RS-17-158, Fifth Inservice Inspection Interval Relief Request 15R-16

Fifth Inservice Inspection Interval Relief Request 15R-16

ML17312A293
Person / Time
Site:	Dresden
Issue date:	11/07/2017
From:	Simpson P Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-17-158
Download: ML17312A293 (18)

Text

4300 Winfield Road Warrenville, IL 60555 ExeLon G 630 657 2000 Office RS-17-158 10 CFR 50.55a(z)(1)

November 7, 2017 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249

Subject:

Dresden Nuclear Power Station Fifth Inservice Inspection Interval Relief Request 15R-16 In accordance with 10 CFR 50.55a(z)(1), Exelon Generation Company, LLC (EGC) requests NRC approval of the attached relief request for Dresden Nuclear Power Station (DNPS), Units 2 and 3. DNPS, Units 2 and 3 are currently within their fifth inservice inspection (ISI) interval, which complies with the 2007 Edition with 2008 Addenda of the American Society of Mechanical Engineers (ASME) Code,Section XI. The fifth interval began on January 20, 2013, and is currently scheduled to end on January 19, 2023. Specifically, EGC is requesting relief from the ASME Section XI, Appendix VIII, Supplement 11 qualification requirements for full structural overlaid wrought austenitic piping welds. EGC requests approval to use the proposed alternatives as implemented by the Performance Demonstration Initiative (PDI) Program to the requirements within ASME Section XI, 2007 Edition 2008 Addenda, Appendix Vlll, Supplement 11, "Qualification Requirements for Full Structural Overlaid Wrought Austenitic Piping Welds." Compliance with the proposed alternatives within this relief request, versus those in the 2007 Edition with 2008 Addenda of ASME Section XI, Appendix VIII, Supplement 11, will provide an acceptable level of quality and safety.

Implementation of the PDI Program will allow EGC to perform preservice inspections of an emergent weld overlay repair required by the identification of recordable ultrasonic (UT) indications in Weld JP1A/N20A-6 (i.e., a reducer-to-pipe weld on the Unit 2 "A" jet pump instrumentation loop header).

November 7, 2017 U.S. Nuclear Regulatory Commission Page 2 Approval of this relief request is requested by November 9, 2017, to support the current refueling outage.

There are no regulatory commitments contained within this letter.

Should you have any questions concerning this letter, please contact Mr. Mitchel A. Mathews at (630) 657-2819.

S' erely, Patrick R. Simpson Manager Licensing Exelon Generation Company, LLC

Attachment:

10 CFR 50.55a Relief Request No. 1519-16

ATTACHMENT 10 CFR 50.55a Relief Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety--

1. ASME Code Component(s) Affected:

Class 1 Pressure Retaining Piping Welds subject to Ultrasonic (UT) examination using procedures, personnel, and equipment qualified by demonstration to American Society of Mechanical Engineers (ASME)Section XI, 2007 Edition with 2008 Addenda, Appendix VIII, Supplement 11.

2. Applicable Code Edition and Addenda:

Dresden Nuclear Power Station (DNPS), Units 2 and 3 are currently in the Fifth Inservice Inspection Program (ISI) Interval, which is based on the ASME Boiler and Pressure Vessel (B&PV) Code,Section XI, 2007 Edition through the 2008 Addenda. The DNPS fifth 10-year ISI interval commenced on January 20, 2013, and will end on January 19, 2023.

3. Applicable Code Requirement

The following codes are applicable:

• ASME B&PV Code,Section XI, 2007 Edition, with the 2008 Addenda, Appendix VIII provides requirements for performance demonstration for ultrasonic examination systems.

• ASME Section XI, Appendix VIII, Supplement 11 provides the "Qualification Requirements for Full Structural Overlaid Wrought Austenitic Piping Welds."

• ASME Section XI Code Case N-653-1, "Qualification Requirements for Full Structural Overlaid Wrought Austenitic Piping Welds,Section XI, Division 1" provides approved alternative requirements for qualification requirements for detection and length and depth sizing for both service-induced and fabrication-induced flaws governed by ASME Section XI, Appendix VIII, Supplement 11.

