CNL-16-022, Request for Approval for Use of Alternate Calibration Block Reflector Requirements 16-PDI-5
ML16151A010 | |
Person / Time | |
---|---|
Site: | Browns Ferry, Watts Bar, Sequoyah |
Issue date: | 05/27/2016 |
From: | James Shea Tennessee Valley Authority |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
CNL-16-022 | |
Download: ML16151A010 (22) | |
Text
Tennessee Valley Authority,1101 Market Street, Chattanooga, Tennessee 37402 CNL-16-022 May 27, 2016 10 CFR 50.55a ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 1 and 2 Facility Operating License Nos. NFP-90 and NFP-96 NRC Docket Nos. 50-390 and 50-391 Browns Ferry Nuclear Plant, Units 1, 2, and 3 Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 NRC Docket Nos. 50-259, 50-260, and 50-296 Sequoyah Nuclear Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327 and 50-328
Subject:
Browns Ferry Nuclear Plant Units 1, 2, and 3, Sequoyah Nuclear Plant Units 1 and 2, and Watts Bar Nuclear Plant Units 1 and 2 - Request for Approval for Use of Alternate Calibration Block Reflector Requirements 16-PDI-5
Reference:
- 1. TVA letter , L.M. Mills to A. Schwencer, Request for Relief ISI-1, dated August 13, 1980, (ML073520649)
- 2. NUREG-0847 Supplement 10, Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant Units 1 and 2, dated October 1992 (ML072060473)
In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.55a, Codes and Standards, paragraph (z)(1), Tennessee Valley Authority (TVA) is requesting the Nuclear Regulatory Commission (NRC) approval of the enclosed request for an alternative (16-PDI-5) to the requirements of the 2001 Edition through 2003 Addenda and the 2007 Edition through 2008 Addenda of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code Section XI, Mandatory Appendix III, Subsubarticle III-3430, Calibration Reflectors, including Mandatory Appendix III, Supplement 1, Paragraph (b)(3), for the Watts Bar Nuclear Plant (WBN) Units 1 and 2 , Sequoyah Nuclear Plant (SQN) Units 1 and 2, and Browns Ferry Nuclear Plant (BFN) Units 1, 2, and 3 basic calibration blocks. Refer to Section 2 of the Enclosure for the applicable code of records.
U.S. Nuclear Regulatory Commission CNL-16-022 Page 2 May 27, 2016 ASME B&PV Code Section XI , Mandatory Appendix Ill , Subsubarticle 111-3430 states that basic calibration blocks shall have a notch depth as specified in Table 111-3430-1 . Table 111-3430-1 specifies that for a nominal pipe wall thickness (t) of 0.312 to 6.0 inches, the calibration block shall have a notch depth of 0.104t - o.oogf (10% oft for austenitic and dissimilar metals welds) with a tolerance of +10% to -20%. This equates to a nominal notch depth from 5%t to approximately 10%t for ferritic materials. TVA requests NRC approval to continue to utilize calibration blocks that were fabricated with alternative notch depths of 5%t with +10% to -20%
tolerance. The 5%t calibration blocks were fabricated for TVA and result in more conservative and sensitive ultrasound examinations.
The enclosure provides a description and assessment of the proposed request for alternative, and the basis as to why the proposed alternative provides an acceptable level of quality and safety in accordance with 10 CFR 50.55a(z)(1).
TVA requests approval of this request by October 1, 2016, which is the scheduled start date for the BFN Unit 1 refueling outage because the potential exists that these calibration blocks will be used during that outage. TVA also requests that approval be granted for the remainder of plant life for BFN Units 1, 2, and 3, SQN Units 1 and 2, and WBN Units 1 and 2.
There are no new regulatory commitments associated with this submittal. Please address any questions regarding this request to Mr. Ed Schrull at 423-751-3850.
Relljll~
Ji . 1 Shea Vice President, Nuclear Licensing
Enclosure:
Request for Alternative Number 16-PDl-5 cc (Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Watts Bar Nuclear Plant NRC Senior Resident Inspector- Browns Ferry Nuclear Plant NRC Senior Resident Inspector- Sequoyah Nuclear Plant NRR Project Manager - Watts Bar Nuclear Plant NRR Project Manager - Browns Ferry Nuclear Plant NRR Project Manager - Sequoyah Nuclear Plant
Enclosure Tennessee Valley Authority Browns Ferry Nuclear Plant Units 1, 2, and 3 Sequoyah Nuclear Plant Units 1 and 2 Watts Bar Nuclear Plant Units 1 and 2 Request for Alternative Number 16-PDI-5 I. Systems/Components Affected Basic calibration blocks, used for ultrasonic testing (UT), are standards that provide a means to correlate an ultrasonic system with reference reflectors of known dimensions. Reference reflectors are dimensioned surfaces, used to establish accurately reproducible reference levels of ultrasonic sensitivity, resolution and sound path distance.
The basic calibration blocks are used to provide a calibration standard for ultrasonic systems used for testing thin-walled vessel (less than or equal to 2 thickness) and piping welds. This request for alternate approval is for basic calibration blocks with a nominal pipe wall thickness (t) five percent (5%)t notch depth. Attachment A provides a list of 5%t notch depth calibration blocks currently in use at TVA nuclear plants.
II. Applicable Code Edition and Addenda The current in-service inspection (ISI) and pre-service inspection (PSI) code of record for Browns Ferry Nuclear Plant (BFN) Unit 1 (third interval), Unit 2 (fifth interval), and Unit 3 (fourth interval) is the American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel (B&PV) Code Section XI, 2007 Edition through 2008 Addenda.
The current ISI and PSI code of record for Sequoyah Nuclear Plant Units 1 and 2 (SQN)
Unit 1 (third interval), Unit 2 (third interval), and for Watts Bar Nuclear Plan (WBN) Unit 1 (second interval) is the ASME B&PV Code Section XI, 2001 Edition through 2003 Addenda.
WBN Unit 2 is currently in the PSI period. The PSI code of record for WBN Unit 2 is the ASME B&PV Code Section XI, 2001 Edition through 2003 Addenda.
SQN Units 1 and 2 and WBN Units 1 and 2 are in the process of transitioning to the ASME B&PV Code Section XI, 2007 Edition through 2008 Addenda for their next upcoming ISI intervals.
CNL-16-022 E-1 of 20
III. Applicable Code ASME Code Components Affected:
ASME Code Classes: 1&2
References:
IWA-2232 Appendix III, Subsubarticle III-3430 Appendix III, Supplement 1(b)(3)
Examination Categories: B-F, B-J, B-O, C-F-1, C-F B-B, C-A Item Numbers: B5.10, B5.130, B9.11, B9.12, B9.31, B14.20, C5.11, C5.12, C5.52
==
Description:==
Alternative to Appendix III Calibration Reflector Requirements Component Numbers: ASME Class 1 and 2 components subject to examination in accordance with Appendix III of Section XI.
IV. Reason for Request ASME B&PV Code Section XI (see the code of record previously specified for each unit in Section II of this enclosure), Mandatory Appendix III, Subsubarticle III-3430 states that basic calibration blocks shall have a notch depth as specified in Table III-3430-1. Table III-3430-1 specifies that for a nominal pipe wall thickness (t) of 0.312 to 6.0 inches, the calibration block shall have a notch depth of 0.104t - 0.009t2 with a tolerance of +10% to -20%. This equates to a nominal notch depth from 5%t to approximately 10%t for ferritic materials.
Appendix III, Supplement I paragraph (b)(3) requires calibration blocks for austenitic and dissimilar metals welds to have a notch depth of 10%t.
The nondestructive examination (NDE) requirements were revised to comply with the 1989 Edition of the ASME Section XI Code for all nuclear sites (WBN, SQN, and BFN). This upgrade was a result of the second interval update for SQN (December 16, 1995 through May 31, 2006). The NDE upgrade provided a consistency in procedure implementation at all TVA nuclear sites. When TVA NDE requirements were revised to comply with the 1989 Edition of the ASME Section XI Code, the code requirements included use of basic calibration blocks with notch depths in the range of 5%t to approximately 10%t, depending on wall thickness. In this edition of the ASME B&PV Code, up to the 1999 Edition of the ASME B&PV Code, provisions were made in Section XI, Division 1, Appendix III, Subarticle III-1100 that allowed alternative designs for basic calibration blocks in accordance with Subsubarticle IWA-2240. Thus, some basic calibration blocks were fabricated by the Tennessee Valley Authority (TVA) with 5%t (+10% to -20% tolerance) notches for piping and vessels 2 or less in thickness versus the 5%t to approximately 10%t range of depths defined in Table III-3430-1 for ferritic material and the 10%t notch depth defined in Appendix III, Supplement 1(b)(3) for austenitic or dissimilar metal welds.
In the 1999 Addenda of Section XI, Subsubarticle III-1100 was revised to add the following phrase after the reference to IWA-2240: except when the requirements of Subsubarticle III-3430 apply. The inclusion of this phrase removed provisions for using alternative notch depths for ISI examinations performed to the 1999, or later, code year of Section XI.
CNL-16-022 E-2 of 20
Alternative calibration notch depths are required to ensure that TVA can comply with the requirements of IWB 2200(b)(2) with regards to comparing ISI results with previous ISI or PSI results. In addition, these alternative notch depth requirements will allow TVA to continue use of basic calibration blocks that were fabricated with alternative notch depths without the necessity of fabricating new blocks.
V. Proposed Alternative and Basis for Use Proposed Alternative:
For ASME Class 1 and ASME Class 2 components subject to ultrasonic examination in accordance with ASME Section XI, Appendix III, TVA requests the Nuclear Regulatory Commission (NRC) approval to use calibration blocks with 5%t notches in lieu of the 5%t to approximately 10%t range specified in Table III-3430-I and the 10%t specified in Supplement 1 paragraph (b)(3). This does not eliminate the option for TVA to use calibration blocks with notches as specified by Appendix III.
Basis For Use:
When TVA nondestructive examination (NDE) requirements were revised to comply with the 1989 Edition of the ASME Section XI Code, the code requirements included use of basic calibration blocks with notch depths in the range of 5%t to approximately 10%t, depending on wall thickness. A technical justification and demonstrations (Attachments B and C to the enclosure) were performed in accordance with IWA-2240, which provided documented alternatives to the Supplement III notch depth requirements, by allowing the use of 5%t notches for all pipe thicknesses up to six inches.
