ML14310A187
ML14310A187 | |
Person / Time | |
---|---|
Site: | Millstone ![]() |
Issue date: | 10/31/2014 |
From: | Sartain M D Dominion, Dominion Nuclear Connecticut |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
14-524 | |
Download: ML14310A187 (11) | |
Text
1JrDomi n ionDominion Nuclear Connecticut, Inc.5000 Dominion Boulevard, Glen Allen, VA 23060Web Address: www.dom.comU.S Nuclear Regulatory CommissionAttention: Document Control DeskWashington, DC 20555October 31, 2014Serial No.NSSL/MLCDocket No.License No.14-524RO50-336DPR-65DOMINION NUCLEAR CONNECTICUT, INC.MILLSTONE POWER STATION UNIT 2LICENSE AMENDMENT REQUEST TO REVISE THE FINAL SAFETY ANALYSISREPORT -EXAMINATION REQUIREMENTS FOR ANSI B31.1.0 PIPING WELDSPursuant to 10 CFR 50.90, Dominion Nuclear Connecticut, Inc. (DNC) hereby requests anamendment to Facility Operating License No. DPR-65 for Millstone Power Station Unit 2(MPS2). This amendment request proposes to revise the MPS2 Final Safety AnalysisReport (FSAR) to allow the use of the encoded ultrasonic examination technique in lieu ofthe FSAR committed additional radiography examination for certain piping welds fabricatedto ANSI B31.1.0.Attachment 1 provides the description, technical analysis, regulatory analysis andenvironmental analysis for the proposed amendment. A mark-up of the proposed changesto the MPS2 FSAR are provided in Attachment 2.The proposed amendment does not involve a significant hazards consideration pursuant tothe provisions of 10 CFR 50.92. The Facility Safety Review Committee has reviewed andconcurred with the determination herein.Issuance of this amendment is requested by October 30, 2015 with the amendment to beimplemented within 30 days of NRC approval.In accordance with 10 CFR 50.91(b), a copy of this request is being provided to the State ofConnecticut. .Should you have any questions in regard to this submittal, please contact Wanda Craft at(804) 273-4687.Sincerely,M. D. SartainVice President -Nuclear EngineeringCRAIG D SLYCommonwealth of VirginiaCommonweali of ,i iReg. # 7518653My Commission Expires December 31,COMMONWEALTH OF VIRGINIACOUNTY OF HENRICO)))The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mark D. Sartain, who is VicePresident -Nuclear Engineering of Dominion Nuclear Connecticut, Inc. He has affirmed before me that he is duly authorized to execute and file theforegoing document in behalf of that Company, and that the statements in the document are true to the best of his knowledge and belief.Acknowledged before me this .1 cday of 6)17 9-t'< , 2014.My Commission Expires: 1/ lbNotypWic4Q55 Serial No. 14-524Docket No. 50-336Page 2 of 2Commitments: None.Attachments:1, Evaluation of Proposed Change2. Mark-up of Proposed FSAR Changescc: U.S. Nuclear Regulatory CommissionRegion I2100 Renaissance Blvd, Suite 100King of Prussia, PA 19406-2713Mohan C. ThadaniNRC Senior Project ManagerU.S. Nuclear Regulatory Commission, Mail Stop 08 B1One White Flint North11555 Rockville PikeRockville, MD 20852-2738NRC Senior Resident InspectorMillstone Power StationDirector, Bureau of Air ManagementMonitoring and Radiation DivisionDepartment of Energy and Environmental Protection79 Elm StreetHartford, CT 06106-5127 Serial No. 14-524Docket No. 50-336ATTACHMENT IEVALUATION OF PROPOSED CHANGEDOMINION NUCLEAR CONNECTICUT, INC.MILLSTONE POWER STATION UNIT 2 Serial No. 14-524Docket No. 50-336Attachment 1, Page 1 of 6Evaluation of Proposed Change1.0 SummaryPursuant to 10 CFR 50.90, Dominion Nuclear Connecticut, Inc. (DNC) herebyrequests an amendment to Facility Operating License No. DPR-65 for MillstonePower Station Unit 2 (MPS2). This amendment request proposes to revise theMPS2 Final Safety Analysis Report (FSAR) to allow the use of the encodedultrasonic (UT) examination technique in lieu of the FSAR committed additionalradiography (RT) examination for certain piping welds fabricated to ANSI B31.1.0.2.0 Proposed AmendmentDNC proposes to amend the MPS2 FSAR to allow the use of the encoded UTexamination technique in lieu of the FSAR committed additional radiography (RT)examination for certain piping welds fabricated to ANSI B31.1.0. Specifically, DNCproposes to revise Figure 9.0.3, General Piping and Instrumentation DiagramLegend Notes, to delete the references to "radiography" and replace them withvolumetric examination." The figure number and title have also been added to thispage. A mark-up of the proposed FSAR change is provided in Attachment 2.3.0 Technical EvaluationDNC is proposing this change to allow the use of the encoded UT