of the PS AR commits to WASH 1283, Revis ion 1, s ich includes Regulatory Guide 1.64 wh ich, in turn, endorses ANSI N45.2.11, Draf t No. 3, Revision 1 - July, 1973.
ANSI N45.2.11 requires that design act ivities be ac compli shed s uch that ap plicab le de s ign inputs are correctly trans la t ed into the s pe ci fica t ions, dr awing s, pr oced ur es, and ins truc-t io ns.
The de s ign input is req uir ed to be s peci fied to the level of detail necessary to pe rmi t the design act ivity to be carried out in a correct manner.
Contrary to the ab ove, as of May 2 3, 1983, de ad we igh t, a design input fo r stress analyses fo r piping compo nent s and s uppo rt s, was not trans la t ed into pr ocur ement s peci fica t ions for pipe fittings to the level of detail necessary to pe rmi t s uch design analyses to be ca rried out in a correct manner.
As a result, the calcula t ions fo r piping compo nent s EDG 3-1 and EDG 14-1 were incorrectly pe rfo rmed in that the actual wall th icknes s and weight of elbows and tees used in the 8309090463 830823 PDR ADOCK 05000412 G
United States Nuclear Regulatory Commit,aion Mr. Richard W. Starostecki Page 2 ins tallation were ab out twice the nominal values used in procurement specifications and design analyses.
This is a Severity Level IV Violation (Eupplement II).
RESPONSE
The use of represent ative values of variables that influence piping analysis, including the use of nominal wall thickness
. for pipe and fittings versus actual thickness (actual damping, actual material prope rt ies, actual structural nonlinearities,
etc.) provides adequate assurance that the piping systems will perform their design funct ion.
This approach has been proven through many ye ars of success in operating plant s, some of which have been subjected to significant loads.
The alt erna-t ive is to attempt to accurately quant ify each and every this is neither pract ical nor cos t ef fect ive.
variable Therefore, we do not consider the use of nominal thickness of fittings to be inappropriate for piping analysis.
Further analysis shows that the ef fect s of increased fitting thickness are not immediately obvious and depend on individual piping system geometry and loading environment. The result ant increase in elbow stif fnes s, for example, may un load one suppo rt at the expense of another, while the increased thick-nes s would also result in a reduced s tr es s int ens ifica tion f acto r in the elbow or_ tee, which often is the controlling s tress -in the piping system.
Similar ef fect s would occur fo r l
thermal loading, that. is, there would be some redis tribut ion of loads among su ppo rt s, but the ef fect s on the calcula t ed pipe _ stress are unlikely to be significant.
The ef fect s in a i
dynamic loading environment, such as earthquakes, has similar unce rt aint ies.
The mass would increase with increased thick-j nes s, but so would stif fness of elbows and tees.
This would i
t end to cancel ef fect s on dynamic response and is cons ide red to be les s significant than other variab les, part icularly in i
view.of the significant margin of safety in the ove rall
[
seismic analysis process.
Beaver Valley - 2 is reanalyzing the exhau s t piping cited in the infract ion. This system is not representative of ASME III i
piping sys t ems, since it is in fact a low pr es sur e, high l
temperature duct system which carries the exhaust gasses away from the diesel ge nera to r and exhau s t s them to atmosphere.
typically more complex, higher ASME III piping sys t ems are pres sure closed sys tems, that involve various other components s uch as valves, pumps, heat exch ange rs, etc.
The refo re, it i-would not be ap propriat e to fo rm any ge neral conc lusions i
i-t
United States Nuclear Regulatory Commission Mr. - Richard W. Staros tecki Page 3 regarding the ef fects of increased fitting thickness on piping s tr es s analysis from the results of the analysis of this exhaust sys tem.
The reanalysis is expected to be completed by August 5,1983, and would be available to the Resident Ins pec-tor upon req ue s t.
With respect to the generic influences of heavy wall fittings, we are reviewing the ef fects of selected NRC benchmark piping problems (Reference 2) and will report on the progress in this regard by August 20, 1983.
DUQUESNE LIGHT COMPANY By e
E. J/. Noolever Vice President JS/wjs cc:
Mr. G. Walton, NRC Resident Inspector Ms. L. Lazo, Project Manager NRC Document Control Desk
REFERENCES:
1.
NRC letter Docket No. 50-412 dated June 10, 1983 2.
Piping Benchmark Problem, Dynamic Analysis, NUREG-CR/1677 and BNL-NUREG-51267, Vol. 1 COMMONWEALTH OF PENNSYLVANIA )
)
SS:
COUNTY OF ALLEGHENY
)
On this
/.2 M day of
//[3 before me, a Notary Public in and for said Commonwealth and County, personally appeared E.
J.
Woolever, who being duly sworn, deposed and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the fo regoing S ubmi t tal on behalf of said Company, and (3) the s tatement s set fo rth in the Submittal are true and correct to the best of his knowledge, fl LL ($uld b1b Not ary Pub lic ANITA ELAINE REITER, NOTARY PUBLIC ROBINSON TOWNSHIP, ALLEGHENY COUNTY MY COMMISSION EXPIRES OCTOBER 20,1986