To demonstrate that calibration blocks with 5%t notch depths provide an equivalent or better quality of examination, two demonstrations were conducted on a sampling of blocks that had both 5%t and 10%t nominal notches.
The first demonstration, conducted in 1996 before a TVA site Authorized Nuclear Inspection Inspector (ANII) Supervisor using conventional UT methods, concluded that the 5%t notches increased examination sensitivity by +2 to +6 dB. This demonstration is provided in Attachment B.
The second demonstration was performed in 2014, for the SQN site ANII, using linear phased array (LPA) techniques. This demonstration is provided in Attachment C. Similar to the demonstration in Attachment B, this demonstration concluded that the nominal 5%t notches result in a similar increase (+2 to +6 dB) in calibration sensitivity when compared to the nominal 10%t notches.
These demonstrations provide an acceptable level of quality and safety because the information and data obtained provides sufficient information to determine that applicable UT calibrations will conservatively establish a marginally more sensitive gain setting.
Therefore, pursuant to 10 CFR 50.55a(z)(1), TVA requests NRC approval for the alternate design of the calibration blocks.
Additionally, in Reference 1, TVA submitted a relief request (ISI-1) for WBN Units 1 and 2 to request the use of circumferential notches located on the I.D. and O.D. surface at a nominal depth of 5%t as reference reflectors. Relief was requested to use 5%t or optionally 10%t notches in lieu of the requirements of ASME Code Section XI, 1974 Edition, Summer 1975 CNL-16-022 E-3 of 20
Addenda. The NRC in Appendix Z, Section 3.1 of Reference 2, authorized the use of this relief request and stated, that the use of the notched calibration reflectors, and the recording and reporting level for indications for the pre-service examinations of relatively thin-walled vessel welds are acceptable alternatives to the code requirements.
VI. Duration of Proposed Alternative and Implementation Schedule:
TVA requests that approval be granted for the remainder of plant life for BFN Units 1, 2, and 3, SQN Units 1 and 2, and WBN Units 1 and 2.
TVA requests approval of this request by October 1, 2016, which is the scheduled start date for the BFN Unit 1 refueling outage because the potential exists that these calibration blocks will be used during that outage.
VII. Precedents:
This request for alternative is similar to alternative request NDE-R014 that was approved by the NRC for the Duane Arnold Energy Center (DAEC) in Reference 3. Specifically, the NRC approved an alternative to Section XI, Appendix III, Subsubarticle Appendix III-3430 that allowed DAEC to use calibration blocks that were procured when the plant was built. These calibration blocks had notches of various depth that deviated from the requirements of Section XI, Appendix III, Table III-3430-1.
VIII. References
- 1. TVA letter , L.M. Mills to A. Schwencer, Request for Relief ISI-1, dated August 13, 1980, (ML073520649)
- 2. NUREG-0847 Supplement 10, Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant Units 1 and 2, dated October 1992 (ML072060473)
- 3. NRC Letter, Evaluation of the Third 10-year Inservice Inspection Interval Program Plan Requests for Relief for the Duane Arnold Energy Center (TAC No. M95412), dated March 23, 1998 (ML9804010216)
IX. List of Attachments Attachment A- Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth Attachment B- Ultrasonic Calibration Standards (L18 960329 800)
Attachment C- Ultrasonic Basic Calibration Block Demonstration (N-GP-18)
(W47140528001)
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Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
BF001 4"SCH80 0.326 A106GR.BCS
BF002 4"SCH80 0.332 A358TP304SS
BF003 10"SCH40 0.375 A106GR.BCS
BF004 6"SCH140 0.752 A358TP304SS
BF005 10"SCH100 0.730 A106GR.BCS
BF006 8"SCH100 0.767 A358TP304SS
BF007 14"pipeSch.80 0.698" A106GR.BCS
BF010 48"x125/16"x4" 4" A533Gr.B
BF011 61/2"x4"x4" 4" A515Gr.70
BF012 12x3x2FlatPlate 3 A515Gr.55
BF014 3/4"SCH160 0.226" SAI06GRBCS
BF015 10"SCH160 1.53" A519GR.MT1020CS
BF016 20"XII"X10"NozzleBlock 10" SA533GR.B.CS
Clad
BF018 24"X6"X6"FlatBlock 6.125" A533GR.BCS
BF019 24"X6"X4FlatBlock 41/64" SA533GRB.CS
BF026 12"X4".75"FlatBlock 0.75" ASMESAI06CS
BF029 4"SCH160 0.506" AI06GRB.CS
BF030 6"SCH160 0.754" AI06CS
BF032 20"X9"X1"FlatBlock 1.140" ASTM516GR70
BF034 6"sch80 0.399 A53Gr.B
BF035 8"sch100 0.520 A106GR.BCS
BF036 5"sch40pipe 0.344 A106GR.BCS
BF037 14"sch30pipe 0.364 A106GR.BCS
BF040 FlatPlate20"x97/8"x1" 0.944 A106GR.BCS
BF041 4"sch160SSPipe 0.452 SA376TP316
BF042 10"Sch80CSPipe 0.597 A106GR.BCS
BF043 FlatPlate20"x927/32"x 1.036 316L
1
BF044 FlatPlate20"x10"x1.5" 1.552 TP304
BF045 6"sch40CSPipe 0.275 SA106GA
BF046 10"Sch80SSPipe 0.588 A312TP304SS
BF048 20"Sch80SSPipe 1.6875 TP304
w/Overlay
BF049 22"Sch80Pipew/Overlay 1.342 SA240TP304
BF050 12"Sch100Pipe 1.139 TP304
w/Overlay
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Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
BF051 12"Sch100Pipe 0.947 TP304
w/Overlay
BF052 22"x12"Sweepolet(Recirc 0.948 SA240TP304
Loops)
BF053 6"sch160SSPipe 1.122 TP304
BF054 6"sch160SSPipe 1.328 TP304
BF056 14"Sch.100CSPipe 0.938 A106GR.BCS
BF057 FlatPlate20"x47/8"x 1.269 SS304L
1.25"
BF058 1"Sch160CSPipe 0.222 A106GR.BCS
BF059 JetPump .9229 SA182F316
BF060 5"schxxHvySSPipe 0.758 SA312T316L
BF061 6"SCH120 TP304Gr.316
BF062 4"XXSSSPipe/Weld 1.89 SS
Buildup
BF063 6"XXSSSPipe 0.840 SA312/SA376TP304
BF064 2sch160SSPipe 0.375 SA312TP304
BF065 12"Sch160SSPipe 1.345 SA376TP304SS
BF066 4"SchXXHvy 0.685 SA312
BF067 14"Sch160SS 1.339 SA376TP316
BF068 0.863"Diax12.5" 0.046 AdmiraltyBrass
BF069 10"x2"x1"FlatBlock 0.950 Carbon/SS
BF069A 10"x2"x1"FlatBlock 0.900 Carbon/SS
BF070 12"CarbonSteelPipe 1.32" ASMESA376TP316
SegmentWithStainless
Butter
BF071 12"SCH80CladBlock Varies SA358GR304SS
BF072 CladBlockforNozzles 1.32 ASTMA508CL2CS
BF074 20"SCH20 0.187 SA106GrBCS
BF075 12"SCH80 0.688 SA106GrBCS
BF076 5.38"00x12" 0.846 SA508CL2
BF077 16"SCH30 0.375 SA106GrBCS
BF079 12"SCH80 0.691 SA358GR304SS
BF080 6"SCH80 0.860" SA376TP304SS
BF082 28"DiaPipeSeg. 1.250" A358GR304SS
BF083 28"DiaPipeSeg. 1.750" A358GR304SS/308L
BF084 N1N2N3NozzleIR Varies SA508CL2
BF085 N2N5N9NozzleInner Varies ASTMA508CL2
Radius
BF086 N8NozzleInnerRadius ASTMA508CL2
CNL-16-022 E-6 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
BF087 20"SSPipe 1.031 SA376TP316
BF088 22"SSPipe 1.031 SA376TP316
BF089 24"SSPipe 1.285 SA376TP316
BF090 28"SSPipe 1.44 SA376TP316
BF091 6"CSPipe 0.562 ASTMA106GradeB
BF092 8"CSPipe 0.322 ASTMA106GradeB
BF093 12"CSPipe 0.843 ASTMA106GradeB
BF094 16"CSPipe 1.031 ASTMA106GradeB
BF095 18"CSPipe 0.312 ASTMA106GradeB
BF096 18"CSPipe 0.500 ASTMA106GradeB
BF097 18"CSPipe 0.938 ASTMA106GradeB
BF098 20"CSPipe 0.500 ASTMA106GradeB
BF099 20"CSPipe 1.281 ASTMA106GradeB
BF100 24"CSPipe 0.375 ASTMA106GradeB
BF101 24"CSPipe 0.500 ASTMA106GradeB
BF102 24"CSPipe 1.531 ASTMA106GradeB
BF103 24"CSPipe 2.5 ASTMA106GradeB
BF104 26"Pipe 0.950 ASTMA155KC70
BF105 30"CSPipe 0.375 ASTMA106GradeB
BF106 CoreSprayNozzle 1.358 SA508CL2
BF107 RecircOutletNozzle 1.737 SA508CL2