examinationtechnique in lieu of the FSAR committed additional RT examination for certainpiping welds fabricated to ANSI B31.1.0. Similar techniques are being usedthroughout the nuclear industry for examination of dissimilar metal welds, overlaidwelds, and ANSI B31.1.0 piping replacement welds. This proposed changeincludes requirements that provide an acceptable level of quality and safety.Table 1.2-1 of the MPS2 FSAR summarizes the codes and standards forcomponents of water-cooled nuclear power units. Certain piping systems orportions of piping systems designed and fabricated to ANSI B31.1.0 have beendesignated to have additional testing and examination requirements performedover and above those required by the code. RT has been specified as theadditional volumetric examination method for the selected piping systems. At thetime of the commitment to perform the additional volumetric examination(Reference 6.1), RT was the appropriate non-destructive examination (NDE)method for volumetric examination to satisfy the code requirements. However,with the advances in technology, the UT examination method has become anacceptable alternative to performing RT for volumetric examinations. The latereditions of the ANSI B31.1.0 Code (now referred to as the ASME B31.1 Code),2004 Edition and later, has included UT examination as an alternative to RT tosatisfy the volumetric examination requirement.
Serial No. 14-524Docket No. 50-336Attachment 1, Page 2 of 6The proposed change to the MPS2 FSAR commitment is to allow the use of theUT examination technique to perform the volumetric examination, whereappropriate, as incorporated into the later editions of the ASME B31.1 Code. It isrecognized that not all weld joint configurations allow effective use of the UTexamination method to obtain the necessary coverage of the examination volume.For those joint configurations where effective coverage cannot be obtained with UTexamination techniques, RT is still applicable to satisfy the volumetric examinationcommitment.The later ASME B31.1 editions require the use of encoded technology when usingUT for the weld examinations. The encoded UT examination technology iscapable of recording the UT data to facilitate the analysis by a third party andprovides repeatability for subsequent examinations. In addition, the encoded UTexamination technology provides a permanent record of the data along withimaging capabilities. The electronic data files for the UT examinations can bestored as part of the archival-quality record. In addition to the electronic data, hardcopy prints of the data can also be included as part of the record that allowsviewing without the use of hardware or software. Examination personnel,procedures, and equipment used to collect and analyze UT data are required todemonstrate their ability to perform an acceptable examination prior to performingthe examinations.The reasons for this change are grouped into two areas; personnel safety andoutage support. The use of UT examination techniques will eliminate thepersonnel safety risk of radiological exposure associated with RT examinationscurrently required by the FSAR. Specifically, the planned exposure associatedwith transporting, positioning, and exposing a source for the RT examination, iseliminated. Reducing the potential of accidental exposure is an equally importantconsideration. Accidental exposures can occur as a result of human error,equipment malfunction or inadequate boundary control. In addition to reducingpersonnel safety risk, there is an overall reduction in dose for the examinations.This is realized by the use of an encoded scanner, remote analysis processes, andthe limited number of personnel needed to perform the examinations. The crewsize using encoded UT for the volumetric examination would require two to threepeople; whereas, RT crews range from five to fifteen people.With regard to outage support, the use of UT will reduce the time associated with agiven weld examination and subsequent documentation of examination results.The encoded UT examinations can be performed as soon as the weld joint surfaceis prepared. In addition, other outage activities in the area are not impacted duringthe examination. There is also a reduction in overall outage risk by eliminating theneed to stop and start critical maintenance and operations activities affected by theRT exclusion area. Additional savings are realized by eliminating the need forlarge amounts of support from radiation protection personnel, boundary guards,and other support personnel.
