ML14084A383
| ML14084A383 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 03/14/2014 |
| From: | Sartain M D Dominion Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 14-145, TAC MF2520 | |
| Download: ML14084A383 (10) | |
Text
Dominion Nuclear Connecticut, Inc.5000 Dominion Boulevard, Glen Allen, VA 23060Web Address: www.dom.comMarch 14, 2014U.S. Nuclear Regulatory CommissionAttention: Document Control DeskWashington, DC 20555DOMINION NUCLEAR CONNECTICUT. INC.ADominiontSerial No. 14-145NLOS/WDC RODocket No. 50-336License No. DPR-65MILLSTONE POWER STATION UNIT 2RESPONSE TO SECOND REQUEST FOR ADDITIONAL INFORMATION FORALTERNATIVE REQUEST RR-04-16 FOR THE USE OF ENCODED PHASEDARRAY ULTRASONIC EXAMINATION TECHNIQUES (PAUT) IN LIEU OFRADIOGRAPHY (TAC NO. MF2520)In a letter dated August 1, 2013, Dominion Nuclear Connecticut, Inc. (DNC) requestedrelief from the requirements of the American Society of Mechanical Engineers (ASME)Boiler and Pressure Vessel Code Section III for Millstone Power Station Unit 2(MPS2). Specifically, DNC requested approval to use encoded Phased ArrayUltrasonic Examination Techniques as an alternative to radiographic examination forASME Class 2 carbon steel circumferential pipe weld joints to satisfy nondestructiveexamination requirements. In a letter dated October 1, 2013, the Nuclear RegulatoryCommission (NRC) transmitted a request for additional information (RAI) to DNCrelated to the alternative request. In letters dated November 22, 2013 and February27, 2014, DNC responded to the RAI. On March 12, 2014, the NRC transmitted asecond RAI related to the alternative request.The attachment to this letter contains DNC's response to the RAI.If you have any questions regarding this submittal, please contact Wanda Craft at(804) 273-4687.Sincerely,Mark D. SartainVice President -Nuclear EngineeringAttachment:1. Response to Second Request for Additional Information for AlternativeRequest RR-04-16 Proposed Alternative to ASME Section IIICommitments made in this letter: NoneA-0c47 Serial No. 14-145Docket No. 50-336Page 2 of 2cc: U.S. Nuclear Regulatory CommissionRegion I2100 Renaissance BlvdSuite 100King of Prussia, PA 19406-2713James S. KimProject ManagerU.S. Nuclear Regulatory CommissionOne White Flint North, Mail Stop 08 C2A11555 Rockville PikeRockville, MD 20852-2738Mohan C. ThadaniProject ManagerU.S. Nuclear Regulatory CommissionOne White Flint North, Mail Stop 08 B 111555 Rockville PikeRockville, MD 20852-2738NRC Senior Resident InspectorMillstone Power Station Serial No. 14-145Docket No. 50-336ATTACHMENTRESPONSE TO SECOND REQUEST FOR ADDITIONAL INFORMATION FORALTERNATIVE REQUEST RR-04-16PROPOSED ALTERNATIVE TO ASME SECTION IIIMILLSTONE POWER STATION UNIT 2DOMINION NUCLEAR CONNECTICUT, INC.
Serial No. 14-145Docket No. 50-336Attachment 1, Page 1 of 7BackqroundIn a letter dated August 1, 2013, Dominion Nuclear Connecticut, Inc. (DNC) requestedrelief from the requirements of the American Society of Mechanical Engineers (ASME)Boiler and Pressure Vessel Code Section III for Millstone Power Station Unit 2 (MPS2).Specifically, DNC requested approval to use encoded Phased Array UltrasonicExamination Techniques (PAUT) as an alternative to radiographic examination forASME Class 2 carbon steel circumferential pipe weld joints to satisfy nondestructiveexamination requirements. In a letter dated October 1, 2013, the Nuclear RegulatoryCommission (NRC) transmitted a request for additional information (RAI) to DNCrelated to the alternative request. In letters dated November 22, 2013 and February 27,2014, DNC responded to the RAI. On March 12, 2014, the NRC transmitted a secondRAI related to the alternative request. This attachment provides DNC's response to theRAI.Question 1Describe the radiographic testing procedure used to characterize the specimensdescribed in the letter dated February 27 in detail. Identify if the radiographic testingprocedure used single or double wall viewing and how many shots and angles weretaken per weld.DNC ResponseThe radiographic examinations were performed with the examination personnel havingno knowledge of the location or type of flaws implanted within the mockups. Theradiographic testing procedure used to characterize the mockups consisted of ASMESection V, Article 2 radiographic examination techniques, typical of examinationsperformed in the plant. The examinations were performed using an Iridium 192 sourcewith the direction of the central beam of radiation centered on the area of interest andperpendicular to the film, to the extent possible. Each weld consisted of four film views;0 to 90 degrees, 90 to 180 degrees, 180 to 270 degrees, and 270 to 0 degrees, withadequate overlap to provide complete coverage of the entire weld length. Single wallviewing was used to interpret the film.
Serial No. 14-145Docket No. 50-336Attachment 1, Page 2 of 7Question 2Did the radiographic testing procedure used to evaluate the specimens described in theletter dated February 27 meet the requirements of ASME Code Section V Article 2?DNC ResponseYes, the radiographic testing procedure used to evaluate the specimens described inthe letter dated February 27 meets the requirements of ASME Code Section V, Article2.Question 3Provide a table describing the implanted flaws used to qualify the ultrasonic inspectionprocedure. Include the flaw types and dimensions. The NRC staff understands thatreleasing this information may compromise the blind qualification testing. If thisinformation is proprietary include the necessary affidavit for the NRC staff to treat theinformation as proprietary.DNC ResponseTo maintain the integrity of the test qualification material, the information will be madeavailable for NRC review.Question 4Provide examples of successful ultrasonic detection of planar flaws in the 0.28 inchthick test blocks.DNC ResponseThe following Figures 1 through 5 provide examples of the ultrasonic data representingsuccessful detections and characterizations of typical fabrication flaws from theDominion procedure qualification data. These figures provide examples of lack offusion defects, lack of penetration defects, and cracks, which were implanted into the 6inch diameter, 0.28 inch thick welded mockups. These mockups represent the weldconfigurations and welding processes to be used for the replacement welds. The flawmap for each of these examples is included in the applicable figures. The planar flawsidentified in Figures 2, 3, and 4 were not detected with the radiographic examinationperformed.
Serial No. 14-145Docket No. 50-336Attachment 1, Page 3 of 7Figure 1Weld 4 -Flaw 3, Incomplete PenetrationIt= 4r--..,, -i %v- , .Upstream Detection Using First Leg.~IIII=Down Stream Detection Using First Leg Serial No. 14-145Docket No. 50-336Attachment 1, Page 4 of 7Figure 2Weld 4 -Flaw 5, Crack*.."'PDown Stream (Near Side) Detection Using First Leg Serial No. 14-145Docket No. 50-336Attachment 1, Page 5 of 7Figure 3Weld 5 -Flaw 2, CrackI,,...Down Stream (Near Side) Detection Using First Leg Serial No. 14-145Docket No. 50-336Attachment 1, Page 6 of 7Figure 4Weld 5 -Flaw 4, Lack of FusionDon S-.4Down Stream (Near Side) Detection Using First and Second Leg Serial No. 14-145Docket No. 50-336Attachment 1, Page 7 of 7Figure 5Weld 5 -Flaw 5, CrackFLAW 5 r- 0, 105"Down Stream Detection Using Second Leg