RS-12-202, Supplement to the Dresden Nuclear Power Station Fifth Inservice Inspection Interval Relief Request I5R-01

Supplement to the Dresden Nuclear Power Station Fifth Inservice Inspection Interval Relief Request I5R-01

ML123250319
Person / Time
Site:	Dresden
Issue date:	11/19/2012
From:	Simpson P Exelon Generation Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
RS-12-202
Download: ML123250319 (4)

Text

1 RS-12-202 10 10 CFR 50.55a November 19, 2012 November U. S. Nuclear Nuclear Regulatory Regulatory Commission Commission ATTN: Document Control Control Desk Washington,D.C.

Washington, D.C. 20555-0001 Dresden Nuclear Power Station, Dresden Units 2 and 3 Station, Units Renewed Facility FacilityOperating License Nos. DPR Operating License DPR 19 and DPR-25 NRC Docket NRC Docket Nos.

Nos. 50-237 50-237 and 50-249

Subject:

Supplement to the Dresden Nuclear NuclearPowerPowerStation StationFifth FifthInservice InserviceInspection Inspection Interval Relief Request Interval Request 15R-01 15R-01

Reference:

from D.

Letter from D. M.

M. Gullott Gullott(Exelon (Exelon Generation Generation Company, Company, LLC LLC (EGC))

(EGC>> to to U.

U. S.

S.

NRC, "Dresden NuclearNuclear Power Power Station, Station,UnitsUnits22andand3,3,Fifth FifthInterval Inservice Intervallnservice Inspection Program Inspection Program Plan Plan and and Relief Relief Requests,"

Requests," dateddated September 28, 2012 28,2012 In the In the referenced letter, letter, EGC EGC submitted relief relief requests associated associatedwith withthe thefifth fifth inservice inservice inspection (ISI) interval for Dresden Nuclear Power Station (lSI) interval for Dresden Nuclear Power Station (DNPS), Units 2 (DNPS), Units 2 and 3. Upon Uponfurther further review of review of Relief Relief Request Request 15R-01, 15R-01, itit became became apparent that that 10 10 CFR CFR 50.55a 50.55a (a)(3)(ii)

(a)(3)(ii) is the appropriate relief appropriate reliefcriterion criterionforforthis thisrequest.

request.Therefore, Therefore,EGC EGCrequests requests toto supersede supersede the theversion version of 15R-01 15R-01 in in the referenced letterletter with with the version version in in the the attachment attachmenttotothisthisletter letterininitsitsentirety.

entirety.

EGC EGC continues to request approval approval of of this this relief relief request request by by September September 28, 2013, 2013, to to support support examination of components components during during the DNPS, DNPS, UnitUnit 22 Fall Fall 2013 2013refueling refueling outage outagewhichwhichfallsfalls within within the fifth 10-year ISI interval.

fifth 10-year lSI interval.

There There are are nonoregulatory regulatorycommitments commitmentscontained containedwithin within this this letter.

letter.

Should you have have any anyquestions questionsconcerning concerningthis thisletter, letter,please pleasecontact contactMr.Mr.Mitchel MitchelA. A.Mathews Mathewsatat (630) 657-2819.

Patrick R.R. Simpson Simpson Manager Manager - Licensing Licensing Exelon Generation Company, LLC LLC

Attachment:

10 CFR CFR 50.55a 50.55aRequest RequestNumber Number15R-01, 15R-01,Revision Revision 11

ATTACHMENT 10 CFR CFR 50.55a SO.SSaRequest RequestNumber Number15R -01, Revision ISR-01, Revision 11 Proposed Alternative Alternative In In Accordance Accordance with with 1010 CFR CFR 50.55a(a)(3)(ii)

SO.SSa(a)(3}(ii}

--Hardship

--Hardship or or Unusual Unusual Difficulty Difficulty without without Compensating Compensating Increase Increase in in Level of Quality and Safety-- Safety--

1. ASME ASME Code Code Component(s)

Component(s)Affected: Affected:

Class:

Code Class: 11

Reference:

IWB-2500, IWB-2500, Table Table IWB-2500-1 IWB-2500-1 Category:

Examination Category: B-D Item Number: B3.100 83.100

Description:

Inspection of Standby Standby Liquid Liquid Control Control Nozzle Nozzle Inner InnerRadius Radius Component Number:

Component Number: Unit 2: N12-1 N12-1 Unit 3: N12-1 N12-1 Number:

Drawing Number: Unit 2:

2: ISI-128, ISI-128, Sheet Sheet 33 Unit 3: ISI-125, Sheet 3: ISI-125, Sheet 33 Applicable

2. Code Edition Applicable Code and EditionAddenda:

and Addenda:

Dresden Nuclear The Dresden NuclearPowerPowerStation Station(DNPS),

(DNPS), UnitsUnits 22andand33Inservice InserviceInspection Inspection Program is based basedon onthe theAmerican AmericanSociety SocietyofofMechanical MechanicalEngineers Engineers(ASME) (ASME) BoilerBoiler and Pressure Vessel Pressure Vessel(B&PV)(B&PV) Code, Code, Section Section XI, XI, 2007 Edition Edition through the 2008 Addenda.

3. Applicable Applicable Code Code Requirement:

IWB-2500 IWB-2500states states that that components components shall shall be examined and tested tested as asspecified specified in in Table IWB-2500-1.

Table IWB-2500-1.