BF108 24"Sch.80CSPipe 1.218 A106GR.BCS
BF109 147"RadiusRVWall 6.60 SA533Gr.Bclass1
BF111 3/4"Pipe 0.154 SA376TP316
BF112 1"Pipe 0.179 SA376TP316
BF113 1.25"pipe 0.191 SA376TP316
BF114 1.5"Pipe 0.200 SA376TP316
BF115 2"Pipe 0.154 SA376TP316
BF116 3"pipe 0.300 SA376TP316
BF117 4"pipe 0.337 SA376TP316
BF118 6"pipe 0.432 SA376TP316
BF127 12"PipeUTCalBlock 0.375" ASTMA106GradeB
BF128 20"pipeUTCalBlock 0.375" ASTMA106GradeB
BF129 RPVInstrumentNozzleto 1.0" ASTMA105Grade2
FlangeUTCalBlock
BF130 RPVInstrumentNozzleto 1.0" A105Grade2
FlangeUTCalBlock
BF131 4"AxialScanUT 2" 304SS
BF132 4"CircumferentialScan Varies 304SS
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Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
BF133 FlatProbeUT 3.00 304SS
BF136 3"ContourBlock 1.00 316/316L
BF137 3"CircumferentialScan 1.00 316LSS
BF138 28"/29"OD/IDAxialScan 3.9 304SS
BF139 28"ODCircScan 2.4 304SS
BFN134 12"AxialScan 2.92 304SS
BFN135 12"SSCircumferential 1.27 304SS
Scan
IRCSCL38PEB O.DInnerRadiusUTCal Varies SA508CLII
BlockN1N2N3N4N5
SQ001 6"SCH160 0.707" TP304SS
SQ002 6"SCH160 0.707" TP304SS
SQ003 12"SCH140 1.209" TP316SS
SQ005 32"Dia.PipeSeg. 1.429" A516GR.70
SQ006 2"SCH160 0.340" TP304SS
SQ007 8"SCH120 0.760" TP304SS
SQ008 12"SCH80 0.764" TP316SS
SQ009 8SCH80 0.311" A312TP316SS
SQ010 14"SCH160 1.358" A312TP304SS
SQ012 2.5"SCH160 0.430" A312TP304SS
SQ013 4"SCH120 0.436" A312TP304SS
SQ014 12"X4"X1.5"FlatBlock 1.5" A516GR.70CS
SQ015 12"X4"X1"FlatBlock 1.022" TP304SS
SQ016 12"SCH160 1.310" A403WP316SS
SQ017 6"SCH120 0.580" A276TP304SS
SQ018 18"SCH80 0.977" A333GR.1CS
SQ019 6"Dble.E.H. 0.875" A106GR.BCS
SQ020 1.5SCH160 0.324" A376TP304SS
SQ021 10"Pipe1.5"Thick 1.50" SA106GrBCS
SQ029 6"Dia.PipeSeg. 1.2" 304SS
SQ030 5"Dia.E.H. 0.897" 304SS
SQ037 TransferredtoBFNP 0.502 A36A283
SQ039 18"SCH40 0.640" 304SS
SQ040 12"X6"X3"VesselBlock 3.0" SA533GR.ACL2CS
SQ041 12"X6"X4"(3/16Clad) 37/8" SA533GR.ACL2CS
Vessel
SQ043 22"X6"X6"(7/32Clad) 513/16" A508CL2CS
Vessel
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Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
SQ044 33"X6"X811/16"(1/4 811/16" A508CL2CS
Clad)Vessel
SQ045 43"X6"X11"(5/16Clad) 111/8" A508CL2CS
Vessel
SQ046 27"X6"X7"(7/32Clad) 71/16" A508CL2CS
Vessel
SQ049 15"X6"X5"(1/4Clad) 5" SA216GR.WCCCS
SQ050 101/2"O.D.X7"I.D.Nut 1.75" SA540GR.B24
Block
SQ051 12"X6"X6"(3/16"Clad) 529/32" A508CL2CS
SQ053 26"X23"X6"(3/16Clad) Varies A508CL2CS
Nozzle
SQ054 16"Rad.(1/4Clad) Varies A508CL2CS
SQ055 21/2"Dia.x93/4"Stud Stud A193GR.B7CS
SQ056 LetdownHeatExchanger 0.428" AISITP304SS
Block
SQ057 24"X6"X4"VesselBlock 4" SA533GR.ACL1CS
SQ058 3/4"Dia.X135/8" .049" AdmiraltyBrass
SQ059 SGPrimaryNozzleI.R. 16.0" A216GR.WCCCS
W/Clacd
SQ061 S.G.FeedwaterNozzle .837" A333GR.1CS
SQ062 S.G.NozzletoTransition 0.6 SA508CL.2CS
Spool
SQ065 3"Dia.BranchConnection 1.313" A182,F316SS
SQ066 6"Dia.BranchConnection 1.85 A182,F316SS
SQ067 10"Dia.BranchConnection 2.490" A182,F316SS
SQ068 16X16"X4"RCPFlywheel 3.75" SA533,GR.BCS
Block
SQ069 4"Dia.BranchConnection 1.530" A182,F316SS
SQ070 8"Dia.BranchConnection 2.090" A182,F316SS
SQ071 12"Dia.BranchConnection 2.99" A182,F316SS
SQ072 4"Dia.LiftingRig 4.00" A322,GR4340
SQ073 4"Dia.LiftingRig 4.00" A322,GR4340
SQ074 4"Dia.LiftingRig 4.00" A322,GR4340
SQ075 3.5"Dia.LiftingRig 3.50" A564,GR630
SQ076 Mainsteam/Feedwater 14" A508CL.2
NozzleI.R.
SQ077 PressurizerNozzleI.R. 13.624" A508CL.2
SQ078 FlywheelCal.Block 4.5 SA533GrB
SQ079 4"CSSch80Cal.Block .337 A106GR.BCS
SQ080 UHIInconelCalBlock .531" ASMESB166
CNL-16-022 E-9 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
SQ081 UHIStainlessCalBlock .527" ASMESA479
SQ082 CRDMInconelCalBlock .625" ASMESB166
SQ083 CRDMStainlessCalBlock .622" ASMESA479
SQ085 2"Sch80Cal.Block .210" SA376304
SQ086 3"Sch80Cal.Block .308" SA376304
SQ087 3"Sch40Cal.Block .214" SA376304
SQ088 4"Sch80Cal.Block .370" SA376304
SQ089 16"Cal.Block .400" SA358304
SQ090 20"Cal.Block .420" SA358304
SQ091 24"Cal.Block .407" SA358304
SQ092 3.38"MainSteamCalBlock 3.38" ASTMA105
SQ093 14"Sch40CalBlock .438" SA376GR304
SQ103 2.35fX13.5 Stud ASTM193,GRB6
SQ104 12x6x.75FlatBlock .75 TP304SS
SQ105 12x6x.5FlatBlock .5 TP304SS
SQ106 12"x4"X.75"SSCLADFLAT .775" SA515,GR70
BLOCK
SQ108 18"x6"x3"FlatBlock 3.00" SA508,CL.3.
SQ110 27"x7"CLADBLOCK(0.2") 7.00" SA508,CL.3
SQ111 CLADSGNOZZLEBLOCK 9.00" SA508,CL.3
I.R.
SQ112 25"x7.5"NOZZLEBLOCK 7.54" SA336F316LN
SQ113 12"X10"FWNozzleIR Varies SA508,CL3
SQ124 9.75"X6"X0.750" ASTMA36
SQ131 8Ax.OverlayCalBlock 2.000 304SS
SQ132 16Ax.OverlayBlock 2.000 304SS
SQ133 FlatOverlayBlock 3.000 304SS
SQ134 8CircScanOverlayBlock 2.248 304SS
SQ135 16CircScanOverlayBlock 2.500 302SS
SQ136 6Circ.ScanOverlayBlock 1.617 304SS
SQ137 6"AxialScanOverlayBlock 2.502 305SS
WB001 6"SCH160Pipesegment 0.715 SA376TP304SS
WB002 8"SCH160PipeSegment 0.942 SA376TP304SS
WB003 12"SCH140PipeSegment 1.158 SA376TP316
WB004 16"SCH80PipeSegment 0.754 SA333GR.6
WB005 16"SCH140PipeSegment 1.410 SA515,GR70
WB006 2"SCH160 0.346 TP304
WB007 8"SCH120PipeSegment 0.758 TP304
WB008 12"SCH80PipeSegment 0.767 SA376TP316
WB009 8"SCH40PipeSegment 0.307 A312TP316SS
CNL-16-022 E-10 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
WB010 14"SCH160 1.352 A312TP304SS
WB011 3"SCH160PipeSegment 0.450 304H
WB012 2"SCH160PipeSegment 0.395 SA376TP304SS
WB014 1.5"FlatBlock 1.482 SA516SR70
WB015 1"FlatBlock 1.028 SA376TP304SS
WB016 12"Sch160SSPipe 1.322 SA376TP304SS
WB017 5"Sch160Pipe 0.585 SA403WP315
WB018 18"SCH80Pipe 0.938 SA333GR.6
WB019 5"schxxHvyPipe 0.782 A106GR.BCS
WB020 11/2"SCH160Pipe 0.312 SA376TP304SS
WB021 10"Pipe1.5"Thick 1.493 SA106GrBCS
WB027 2"RoundBar 2.00 SA193GRB7
WB029 4"PipeSegment 1.206 SA376TP304SS
WB030 3"PipeSegment 0.918 SA376TP304SS
WB033 10"x1"thickpipesegment 1.005 TP304
WB034 12"pipesegment 1.247 TP304
WB037 6"SCH80 0.433 SA53GrB
WB038 8"Sch.80 0.484 SA106Gr.B
WB039 Vessel 4.015 SA533GRACL2CS
WB041 12"Sch40SPipeSegment 0.363 SA312TP304
WB042 18"Sch30PipeSegment 0.431 SA403TP304
WB043 18"SCH40PipeSegment 0.641 SA240TP304
WB044 2.15"ThickBar 2.15 SA240TP304
WB045 2.5"diax10"longStud 2.5 SA193GRB7
WB046 14"Sch40PipeSegment 0.470 SA358GR304SS
WB052 CRDMStainless/Inconel 0.626 SA182TP304/ASME
Block SB167
WB053 3"thickSafeEnd 3.00 SA182TP304/SA508
CL.2
WB061 2"Sch80PipeSegment .225 SA376TP304SS
WB062 3"Sch40PipeSegment 0.265 SA376
WB063 3"SCH80PipeSegment 0.287 SA376TP304SS
WB064 4"SCH40PipeSegment 0.268 SA376TP304SS
WB065 4"SCH80PipeSegment 0.343 SA376TP304SS
WB066 14"PipeSegment 0.370 SA358TP304SS
WB067 16"PipeSegment 0.395 SA358TP304SS
WB068 20"PipeSegment 0.414 SA358TP304SS
WB069 24"PipeSegment 0.400 SA358TP304SS
WB071 UpperInjectionNozzle 0.785 SB168TP600
WB072 UpperInjectionNozzle 0.785 SA479304L/SA182
CNL-16-022 E-11 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
WB073 CRDMPipeSegment 0.625 SB168TP600
WB074 CRDMPipeSegment 0.625 SA479304L/SA182
WB075 RecircCoolantPumpBolt 4.5 SA540E4340H
WB077 NozzletoShellUT 2.5/1.0
CNL-16-022 E-12 of 20
Attachment B Ultrasonic Calibration Standards (L18 960329 800)
CNL-16-022 E-13 of 20
Tennessee Valley Authority. Post Office Box 2000, Soddy-Daisy. Tennessee 37379-2000 L 18 960329 800 March 29, 1996 Mr. Ernest Farrow Hartford Steam Boiler Inspection & Insurance Co.