Serial No. 14-524Docket No. 50-336Attachment 1, Page 3 of 6The overall basis for this change is that encoded UT is equivalent to or superior fordetecting and sizing critical (planar) flaws as compared to the required RTexamination. This proposed use of UT as a volumetric examination methodincludes requirements that provide an acceptable level of quality and safety.Similar techniques are being used throughout the nuclear industry for examinationof dissimilar metal welds, overlaid welds, as well as other applications; includingASME B31.1 piping replacements. The use of the UT as an alternative volumetricNDE method for weld acceptance is widely documented in References 6.2 through6.16.4.0 Regulatory AnalysisNo Significant Hazards ConsiderationThe NRC has provided standards for determining whether a significant hazardsconsideration exists as stated in 10 CFR 50.92(c). A proposed amendment to anoperating license for a facility involves no significant hazards consideration ifoperation of the facility in accordance with a proposed amendment would not: 1)involve a significant increase in the probability or consequences of an accidentpreviously evaluated; or 2) create the possibility of a new or different kind ofaccident from any accident previously evaluated; or 3) involve a significantreduction in a margin of safety. DNC has evaluated whether or not a significanthazards consideration (SHC) is involved with the proposed change. A discussionof these standards as they relate to this change request is provided below.Criterion IDoes the proposed amendment involve a significant increase in theprobability or consequences of an accident previously evaluated?Response: NoPreviously evaluated accident consequences are not impacted by the proposedamendment because credited mitigating equipment continues to perform its designfunction. The proposed amendment does not significantly impact the probability ofan accident previously evaluated because those Systems, Structures andComponents (SSCs) that can initiate an accident are not significantly impacted.Based on the above, DNC concludes that the proposed amendment to the MPS2FSAR to allow the use of UT in lieu of RT examination for certain piping weldsfabricated to ANSI B31.1.0, does not involve a significant increase in theprobability or consequences of an accident or transient previously evaluated in thesafety analysis report.
Serial No. 14-524Docket No. 50-336Attachment 1, Page 4 of 6Criterion 2Does the proposed amendment create the possibility for a new or differentkind of accident from any accident previously evaluated?Response: NoThe proposed amendment does not create a new or different kind of accident fromany accident previously evaluated because previously credited SSCs are notsignificantly impacted. The proposed amendment does not involve a physicalalteration of the plant and no new or different types of equipment will be installed.There is no impact upon the existing failure modes and effects analysis; andconformance to the single failure criterion is maintained.Based on the above, DNC concludes that the proposed amendment to the MPS2FSAR to allow the use of UT in lieu of RT examination for certain piping weldsfabricated to ANSI B31.1.0, does not create the possibility of a new or differentkind of accident or transient from any previously evaluated.Criterion 3Does the proposed amendment involve a significant reduction in the marginof safety?Response: NoThe proposed amendment to the MPS2 FSAR will not cause an accident to occurand will not result in any change in the operation of the associated accidentmitigation equipment. The proposed amendment does not involve a significantreduction in margin of safety because plant response to any transient or analyzedaccident event is unchanged.Based on the above, DNC concludes the proposed amendment to the MPS2FSAR to allow the use of UT in lieu of RT examination for certain piping weldsfabricated to ANSI B31.1.0, does not involve a significant reduction in the margin ofsafety.ConclusionDNC concludes that the proposed amendment to the MPS2 FSAR to allow the useof UT in lieu of RT examination for certain piping welds fabricated to ANSI B31.1.0,does not involve a significant hazards consideration.
