ML20100J852
| ML20100J852 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 10/25/1984 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20100J856 | List: |
| References | |
| 2NRC-3-076, 2NRC-3-76, NUDOCS 8412100482 | |
| Download: ML20100J852 (5) | |
Text
t-2NRC-3-076 (412)787 - 5141 Telecopy 7-Nuclear Construction Division October 25, 1983 Robinson Plaza, Building 2, Suite 210 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 Power Station - Unit No. 2 Do cke t No. 50-412 Additional Report to USNRC IE Inspection Report No. 40-512/83-07 r
Gentlemen-This le t ter pr ov ides additional information relative to our previous
/
response to the subject Inspection Report.
As per the commitment s made in Reference 7, this letter provides the
)
Final Report of the influences of heavy wall fittings on the emergency diesel generator exhaust system and the generic influences of heavy wall fittings on selected NRC benchmark piping problems (Reference 2).
Beaver Valley Unit 2 h as emple ted as ses sing the ef fects of heavy wall fittings on the emergency diesel generator exhaust system for comparison with the standard approach of using ~ nominal wall fittings for pipe stress modeling.
The final disposition and assessment for both the generic study and the specific diesel generator I.
exhaust system is attached.
[
SUBSCRIBED AND S ' RN O BEFORE ME THIS DUQUESNE LIGHT COMPANY
[ Y DAY OF
, 1983.
BI '
LVA G. LESONDAK, NOTARY Pgp Puh E(/J. Woolever ROBINIC-N TOWNSHIP, ALLEGHENY COUNTY Vice President f.iY COMMISSION EXFIRES OCTOBER 20,1986 JS/wjs At tachment s :
- 1) Report on Potential Significant Deficiency No. 83-08, " Heavy Wall Thickness on Diesel Generator Exhaust System"
- 2) (B2-12241-65) " Structural Review of Piping Analysis Includ-ing Ef fect of Heavy Elbows," October 1983 cc:
Mr. G. Walton, NRC Resident Inspector (w/ attachment)
Ms. L. Lazo, Project Manager (w/ attachment)
NRC Document Control Desk (w/ attachment) 8412100482 841025 PDR ADOCK 05000412 l
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' United Stctec Nuciscr _Rigulctory Commission-Mr. Richard W. Staros tecki
~ Page 2
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 3.
2NRC-3-041, dated July 12, 1983 4.
2NRC-3-048, dated July 20, 1983
-5.
2DLS-18336, dated August 17, 1983 6,
2DLS-18337, dated August 17, 1983
- 7. ' 2NRC-3-064, dated August 22, 1983 8.
2DLS-18931, dated October 17, 1983 9.
2DLS-18946, dated October 17, 1983 3
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' United Stctco Nuclear RIgulatory Commiesien Mr. Richard W. Starostecki:
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Page 3 COMMONWEALTH OF PENNSYLVANIA )
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SS:
. COUNTY OF ALLEGHENY.
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, before me, On ' this j [
day of _
a. Notary Public in and for said Commonwealth and County,.pe rsonal ly appe ared 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 exe -
cute and file the foregoing Submit t al on behalf of said Company, and - (3) the statements set fo rth in the Submittal are true and correct to the bes t of - his knowledge.
Not ary Public
~
ELVA G.' LESONDAK, NOTARY PUBLIC RCBINSON TOWNSHIP, /,'.LEGHENY COUNTP MY COMMISSION EXPIREROCTOBER 20,1986;
W4 o-I 6'
- BEAVER VALLEY POWER STATION UNIT NO. 2 DUQUESNE LIGHT COMPANY ATTACHMENT 1 Report on Potential Significant Deficiency No. 83-08
" Heavy Wall-Thickness on Diesel Generator Exhaust System" 1.
SUMMARY
During a routine safety ins pect ion by. the NRC r es ide nt ins pecto r, the
- emergency diesel generator exhaus't fittings (spools EDG 3-1 and EDG 14-1) were found to have thicknes s readings of 0.75 in., which is twice their nominal value.
This was cited as an Item of Violation in Inspect ion No.
50-412/83-07.
2.
IMMEDIATE ACTION TAKEN Mr. E.
F.