200 Ashford Center North, Suite 300 Atlanta, GA 30338-4860
Dear Mr. Farrow:
ULTRASONIC CALIBRATI O N STANDARDS
Purpose:
The purpose of this memorandum is to state TVA 's position regarding calibration block design and provide justification \vhy .existing calibration standards surpass current requirements established by the ASME Section XI Code, 1989 Edition.
Background:
Ultrasonic piping calibration blocks for Browns Ferry baseline examinations were fabricated to the 1971 Edition of the ASME Section XI code. These blocks contain 5% sawtooth notches . In addition, baseline calibration blocks for Sequoyah and Watts Bar were fabricated to the 1974 Edition with Surruner 1975 Addenda of Section XI with similar calibration notch design (i e., 5%
notches) for a majority of piping applications .
Ultrasonic calibration blocks for TV A nuclear sites (Browns Ferry, Sequoyah, Watts Bar) continue to be fabricated to the requirements of ASME Section XT with 5% circumferential and axial notches for a majority of austenitic and ferritic applications . Bellefonte calibration blocks used at other TV A sites are reviewed by the inspection agency when used in a specific application.
[n some cases, the calibration standards for austenitic piping may contain 10% notches (e.g ..
centrifugal cast piping) .
The nondestructi ve examination (NOE) requirements were recently revised to comply >vith the 1989 Edition of the ASME Section XI Code for all nuclear sites (WBN. SQN and BFN) This upgrade was a result of the second interval update for Sequoyah. The NDE upgrade provides a generic consistency in procedure implementation at all TV A nuclear sites c:ml t/Icttcrs CNL-16-022 E-14 of 20
}\pplicable Code Requirement Section XI Subsection IWA-2232 requires that ultrasonic examinations be conducted in accordance with Appendix I. The requirements for vessel welds less than or equal to 2 inches in thickness and all piping welds are contained in Appendix ill, as supplemented by Appendix I. The requirements for calibration reflectors are contained in Article III-3430 with reference to Table ill-3430-1 and Appendix ill Supplement 4 for austenitic and dissimilar metal welds.
Applicable Components Full penetration butt welds and adjacent base metal in piping systems having a nominal wall thickness of 0.2 to 6 inches. Vessel welds less than or equal to 2 inches in thickness.
Description of Condition The 1989 edition of the ASME Section XI code currently requires that calibration blocks contain notches within tolerances described in Appendix I and Appendix ill. A majority of piping calibration blocks contain 5% notches which are determined to be conservatively outside the limits of Table ill-3430-1 and Appendix ill Supplement 4, as applicable.
Technical Justification Currently TVA has continued with this conservative measure of using notches less than code requirements due to the following reasons:
L
- Current examination results are compared with previous examination data in order to determine if significant change has occurred (i.e., greater than +6dB). If calibration blocks are remachined to comply with 1989 Section XI tolerances then current results are not comparable.
- The cost to machine deeper notches is not justified and provides no value add to the current Inservice Inspection Program examinations.
- Appendix III, Article ill-3430 of the ASME Section XI code 1989 Edition makes provision for an acceptable alternative block design. In addition, IWA-2240 Alternative Examination methods may be substituted for the methods specified in the applicable Division, provided the results are demonstrated to be equivalent or superior to those of the specified method. Where alternative methods (i .e., the use of 5%
notches) have been demonstrated, the Inspection Agency review has been documented and found to be equivalent or superior.
- Examination sensitivity is increased by + 2 tp +6 dB when using 5% notches as compared to 10% notches.
- TVA procedures require any flaw regardless of amplitude to be recorded.
(
- Sizing of a flaw is not based on reference sensitivity of the notch but actual satellite
'\._,, pulse signals which accurately locate the flaw tip .
c:mltlletters CNL-16-022 E-15 of 20
~onclusion:
TVA's position concludes that the ASME Section XI code contains the requirements essential for the examination of piping and components. More conservative measures (notches that are below the maximum code allowable) are deemed to comply with ASME Section XI. The proposed alternatives do not compensate a decrease in the level of quality and safety. We request that you review the subject position and concur with the technical basis stipulated. Any questions may be directed to myself at (423)843-4355.
Manager, Ultrasonic Group Inspection Services Organization STC 11-SQN cc: George Deaton, CFC lA-BFN Bruce Eamigh, WBN Albert Ladd, CFC lA-BFN Tom McGovern, SQN Neal Jackson Charles Metcalf Bill Rice L
L c:mlt/letters CNL-16-022 E-16 of 20
Attachment C Ultrasonic Basic Calibration Block Demonstration (N-GP-18) (W47 140528 001)
CNL-16-022 E-17 of 20
W47 140528 001 ULTRASONIC BASIC CALIBRATION BLOCK DEMONSTRATION (N-GP-18)
Purpose:
The purpose of this demonstration is to document equivalency (or better) of the typical TVA Basic Piping Calibration Block designs compared to the ASME design defined in ASME Section XI, App_endix Ill, Paragraph 111-3430 {2001 Edition through 2007 Edition with 2008 Addenda). This demonstration is applicable to examinations performed to meet the requirements of Section XI, Appendix VIII.
Background:
Ultrasonic piping calibration blocks for Browns Ferry baseline examinations were fabricated to the 1971 Edition of the ASME Section XI code. These blocks contain 5% saw-tooth notches. In addition, baseline calibration blocks for Sequoyah and Watts Bar were fabricated to the 1974 Edition with Summer 1975 Addenda of Section XI with similar calibration notch design (i.e., 5% notches) for a majority of piping applications.
Ultrasonic calibration blocks for TVA nuclear sites (Browns Ferry, Sequoyah & Watts Bar) conti.nue to be fabricated to the requirements of ASME Section XI with 5% circumferential and axial. notches for a majority of austenitic and ferritic applications. Bellefonte calibration blocks used at other TVA sites are reviewed by the inspection agency when used in a specific application.
In some cases, the calibration standards for austenitic piping may contain 10% notches (e.g., centrifugal cast piping).
When the nondestructive examination (NOE) requirements were revised to comply with the 1989 Edition of the ASME Section XI Code for all nuclear sites (WBN, SQN and BFN), the requirements included use of Basic Calibration Bl.eeks with 10% notches. A technical justification and demonstration were performed in accordance with IWA-2240 (Ref: L18 960329 800), which provided documented alternatives to the 10% notch requirement, by allowing the use of 5% notches.
Applicable Code Requirements:
Section XI Subsection' IWA-2232 requires that ultrasonic examinations be conducted in accordance with Appendix I. For all piping welds, Appendix I requires compliance with Appendix VIII, with no additional Appendix I Supplements.
Most Generk POI and vendor piping procedures that are qualified in accordance with Section XI, Appendix VIII allow for the use of the Basic Calibration Block, designed in accordance with Section XI, CNL-16-022 E-18 of 20
W47 140528 001 Appendix Ill. However, Appendix VIII also offers provisions for alternative calibration methods, provided equivalency (or better) is demonstrated for each applicable angle and sound mode.
Applicable Components:
This demonstration is applicable to fuH penetration butt welds and adjacent base metal in piping systems, with UT requirements defined by Section XI, Appendix VIII.
Problem Statement:
In the 1998 Edition with 1999 Addenda of Section XI, Appendix Ill, Paragraph 111-llOO(c) [111-llOO(d) in later Editions and Addenda], an additional statementwas added which restricts the use of IWA-2240 for notch dimensions. However,Section XI, Appendix VIII, Vlll-4300 provide a means of demonstrating equivalency (or better) of alternative calibration methods for exams performed in accordance with Section XI, Appendix VIII. Thus, PER 833069 was written to address these additional demon.s tration requirements.
Technical Justification:
Currently TVA has continued with this conservative measure of using notches shaflower than code requirements due to the following reasons:
- Current examination results are required to be compared with previous examination data in order to determine if significant change has occurred (Appendix VIII, Vlll-2100). If calibration blocks are re-machined to comply with Section XI tolerances then the results will not be comparable.
- The cost to .machine deeper notches is not justified and provides no value added to the current In-service Inspection Program examinations. *
- Re-machining basic calibration blocks runs the risk of compromising the specimen (i.e. cutting to deep).
- Appendix VIII, Article Vlll-4300 of the ASME Section XI code makes provision for acceptable alternative calibration methods. This may be done without requalification of the procedure.
- TVA procedures require any flaw regardless of amplitude to be recorded.
- Sizing of a flaw is not based on reference sensitivity of the notch but actual satellite pulse signals which accurately locate the flaw tip.
CNL-16-022 E-19 of 20
W47 140528 001 Demonstration Process:
- This demonstration was conducted on 5/28/2014.
- Equipment was selected and calibrated in accordance with N-UT-84, Revision 0002, which incorporates EPRl-PIPE-MPA-1, Rev 0 (EPRI TR 1016650).
- Calibration was performed using a longitudinal and a shear wave transducer on basic calibration block number BF-31.
- Signal response was observed from the 5%T circumferentially oriented ID notch for the following angles:
o Longitudinal Mode: 40-70 degrees in 1 degree increments o Shear Mode: 30-70 degrees in 1 degree increments
- The process was repeated for each angle and sound mode on the 10%T circumferential ID notch and the sensitivity was compared to that of the 5%T notch.
- For each angle and sound m_ode observed, the sensitivity level was higher for t~e 5%T notch compared to that of the 10%T notch.