4. Reason for Request

During the DNPS, Unit 2 Refuel Outage (i.e., D2R25), recordable ultrasonic (UT) indications were identified in Weld JP1A/N20A-6 (i.e., reducer-to-pipe weld on the Unit 2 "A" Jet Pump Instrumentation Loop header). As a result of these indications a full structural weld overlay is being applied to the existing weld in accordance with ASME Section XI Code Case N-504-4, "Alternative Rules for Repair of Classes 1, 2, and 3 Austenitic Stainless Steel Piping Section XI, Division 1," including the conditions for its use as described in NRC Regulatory Guide 1.147, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1," Table 2, "Conditionally Acceptable Section XI Code Cases."

Code Case N-504-4 requires liquid penetrant and ultrasonic examinations of the completed weld repair to be performed. The ultrasonic examination area of the weld overlay includes the newly applied weld reinforcement and the outer 25% of the underlying pipe wall.

Page 1 of 5

ATTACHMENT 10 CFR 50.55a Relief Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety--

The industry utilizes the Performance Demonstration Initiative (PDI) program for the qualification of equipment, procedures, and personnel. The PDI Program does not meet all aspects of the Code requirements identified in ASME Section XI, Appendix VIII, Supplement 11 of the 2007 Edition with Addenda through 2008. As a result, Requests for Relief have been approved and are the basis for the implementation of the PDI Program for Supplement 11 as described in Code Case N-653-1.

The PDI Program provides provisions qualification requirements for detection, length, and depth sizing for both service induced and fabrication induced flaws. The program is applicable to wrought austenitic, ferritic, or dissimilar metal welds overlaid with austenitic weld material. The scope of Appendix VI 11, Supplement 11, has been expanded to address this change in the attached table.

Implementation of the PDI Program in accordance with Code Case N-653-1 will allow EGC to perform preservice inspections of an emergent weld overlay repair required by the identification of recordable ultrasonic (UT) indications in Weld JP1A/N20A-6 (i.e., a reducer-to-pipe weld on the Unit 2 "A" jet pump instrumentation loop header).

5. Proposed Alternate and Basis for Use:

Proposed Alternative In accordance with 10 CFR 50.55a(z)(1), Exelon Generation Company, LLC (EGC) requests approval to use the proposed alternatives as implemented by the PDI Program to the requirements within ASME Section XI, 2007 Edition 2008 Addenda, Appendix VIII, Supplement 11, "Qualification Requirements for Full Structural Overlaid Wrought Austenitic Piping Welds" as shown in the enclosed table for the performance demonstration for ultrasonic (UT) examination procedures, equipment, and personnel. A two column table is provided showing the ASME Section XI, Supplement 11 of the 2007 Edition with Addenda through 2008 and the proposed alternatives as implemented by the PDI Program.

Basis for Use Compliance with the proposed alternatives within this relief request, versus those in the 2007 Edition with 2008 Addenda of ASME Section XI, Appendix VIII, Supplement 11, will provide an acceptable level of quality and safety for the qualification of equipment, procedures, and personnel for examinations of overlays. The enclosed table provides alternative requirements for a broader scope of weld overlays and the technical requirements for the qualification have been modified so that an acceptable level of quality and safety is maintained.

Page 2 of 5

ATTACHMENT 10 CFR 50.55a Relief Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety--

1) The scope was changed to broaden the applicability of Supplement 11 The title of ASME Section XI, Supplement 11 in the 2007 Edition with Addenda through 2008 is "Qualification Requirements for Full Structural Overlaid Wrought Austenitic Piping Welds." When originally written, this was accurate for the extent of usage of weld overlay repairs. However, the use of weld overlays has broadened.

Weld overlays are now being designed that are not intended as full-structural replacements to the original weld and base material. In addition, weld overlays are now being applied over cast austenitic stainless steel piping welds, as well as wrought.

