NL-03-0684, ASME Section XI Requests for Relief Number RR-51 and RR-52 Alternative Repair Technique and Inspection Requirement - Reactor Vessel Head

ASME Section XI Requests for Relief Number RR-51 and RR-52 Alternative Repair Technique and Inspection Requirement - Reactor Vessel Head

ML030920578
Person / Time
Site:	Farley
Issue date:	03/28/2003
From:	Beasley J Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-03-0684
Download: ML030920578 (37)

Text

J. Barnie Beasley, Jr., P.E. Southern Nuclear Vice President Operating Company, Inc.

40 Inverness Center Parkway Post Office Box 1295 Birmingham, Alabama 35201 Tel 205 992 7110 Fax 205 992 0341 SOUTHERNAM 4

COMPANY March 28, 2003 Energy to Serve YourWorld' Docket Nos.: 50-348 NL-03-0684 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant - Unit I ASME Section XI Requests for Relief Number RR-51 and RR-52 Alternative Repair Technique and Inspection Requirement - Reactor Vessel Head Ladies and Gentlemen:

In response to Bulletin 2002-02 and the Order issued February 11, 2003 requiring inspection of reactor pressure vessel (RPV) heads and associated penetration nozzles, Southern Nuclear Operating Company (SNC) has committed to perform bare metal visual (BMV) inspection, ultrasonic testing (UT), and eddy current testing (ECT) at Farley Nuclear Plant (FNP) Unit I during the refueling outage beginning March 29, 2003. The enclosed relief requests RR-51 and RR-52 for FNP Unit 1 are submitted in accordance with the provisions of 10 CFR 50.55a as a contingency to provide an alternate repair method in the event that these inspections indicate any nozzle repairs are necessary. SNC will promptly inform the NRC if the need for such repairs arises.

This letter contains no NRC commitments. If you have any questions, please advise.

Sincerely, JBBfDW~D/sdl

Enclosures:

1. Request for Relief No. 51

2. Request for Relief No. 52 64-7

U. S. Nuclear Regulatory Commission NL-03-0684 Page 2 cc: Southern Nuclear Operating Company Mr. J. D. Woodard, Executive Vice President Mr. D. E. Grissette, General Manager - Plant Farley Document Services RTYPE: CFA04.054; LC # 13753 U. S. Nuclear Regulatory Commission Mr. L. A. Reyes, Regional Administrator Mr. F. Rinaldi, NRR Project Manager - Farley Mr. T. P. Johnson, Senior Resident Inspector - Farley

ENCLOSURE 1 SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 UPDATED PROGRAM REQUEST FOR RELIEF RR-51

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 System/Component(s) for Which Alternative is Requested: Reactor Vessel Closure Head (RVCH), Class 1 Pressure Retaining Partial Penetration Welds in Vessels, ASME Section XI, 1989 Edition, Examination Category B-E, Item B4.1 1, Vent Line Penetration Nozzle J-Groove Weld.

II. Code Requirement:

Farley Unit 1 is currently in the third inspection interval using the 1989 Edition of ASME Section XI with no Addenda. Augmented ultrasonic examinations of the RVCH penetration nozzles are planned, as committed to in response to NRC Bulletin 2002-02 and Order EA-03-009. In the event that defects are discovered in the nozzle base material that exceed the acceptable limits of IWA-3000, IWA-3132.2 requires that they either be removed or the component be repaired to the extent necessary to meet the acceptance standards of IWB-3000. IWB-3133 requires that repairs comply writh the requirements of IWA-4000 and IWB-4000.

IWA-4120(a) requires that "Repairs shall be performed in accordance with the Owner's Design Specification and the original Construction Code of the system. Later editions and Addenda of the Construction Code or of Section III, either in their entirety or portions thereof, and Code Cases may be used. If repair welding cannot be performed in accordance with these requirements, the applicable alternative requirements of IWA-4500 and the following may be used:

(1) IWB-4000 for Class 1 components; (2) ... "

The latest Edition and Addenda of ASME Section III incorporated by reference in 10 CFR 50.55a(b)(1) is the 1998 Edition through the 2000 Addenda. IWA-4120 (c) permits that "Later Editions and Addenda of Section XI, either in their entirety or portions thereof, may be used for the repair program, provided these Editions and Addenda of Section XI at the time of the planned repair have been incorporated by reference in amended regulations of the regulatory authority having jurisdiction at the plant site." The latest Edition and Addenda of ASME Section XI incorporated by reference in 10 CFR 50.55a(b)(2) is the 1998 Edition through the 2000 Addenda.

The Construction Code of record for the Farley Unit 1 reactor vessel and closure head is the 1968 edition of ASME Section I1m with Addenda through Summer 1970.

III. Code Requirement for Which Alternative is Requested: Pursuant to 10 CFR 50.55a(a)(3)(i), the use of a technical alternative is requested in lieu of the rules in the 1989 Edition of ASME Section XI, IWA-4120(a) which require repairs to be performed in accordance with the Owner's Design Specification and the original Construction Code of the system, or the applicable alternative requirements of IWA-4500 and IWB-4000. Augmented ultrasonic examinations of the RVCH penetration nozzles are planned, as committed to in response to NRC Bulletin 2002-02 and Order EA-03-009. In the event a flaw is found in a RVCH vent line penetration nozzle J-groove weld, this technical alternative for repairs will be utilized.