Conclusion:
Based on the results of this demonstration, TVA concludes that the use of 5%T notches in the Basic Calibration Blocks used for Section XI, Appendix VIII purposes are acceptable and comparable - or better
- in sensitivity to those described in Section XI, Appendix Ill, Paragraph 111-3430. Thus, these calibration blocks are deemed to comply with ASME Section XI, Appendix VIII, paragraph VIII- 4300. Should future Appendix VIII examinations include requirements for angles or sound modes outside of those documented in this demonstration, then additional demonstrations may be necessary contingent on the code of record used at that time.
c- 00111011 pr,*e.sffey TVA UT Level Ill Date ANll Concurrence Date CNL-16-022 E-20 of 20
Tennessee Valley Authority,1101 Market Street, Chattanooga, Tennessee 37402 CNL-16-022 May 27, 2016 10 CFR 50.55a ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 1 and 2 Facility Operating License Nos. NFP-90 and NFP-96 NRC Docket Nos. 50-390 and 50-391 Browns Ferry Nuclear Plant, Units 1, 2, and 3 Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 NRC Docket Nos. 50-259, 50-260, and 50-296 Sequoyah Nuclear Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327 and 50-328
Subject:
Browns Ferry Nuclear Plant Units 1, 2, and 3, Sequoyah Nuclear Plant Units 1 and 2, and Watts Bar Nuclear Plant Units 1 and 2 - Request for Approval for Use of Alternate Calibration Block Reflector Requirements 16-PDI-5
Reference:
- 1. TVA letter , L.M. Mills to A. Schwencer, Request for Relief ISI-1, dated August 13, 1980, (ML073520649)
- 2. NUREG-0847 Supplement 10, Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant Units 1 and 2, dated October 1992 (ML072060473)
In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.55a, Codes and Standards, paragraph (z)(1), Tennessee Valley Authority (TVA) is requesting the Nuclear Regulatory Commission (NRC) approval of the enclosed request for an alternative (16-PDI-5) to the requirements of the 2001 Edition through 2003 Addenda and the 2007 Edition through 2008 Addenda of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code Section XI, Mandatory Appendix III, Subsubarticle III-3430, Calibration Reflectors, including Mandatory Appendix III, Supplement 1, Paragraph (b)(3), for the Watts Bar Nuclear Plant (WBN) Units 1 and 2 , Sequoyah Nuclear Plant (SQN) Units 1 and 2, and Browns Ferry Nuclear Plant (BFN) Units 1, 2, and 3 basic calibration blocks. Refer to Section 2 of the Enclosure for the applicable code of records.
U.S. Nuclear Regulatory Commission CNL-16-022 Page 2 May 27, 2016 ASME B&PV Code Section XI , Mandatory Appendix Ill , Subsubarticle 111-3430 states that basic calibration blocks shall have a notch depth as specified in Table 111-3430-1 . Table 111-3430-1 specifies that for a nominal pipe wall thickness (t) of 0.312 to 6.0 inches, the calibration block shall have a notch depth of 0.104t - o.oogf (10% oft for austenitic and dissimilar metals welds) with a tolerance of +10% to -20%. This equates to a nominal notch depth from 5%t to approximately 10%t for ferritic materials. TVA requests NRC approval to continue to utilize calibration blocks that were fabricated with alternative notch depths of 5%t with +10% to -20%
tolerance. The 5%t calibration blocks were fabricated for TVA and result in more conservative and sensitive ultrasound examinations.
The enclosure provides a description and assessment of the proposed request for alternative, and the basis as to why the proposed alternative provides an acceptable level of quality and safety in accordance with 10 CFR 50.55a(z)(1).
TVA requests approval of this request by October 1, 2016, which is the scheduled start date for the BFN Unit 1 refueling outage because the potential exists that these calibration blocks will be used during that outage. TVA also requests that approval be granted for the remainder of plant life for BFN Units 1, 2, and 3, SQN Units 1 and 2, and WBN Units 1 and 2.
There are no new regulatory commitments associated with this submittal. Please address any questions regarding this request to Mr. Ed Schrull at 423-751-3850.
Relljll~
Ji . 1 Shea Vice President, Nuclear Licensing
Enclosure:
Request for Alternative Number 16-PDl-5 cc (Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Watts Bar Nuclear Plant NRC Senior Resident Inspector- Browns Ferry Nuclear Plant NRC Senior Resident Inspector- Sequoyah Nuclear Plant NRR Project Manager - Watts Bar Nuclear Plant NRR Project Manager - Browns Ferry Nuclear Plant NRR Project Manager - Sequoyah Nuclear Plant
Enclosure Tennessee Valley Authority Browns Ferry Nuclear Plant Units 1, 2, and 3 Sequoyah Nuclear Plant Units 1 and 2 Watts Bar Nuclear Plant Units 1 and 2 Request for Alternative Number 16-PDI-5 I. Systems/Components Affected Basic calibration blocks, used for ultrasonic testing (UT), are standards that provide a means to correlate an ultrasonic system with reference reflectors of known dimensions. Reference reflectors are dimensioned surfaces, used to establish accurately reproducible reference levels of ultrasonic sensitivity, resolution and sound path distance.
The basic calibration blocks are used to provide a calibration standard for ultrasonic systems used for testing thin-walled vessel (less than or equal to 2 thickness) and piping welds. This request for alternate approval is for basic calibration blocks with a nominal pipe wall thickness (t) five percent (5%)t notch depth. Attachment A provides a list of 5%t notch depth calibration blocks currently in use at TVA nuclear plants.
II. Applicable Code Edition and Addenda The current in-service inspection (ISI) and pre-service inspection (PSI) code of record for Browns Ferry Nuclear Plant (BFN) Unit 1 (third interval), Unit 2 (fifth interval), and Unit 3 (fourth interval) is the American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel (B&PV) Code Section XI, 2007 Edition through 2008 Addenda.
The current ISI and PSI code of record for Sequoyah Nuclear Plant Units 1 and 2 (SQN)
Unit 1 (third interval), Unit 2 (third interval), and for Watts Bar Nuclear Plan (WBN) Unit 1 (second interval) is the ASME B&PV Code Section XI, 2001 Edition through 2003 Addenda.
WBN Unit 2 is currently in the PSI period. The PSI code of record for WBN Unit 2 is the ASME B&PV Code Section XI, 2001 Edition through 2003 Addenda.
SQN Units 1 and 2 and WBN Units 1 and 2 are in the process of transitioning to the ASME B&PV Code Section XI, 2007 Edition through 2008 Addenda for their next upcoming ISI intervals.
CNL-16-022 E-1 of 20
III. Applicable Code ASME Code Components Affected:
ASME Code Classes: 1&2
References:
IWA-2232 Appendix III, Subsubarticle III-3430 Appendix III, Supplement 1(b)(3)
Examination Categories: B-F, B-J, B-O, C-F-1, C-F B-B, C-A Item Numbers: B5.10, B5.130, B9.11, B9.12, B9.31, B14.20, C5.11, C5.12, C5.52
==
Description:==
Alternative to Appendix III Calibration Reflector Requirements Component Numbers: ASME Class 1 and 2 components subject to examination in accordance with Appendix III of Section XI.
IV. Reason for Request ASME B&PV Code Section XI (see the code of record previously specified for each unit in Section II of this enclosure), Mandatory Appendix III, Subsubarticle III-3430 states that basic calibration blocks shall have a notch depth as specified in Table III-3430-1. Table III-3430-1 specifies that for a nominal pipe wall thickness (t) of 0.312 to 6.0 inches, the calibration block shall have a notch depth of 0.104t - 0.009t2 with a tolerance of +10% to -20%. This equates to a nominal notch depth from 5%t to approximately 10%t for ferritic materials.
Appendix III, Supplement I paragraph (b)(3) requires calibration blocks for austenitic and dissimilar metals welds to have a notch depth of 10%t.
The nondestructive examination (NDE) requirements were revised to comply with the 1989 Edition of the ASME Section XI Code for all nuclear sites (WBN, SQN, and BFN). This upgrade was a result of the second interval update for SQN (December 16, 1995 through May 31, 2006). The NDE upgrade provided a consistency in procedure implementation at all TVA nuclear sites. When TVA NDE requirements were revised to comply with the 1989 Edition of the ASME Section XI Code, the code requirements included use of basic calibration blocks with notch depths in the range of 5%t to approximately 10%t, depending on wall thickness. In this edition of the ASME B&PV Code, up to the 1999 Edition of the ASME B&PV Code, provisions were made in Section XI, Division 1, Appendix III, Subarticle III-1100 that allowed alternative designs for basic calibration blocks in accordance with Subsubarticle IWA-2240. Thus, some basic calibration blocks were fabricated by the Tennessee Valley Authority (TVA) with 5%t (+10% to -20% tolerance) notches for piping and vessels 2 or less in thickness versus the 5%t to approximately 10%t range of depths defined in Table III-3430-1 for ferritic material and the 10%t notch depth defined in Appendix III, Supplement 1(b)(3) for austenitic or dissimilar metal welds.
In the 1999 Addenda of Section XI, Subsubarticle III-1100 was revised to add the following phrase after the reference to IWA-2240: except when the requirements of Subsubarticle III-3430 apply. The inclusion of this phrase removed provisions for using alternative notch depths for ISI examinations performed to the 1999, or later, code year of Section XI.
CNL-16-022 E-2 of 20
Alternative calibration notch depths are required to ensure that TVA can comply with the requirements of IWB 2200(b)(2) with regards to comparing ISI results with previous ISI or PSI results. In addition, these alternative notch depth requirements will allow TVA to continue use of basic calibration blocks that were fabricated with alternative notch depths without the necessity of fabricating new blocks.
V. Proposed Alternative and Basis for Use Proposed Alternative:
For ASME Class 1 and ASME Class 2 components subject to ultrasonic examination in accordance with ASME Section XI, Appendix III, TVA requests the Nuclear Regulatory Commission (NRC) approval to use calibration blocks with 5%t notches in lieu of the 5%t to approximately 10%t range specified in Table III-3430-I and the 10%t specified in Supplement 1 paragraph (b)(3). This does not eliminate the option for TVA to use calibration blocks with notches as specified by Appendix III.
Basis For Use:
When TVA nondestructive examination (NDE) requirements were revised to comply with the 1989 Edition of the ASME Section XI Code, the code requirements included use of basic calibration blocks with notch depths in the range of 5%t to approximately 10%t, depending on wall thickness. A technical justification and demonstrations (Attachments B and C to the enclosure) were performed in accordance with IWA-2240, which provided documented alternatives to the Supplement III notch depth requirements, by allowing the use of 5%t notches for all pipe thicknesses up to six inches.
To demonstrate that calibration blocks with 5%t notch depths provide an equivalent or better quality of examination, two demonstrations were conducted on a sampling of blocks that had both 5%t and 10%t nominal notches.