Therefore, the alternatives proposed within this relief request are required to broaden the applicability of Supplement 11 as written in the 2007 Edition with Addenda through 2008 of the ASME Section XI Code.

2) The names of the grading units were changed from base metal and overlay fabrication to inservice and preservice, respectively.

Originally, Supplement 11 was written to cover the examination of weld overlay repairs of BWR recirculation piping welds, which were applied due to SCC cracking. At the time, SCC cracking was only occurring in the base metal adjacent to the weld (in the heat affected zone). Therefore, for qualification purposes, it was appropriate to refer to the grading units intended to contain cracking in the original pipe as "base metal" grading units.

Subsequently, mechanisms have been discovered that cause cracking not only in the base metal, but also in the weld and buttering of these types of welds. Overlays are being applied to welds in PWRs, as well, where the cracking is primarily found in the weld and buttering material.

Therefore, it is now more appropriate to call the grading unit for the original piping as an "inservice" grading unit, which is a broad enough term to encompass flaws in the base material or weld material. Since the term for grading units in the original piping was being changed to "inservice", it seemed appropriate to change the term for grading units intended to contain fabrication related discontinuities in the weld overlay (i.e. bonding and weld cleanliness) to "preservice". It is during the preservice inspection that these indications are expected to be discovered.

3) The term base metal flaws was changed to service-induced flaws and the term overlay fabrication flaws was changed to fabrication-induced flaws in this revision.

This relief request proposes using "service-induced flaws" as an alternative to the term "base metal flaws" and "fabrication-induced flaws" as an alternative to "overlay fabrication flaws" to describe the flaw types to make them broad enough to encompass all currently recognized degradation mechanisms.

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ATTACHMENT 10 CFR 50.55a Relief Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety--

4) Provisions have been added for qualification of "optimized" weld overlays.

The qualification requirements provided in ASME Section XI, Appendix VIII, Supplement 11 were written strictly for weld overlay repairs designed as full structural replacements for the original weld and base material beneath them. The volumetric examination coverage required for full structural weld overlays was the thickness of the overlay, plus the outer 25% of the original weld and base material. Since that time, the industry has begun to use overlay repairs on larger piping systems, for which full structural overlays are not practical, due to the weight they would add to the piping system and the time it would take to install them. These new "optimized" weld overlays are thinner and are designed as a partial structural replacement to the original piping. They are only designed as a repair for up to a 75% through-wall circumferential crack, instead of a 100% through-wall crack. Because of this, the volumetric examination requirements have also been increased to include the outer 50% of the original base material (a 25% increase over the previous requirement).

The proposed alternatives contain provisions to allow for qualification of this extended examination volume.

There are currently no "optimized" overlays installed at DNPS, Units 2 and 3 and no plans exist to utilize "optimized" overlays.

5) Qualification for width sizing of laminar flaws is now addressed.

The acceptance criteria for laminar flaws in a weld overlay repair are based upon, among other things, the total area of the flaw. However, Supplement 11 only contains provisions for length sizing and is silent on qualification for width sizing. The common technique for both length sizing and width sizing of laminar flaws is to map the edges of the flaw using a 00 (straight beam) transducer. There is virtually no difference in these measurements in terms of axial versus circumferential directions. Therefore, this relief request includes a clarifying sentence for the qualification for both length and width sizing of laminar flaws.

6. Duration of Proposed Alternative:

Relief is requested for the Fifth Ten-Year Inspection Interval for Dresden Nuclear Power Station, Units 2 and 3.

7. Precedent:

The proposed alternative is similar to the alternative that was previously approved by the NRC for St. Lucie Plant, Unit 2 as shown below:

Letter from S. R. Helton (NRC) to M. Nazar (NextEra Energy), "St. Lucie Plant Unit No. 2 Fourth 10-Year Inservice Inspection Interval Relief Request No. 3, Revision 0 JAC No. MF4398)," dated June 3, 2015 (ADAMS Accession No: ML15111A357).