As permitted by Subarticle IWA-4120(c) of ASME Section XI, 1989 Edition, repair of the Farley Unit 1 RVCH vent line penetration nozzle J-groove weld will be performed in accordance with the later 1998 Edition through 2000 Addenda of ASME Section XI. ASME Section XI provides repair requirements that supplement, amend or supercede the repair rules of the Construction Enclosure 1 Page 1 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 Code. Where applicable, compliance with these additional requirements is mandatory. With respect to repair welding of the RVCH vent line penetration nozzle J-groove weld, the following requirements of the 1998 Edition through 2000 Addenda of ASME Section XI apply:

• IWA-4421 - Construction Code and Owner's Requirements IWA-4421 establishes Construction Code and Owner's requirements for performing welding, brazing, defect removal, and installation activities. Additionally, lWA4421 requires that the requirements of lWA4460 be used in lieu of Construction Code requirements for mechanical and thermal metal removal, and that the requirements of IWA4422 be used in lieu of Construction Code requirements for examination of defect removal areas. Supplementing the defect removal requirements in ASME Section m, the requirements of IWA-4421 apply to the performance of localized defect removal and repair welding of RVCH penetration nozzle base materials.

IWA-4421(a) states: "Welding, brazing, defect removal, and installation activities shall be performed in accordance with the Owner's Requirements and the Construction Code of the component or system, except as provided in (b) and (c) below. The requirements of IWA-4460 shall be used in lieu of Construction Code requirements for mechanical and thermal metal removal. The requirements of IWA-4422 shall be used in lieu of Construction Code requirements for examination of defect removal areas."

• IWA-4430 - Alternatives to Construction Code Requirements IWA-4430 provides for the use of alternative welding methods for repairs in lieu of the Construction Code requirements. These alternatives include temper bead welding.

IWA4430 states: "In lieu of the requirements of IWA-4420, the requirements of IWA-4600 may be used for alternative welding methods."

• IWA-4600 - Alternative Welding Methods IWA-4600 of ASME Section Xl establishes alternative repair welding methods for welding under water and temper bead welding. Underwater welding is not applicable to the repair of the RVCH vent line penetration nozzle J-groove welds. However, since postweld heat treatment cannot be performed on the repair weld for the RVCH vent line penetration nozzle J-groove weld, the use of temper bead welding methods is applicable. IWA-4620 applies to temper bead welds in similar materials, IWA-4630 applies to temper bead welds in dissimilar materials and IWA-4640 applies to temper bead welds in cladding. The Farley Unit 1 RVCH vent line penetration nozzle J-groove weld joins the SB-167 Alloy 600 (P-No. 43) nozzle to the SA-533 Gr. B Cl. 1 low alloy steel (P-No. 3) head as shown in Figure 1. This is a dissimilar material combination, so the requirements of IWA-4630 are applicable. IWA-4610 contains general requirements applicable to all materials regarding preheat, thermocouples, recording instruments, welding procedure qualification and performance qualification.

IWA4600(b) and (b)(l) state: "When postweld heat treatment is not to be performed, the following provisions may be used.

Enclosure 1 Page 2 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 (1) The welding methods of IWA-4620, IWA-4630, or IWA-4640 may be used in lieu of the welding and nondestructive examination (NDE) requirements of the Construction Code or Section m, provided the requirements of IWA-4610 are met."

• IWA4610 - General Requirements for All Materials IWA-4610(a) states: "The area to be welded plus a band around the area of at least 1-1/2 times the component thickness or 5 in., whichever is less, shall be preheated and maintained at a minimum temperature of 350 0F for the SMAW process and 3000 F for the GTAW process during welding. The maximum interpass temperature shall be 450oF. Thermocouples and recording instruments shall be used to monitor the process temperatures. Their attachment and removal shall be in accordance with Section III."

IWA-4610(b)(2) states: "Performance Qualification If the weld is to be performed where physical obstructions impair the welder's ability to perform, the welder shall also demonstrate the ability to deposit sound weld metal in the positions required, using the same parameters and simulated physical obstructions as are involved in the repair/replacement activity." This limited accessibility demonstration applies when manual temper bead welding is performed by welders using the Shielded Metal Arc Welding (SMAW) process. It does not apply to "welding operators" who perform machine or automatic Gas Tungsten Arc Welding (GTAW) from a remote location. (This distinction is clearly made in IWA-4610 and IWA-4630.)

Because the proposed ambient temperature temper bead technique described in Attachment 1 utilizes a remote machine GTAW welding process and physical obstructions do not impair a welding operator's ability to perform, limited access demonstrations of "welding operators" are not required. Therefore, the requirement of IWA-4610(b)(2) does not apply.

