ML20081M171
| ML20081M171 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 10/28/1983 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Murley J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 2NRC-3-081, 2NRC-3-81, 83-08, 83-8, NUDOCS 8311170124 | |
| Download: ML20081M171 (4) | |
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$VL vgg 2NRC-3-08i (412) 787 - 5141 Telecopy Nuclear Construction Division October 28' 1983 Robinson Plaza, Building 2, Suite 210 Pittsburgh, PA 15205 United States Nuclear Regulatory Commission Region 1 631 Park Avenue King of Prussia, PA 19406 ATTENTION:
Dr. Thomas E. Murley Adminis tra to r
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Do cke t No. 50-412 Heavy Wall Thickness on Diesel Generator Exhaust System Significant Deficiency Report No. 83-08, Final Report Gentlemen:
This is the Final Report in reference to the pot ent i al ly repo rt ab le Significant Deficiency relating to the use of nuninal wal 1 thic kn es s of fittings to determine the weight used as design input to stres s calculat ions.
An evaluation has been completed to determine the impact of the thick wall fittings on the diesel generator exhaust piping system and concludes there is no safety implication.
Pursuant to the requirement s of 10CFR50.55(e), it is anticipated that no additional reports on this matter need to be submitted.
DUQ'IESNE LIGHT COMPM4Y By Sf 8311170124 031028 PDR ADOCK 05000412 f*" #
S PDR Vice President JS/vjs At t acSment cc:
Mr. R. DeYoung, Director Of fice of Inspect ion and Enforcement (3) (w/ attachment)
Mr. G. Walton, NRC Resident Inspector (w/ attachment)
Ms. L. Lazo, Project Manager (w/ attachment)
NRC Document Control Desk (w/ attachment)
INPO Records Center (w/ attachment)
SUBSCRIBED AND JkpRNjTO B2 FORE ME THIS jfMAY OF /(///,lj 1983.
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Notary Public
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i.LVA G. LESONC/K NOTARY PUBLIC
/f ROBINSON TO'//NSHIP, ALLEGHENY COUNTY MY COMMISSION EXPIRES OCTOBER 20,19S6
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.Unitsd Ststes Nuclear Regulctory Commission Dr. Thonca E. Murley Page 2 COMMONWEALTH OF PENNSYLVANIA )
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- COUNTY 0F ALLEGHENY
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, be fo re me, a On' this J[
day of Notary Public in and fo r said Commonwealth and County, personally appeared E.'J. Wooleve r, who being duly sworn, deposed and said that (1) he is Vice P res ident of Duquesne Light, (2) he is duly ainthorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Submittal are true stil correct to the bes t of his knowledge.
bh Not ary Public ELVA G. LESGNDAK, NOTARY PUBLIC ROBINSON TOV /NSHI?, ALLECHENY COUNTY MY COMMISS!ON EXPIRES OCTOBER 20,1986
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BSAVER' VALLEY POWER STATION UNIT NO. 2 DUQUESNE LIGHT Q)MPANY 4
Report on Potential Significant Deficiency No. 83-08
- Heavy Wall Thickness on Diesel Generator Exhaust System"
' l.
SUMMARY
-During a routine -safety ins pect ion by the NRC res ide nt -ins pe ct o r, the emergency diesel generator exhaust fittings (spools EDG 3-1 and EDG 14-1) were - found to have thicknes s read ing s of 0.75 in., which is twice their
-nominal value.
This was cited as an Item of Violation in Inspection No.
- 50-412/83-07.
2.
IMMEDIATE ACTION TAKEN Mr. E.
F.
Kurtz, ' Jr., ' Manage r of Duquesne Light Com pa ny's Regula to ry
~
l Af fairs Department, not ified Mr. Lowell Tripp of the NRC Region I of fice on June 27, 1983, on this pot ent ially report ab le de fic i ency.
An engi-neering evaluation was unde rt aken to determine the report ability status of tre exhaust system.-
3.
DESCRIPTION OF DEFICIENCY (Extracted -from NRC Ins pect ion Report 83-07 dated June 10, 1983)
In the diesel generator exhaust system, two fittings, EDG-3-1 and EDG : 1, while being ins t al led we re found i to. have thicknes s me as ur ement s of 0.75 in., which is twice the 0.375 in. nominal wall. The sys tem cont ains o'ne 90* long radiu's El1, ' two 45* Ell's, one 38 in, standard tee, one 38 in. flange, and two 38 in. s t anda rd pipes.
The fittings were ordered from Ladish Company'as 38 in. standard (0.375 nominal wall).
The actual wall thickness measurements performed by site quality control by request of the NRC,. found ' the 90* elbow, the two 45' elbows, and the one tee to
.have' an average wall thickness of 0.750 in.
The stress calculations fo r this system were based on the nominal wall thickness.
s 4. -ANALYSIS OF SAFETY IMPLICATIONS At the time of the ci t ed deficiency, the analys is of the EDG exhaust system was ' documented in calculation 12241-NP(T)-X60K-1.
The calcula ted loads on the exh au s t silencer nozzles (from the above calculation) were documented in nozzle Lad summary 12241-NP(T)-NL-526-0.
Since the allow-able nozzle loads were not ava ilab le, the nozzle load summary was appro-priately marked " confirmation required" until the calculated loads would be reconciled agains t the allowables.
Since that time, the nozzle load s have' been reconciled by SWEC and a support sys tem finalized.
The final-
'ized analysis is document?d in calculation 12241-NP(B)-X60K-3.
However, to demons tra t e that the ci ted de ficiency would not have any 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 document ed in calculation 12 241-NP(B)-369-X6-0.
A comparison of the. result s of the analyses (heavy wal L vs. s t anda rd weight fittings), document ed in calculat ion 12241-NP(B)-369-X6-0, indi-cate that the s tres s levels (including suppo rt s and equipment nozzle loads) would have remained within acceptable limits had the heavy wall fittings not been included in - the piping analysis of the EDG exhaust piping.
'Ihe primary concern for the EDG exhaust system was the increase and redistribution of the de adwe igh t ef fect s.
Calcula t io n 12241-NP (B)-
369-X6-0 shows that the redis tribut ed and increased de adwe igh t remains accept ab le.
Thermal ' ef fect s due to - revised elbow flexibility is not a concern since the sys tem is fr ee-ended.
Seismic ef fect s are also not a real concern due to the many conservative as sumpt ions in the analys is such as cons e rvat ive load input, load conbinations, low damping values,
peak broadening of ARS, enveloping ARS, and 'the considerations of spatial and modal components, coupled with low allowable stres ses.
This will be confirmed by SWEC's generic s tudy to assess the ef fect s of heavy fit-t ing s.
The generic study is currently in the process of being finalized and will be' included in the additional response to NRC Inspection Report 83-07 as per the commitment 'in the ~ letter to Mr. R.
W. Staros tecki fr om Mr. E. J. Woolever (2NRC-3-064 dated August 22, 19 83 ).
This engineering evalua t ion of the EDG exhau s t system concludes there is no safety implica t ion.
5.
CORRECTIVE ACTION TO REMEDY DEFICIENCIES Corrective action for the' diesel generator exhaust system is not requi red since there are no safety implications.
6.
ADDITIONAL REPORTS This is the final report concerning the heavy wall thicknes s on the Diesel Generator Exhaust System.
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