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ATTACHMENT 10 CFR 50.55a Relief Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety--

8. Enclosure to the Relief Request:

A two-column table comparing ASME Section XI, Appendix VIII, Supplement 11 of the 2007 Edition with Addenda through 2008 requirements to the proposed alternatives as implemented by the PDI Program.

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ENCLOSURE ASME Section XI, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum PDI Program (Code Case N-653-1)

ASME,Section XI, Appendix VIII 1.0 SPECIMEN REQUIREMENTS SPECIMEN REQUIREMENTS Qualification test specimens shall meet the requirements Qualification test specimens shall meet the requirements listed herein, unless a set of specimens is designed to listed in this document, unless a set of specimens is designed accommodate specific limitations stated in the scope of the to accommodate specific limitations stated in the scope of the examination procedure (e.g., pipe size, weld joint examination procedure (e.g., pipe size, weld joint configuration, access limitations). The same specimens may configuration, access limitations). The same specimens may be used to demonstrate both detection and sizing be used to demonstrate both detection and sizing qualification. qualification.

1.1 General. The specimen set shall conform to the following General requirements.

Specimens shall have sufficient volume to minimize spurious (a) Specimens shall have sufficient volume to minimize reflections that may interfere with the interpretation process.

spurious reflections that may interfere with the interpretation process.

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ENCLOSURE ASME Section X1, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum PDI Program (Code Case N-653-1) '

ASME,Section XI, Appendix VIII (b) The specimen set shall consist of at least three specimens The specimen set shall consist of at least three specimens having different nominal pipe diameters and overlay having different nominal pipe diameters and overlay thicknesses. They shall include the minimum and maximum thicknesses. They shall include the minimum and maximum nominal pipe diameters for which the examination procedure nominal pipe diameters for which the examination procedure is applicable. Pipe diameters within a range of 0.9 to 1.5 times is applicable. Pipe diameters within a range of 0.9 to 1.5 a nominal diameter shall be considered equivalent. If the times the nominal diameter shall be considered equivalent. If procedure is applicable to pipe diameters of 24 in. (600 mm) the procedure is applicable to pipe diameters of 24 in. (610 or larger, the specimen set must include at least one mm) or larger, the specimen set must include at least one specimen 24 in. (600 mm) or larger but need not include the specimen 24 in. (610 mm) or larger but need not include the maximum diameter. The specimen set shall include at least maximum diameter. The specimen set must include one specimen with overlay not thicker than 0.1 in. (2.5 mm) specimens with overlay not thicker than 0.1 in. (2.5 mm) more more than the minimum thickness, and at least one specimen than the minimum thickness, and at least one specimen with with overlay not thinner than 0.25 in. (6 mm) less than the overlay not thinner than 0.25 in. (6 mm) less than the maximum for which the examination procedure is applicable. maximum thickness for which the examination procedure is applicable.

(c) The surface condition of at least two specimens shall The surface condition of at least two specimens shall approximate the roughest surface condition for which the approximate the roughest surface condition for which the examination procedure is applicable. examination procedure is applicable.

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ENCLOSURE ASME Section XI, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum PDI Program (Code Case N-653-1)

ASME,Section XI, Appendix VIII (d) Flaw Conditions Service-Induced Flaws. Service-induced flaws must be in or near the weld, buttering, or heat-affected zone, and open to (1) Base metal flaws. All flaws must be in or near the butt the inside surface. The examination procedure shall specify weld heat-affected zone, open to the inside surface, and the examination volume. If the examination procedure extending at least 75% through the base metal wall.