• IWA-4630 - Alternative Welding Methods for Dissimilar Materials IWA-4630 applies to dissimilar materials, including welds that join P-No. 43 nickel alloy to P-No. 3 low alloy steels. IWA-4631(a) states: "Repair/replacement activities on welds that join P-No. 8 or P-No. 43 material to P-No. 1, 3, 12A, 12B, and 12C material may be made without the specified postweld heat treatment, provided the requirements of IWA-4631(b) and IWA-4632 through IWA-4634 are met." IWA-4631(b) states: "Repair/replacement activities in accordance with this paragraph are limited to those along the fusion line of a nonferritic weld to ferritic base material where 1/8-inch or less of nonferritic weld deposit exists above the original fusion line after defect removal. If the defect penetrates into the ferritic base material, welding of the base material may be performed in accordance with IWA-4633 provided the depth of the weld in the base material does not exceed 3/8-inch. The repair/replacement activity performed on a completed joint shall not exceed one-half the joint thickness. The surface of the completed weld shall not exceed 100 sq in."

IWA-4633.1 establishes procedure technique requirements that apply when using the SMAW process. Because the proposed ambient temperature temper bead technique of Attachment 1 utilizes the machine or automatic GTAW welding process, the SMAW temper bead technique requirements of paragraph IWA-4532.1 do not apply.

IWA-4633.2 applies to temper bead welding performed with the GTAW process. IWA-4633.2(c) states: "The cavity shall be buttered with the first six layers of weld metal as shown in Fig. IWA-4633.2-1, Steps 1 through 3, with the weld heat input for each layer controlled to Enclosure 1 Page 3 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 within +/-10% of that used in the procedure qualification test. Subsequent layers shall be deposited with a heat input equal to or less than that used for layers beyond the sixth in the procedure qualification. The completed weld shall have at least one layer of weld reinforcement deposited and then this reinforcement shall be removed by mechanical means, making the finished surface of the weld substantially flush with the surface surrounding the weld." IWA-4633.2(d) states: "After at least 3/16-inch of weld metal has been deposited, the weld area shall be maintained at a minimum temperature of 300F for a minimum of 2 hr in P-No. 1 materials. For P-No. 3 materials, the minimum holding time shall be 4 hr."

• IWA-4634 - Examination of Alternative Welding Methods for Dissimilar Materials IWA-4634 establishes the requirements for examination of welds performed with the temper bead welding method of IWA-4630 for dissimilar materials. IWA-4634 states: "The weld as well as the preheated band shall be examined by the liquid penetrant method after the completed weld has been at ambient temperature for at least 48 hr. The weld shall be volumetrically examined."

Temper bead repair of RVCH vent line penetration nozzle J-groove weld must be performed in accordance with IWA4610 and IWA4630 whenever the repair cavity is within 1/8-inch of the ferritic base materials of the RVCH. When the GTAW process is used on P-No. 3 base materials in accordance with lWA-4610 and IWA-4630, temper bead welding is performed as follows:

• Only the automatic or machine GTAW process using cold wire feed can be used. Manual GTAW cannot be used.

• A minimum preheat temperature of 3000 F is established and maintained throughout the welding process. Interpass temperature cannot exceed 4500 F.

• The weld cavity is buttered with at least six (6) layers of weld metal.

• Heat input of the initial six layers is controlled to within +10% of that used for the first six layers during procedure qualification testing.

• After the first six weld layers, repair welding is completed with a heat input that is equal to or less than that used in the procedure qualification for weld layers seven and beyond.

• Upon completion of welding, a postweld soak or hydrogen bake-out at a minimum temperature of 300 0 F for a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is required.

• Preheat, interpass, and postweld soak temperatures are monitored using thermocouples and recording instruments.

• The repair weld and preheated band are examined in accordance with IWA-4634 after the completed weld has been at ambient temperature for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

Enclosure 1 Page 4 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 IV. Basis for Alternative:

IWA-4610 and IWA-4630 of ASME Section XI establish requirements for performing temper bead welding of "dissimilar materials". According to IWA-4630, either the automatic or machine GTAW process or SMAW process may be used. When using the machine GTAW process, a minimum preheat temperature of 300'F must be established and maintained throughout the welding process while the interpass temperature is limited to 450'F. Upon completion of welding, a postweld soak is required at 300'F for a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

The IWA4610 and IWA-4630 temper bead welding process is a time and personnel radiation dose intensive process. Resistance heating blankets are attached to the RVCH; typically a capacitor discharge stud welding process is used. Thermocouples must also be attached to the RVCH using a capacitor discharge welding process to monitor preheat, interpass, and postweld soak temperatures. Prior to heat-up, thermal insulation is also installed. Upon completion of repair welding (including the postweld soak), the insulation, heating blankets, studs, and thermocouples must be removed from the RVCH. Thermocouples and stud welds are removed by grinding. Ground removal areas must be subsequently examined by the liquid penetrant or magnetic particle method. A significant reduction in radiation dose could be realized by utilizing an ambient temperature temper bead process. Because the ASME Code does not presently include rules for ambient temperature temper bead welding, Southern Nuclear Operating Company (SNC) proposes the alternative described in Section V below.

Suitability of Proposed Ambient Temperature Temper Bead Technique A. Evaluation of the Ambient Temperature Temper Bead Technique Research by the Electric Power Research Institute (EPRI) and other organizations on the use of an ambient temperature temper bead welding operation using the machine GTAW process is documented in EPRI Report GC-1 11050. According to the EPRI report, repair welds performed with an ambient temperature temper bead procedure utilizing the machine GTAW welding process exhibit mechanical properties equivalent or better than those of the surrounding base material. Laboratory testing, analysis, successful procedure qualifications, and successful repairs have all demonstrated the effectiveness of this process.