Serial No. 14-524Docket No. 50-336Attachment 1, Page 5 of 65.0 Environmental ConsiderationsDNC has evaluated the proposed amendment for environmental considerations.The review has resulted in the determination that the proposed amendment wouldchange a requirement with respect to installation or use of a facility componentlocated within the restricted area, as defined in 10 CFR 20, and would change aninspection or surveillance requirement. However, the proposed amendment doesnot involve (i) a significant hazards consideration, (ii) a significant change in thetypes or significant increase in the amounts of any effluent that may be releasedoffsite, or (iii) a significant increase in individual or cumulative occupationalradiation exposure. Accordingly, the proposed amendment meets the eligibilitycriterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore,pursuant to 10 CFR 51.22(b), no environmental impact statement or environmentalassessment need be prepared in connection with the proposed amendment.6.0 References6.1 Millstone Power Station Unit 2, Amendment No. 17 to License Application inDocket No. 50-336, July 2, 1973.6.2 Millstone Power Station Unit 2 Alternative Request RR-04-16, dated August1, 2013, (ADAMS Accession No. ML13220A019). NRC approval dated April4, 2014 (ADAMS Accession No. ML14091A973).6.3 ASME Section III Code Case N-659-2, dated June 9, 2008, Use ofUltrasonic Examination in Lieu of Radiography for Weld ExaminationSection III, Divisions 1 and 3.6.4 Pacific Northwest National Laboratory Report PNNL-19086, Replacement ofRadiography with Ultrasonics for the Nondestructive Inspection of Welds -Evaluation of Technical Gaps -An Interim Report, dated April 2010.6.5 ASME B31.1, Case 168, dated June 1997, Use of Ultrasonic Examination inLieu of Radiography for B31. 1 Application.6.6 ASME Section III Code Case N-818, dated December 6, 2011, Use ofAnalytical Evaluation approach for Acceptance of Full Penetration ButtWelds in Lieu of Weld Repair.6.7 ASME Code Case 2235-9, dated October 11, 2005, Use of UltrasonicExamination in Lieu of Radiography Section I,Section VIII, Divisions 1 and2, and Section XII.6.8 Journal of Pressure Vessel Technology, Technical Basis for ASME SectionVIII Code Case 2235 on Ultrasonic Examination of Welds in Lieu ofRadiography, Rana, Hedden, Cowfer and Boyce, Volume 123, dated August2001.
Serial No. 14-524Docket No. 50-336Attachment 1, Page 6 of 66.9 ASME Code Case 2326, dated January 20, 2000, Ultrasonic Examination inLieu of Radiographic Examination for Welder Qualification Test CouponsSection IX.6.10 ASME Code Case 2541, dated January 19, 2006, Use of Manual PhasedArray Ultrasonic Examination Section V.6.11 ASME Code Case 2558, dated December 30, 2006, Use of Manual PhasedArray E-Scan Ultrasonic Examination Per Article 4 Section V.6.12 ASME Code Case 2599, dated January 29, 2008, Use of Linear PhasedArray E-Scan Ultrasonic Examination Per Article 4 Section V.6.13 ASME Code Case 2600, dated January 29, 2008, Use of Linear PhasedArray S-Scan Ultrasonic Examination Per Article 4 Section V.6.14 ASME Section Xl Code Case N-713, dated November 10, 2008, UltrasonicExamination in Lieu of Radiography.6.15 EPRI presentation, dated May 2010, Ultrasonic Capability study forreduction of weld repair during the construction-UT Technical Presentation.6.16 ASME B31.1, 2004 Edition and later.
Serial No. 14-524Docket No. 50-336ATTACHMENT 2MARK-UP OF PROPOSED FSAR CHANGESDOMINION NUCLEAR CONNECTICUT, INC.MILLSTONE POWER STATION UNIT 2 Serial No. 14-524Docket No. 50-336MPS-2 FSAR Figure 9.0.3, General Pipingand Instrumentation DiagramLegend Notes (continued)Field Fabrication &Third Letter Design Code Shop Fabrication InstallationA Nuclear Power Piping, ANSI B31.7-69 ASME Section II1, 1971Class IB Nuclear Power Piping, ANSI B31.7-69 ASME Section Il1, 1971Class IIC Nuclear Power Piping, ANSI B31.7-69 ASME Section II, 1971Class IIID Code for Pressure Piping,ANSI B 31.1.01.3 Certain piping systems or portions of piping systems designed and fabricated to ANSI B31.1.0 shall have additional testing and examination requirements over and above thoserequired by that code. These additional requirements will be identified by a fourth codeletter. The code letters and corresponding requirements are described as follows:Fourth Letter -Additional Specifc RequirementsA. ANSI B 31.1.0 Requirements Plus: volumetric examination1. 100 percent of Butt Welds2. Seismic Analysis3. Base Material Traceability (as per Paragraph 1-723.1.3, ANSI B 31.7)B. ANSI B 3 1.1.0 Requirements Plus: volumetricexamination1. Random ofButtWelds r2. Base Material Identification (as per Paragraph 3-723, ANSI B 31.7)3. Seismic AnalysisC. ANSI B 31.1.0 Requirements Plus:1. Base Material Identification (as per ASTM requirements)2. Seismic Analysisbe examined volumetrically(1) On Butt Welds over four inch n o alpipe size, a minimum of 10 percent of the Butt Welds in aspecified class shall b m-- .ad._"-,-hy. Those welds madieg dd must include welds by eachwelder or welding operator performing welding in the specified clss.Rev.28.2June 10, 1982