specifies an examination volume greater than the outer 25%

Intentional overlay fabrication flaws shall not interfere with of the base metal wall thickness, the detection and sizing test ultrasonic detection or characterization of the base metal sets shall include at least five representative flaws suitable to flaws. At least 70% of the flaws in the detection and sizing demonstrate the procedure capability in this extended tests shall be actual cracks. Specimens containing IGSCC volume. Intentional fabrication-induced flaws shall not shall be used if they are available. If implantation of actual interfere with ultrasonic detection or characterization of the cracks produces spurious reflectors that are not characteristic service-induced flaws. At least 70% of the flaws in the of actual flaws, alternative flaws may be used but shall detection and sizing tests shall be cracks. Specimens comprise not more than 30% of the total of base material containing stress corrosion cracking (SCC) shall be used flaws. Alternative flaws, if used, shall provide crack-like when available. If implantation of actual cracks produces reflective characteristics and shall be semielliptical. The tip spurious reflectors that are not characteristic of actual flaws; width of the alternative flaws shall not exceed 0.002 in.

alternative flaws may be used but shall comprise not more than 30% of the total of base material flaws. Alternative flaw mechanisms, if used, shall provide crack-like reflective characteristics. The shape of the alternative flaw is intended to simulate the growth pattern of actual flaws and may be semielliptical. The tip width of the alternative flaws shall not exceed 0.002 inches (0.05mm).

(2) Overlay fabrication flaws. At least 40% of the flaws shall be Fabrication-Induced Flaws. At least 40% of the flaws shall noncrack fabrication flaws (e.g., sidewall lack of fusion or be non-crack fabrication flaws (e.g., sidewall lack of fusion or laminar lack of bond) in the overlay or the pipe-to-overlay laminar lack of bond) in the overlay or the pipe-to-overlay interface. At least 20% of the flaws shall be cracks. The interface. At least 20% of the flaws shall be cracks wholly balance of the flaws shall be of either type. contained in the overlay. The balance of the flaws shall be of either type.

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ENCLOSURE ASME Section XI, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum ASME,Section XI, Appendix VIII PDI Program (Code Case N-653-1)

(e) Detection Specimens Detection Specimens.

(1) At least 20% but less than 40% of the base metal flaws At least 20% but less than 40% of the service-induced flaws shall be oriented within +/-20 deg of the pipe axial direction. shall be oriented within +20 deg. of the pipe axial direction.

The remainder shall be oriented circumferentially. Flaws shall The remainder shall be oriented circumferentially. Flaws shall not be open to any surface to which the candidate has not be open to any surface to which the candidate has physical or visual access. physical or visual access.

(2) Specimens shall be divided into base metal and overlay Specimens shall be divided into inservice inspection (ISI) and fabrication grading units. Each specimen shall contain one or preservice inspection (PSI) grading units.

both types of grading units. Flaws shall not interfere with ISI Grading Unit. A grading unit designed to include a portion ultrasonic detection or characterization of other flaws.

of the original weld and base material and the weld overlay material above it and designed to contain service-induced flaws (cracks)

PSI Grading Unit. A grading unit designed to include a portion of the weld overlay, including the interface between the weld overlay and the original weld and base material, and designed to contain fabrication-induced flaw types (e.g.

interbead lack of fusion, laminar lack of bond, cracks).

Each specimen shall contain one or both types of grading units. Flaws shall not interfere with ultrasonic detection or characterization of other flaws.

Page 4 of 11

ENCLOSURE ASME Section XI, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum I PDI Program (Code Case N-653-1)

ASME,Section XI, Appendix VIII (a)(1) A base metal grading unit includes the overlay material ISI grading units include the overlay material and the and the outer 25% of the original overlaid weld. The base examination volume specified in the examination procedure.

metal grading unit shall extend circumferentially for at least 1 ISI grading units shall extend circumferentially for at least 1 in. (25 mm) and shall start at the weld centerline and be wide inch (25 mm) and shall start at the weld centerline and shall enough in the axial direction to encompass one half of the be wide enough in the axial direction to encompass one-half original weld crown and at least 112 in. (13 mm) of the adjacent of the original weld crown and at least 1/2 inch (13 mm) of the base material. For axially-oriented discontinuities, the axial adjacent base material. The grading units shall be of various dimension of the base metal grading unit may encompass the sizes. For an axially oriented discontinuity, the axial original weld crown and at least 1/2 in. (13 mm) of the adjacent dimension of the ISI grading unit may encompass the original base materials. weld crown and at least 112 inch (13 mm) of both adjacent base materials.