The first demonstration, conducted in 1996 before a TVA site Authorized Nuclear Inspection Inspector (ANII) Supervisor using conventional UT methods, concluded that the 5%t notches increased examination sensitivity by +2 to +6 dB. This demonstration is provided in Attachment B.
The second demonstration was performed in 2014, for the SQN site ANII, using linear phased array (LPA) techniques. This demonstration is provided in Attachment C. Similar to the demonstration in Attachment B, this demonstration concluded that the nominal 5%t notches result in a similar increase (+2 to +6 dB) in calibration sensitivity when compared to the nominal 10%t notches.
These demonstrations provide an acceptable level of quality and safety because the information and data obtained provides sufficient information to determine that applicable UT calibrations will conservatively establish a marginally more sensitive gain setting.
Therefore, pursuant to 10 CFR 50.55a(z)(1), TVA requests NRC approval for the alternate design of the calibration blocks.
Additionally, in Reference 1, TVA submitted a relief request (ISI-1) for WBN Units 1 and 2 to request the use of circumferential notches located on the I.D. and O.D. surface at a nominal depth of 5%t as reference reflectors. Relief was requested to use 5%t or optionally 10%t notches in lieu of the requirements of ASME Code Section XI, 1974 Edition, Summer 1975 CNL-16-022 E-3 of 20
Addenda. The NRC in Appendix Z, Section 3.1 of Reference 2, authorized the use of this relief request and stated, that the use of the notched calibration reflectors, and the recording and reporting level for indications for the pre-service examinations of relatively thin-walled vessel welds are acceptable alternatives to the code requirements.
VI. Duration of Proposed Alternative and Implementation Schedule:
TVA requests that approval be granted for the remainder of plant life for BFN Units 1, 2, and 3, SQN Units 1 and 2, and WBN Units 1 and 2.
TVA requests approval of this request by October 1, 2016, which is the scheduled start date for the BFN Unit 1 refueling outage because the potential exists that these calibration blocks will be used during that outage.
VII. Precedents:
This request for alternative is similar to alternative request NDE-R014 that was approved by the NRC for the Duane Arnold Energy Center (DAEC) in Reference 3. Specifically, the NRC approved an alternative to Section XI, Appendix III, Subsubarticle Appendix III-3430 that allowed DAEC to use calibration blocks that were procured when the plant was built. These calibration blocks had notches of various depth that deviated from the requirements of Section XI, Appendix III, Table III-3430-1.
VIII. References
- 1. TVA letter , L.M. Mills to A. Schwencer, Request for Relief ISI-1, dated August 13, 1980, (ML073520649)
- 2. NUREG-0847 Supplement 10, Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant Units 1 and 2, dated October 1992 (ML072060473)
- 3. NRC Letter, Evaluation of the Third 10-year Inservice Inspection Interval Program Plan Requests for Relief for the Duane Arnold Energy Center (TAC No. M95412), dated March 23, 1998 (ML9804010216)
IX. List of Attachments Attachment A- Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth Attachment B- Ultrasonic Calibration Standards (L18 960329 800)
Attachment C- Ultrasonic Basic Calibration Block Demonstration (N-GP-18)
(W47140528001)
CNL-16-022 E-4 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
BF001 4"SCH80 0.326 A106GR.BCS
BF002 4"SCH80 0.332 A358TP304SS
BF003 10"SCH40 0.375 A106GR.BCS
BF004 6"SCH140 0.752 A358TP304SS
BF005 10"SCH100 0.730 A106GR.BCS
BF006 8"SCH100 0.767 A358TP304SS
BF007 14"pipeSch.80 0.698" A106GR.BCS
BF010 48"x125/16"x4" 4" A533Gr.B
BF011 61/2"x4"x4" 4" A515Gr.70
BF012 12x3x2FlatPlate 3 A515Gr.55
BF014 3/4"SCH160 0.226" SAI06GRBCS
BF015 10"SCH160 1.53" A519GR.MT1020CS
BF016 20"XII"X10"NozzleBlock 10" SA533GR.B.CS
Clad
BF018 24"X6"X6"FlatBlock 6.125" A533GR.BCS
BF019 24"X6"X4FlatBlock 41/64" SA533GRB.CS
BF026 12"X4".75"FlatBlock 0.75" ASMESAI06CS
BF029 4"SCH160 0.506" AI06GRB.CS
BF030 6"SCH160 0.754" AI06CS
BF032 20"X9"X1"FlatBlock 1.140" ASTM516GR70
BF034 6"sch80 0.399 A53Gr.B
BF035 8"sch100 0.520 A106GR.BCS
BF036 5"sch40pipe 0.344 A106GR.BCS
BF037 14"sch30pipe 0.364 A106GR.BCS
BF040 FlatPlate20"x97/8"x1" 0.944 A106GR.BCS
BF041 4"sch160SSPipe 0.452 SA376TP316
BF042 10"Sch80CSPipe 0.597 A106GR.BCS
BF043 FlatPlate20"x927/32"x 1.036 316L
1
BF044 FlatPlate20"x10"x1.5" 1.552 TP304
BF045 6"sch40CSPipe 0.275 SA106GA
BF046 10"Sch80SSPipe 0.588 A312TP304SS
BF048 20"Sch80SSPipe 1.6875 TP304
w/Overlay
BF049 22"Sch80Pipew/Overlay 1.342 SA240TP304
BF050 12"Sch100Pipe 1.139 TP304
w/Overlay
CNL-16-022 E-5 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
BF051 12"Sch100Pipe 0.947 TP304
w/Overlay
BF052 22"x12"Sweepolet(Recirc 0.948 SA240TP304
Loops)
BF053 6"sch160SSPipe 1.122 TP304
BF054 6"sch160SSPipe 1.328 TP304
BF056 14"Sch.100CSPipe 0.938 A106GR.BCS
BF057 FlatPlate20"x47/8"x 1.269 SS304L
1.25"
BF058 1"Sch160CSPipe 0.222 A106GR.BCS
BF059 JetPump .9229 SA182F316
BF060 5"schxxHvySSPipe 0.758 SA312T316L
BF061 6"SCH120 TP304Gr.316
BF062 4"XXSSSPipe/Weld 1.89 SS
Buildup
BF063 6"XXSSSPipe 0.840 SA312/SA376TP304
BF064 2sch160SSPipe 0.375 SA312TP304
BF065 12"Sch160SSPipe 1.345 SA376TP304SS
BF066 4"SchXXHvy 0.685 SA312
BF067 14"Sch160SS 1.339 SA376TP316
BF068 0.863"Diax12.5" 0.046 AdmiraltyBrass
BF069 10"x2"x1"FlatBlock 0.950 Carbon/SS
BF069A 10"x2"x1"FlatBlock 0.900 Carbon/SS
BF070 12"CarbonSteelPipe 1.32" ASMESA376TP316
SegmentWithStainless
Butter
BF071 12"SCH80CladBlock Varies SA358GR304SS
BF072 CladBlockforNozzles 1.32 ASTMA508CL2CS
BF074 20"SCH20 0.187 SA106GrBCS
BF075 12"SCH80 0.688 SA106GrBCS
BF076 5.38"00x12" 0.846 SA508CL2
BF077 16"SCH30 0.375 SA106GrBCS
BF079 12"SCH80 0.691 SA358GR304SS
BF080 6"SCH80 0.860" SA376TP304SS
BF082 28"DiaPipeSeg. 1.250" A358GR304SS
BF083 28"DiaPipeSeg. 1.750" A358GR304SS/308L
BF084 N1N2N3NozzleIR Varies SA508CL2
BF085 N2N5N9NozzleInner Varies ASTMA508CL2
Radius
BF086 N8NozzleInnerRadius ASTMA508CL2
CNL-16-022 E-6 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
BF087 20"SSPipe 1.031 SA376TP316
BF088 22"SSPipe 1.031 SA376TP316
BF089 24"SSPipe 1.285 SA376TP316
BF090 28"SSPipe 1.44 SA376TP316
BF091 6"CSPipe 0.562 ASTMA106GradeB
BF092 8"CSPipe 0.322 ASTMA106GradeB
BF093 12"CSPipe 0.843 ASTMA106GradeB
BF094 16"CSPipe 1.031 ASTMA106GradeB
BF095 18"CSPipe 0.312 ASTMA106GradeB
BF096 18"CSPipe 0.500 ASTMA106GradeB
BF097 18"CSPipe 0.938 ASTMA106GradeB
BF098 20"CSPipe 0.500 ASTMA106GradeB
BF099 20"CSPipe 1.281 ASTMA106GradeB
BF100 24"CSPipe 0.375 ASTMA106GradeB
BF101 24"CSPipe 0.500 ASTMA106GradeB
BF102 24"CSPipe 1.531 ASTMA106GradeB
BF103 24"CSPipe 2.5 ASTMA106GradeB
BF104 26"Pipe 0.950 ASTMA155KC70
BF105 30"CSPipe 0.375 ASTMA106GradeB
BF106 CoreSprayNozzle 1.358 SA508CL2
BF107 RecircOutletNozzle 1.737 SA508CL2
BF108 24"Sch.80CSPipe 1.218 A106GR.BCS
BF109 147"RadiusRVWall 6.60 SA533Gr.Bclass1
BF111 3/4"Pipe 0.154 SA376TP316
BF112 1"Pipe 0.179 SA376TP316