Kur t z,, J r., Manager of Duquesne Light Company's Regulatvry d
Af fairs Department, notified Mr. Lowell Tripp of the NRC Regio'n I of fice on June 27, 19 83, on this potentially reportable de fic iency.
An engi-neering. evaluation was undertaken to determine the-reportability status of the exhaust system.
- 3.. DESCRIPTION - OF DEFICIENCY. (Extracted from NRC Ins pect ion ' Repo rt 83-07 dated June 10, 1983)
In the diesel generator exhaust system, two fit tings, EDG-3-1 and EDG 1, while be'ing installed were found to have.thicknes s measurements of, 0.75 in., which is twice the 0.375 in, nominal wall. The system contains one 90* long radius Ell, two 45* Ell's, one 38 in. ' standard t'ee, one 38
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flange, and two 38 in. standard pipes.
The fittings were -ordered '
in.
from Ladish Company as 38 in. standard (0.375 nominal wall).
The actual wall thickness measurements performed by site quality control by request ofLthe NRC, found the ' 90* elbow, the two 45* elbows,' and the one tce to have an ayerage wall thicknes s of 0.750 in.
The stres s' calculations fo r this system were based on the nominal wall thickness.
4.
ANALYSIS OF SAFETY IMPLICATIONS At the time of the ci ted de f ic i ency, the analysis.of the EDG exhau st system was documented in calculation 12241-NP(T)-X60K-1.
The calculated loads on the exh au s t silencer nozzles ( fr om the ab ove calculation) were documented in nozzle load summary L2241-NP(T)-NL-526-0.
Since the allow-able nozzle loads were not ava ilab le, the nozzle load summary was appro-priately marked "c onfi rma t ion req'uired" unt il the.'calculat ed loads would be reconciled agains t the al lowab les.
Since that' time, the nozzle, loads have been reconciled by SWEC and a support - sys tem finalized.
The final-ized analysis is documented in calculation 12241-NP(B)-X60K-3.
However, to demonstrate that the ci ted deficiency would not - have any i
detrimental impact on the analysis res ult s, the finalized support system was remodelled and reanalyzed to include the ef fect s of the heavy wall fittings.
This analysis is documented in calculation 12241-NP( B)-369-X6-0.
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- A': comparison of 'the ; result s of the analyses (he avy ' wall vs. s tanda rd weight. ' fittings), documented in calculation - 12241-NP(B)-369-X6-0, - indi '
. cate' th'at, the stress levels 1(including support s ' and. equipment"; nozzle,
J
- loads) would 'have. remained ' within acceptable limits had L the heavy fwall fit tings 1 not. ' been included: in_ the piping analysis of the,EDG : exhaust
- piping.
The primary concern for..the EDG - exhaust 'sy's tem w'as the. increase.'
.'and - redistribution of _ the deadweight' ef fect s.
. Calculation 12241-NP(IO -
369-X6-0 shows that the redistributed ' and increased de adweigh t rema ins accept ab le.
Thermal ef fects due to revised. elbow flexibili ty l is not ~ a concern since the.sys tem is fr ee-e nd ed.
Seismic ef fects are also not a real concern due to -the many conservative as sumpt ions in the ' analys is'
- s uch = as conse rvative load input,. load combinations, ' low ' damping values,
peak broadening of ARS,. enveloping ARS, and the considerations of spatial
- and modal component s, coupled with ' low allowable.stres ses.
This will be confirmed by: SWEC's generic. study to as ses s the - ef fect s 'of' heavy fit-
. tings. _ The generic study is. currently in the _ process of being finalized a'nd.. will be included in the : additional response to NRC Inspection Report
=
. 83-07 as per the commitment in the letter 2NRC-3-064, dated ; August 22,
~
1983.
This engineering evaluation of the EDG exhaust sys tem concludes
- there is no safety implication.
5.
CORRECTIVE ACTION TO REMEDY DEFICIENCIES
' Correct ive action for the diesel generator exhaust.sys tem is not. required C1
~ ince there ~are no safety implications.
s
- 6. ^ ADDITIONAL REPORTS t
_ ' This 1 is the final ' report. conce rtiing the heavy wall' thicknes s oa-the Diesel Generator Exhaust-System.
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