(2) When base metal flaws penetrate into the overlay material, If service-induced flaws penetrate into the overlay material, the base metal grading unit shall not be used as part of any the ISI grading unit shall not be used as part of any PSI overlay grading unit. grading unit.

(3) Sufficient unflawed overlaid weld and base metal shall Sufficient unflawed area shall exist on all sides of the grading exist on all sides of the grading unit to preclude interfering unit to preclude interfering reflections from adjacent flaws.

reflections from adjacent flaws.

(b)(1) An overlay fabrication grading unit shall include the PSI grading units shall include the overlay material and the overlay material and the base metal-to-overlay interface for a overlay-to-component interface for a length of at least 1 inch length of at least 1 in. (25 mm). (25 mm).

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ENCLOSURE ASME Section XI, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum PDI Program (Code Case N-653-1)

ASME,Section XI, Appendix VIII (2) Overlay fabrication grading units designed to be unflawed PSI grading units designed to be unflawed shall be separated shall be separated by unflawed overlay material and unflawed by unflawed overlay material and unflawed overlay-to-base metal-to-overlay interface for at least 1 in. (25 mm) at component interface for at least 1 inch (25 mm) at both ends.

both ends. Sufficient unflawed overlaid weld and base metal Sufficient unflawed overlaid weld and base metal shall exist shall exist on both sides of the overlay fabrication grading unit on both sides of the PSI grading unit to preclude interfering to preclude interfering reflections from adjacent flaws. The reflections from adjacent flaws. The specific area used in one specific area used in one overlay fabrication grading unit shall PSI grading unit shall not be used in another PSI grading not be used in another overlay fabrication grading unit. unit. PSI grading units need not be spaced uniformly about Overlay fabrication grading units need not be spaced the specimen.

uniformly about the specimen.

(3) Detection sets shall be selected from Table VIIIS2-1. The Detection sets shall be selected from Table VIII-S2-1. The minimum detection sample set is five flawed base metal detection sample sets shall contain at least ten flawed ISI grading units, ten unflawed base metal grading units, five grading units and five flawed PSI grading units. Additionally, flawed overlay fabrication grading units, and ten unflawed for each type of grading unit, the sets shall contain at least overlay fabrication grading units. For each type of grading twice as many unflawed as flawed grading units. For initial unit, the set shall contain at least twice as many unflawed as procedure qualification, detection sets shall include the flawed grading units. For initial procedure qualification, equivalent of three personnel qualification sets. To qualify detection sets shall include the equivalent of three personnel new values of essential variables, at least one personnel qualification sets. To qualify new values of essential variables, qualification set is required.

at least one personnel qualification set is required.

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ENCLOSURE ASME Section XI, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum PDI Program (Code Case N-653-1)

ASME,Section XI, Appendix VIII (f) (f) Sizing Specimen Sizing Specimens.

(1) The minimum number of flaws shall be ten. At least 30% Sizing sample sets shall contain at least ten flaws. At least of the flaws shall be overlay fabrication flaws. At least 40% of 30% of the flaws shall be fabrication-induced flaws. At least the flaws shall be open to the inside surface. To assess sizing 40% of the flaws shall be service-induced flaws and shall be capabilities, sizing sets shall contain a representative open to the inside surface. Sizing sets shall contain a distribution of flaw dimensions. For initial procedure representative distribution of flaw dimensions that cover the qualification, sizing sets shall include the equivalent of three examination volume specified in the examination procedure.

personnel qualification sets. To qualify new values of essential For initial procedure qualification, sizing sets shall include the variables, at least one personnel qualification set is required. equivalent of three personnel qualification sets. To qualify new values of essential variables, at least one personnel qualification set is required.

(2) At least 20% but less than 40% of the flaws shall be At least 20% but less than 40% of the flaws shall be oriented oriented axially. The remainder shall be oriented axially. The remainder shall be oriented circumferentially.

circumferentially. Flaws shall not be open to any surface to Flaws shall not be open to any surface to which the candidate which the candidate has physical or visual access. has physical or visual access.