The effects of the ambient temperature temper bead welding process of Attachment I on mechanical properties of repair welds, hydrogen cracking, and restraint cracking are addressed below.

1. MECHANICAL PROPERTIES The principal reasons to preheat a component prior to repair welding is to minimize the potential for cold cracking. The two cold cracking mechanisms are hydrogen cracking and restraint cracking. Both of these mechanisms occur at ambient temperature.

Preheating slows down the cooling rate resulting in a ductile, less brittle microstructure thereby lowering susceptibility to cold cracking. Preheat also increases the diffusion rate of monatomic hydrogen that may have been trapped in the weld during solidification. As an alternative to preheat, the ambient temperature temper bead welding process utilizes the tempering action of the welding procedure to produce tough and ductile Enclosure 1 Page 5 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-5 1 microstructures. Because precision bead placement and heat input control is characteristic of the machine GTAW process, effective tempering of weld heat affected zones is possible without the application of preheat. According to Section 2.1 of EPRI Report GC-1 11050, "The temper bead process is carefully designed and controlled such that successive weld beads supply the appropriate quantity of heat to the untempered heat affected zone such that the desired degree of carbide precipitation (tempering) is achieved. The resulting microstructure is very tough and ductile."

The IWA-4630 temper bead process also includes a postweld soak requirement.

Performed at 300'F for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> (P-No. 3 base materials), this postweld soak assists diffusion of any remaining hydrogen from the repair weld. As such, the postweld soak is a hydrogen bake-out and not a postweld heat treatment as defined by the ASME Code.

At 300'F, the postweld soak does not stress relieve, temper, or alter the mechanical properties of the weldment in any manner.

Section 2.1 of Attachment 1 establishes detailed welding procedure qualification requirements. Simulating base materials, filler metals, restraint, impact properties, and procedure variables, the qualification requirements of Section 2.1 provide assurance that the mechanical properties of repair welds will be equivalent or superior to those of the surrounding base material. It should also be noted that the qualification requirements of Section 2.1 of Attachment 1 are identical to those in IWA-4630. The Westinghouse/PCI ambient temperature temper bead welding procedure specification (WPS) 343/52-TB MC-GTAW-N638 was qualified in accordance with Attachment 1. Based upon the procedure qualification test results, the impact properties of the base material heat affected zone were superior to those of the unaffected base material. The mechanical testing results for the procedure qualification are summarized in Section IV.C below.

2. HYDROGEN CRACKING Hydrogen cracking is a form of cold cracking. It is produced by the action of internal tensile stresses acting on low toughness heat affected zones. The internal stresses are produced from localized build-ups of monatomic hydrogen. Monatomic hydrogen forms when moisture or hydrocarbons interact with the welding arc and molten weld pool. The monatomic hydrogen can be entrapped during weld solidification and tends to migrate to transformation boundaries or other microstructure defect locations. As concentrations build, the monatomic hydrogen will recombine to form molecular hydrogen, thus generating localized internal stresses at these internal defect locations. If these stresses exceed the fracture toughness of the material, hydrogen induced cracking will occur.

This form of cracking requires the presence of hydrogen and low toughness materials. It is manifested by intergranular cracking of susceptible materials and normally occurs within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of welding.

IWA-4610 establishes elevated preheat and postweld soak requirements. The elevated preheat temperature of 300 0 F increases the diffusion rate of hydrogen from the weld.

The postweld soak at 300'F was also established to bake-out or facilitate diffusion of any remaining hydrogen from the weldment. However, while hydrogen cracking is a concern for SMAW which uses flux covered electrodes, the potential for hydrogen cracking is significantly reduced when using the machine GTAW welding.

Enclosure 1 Page 6 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-5 1 The machine GTAW welding process is inherently free of hydrogen. Unlike the SMAW process, GTAW welding filler metals do not rely on flux coverings that are susceptible to moisture absorption from the environment. Conversely, the GTAW process utilizes dry inert shielding gases that cover the molten weld pool from oxidizing atmospheres. Any moisture on the surface of the component being welded will be vaporized ahead of the welding torch. The vapor is prevented from being mixed with the molten weld pool by the inert shielding gas that blows the vapor away before it can be mixed. Furthermore, modem filler metal manufacturers produce wires having very low residual hydrogen.

This is important because filler metals and base materials are the most realistic sources of hydrogen for automatic or machine GTAW temper bead welding.

As explained above, the potential for hydrogen induced cracking is greatly reduced by using machine GTAW process. However, should it occur, cracks would be detected by the final NDE performed after the completed repair weld has been at ambient temperature for at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> as required in Section 4.0 of Attachment 1. Regarding this issue, EPRI Report GC-1 11050, Section 6.0 concluded the following:

"No preheat temperature or postweld bake above ambient temperature is required to achieve sound machine GTAW temper bead repairs that have high toughness and ductility. This conclusion is based on the fact that the GTAW process is an inherently low hydrogen process regardless of the welding environment. Insufficient hydrogen is available to be entrapped in solidifying weld material to support hydrogen delayed cracking. Therefore, no preheat nor postweld bake steps are necessary to remove hydrogen because the hydrogen is not present with the machine GTAW process."