BF113 1.25"pipe 0.191 SA376TP316
BF114 1.5"Pipe 0.200 SA376TP316
BF115 2"Pipe 0.154 SA376TP316
BF116 3"pipe 0.300 SA376TP316
BF117 4"pipe 0.337 SA376TP316
BF118 6"pipe 0.432 SA376TP316
BF127 12"PipeUTCalBlock 0.375" ASTMA106GradeB
BF128 20"pipeUTCalBlock 0.375" ASTMA106GradeB
BF129 RPVInstrumentNozzleto 1.0" ASTMA105Grade2
FlangeUTCalBlock
BF130 RPVInstrumentNozzleto 1.0" A105Grade2
FlangeUTCalBlock
BF131 4"AxialScanUT 2" 304SS
BF132 4"CircumferentialScan Varies 304SS
CNL-16-022 E-7 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
BF133 FlatProbeUT 3.00 304SS
BF136 3"ContourBlock 1.00 316/316L
BF137 3"CircumferentialScan 1.00 316LSS
BF138 28"/29"OD/IDAxialScan 3.9 304SS
BF139 28"ODCircScan 2.4 304SS
BFN134 12"AxialScan 2.92 304SS
BFN135 12"SSCircumferential 1.27 304SS
Scan
IRCSCL38PEB O.DInnerRadiusUTCal Varies SA508CLII
BlockN1N2N3N4N5
SQ001 6"SCH160 0.707" TP304SS
SQ002 6"SCH160 0.707" TP304SS
SQ003 12"SCH140 1.209" TP316SS
SQ005 32"Dia.PipeSeg. 1.429" A516GR.70
SQ006 2"SCH160 0.340" TP304SS
SQ007 8"SCH120 0.760" TP304SS
SQ008 12"SCH80 0.764" TP316SS
SQ009 8SCH80 0.311" A312TP316SS
SQ010 14"SCH160 1.358" A312TP304SS
SQ012 2.5"SCH160 0.430" A312TP304SS
SQ013 4"SCH120 0.436" A312TP304SS
SQ014 12"X4"X1.5"FlatBlock 1.5" A516GR.70CS
SQ015 12"X4"X1"FlatBlock 1.022" TP304SS
SQ016 12"SCH160 1.310" A403WP316SS
SQ017 6"SCH120 0.580" A276TP304SS
SQ018 18"SCH80 0.977" A333GR.1CS
SQ019 6"Dble.E.H. 0.875" A106GR.BCS
SQ020 1.5SCH160 0.324" A376TP304SS
SQ021 10"Pipe1.5"Thick 1.50" SA106GrBCS
SQ029 6"Dia.PipeSeg. 1.2" 304SS
SQ030 5"Dia.E.H. 0.897" 304SS
SQ037 TransferredtoBFNP 0.502 A36A283
SQ039 18"SCH40 0.640" 304SS
SQ040 12"X6"X3"VesselBlock 3.0" SA533GR.ACL2CS
SQ041 12"X6"X4"(3/16Clad) 37/8" SA533GR.ACL2CS
Vessel
SQ043 22"X6"X6"(7/32Clad) 513/16" A508CL2CS
Vessel
CNL-16-022 E-8 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
SQ044 33"X6"X811/16"(1/4 811/16" A508CL2CS
Clad)Vessel
SQ045 43"X6"X11"(5/16Clad) 111/8" A508CL2CS
Vessel
SQ046 27"X6"X7"(7/32Clad) 71/16" A508CL2CS
Vessel
SQ049 15"X6"X5"(1/4Clad) 5" SA216GR.WCCCS
SQ050 101/2"O.D.X7"I.D.Nut 1.75" SA540GR.B24
Block
SQ051 12"X6"X6"(3/16"Clad) 529/32" A508CL2CS
SQ053 26"X23"X6"(3/16Clad) Varies A508CL2CS
Nozzle
SQ054 16"Rad.(1/4Clad) Varies A508CL2CS
SQ055 21/2"Dia.x93/4"Stud Stud A193GR.B7CS
SQ056 LetdownHeatExchanger 0.428" AISITP304SS
Block
SQ057 24"X6"X4"VesselBlock 4" SA533GR.ACL1CS
SQ058 3/4"Dia.X135/8" .049" AdmiraltyBrass
SQ059 SGPrimaryNozzleI.R. 16.0" A216GR.WCCCS
W/Clacd
SQ061 S.G.FeedwaterNozzle .837" A333GR.1CS
SQ062 S.G.NozzletoTransition 0.6 SA508CL.2CS
Spool
SQ065 3"Dia.BranchConnection 1.313" A182,F316SS
SQ066 6"Dia.BranchConnection 1.85 A182,F316SS
SQ067 10"Dia.BranchConnection 2.490" A182,F316SS
SQ068 16X16"X4"RCPFlywheel 3.75" SA533,GR.BCS
Block
SQ069 4"Dia.BranchConnection 1.530" A182,F316SS
SQ070 8"Dia.BranchConnection 2.090" A182,F316SS
SQ071 12"Dia.BranchConnection 2.99" A182,F316SS
SQ072 4"Dia.LiftingRig 4.00" A322,GR4340
SQ073 4"Dia.LiftingRig 4.00" A322,GR4340
SQ074 4"Dia.LiftingRig 4.00" A322,GR4340
SQ075 3.5"Dia.LiftingRig 3.50" A564,GR630
SQ076 Mainsteam/Feedwater 14" A508CL.2
NozzleI.R.
SQ077 PressurizerNozzleI.R. 13.624" A508CL.2
SQ078 FlywheelCal.Block 4.5 SA533GrB
SQ079 4"CSSch80Cal.Block .337 A106GR.BCS
SQ080 UHIInconelCalBlock .531" ASMESB166
CNL-16-022 E-9 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
SQ081 UHIStainlessCalBlock .527" ASMESA479
SQ082 CRDMInconelCalBlock .625" ASMESB166
SQ083 CRDMStainlessCalBlock .622" ASMESA479
SQ085 2"Sch80Cal.Block .210" SA376304
SQ086 3"Sch80Cal.Block .308" SA376304
SQ087 3"Sch40Cal.Block .214" SA376304
SQ088 4"Sch80Cal.Block .370" SA376304
SQ089 16"Cal.Block .400" SA358304
SQ090 20"Cal.Block .420" SA358304
SQ091 24"Cal.Block .407" SA358304
SQ092 3.38"MainSteamCalBlock 3.38" ASTMA105
SQ093 14"Sch40CalBlock .438" SA376GR304
SQ103 2.35fX13.5 Stud ASTM193,GRB6
SQ104 12x6x.75FlatBlock .75 TP304SS
SQ105 12x6x.5FlatBlock .5 TP304SS
SQ106 12"x4"X.75"SSCLADFLAT .775" SA515,GR70
BLOCK
SQ108 18"x6"x3"FlatBlock 3.00" SA508,CL.3.
SQ110 27"x7"CLADBLOCK(0.2") 7.00" SA508,CL.3
SQ111 CLADSGNOZZLEBLOCK 9.00" SA508,CL.3
I.R.
SQ112 25"x7.5"NOZZLEBLOCK 7.54" SA336F316LN
SQ113 12"X10"FWNozzleIR Varies SA508,CL3
SQ124 9.75"X6"X0.750" ASTMA36
SQ131 8Ax.OverlayCalBlock 2.000 304SS
SQ132 16Ax.OverlayBlock 2.000 304SS
SQ133 FlatOverlayBlock 3.000 304SS
SQ134 8CircScanOverlayBlock 2.248 304SS
SQ135 16CircScanOverlayBlock 2.500 302SS
SQ136 6Circ.ScanOverlayBlock 1.617 304SS
SQ137 6"AxialScanOverlayBlock 2.502 305SS
WB001 6"SCH160Pipesegment 0.715 SA376TP304SS
WB002 8"SCH160PipeSegment 0.942 SA376TP304SS
WB003 12"SCH140PipeSegment 1.158 SA376TP316
WB004 16"SCH80PipeSegment 0.754 SA333GR.6
WB005 16"SCH140PipeSegment 1.410 SA515,GR70
WB006 2"SCH160 0.346 TP304
WB007 8"SCH120PipeSegment 0.758 TP304
WB008 12"SCH80PipeSegment 0.767 SA376TP316
WB009 8"SCH40PipeSegment 0.307 A312TP316SS
CNL-16-022 E-10 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
WB010 14"SCH160 1.352 A312TP304SS
WB011 3"SCH160PipeSegment 0.450 304H
WB012 2"SCH160PipeSegment 0.395 SA376TP304SS
WB014 1.5"FlatBlock 1.482 SA516SR70
WB015 1"FlatBlock 1.028 SA376TP304SS
WB016 12"Sch160SSPipe 1.322 SA376TP304SS
WB017 5"Sch160Pipe 0.585 SA403WP315
WB018 18"SCH80Pipe 0.938 SA333GR.6
WB019 5"schxxHvyPipe 0.782 A106GR.BCS
WB020 11/2"SCH160Pipe 0.312 SA376TP304SS
WB021 10"Pipe1.5"Thick 1.493 SA106GrBCS
WB027 2"RoundBar 2.00 SA193GRB7
WB029 4"PipeSegment 1.206 SA376TP304SS
WB030 3"PipeSegment 0.918 SA376TP304SS
WB033 10"x1"thickpipesegment 1.005 TP304
WB034 12"pipesegment 1.247 TP304
WB037 6"SCH80 0.433 SA53GrB
WB038 8"Sch.80 0.484 SA106Gr.B
WB039 Vessel 4.015 SA533GRACL2CS
WB041 12"Sch40SPipeSegment 0.363 SA312TP304
WB042 18"Sch30PipeSegment 0.431 SA403TP304
WB043 18"SCH40PipeSegment 0.641 SA240TP304
WB044 2.15"ThickBar 2.15 SA240TP304
WB045 2.5"diax10"longStud 2.5 SA193GRB7
WB046 14"Sch40PipeSegment 0.470 SA358GR304SS
WB052 CRDMStainless/Inconel 0.626 SA182TP304/ASME
Block SB167
WB053 3"thickSafeEnd 3.00 SA182TP304/SA508
CL.2
WB061 2"Sch80PipeSegment .225 SA376TP304SS
WB062 3"Sch40PipeSegment 0.265 SA376
WB063 3"SCH80PipeSegment 0.287 SA376TP304SS
WB064 4"SCH40PipeSegment 0.268 SA376TP304SS
WB065 4"SCH80PipeSegment 0.343 SA376TP304SS
WB066 14"PipeSegment 0.370 SA358TP304SS
WB067 16"PipeSegment 0.395 SA358TP304SS
WB068 20"PipeSegment 0.414 SA358TP304SS
WB069 24"PipeSegment 0.400 SA358TP304SS
WB071 UpperInjectionNozzle 0.785 SB168TP600
WB072 UpperInjectionNozzle 0.785 SA479304L/SA182
CNL-16-022 E-11 of 20
Attachment A Current List of TVA Calibration Blocks with Nominal 5%t Notch Depth DocLink GeneralDescription ActualWall MaterialType
Thickness
WB073 CRDMPipeSegment 0.625 SB168TP600
WB074 CRDMPipeSegment 0.625 SA479304L/SA182
WB075 RecircCoolantPumpBolt 4.5 SA540E4340H
WB077 NozzletoShellUT 2.5/1.0
CNL-16-022 E-12 of 20
Attachment B Ultrasonic Calibration Standards (L18 960329 800)
CNL-16-022 E-13 of 20
Tennessee Valley Authority. Post Office Box 2000, Soddy-Daisy. Tennessee 37379-2000 L 18 960329 800 March 29, 1996 Mr. Ernest Farrow Hartford Steam Boiler Inspection & Insurance Co.