(3) Base metal flaws used for length sizing demonstrations Service-induced flaws used for length sizing demonstrations shall be oriented circumferentially. shall be oriented circumferentially.

(4) Depth sizing specimen sets shall include at least two Depth sizing specimen sets shall include at least two distinct distinct locations where a base metal flaw extends into the locations where a service-induced flaw extends into the overlay material by at least 0.1 in. (2.5 mm) in the through-wall overlay material by at least 0.1 inches (2.5 mm) in the direction. through-wall direction.

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ENCLOSURE ASME Section XI, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum PDI Program (Code Case N-653-1)

ASME,Section XI, Appendix VIII 2.0 CONDUCT OF PERFORMANCE DEMONSTRATIONS PERFORMANCE DEMONSTRATION The specimen inside surface and identification shall be The specimen inside surface and identification shall be concealed from the candidate. All examinations shall be concealed from the candidate. All examinations shall be completed prior to grading the results and presenting the completed prior to grading the results and presenting the results to the candidate. Divulgence of particular specimen results to the candidate. Divulgence of particular specimen results or candidate viewing of unmasked specimens after the results or candidate viewing of unmasked specimens after performance demonstration is prohibited. The overlay the performance demonstration is prohibited. The PSI test fabrication flaw test and the base metal flaw test may be I and the ISI test may be performed separately.

performed separately.

2.1 Detection Test. Flawed and unflawed grading units shall Detection Test.

be randomly mixed. Although the boundaries of specific Flawed and unflawed grading units shall be randomly mixed.

grading units shall not be revealed to the candidate, the Although the boundaries of specific grading units shall not be candidate shall be made aware of the type or types of grading revealed to the candidate, the candidate shall be made aware units (base or overlay) that are present for each specimen.

of the type or types of grading units (ISI or PSI) in each specimen.

2.2 Length Sizing Test Length Sizing Test (a) The length sizing test may be conducted separately or in Length sizing tests may be conducted separately or in conjunction with the detection test. conjunction with the detection test.

(b) If the length sizing test is conducted in conjunction with the If the length sizing test is conducted in conjunction with the detection test and the detected flaws do not satisfy the detection test and the detected flaws do not satisfy the requirements of 1.1(f), additional specimens shall be provided requirements for the sizing specimens detailed above, to the candidate. The regions containing a flaw to be sized additional specimens shall be provided to the candidate. The shall be identified to the candidate. The candidate shall regions of the additional specimens containing flaws to be determine the length of the flaw in each region. sized shall be identified to the candidate. The candidate shall determine the length of the flaw in each region.

Page 8 of 11

ENCLOSURE ASME Section XI, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum PDI Program (Code Case N-653-1)

ASME,Section XI, Appendix VIII (c) For a separate length sizing test, the regions of each For a separate length sizing test, the regions of each specimen containing a flaw to be sized shall be identified to specimen containing flaws to be sized shall be identified to the candidate. The candidate shall determine the length of the candidate. The candidate shall determine the length of the flaw in each region. the flaw in each region.

(d) For flaws in base metal grading units, the candidate shall For flaws in ISI grading units, the candidate shall estimate the estimate the length of that part of the flaw that is in the outer length of that part of the flaw that is in the examination 25% of the base metal wall thickness. volume specified in the examination procedure.

2.3 Depth Sizing Test Depth Sizing Test (a) Depth sizing consists of measuring the metal thickness Depth sizing consists of measuring the metal thickness above above the flaw (i.e., remaining ligament), and may be the flaw (i.e., remaining ligament) and may be conducted conducted separately or in conjunction with the detection test. separately or in conjunction with the detection test.