3. COLD RESTRAINT CRACKING Cold cracking generally occurs during cooling at temperatures approaching ambient temperature. As stresses build under a high degree of restraint, cracking may occur at defect locations. Brittle microstructures with low ductility are subject to cold restraint cracking. However, the ambient temperature temper bead process is designed to provide a sufficient heat inventory so as to produce the desired tempering for high toughness.

Because the machine GTAW temper bead process provides precision bead placement and control of heat, the toughness and ductility of the heat affected zone will typically be superior to the base material. Therefore, the resulting structure will be appropriately tempered to exhibit toughness sufficient to resist cold cracking. Additionally, even if cold cracking were to occur, it would be detected by the final NDE which is performed after the completed repair weld has been at ambient temperature for at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> as required in Section 4.0 of Attachment 1.

In conclusion, no elevated preheat or postweld soak above ambient temperature is required to achieve sound and tough repair welds when performing ambient temperature temper bead welding using the machine GTAW process. This conclusion is based upon strong evidence that hydrogen cracking will not occur with the GTAW process. In addition, automatic or machine temper bead welding procedures without preheat will produce satisfactory toughness and ductility properties both in the weld and weld heat affected zones. The results of previous industry qualifications and repairs further support this conclusion. The use of an ambient temperature temper bead welding procedure will Enclosure 1 Page 7 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 improve the feasibility of performing localized weld repairs with a significant reduction in radiological exposure. EPRI Report GC-1 11050, Section 6.0 concluded the following:

"Repair of RPV components utilizing machine GTAW temper bead welding at ambient temperature produces mechanical properties that are commonly superior to those of the service-exposed substrate. The risk of hydrogen delayed cracking is minimal using the GTAW process. Cold stress cracking is resisted by the excellent toughness and ductility developed in the weld HAZ (heat affected zone). Process design and geometry largely control restraint considerations, and these factors are demonstrated during weld procedure qualification."

B. Evaluation of Proposed Alternatives to ASME Section Xl, IWA-4610 and IWA-4630

1. According to IWA-4600(b), repairs may be performed to dissimilar base materials and welds without the specified postweld heat treatment of ASME Section m provided the requirements of IWA-4610 and IWA-4630 are met. The temper bead rules of IWA-4610 and IWA-4630 apply to dissimilar materials such as P-No. 43 to P-No. 3 base materials welded with F-No. 43 filler metals. When using the GTAW-machine process, the IWA-4610 and IWA-4630 temper bead process is based fundamentally on an elevated preheat temperature of 300'F, a maximum interpass temperature of 4500 F, and a postweld soak of 3000F. The proposed alternative of Attachment 1 also establishes requirements to perform temper bead welding on dissimilar material welds that join P-No. 43 to P-No. 3 base materials using F-No. 43 filler metals. However, the temper bead process of Attachment 1 is an ambient temperature technique which only utilizes the GTAW-machine or GTAW-automatic process. The suitability of the proposed ambient temperature temper bead technique is evaluated in this section. The results of this evaluation demonstrate that the proposed ambient temperature temper bead technique provides an acceptable level of quality and safety.

2. According to IWA-461 0(a), the weld area plus a band around the repair area of at least 1-1/2 times the component thickness or 5 inches, whichever is less, shall be preheated and maintained at a minimum temperature of 300'F for the GTAW process during welding while the maximum interpass temperature is limited to 450'F. The ambient temperature temper bead technique of Attachment 1 also establishes a preheat band of at least 1-1/2 times the component thickness or 5 inches, whichever is less. However, the proposed alternative ambient temperature temper bead technique requires a minimum preheat temperature of 550F, a maximum interpass temperature of 150'F for the first three layers, and a maximum interpass temperature of 3500 F for the balance of welding. The suitability of an ambient temperature temper bead technique with reduced preheat and interpass temperatures is addressed in Section IV.A above.

3. According to IWA-4610(a), thermocouples and recording instruments shall be used to monitor process temperatures. As an alternative to IWA4610(a), SNC proposes to monitor preheat and interpass temperatures using an infrared thermometer. Infrared thermometers are hand-held devices that can be used to monitor process temperature from a remote location. To determine the preheat and interpass temperatures during the welding operation, the infrared thermometer is pointed at a target location adjacent to the repair weld. The target location is identified by a circle consisting of eight laser spots. A single laser spot in the center of the circle identifies the center of the measurement area.

Enclosure 1 Page 8 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 As the distance (D) from the object being measured increases, the diameter of the target location or "spot size" (S) also increases. The optics of the infrared thermometer sense emitted, reflected, and transmitted energy from the target location that is collected and focused onto a detector. The infrared thermometer's electronics translate the information into a temperature reading that is displayed on the unit. The infrared thermometer measures the maximum, minimum, differential, and average temperatures across the target location. This data can be stored and recalled until a new measurement is taken.