200 Ashford Center North, Suite 300 Atlanta, GA 30338-4860
Dear Mr. Farrow:
ULTRASONIC CALIBRATI O N STANDARDS
Purpose:
The purpose of this memorandum is to state TVA 's position regarding calibration block design and provide justification \vhy .existing calibration standards surpass current requirements established by the ASME Section XI Code, 1989 Edition.
Background:
Ultrasonic piping calibration blocks for Browns Ferry baseline examinations were fabricated to the 1971 Edition of the ASME Section XI code. These blocks contain 5% sawtooth notches . In addition, baseline calibration blocks for Sequoyah and Watts Bar were fabricated to the 1974 Edition with Surruner 1975 Addenda of Section XI with similar calibration notch design (i e., 5%
notches) for a majority of piping applications .
Ultrasonic calibration blocks for TV A nuclear sites (Browns Ferry, Sequoyah, Watts Bar) continue to be fabricated to the requirements of ASME Section XT with 5% circumferential and axial notches for a majority of austenitic and ferritic applications . Bellefonte calibration blocks used at other TV A sites are reviewed by the inspection agency when used in a specific application.
[n some cases, the calibration standards for austenitic piping may contain 10% notches (e.g ..
centrifugal cast piping) .
The nondestructi ve examination (NOE) requirements were recently revised to comply >vith the 1989 Edition of the ASME Section XI Code for all nuclear sites (WBN. SQN and BFN) This upgrade was a result of the second interval update for Sequoyah. The NDE upgrade provides a generic consistency in procedure implementation at all TV A nuclear sites c:ml t/Icttcrs CNL-16-022 E-14 of 20
}\pplicable Code Requirement Section XI Subsection IWA-2232 requires that ultrasonic examinations be conducted in accordance with Appendix I. The requirements for vessel welds less than or equal to 2 inches in thickness and all piping welds are contained in Appendix ill, as supplemented by Appendix I. The requirements for calibration reflectors are contained in Article III-3430 with reference to Table ill-3430-1 and Appendix ill Supplement 4 for austenitic and dissimilar metal welds.
Applicable Components Full penetration butt welds and adjacent base metal in piping systems having a nominal wall thickness of 0.2 to 6 inches. Vessel welds less than or equal to 2 inches in thickness.
Description of Condition The 1989 edition of the ASME Section XI code currently requires that calibration blocks contain notches within tolerances described in Appendix I and Appendix ill. A majority of piping calibration blocks contain 5% notches which are determined to be conservatively outside the limits of Table ill-3430-1 and Appendix ill Supplement 4, as applicable.
Technical Justification Currently TVA has continued with this conservative measure of using notches less than code requirements due to the following reasons:
L
- Current examination results are compared with previous examination data in order to determine if significant change has occurred (i.e., greater than +6dB). If calibration blocks are remachined to comply with 1989 Section XI tolerances then current results are not comparable.
- The cost to machine deeper notches is not justified and provides no value add to the current Inservice Inspection Program examinations.
- Appendix III, Article ill-3430 of the ASME Section XI code 1989 Edition makes provision for an acceptable alternative block design. In addition, IWA-2240 Alternative Examination methods may be substituted for the methods specified in the applicable Division, provided the results are demonstrated to be equivalent or superior to those of the specified method. Where alternative methods (i .e., the use of 5%
notches) have been demonstrated, the Inspection Agency review has been documented and found to be equivalent or superior.
- Examination sensitivity is increased by + 2 tp +6 dB when using 5% notches as compared to 10% notches.
- TVA procedures require any flaw regardless of amplitude to be recorded.
(
- Sizing of a flaw is not based on reference sensitivity of the notch but actual satellite
'\._,, pulse signals which accurately locate the flaw tip .
c:mltlletters CNL-16-022 E-15 of 20
~onclusion:
TVA's position concludes that the ASME Section XI code contains the requirements essential for the examination of piping and components. More conservative measures (notches that are below the maximum code allowable) are deemed to comply with ASME Section XI. The proposed alternatives do not compensate a decrease in the level of quality and safety. We request that you review the subject position and concur with the technical basis stipulated. Any questions may be directed to myself at (423)843-4355.
Manager, Ultrasonic Group Inspection Services Organization STC 11-SQN cc: George Deaton, CFC lA-BFN Bruce Eamigh, WBN Albert Ladd, CFC lA-BFN Tom McGovern, SQN Neal Jackson Charles Metcalf Bill Rice L
L c:mlt/letters CNL-16-022 E-16 of 20
Attachment C Ultrasonic Basic Calibration Block Demonstration (N-GP-18) (W47 140528 001)
CNL-16-022 E-17 of 20
W47 140528 001 ULTRASONIC BASIC CALIBRATION BLOCK DEMONSTRATION (N-GP-18)
Purpose:
The purpose of this demonstration is to document equivalency (or better) of the typical TVA Basic Piping Calibration Block designs compared to the ASME design defined in ASME Section XI, App_endix Ill, Paragraph 111-3430 {2001 Edition through 2007 Edition with 2008 Addenda). This demonstration is applicable to examinations performed to meet the requirements of Section XI, Appendix VIII.
Background:
Ultrasonic piping calibration blocks for Browns Ferry baseline examinations were fabricated to the 1971 Edition of the ASME Section XI code. These blocks contain 5% saw-tooth notches. In addition, baseline calibration blocks for Sequoyah and Watts Bar were fabricated to the 1974 Edition with Summer 1975 Addenda of Section XI with similar calibration notch design (i.e., 5% notches) for a majority of piping applications.
Ultrasonic calibration blocks for TVA nuclear sites (Browns Ferry, Sequoyah & Watts Bar) conti.nue to be fabricated to the requirements of ASME Section XI with 5% circumferential and axial. notches for a majority of austenitic and ferritic applications. Bellefonte calibration blocks used at other TVA sites are reviewed by the inspection agency when used in a specific application.
In some cases, the calibration standards for austenitic piping may contain 10% notches (e.g., centrifugal cast piping).
When the nondestructive examination (NOE) requirements were revised to comply with the 1989 Edition of the ASME Section XI Code for all nuclear sites (WBN, SQN and BFN), the requirements included use of Basic Calibration Bl.eeks with 10% notches. A technical justification and demonstration were performed in accordance with IWA-2240 (Ref: L18 960329 800), which provided documented alternatives to the 10% notch requirement, by allowing the use of 5% notches.
Applicable Code Requirements:
Section XI Subsection' IWA-2232 requires that ultrasonic examinations be conducted in accordance with Appendix I. For all piping welds, Appendix I requires compliance with Appendix VIII, with no additional Appendix I Supplements.
Most Generk POI and vendor piping procedures that are qualified in accordance with Section XI, Appendix VIII allow for the use of the Basic Calibration Block, designed in accordance with Section XI, CNL-16-022 E-18 of 20
W47 140528 001 Appendix Ill. However, Appendix VIII also offers provisions for alternative calibration methods, provided equivalency (or better) is demonstrated for each applicable angle and sound mode.
Applicable Components:
This demonstration is applicable to fuH penetration butt welds and adjacent base metal in piping systems, with UT requirements defined by Section XI, Appendix VIII.
Problem Statement:
In the 1998 Edition with 1999 Addenda of Section XI, Appendix Ill, Paragraph 111-llOO(c) [111-llOO(d) in later Editions and Addenda], an additional statementwas added which restricts the use of IWA-2240 for notch dimensions. However,Section XI, Appendix VIII, Vlll-4300 provide a means of demonstrating equivalency (or better) of alternative calibration methods for exams performed in accordance with Section XI, Appendix VIII. Thus, PER 833069 was written to address these additional demon.s tration requirements.
Technical Justification:
Currently TVA has continued with this conservative measure of using notches shaflower than code requirements due to the following reasons:
- Current examination results are required to be compared with previous examination data in order to determine if significant change has occurred (Appendix VIII, Vlll-2100). If calibration blocks are re-machined to comply with Section XI tolerances then the results will not be comparable.
- The cost to .machine deeper notches is not justified and provides no value added to the current In-service Inspection Program examinations. *
- Re-machining basic calibration blocks runs the risk of compromising the specimen (i.e. cutting to deep).
- Appendix VIII, Article Vlll-4300 of the ASME Section XI code makes provision for acceptable alternative calibration methods. This may be done without requalification of the procedure.
- TVA procedures require any flaw regardless of amplitude to be recorded.
- Sizing of a flaw is not based on reference sensitivity of the notch but actual satellite pulse signals which accurately locate the flaw tip.
CNL-16-022 E-19 of 20
W47 140528 001 Demonstration Process:
- This demonstration was conducted on 5/28/2014.
- Equipment was selected and calibrated in accordance with N-UT-84, Revision 0002, which incorporates EPRl-PIPE-MPA-1, Rev 0 (EPRI TR 1016650).
- Calibration was performed using a longitudinal and a shear wave transducer on basic calibration block number BF-31.
- Signal response was observed from the 5%T circumferentially oriented ID notch for the following angles:
o Longitudinal Mode: 40-70 degrees in 1 degree increments o Shear Mode: 30-70 degrees in 1 degree increments
- The process was repeated for each angle and sound mode on the 10%T circumferential ID notch and the sensitivity was compared to that of the 5%T notch.
- For each angle and sound m_ode observed, the sensitivity level was higher for t~e 5%T notch compared to that of the 10%T notch.
Conclusion:
Based on the results of this demonstration, TVA concludes that the use of 5%T notches in the Basic Calibration Blocks used for Section XI, Appendix VIII purposes are acceptable and comparable - or better
- in sensitivity to those described in Section XI, Appendix Ill, Paragraph 111-3430. Thus, these calibration blocks are deemed to comply with ASME Section XI, Appendix VIII, paragraph VIII- 4300. Should future Appendix VIII examinations include requirements for angles or sound modes outside of those documented in this demonstration, then additional demonstrations may be necessary contingent on the code of record used at that time.
c- 00111011 pr,*e.sffey TVA UT Level Ill Date ANll Concurrence Date CNL-16-022 E-20 of 20