Table IWB-2500-1 IWB-2500-1 requires aa volumetricvolumetric examination to be be performed performed on on the theinner innerradius radius section of all all reactor reactor pressure vessel nozzles pressure vessel nozzleseach eachinspection inspectioninterval.

interval.

Reason 4. forReason Request: for Request:

Pursuant Pursuant to 10 10 CFR CFR 50.55a(a)(3)(ii),

50.55a(a)(3)(ii), reliefrelief isis requested requested on the the basis basisthat thatconformance conformancewith with the Code requirements requirements impose imposehardship hardshipwithout without aa compensating compensatingincrease increaseininthethelevel levelofof quality andand safety.

StandbyLiquid The Standby Liquid Control Control (SBLC)

(SBLC) nozzle, as as shown shownininFigure Figure15R-01.1, 15R-01.1, isis designed designedwith with an integral integral socket socket to to which which the the boron boron injection injection piping is fillet filletwelded.

welded. The SBLC nozzle is located near near the the bottom bottom of of the the vessel vesselin in an anarea areawhich whichisisinaccessible inaccessiblefor forultrasonic ultrasonic examinations from from thethe inside inside ofof the the vessel. Therefore, ultrasonic vessel. Therefore, ultrasonic examinations would need to be performed performed from from the outside diameterdiameter of of the vessel.

vessel. As Asshown shownininFigure Figure15R-01.1, 15R-01.1, thethe ultrasonic scan would need ultrasonic need to to travel travel through the full full thickness thickness of of the the vessel into a complex cladding/socket configuration.

configuration. These Thesegeometric geometricand andmaterial materialreflectors reflectorsinherent inherentin in the the design prevent prevent aa meaningful meaningful examination examination from from being performed on the inner inner radius of of the SBLC nozzle.

In In addition, addition,the the inner inner radius radius socket attaches attachesto topiping piping which which injects injects boron boron atat locations locations farfar removed from from thethe nozzle. Therefore, Therefore, the theSBLC SBLC nozzle nozzle inner inner radius radius isis not not subjected subjectedto to turbulent mixing mixingconditions conditionsthat thatareare aa concern concern at other nozzles.

Page 1 of 3

ATTACHMENT 50.55a Request 10 CFR SO.SSa Request Number Number15R-01, ISR-01, Revision Revision 11 Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(ii)

Proposed SO.SSa(a}(3}(ii}

--Hardship or Unusual Difficulty without Compensating Increase in in Level Level of Quality and Safety--

Compliance with with the the applicable applicable Code Code requirements would require an ultrasonic ultrasonic examination examination to be performed performed on on the the outside outside diameter diameter of ofthe thereactor reactorpressure pressure vessel. Geometric and vessel. Geometric material material reflectors reflectors would would prevent prevent a meaningful examination, resulting resulting in inaccurate inaccurate data.

data.

Based on this, this, the Code requirements impose hardship without without aa compensating increase increase in in the level of quality quality and and safety inin accordance accordance with with 10 10 CFR CFR 50.55a(a)(3)(ii).

50.55a(a)(3)(ii).

ProposedS.

5.Alternate Proposedand Basis Alternate for for and Basis Use:Use:

As an alternate examination, Exelon Generation Company, LLC LLC will willperform perform aa VT-2 visual examination examination of of the the subject subject nozzles DNPS, Units nozzles at DNPS, Units 22 and and 33each eachrefueling refuelingoutage outageinin conjunction conjunctionwith withthe theClass Class 11 System System Leakage Test. Test.

6. Duration of Proposed Alternative:

Alternative:

Relief is requested requested forfor the Fifth Fifth Ten-Year Ten-Year Inspection Interval Intervalfor forDresden Dresden Nuclear Nuclear Power Station Units Units 2 and 3.

7.

Precedents:

7. Precedents:

DNPS, Units Units 22 and and 33fourth fourth inspection inspection interval interval Relief Relief Request Request14R14R-01 was authorized

-01 was authorized in in an NRC NRC safety evaluation evaluation (SE)

(SE) dated September 4, 2003. The Thefifth fifth inspection interval interval relief (Le., 15R-01, relief request (i.e., 15R-01, Revision 1) 1) utilizes utilizes aasimilar similar approach approach thatthat was waspreviously previously approved.

Quad Cities Cities Nuclear Nuclear Power Power Station, Station, Units Units 11and and22fourth fourth inspection inspectioninterval intervalRelief Relief 14R-01 was Request 14R-01 was authorized authorized in in an an NRC NRC SE SE dated January 28, dated January 28, 2004.

2004.

Page 22 of of33

ATTACHMENT ATTACHMENT 10 CFR CFR 50.55a 50.55a Request RequestNumber Number15R-01, 15R-01,Revision Revision11 Proposed Alternative In In Accordance Accordance withwith 1010 CFR CFR 50.55a(a)(3)(ii) 50.55a(a}(3}(ii}

--Hardship or or Unusual Unusual Difficulty Difficulty without without Compensating Compensating Increase in Level ofof Quality Quality andand Safety--

Safety--

Vessel Vessel (Mn-Mo)

(Mn-MO)\

1. D. Cladding I.D.

Safe-End (Stainless Steel)

Steel) Nozzle (Stainless Pipe (Mn-Mo)

(Stainless Steel) 1 15/16" 1/8" Min 3/4" R Min 6 3/8" FIGURE 15R-01.1: Two (2) Inch FIGURE 15R-01.1: Inch Standby Standby Liquid Liquid Control Control Nozzle Nozzle Page 3 of3of 3