SNC plans to use an infrared thermometer such as the Raytek Raynger ST80 (or equivalent). The Raytek Raynger ST80 infrared thermometer measures temperatures from -250 F to 1400'F over the target location with the following accuracy: +31F over the 00 F - 730 F temperature range and +/-1% of reading or 20 F, whichever is greater, above 730 F. Display resolution is 0.10 F. The distance (D) to spot size (S) ratio is 50:1 for the Raytek Raynger ST80 infrared thermometer. Since the distance (D) to the target location on the RPV penetration nozzle or J-groove weld is estimated to range from 3 feet to 6 feet, the spot size (S) will also range from 0.72 inch to 1.44 inches. The infrared thermometer will be appropriately calibrated prior to use. Additionally, since thermocouples are not used with an infrared thermometer, the thermocouple attachment and removal requirements of IWA-4610(a) do not apply.

4. IWA-4610(b)(1) establishes procedure qualification requirements but does not specifically address joint design access qualification of the repair cavity, except for included angle of the cavity. As an alternative to IWA4610(b)(1)(c), SNC proposes to qualify the root width and included angle of the proposed repair cavity. Paragraph 2.1(c) of Attachment 1 requires that the root width and included angle of the repair cavity in the test assembly be no greater than the minimum specified for the repair. This requirement ensures that the welding procedure is only used in repair cavity configurations where it has demonstrated capability (i.e. sufficient access to deposit root passes, tie-in to the beveled or tapered walls of the repair cavity, provide appropriate tempering, and ensure complete weld fusion).

5. IWA-4633.1 establishes procedure technique requirements that apply when using the SMAW process. Because the proposed ambient temperature temper bead technique of Attachment 1 utilizes the machine or automatic GTAW welding process, the SMAW temper bead technique requirements of paragraph IWA-4532.1 do not apply.

6. According to IWA-4633.2(c), the repair cavity shall be buttered with six layers of weld metal in which the heat input of each layer is controlled to within d10% of that used in the procedure qualification test, and heat input control for subsequent layers shall be deposited with a heat input equal to or less than that used for layers beyond the sixth in the procedure qualification. As an alternative to IWA-4633.2, SNC proposes to butter the repair cavity or weld area with at least three layers of weld metal to obtain a minimum butter thickness of'l/8-inch. The heat input of each layer in the 1/8-inch thick buttered section shall be controlled to within +/-1 0% of that used in the procedure qualification test.

The heat input for subsequent weld layers shall not exceed the heat input used for layers beyond the 1/8-inch thick buttered section (first three weld layers) in the procedure qualification. When using the ambient temperature temper bead technique of Attachment 1, the machine GTAW process is used. Machine GTAW is a low heat input process that produces consistent small volume heat affected zones. Subsequent GTAW weld layers introduce heat into the heat affected zone produced by the initial weld layer. The heat Enclosure 1 Page 9 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-5 1 penetration of subsequent weld layers is carefully applied to produce overlapping thermal profiles that develop a correct degree of tempering in the underlying heat affected zone.

When welding dissimilar materials with nonferritic weld metal, the area requiring tempering is limited to the weld heat affected zone of the ferritic base material along the ferritic fusion line.

After buttering the ferritic base material with at least 1/8-inch of weld metal (first 3 weld layers), subsequent weld layers should not provide any additional tempering to the weld heat affected zone in the ferritic base material. Therefore, less restrictive heat input controls are adequate after depositing the 1/8-inch thick buttered section. It should also be noted that IWA4630 does not require temper bead welding except "where 1/8-inch or less of nonferritic weld deposit exists above the original fusion line after defect removal".

The proposed heat input controls of Attachment 1 were utilized in the qualification of Westinghouse/PCI WPS 343/52-TB MC-GTAW-N638. Based on Charpy V-notch testing of the procedure qualification test coupon, impact properties in weld heat affected zone were superior to those of the unaffected base material. Therefore, the proposed heat input controls of Attachment 1 provide an appropriate level of tempering. Test results of the WPS qualification are provided in Section IV.C below.

7. According to IWA4633.2(c), at least one layer of weld reinforcement shall be deposited on the completed weld and with this reinforcement being subsequently removed by mechanical means. In the proposed alternative of Attachment 1, the deposition and removal of a reinforcement layer is not required. A reinforcement layer is required when a weld repair is performed to a ferritic base material or ferritic weld using a ferritic weld metal. On ferritic materials, the weld reinforcement layer is deposited to temper the last layer of untempered weld metal of the completed repair weld. Because the weld reinforcement layer is untempered (and unnecessary), it is removed. However, when repairs are performed to dissimilar materials using nonferritic weld metal, a weld reinforcement layer is not required because the nonferritic weld metal does not require tempering. When performing a dissimilar material weld with a nonferritic filler metal, the only location requiring tempering is the weld heat affected zone in the ferritic base material along the weld fusion line. However, the three weld layers of the 1/8-inch thick butter section are designed to provide the required tempering to the weld heat affected zone in the ferritic base material. Therefore, a weld reinforcement layer is not required.

While SNC recognizes that IWA4633.2(c) does require the deposition and removal of a reinforcement layer on repair welds in dissimilar materials, SNC does not believe that this reinforcement layer is necessary. This position is supported by the fact that ASME Code Case N-638 only requires the deposition and removal of a reinforcement layer when performing repair welds on similar (ferritic) materials. Repair welds on dissimilar materials are exempt from this requirement.