(b) If the depth sizing test is conducted in conjunction with the If the depth sizing test is conducted in conjunction with the detection test and the detected flaws do not satisfy the detection test and the detected flaws do not satisfy the requirements of 1.1(f), additional specimens shall be provided requirements for the sizing specimens above, additional to the candidate. The regions containing a flaw to be sized specimens shall be provided to the candidate. The regions of shall be identified to the candidate. The candidate shall the additional specimens containing flaws to be sized shall be determine the maximum depth of the flaw in each region. identified to the candidate. The candidate shall determine the maximum depth of the flaw in each region.

(c) For a separate depth sizing test, the regions of each For a separate depth sizing test, the regions of each specimen containing a flaw to be sized shall be identified to specimen containing a flaw to be sized shall be identified to the candidate. The candidate shall determine the maximum the candidate. The candidate shall determine the maximum depth of the flaw in each region. depth of the flaw in each region.

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ENCLOSURE ASME Section XI, Appendix Vill VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum PDI Program (Code Case N-653-1)

ASME,Section XI, Appendix VIII 3.0 ACCEPTANCE CRITERIA ACCEPTANCE CRITERIA 3.1 Detection Acceptance Criteria. Procedure Qualification (a) Examination procedures shall be qualified as follows: In addition to the specimen and performance demonstration requirements, procedure qualification shall satisfy the (1) All flaws within the scope of the procedure shall be following; detected, and the results of the performance demonstration shall satisfy the acceptance criteria of Table VIII-S2-1 for false The specimen set shall include the equivalent of at least calls. three personnel performance demonstration test sets.

Successful personnel demonstrations may be combined to (2) At least one successful personnel demonstration shall be satisfy these requirements.

performed meeting the acceptance criteria defined in 3.1(b).

At least one successful personnel demonstration shall be performed.

Detectability of all flaws in the procedure qualification test set within the scope of the procedure shall be demonstrated.

Length and depth sizing shall meet the requirements of the below paragraphs.

(b) Examination equipment and personnel shall be considered Examination equipment and personnel shall be considered qualified for detection if the results of the performance qualified for detection if the results of the performance demonstration satisfy the acceptance criteria of Table VI II-S2- ' demonstration satisfy the acceptance criteria of Table VIII-1 for both detection and false calls. S2-1 for both detection and false calls.

If the procedure is intended to be used to examine greater than the upper 25% of the original pipe volume, a candidate for personnel qualification shall not fail to detect more than one of the flaws located in the extended volume.

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ENCLOSURE ASME Section XI, Appendix VIII VS. PDI Program Dresden Nuclear Power Station, Units 2 and 3, 10 CFR 50.55a Request No. 1513-16 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

--Alternative Provides an Acceptable Level of Quality and Safety-2007 Edition with 2008 Addendum PDI Program (Code Case N-653-1)

ASME,Section XI, Appendix VIII '

(c) The criteria in 3.1(a) and 3.1(b) shall be satisfied The detection test, length sizing test, and depth sizing test separately by the demonstration results for base metal criteria shall be satisfied separately by the demonstration grading units and by those for overlay fabrication grading results for ISI grading units and by those for PSI grading units. units.

3.2 Sizing Acceptance Criteria. Examination procedures, Examination procedures, equipment, and personnel are equipment, and personnel are qualified for sizing when the qualified for length sizing if the RMS error of the results of the performance demonstration satisfy the following circumferential flaw length measurements, compared to the criteria. true circumferential flaw lengths, is not more than 0.75 in.

(19 mm). The length of a service-induced flaw is measured (a) The RMS error of the flaw length measurements, as in accordance with the length sizing test requirements.

compared to the true flaw lengths, is less than or equal to 0.75 in. (19 mm). The length of a base metal flaw is measured Examination procedures, equipment, and personnel qualified at the 75% through-base-metal position. for length sizing in accordance with the criteria above are considered qualified for both length and width sizing of laminar flaws.

(b) The RMS error of the flaw depth measurements, as Examination procedures, equipment and personnel are compared to the true flaw depths, is less than or equal to qualified for depth sizing if the RMS error of the flaw depth 0.125 in. (3.2 mm). measurements, as compared to the true flaw depths, is less than or equal to 0.125 in (3.2 mm).

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