8. According to IWA4633.2(d), the weld area shall be maintained at a temperature of 3001F for a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> (for P-No. 3 materials) after at least 3/16-inch of weld metal has been deposited. In the proposed alternative of Attachment 1, a postweld soak is not required. The suitability of an ambient temperature temper bead technique without a postweld soak is addressed in Section IV.A above.

9. According to IWA-4633.2(e), after depositing at least 3/16-inch of weld metal and performing a postweld soak at 300°F, the balance of welding may be performed at an Enclosure 1 Page 10 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 interpass temperature of 350'F. As an alternative, SNC's proposes that an interpass temperature of 350 0 F may be used after depositing at least 1/8-inch of weld metal without a postweld soak. The proposed ambient temperature temper bead process of Attachment 1 is carefully designed and controlled such that successive weld beads supply the appropriate quantity of heat to the untempered heat affected zone such that the desired degree of tempering is achieved. The resulting microstructure is very tough and ductile.

This point is validated by the qualification of Westinghouse/PCI WPS 3-43/52-TB MC-GTAW-N638. Based on Charpy V-notch testing of the procedure qualification test coupon, impact properties in weld heat affected zone were superior to those of the unaffected base material. Test results of the WPS qualification are provided in Section IV.C below. The suitability of an ambient temperature temper bead technique without a postweld soak is addressed in Section IV.A above.

10. IWA-4634 specifies that the repair weld shall be volumetrically examined after the completed repair weld has been at ambient temperature for at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. As an alternative to the volumetric examinations of IWA-4634, SNC proposes the examinations of repair welds in RPV penetration nozzle J-groove welds described below. The suitability of the alternative examinations is addressed in Section IV.D below.

• Repair welds will be progressively examined by the liquid penetrant method in accordance with NB-5245 of ASME Section III for partial penetration welded joints.

The liquid penetrant examinations will be performed in accordance with NB-5000.

Acceptance criteria shall be in accordance with NB-5350.

C. Mechanical Properties of WPS 3-43/52-TB MC-GTAW-N638 Westinghouse/PCI WPS 3-43/52-TB MC-GTAW-N638 was qualified in accordance with Attachment 1. The welding procedure qualification test assembly was 3 inches thick and consisted of SA-533, Gr. B, Cl. 1 (P-No. 3, Group 3) and SB-166, N06690 (P- No. 43) base materials. Prior to welding, the SA-533, Gr. B, C1. 1 portion of the test assembly was heat treated for 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> at 1200'F. The repair cavity in the test assembly was 1-1/2 inches deep.

The test assembly cavity was welded in the 3G (vertical) position using ERNiCrFe-7 (F-No.

43) filler metal. Results of the welding procedure qualification were documented on procedure qualification record PQR 707. Results of mechanical testing (tensile testing, bend testing, Charpy V- notch testing, and drop weight testing) are summarized below. WPS 3-43/52-TB MC-GTAW-N638 will be used to perform the repair welding activities described in Section V below.

Tensile test specimens exhibited a tensile strength that exceeded the 80,000 psi minimum required for SA-533, Gr. B, C1. 1 and were acceptable per ASME Section IX. The bend testing was also acceptable. Test results are as follows:

Tensile Test Results Specimen Tensile Actual Tensile Failure No. Specimen Strength Test 1-1 0.505" Turned Specimen 86,600 psi Ductile/Base Test 1-2 0.505" Turned Specimen 84,500 psi Ductile/Base Test 2-3 0.505" Turned Specimen 82,400 psi Fusion Line Test 2-4 0.505" Turned Specimen 86,600 psi Ductile/Weld Metal Enclosure 1 Page 11 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 Bend Test Results Specimen Type and Figure No. Result Side Bend 1 QW-462.2 Acceptable Side Bend 2 QW-462.2 Acceptable Side Bend 3 OW-462.2 Acceptable Side Bend 4 QW-462.2 Acceptable

• Drop weight and Charpy V-notch testing of the SA-533, Gr. B, Cl. 1 unaffected base material was performed. Based upon drop weight testing of the SA-533, Gr. B, Cl. 1 unaffected base material, a nil ductility transition temperature (TNDT) of -50'F was 0

established. Charpy V-notch testing was also performed at +10 F. All three Charpy V-notch specimens exhibited at least 35 mils lateral expansion and 50 ft-lbs absorbed energy. Based upon the above testing, an RTNDT of -50'F was established for the SA-533 Gr. B Cl. 1 base material. Test results are as follows:

Drop Weight Test - Unaffected Base Material Specimen Specimen Test Drop Weight ID Type Temperature Break TNDT DWI P-3 40 0 F No -50F DW2 P-3 40 0 F No -500 F Charpy V-Notch Tests - Unaffected Base Material Specimen Test Absorbed Lateral  % Shear ID Temperature Energy (ft-lbs) Expansion (mils) Fracture 1 +10 0 F 59.0 50.0 60.0 2 +10°F 51.0 43.0 50.0 3 +10°F 50.0 45.0 50.0 Average +10°F 53.3 46.0 53.3

• Charpy V-notch testing of the SA-533, Gr. B, Cl. 1 heat affected zone was also performed at +10°F. The absorbed energy, lateral expansion, and percent shear fracture of the heat affected zone test specimens were compared to the test values of the unaffected base material specimens. The average values of the three heat affected zone specimens were greater than those of the unaffected base material specimens. Based upon these results, it is clear that the proposed ambient temperature temper bead process improved the heat affected zone properties. Test results are as follows:

Charpy V-Notch Tests - Heat Affected Zone ID Test Absorbed Lateral  % Shear Temperature Energy (ft-lbs) Expansion (mils) Fracture 1 +10 0 F 85.0 65.0 90.0

+10 F0 136.0 64.0 75.0 2

3 +10°F 124.0 49.0 30.0 Average +100 F 115.0 59.3.0 65.0 Enclosure 1 Page 12 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 Supplemental microstructural evaluations were also performed on the test coupon weld of the procedure qualification. Microstructural evaluations consisted of micro-hardness testing (Vickers) and metallography. Vickers micro-hardness testing was performed at three different locations:

1. 0.125 inch below the surface of the weld,

2. 0.625 inch below the surface of the weld, and

3. 0.125 inch above the root of the weld.

Micro-hardness test values are provided in the table below.

Metallography was performed at IOOX and 50OX magnifications. According to CONAM Laboratory Report #2333, "There were a few colonies of tempered martensite observed near the root of the weld. These seem to be associated with the slight banding present in the base material. There was no indication of untempered martensite. The remaining areas of the heat affected zone consist of a mixed microstructure of by-products of high temperature pearlite degeneration, bainite and a small amount of ferrite." Regarding the presence of carbides, the CONAM report stated, "There was no evidence of massive carbides or carbide networks."

Vickers Micro-Hardness Tests Results Weld Zone 0.125" 0.625" 0.125" Location - From Surface From Surface Above Weld Root y(V) (HV) (HV) 224 219 224 Unaffected 224 217 240 Base 222 214 245 Material 224 214 226 219 224 234 219 212 248 HAZ 266 283 330 Grain Coarsened 273 276 358 Region 273 260 358 HAZ 279 287 334 Adjacent to Fusion 287 287 343 Line 293 276 343 222 212 205 Weld 208 201 208 Metal 219 217 214 219 217 224 208 222 224 199 219 232 D. Suitability of Alternative NDE IWA-4634 specifies that the repaired region shall be examined by liquid penetrant and volumetric examination methods. The NDE requirements of IWA-4634 were established Enclosure 1 Page 13 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 based upon a temper bead weld repair to butt welds. Figures IWA4633.1-1 and IWA-4633.2-1 clearly indicate this. While the requirement to perform a volumetric examination of a butt weld between a nozzle and pipe is appropriate, volumetric examinations are not appropriate for weld repairs of RVCH vent line penetration nozzle J-groove welds. See Figure 1.

Suitability of Proposed Alternative Radiographic examination of weld repairs of RVCH penetration nozzle J-groove welds is not practical. Meaningful radiographic examination cannot be performed due to the weld configuration and access limitations. The weld configuration and geometry of the penetration in the head provide an obstruction for the radiography and interpretation would be very difficult. Ultrasonic examination of the J-groove weld would also be impractical.

As an alternative to volumetric examinations, SNC proposes to perform a progressive liquid penetrant examination of the J-groove weld repair weld in accordance with NB-5245 of ASME Section III. It should be noted that ASME Section III does not require volumetric examination of these partial penetration J-groove welds. According to NB-3352.4(d)(1), "Partial penetration welds used to connect nozzles as permitted in NB-3337.3 shall meet the fabrication requirements of NB-4244(d) and shall be capable of being examined in accordance with NB-5245." NB-4244(d) establishes fabrication details for nozzles welded with partial penetration welds as shown in Figures NB-4244(d)-i and NB-4244(d)-2.

According to NB-5245, "Partial penetration welds, as permitted in NB-3352.4(d), and as shown in Figures NB-4244(d)-l and NB-4244(d)-2, shall be examined progressively using either the magnetic particle or liquid penetrant methods. The increments of examination shall be the lesser of one-half of the maximum welded joint dimension measured parallel to the centerline of the connection or 1/2-inch. The surface of the finished welded joint shall also be examined by either method."

The partial penetration J-groove welds of the RVCH penetration nozzles were designed and fabricated in accordance with NB-3352.4(d) and NB-4244(d). Therefore, according to NB-3352.4(d), the code required examination for these partial penetration J-groove welds is a progressive liquid penetrant examination performed in accordance with NB-5245. A volumetric examination is not required.

V. Alternative Requirements: Pursuant to 10CFR50.55a(a)(3)(i), SNC proposes alternatives to the GTAW-machine temper bead welding requirements of IWA-4610 and IWA-4630 of ASME Section XI, 1998 Edition through 2000 Addenda. Specifically, SNC proposes to perform ambient temperature temper bead welding in accordance with Attachment 1, "Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique." SNC has reviewed the proposed ambient temperature temper bead welding techniques of Attachment 1 against the GTAW-machine temper bead welding requirements of IWA-4610 and IWA-4630. This review was performed to identify differences between Attachment 1, IWA-4610 and IWA-4630. Based upon this review, SNC proposes alternatives to the following ASME Section XI requirements of IWA-4610 and IWA-4630:

Enclosure 1 Page 14 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51

1. IWA-4600(b)(1) permits repairs to base materials and welds identified in IWA-4630 to be performed without the specified postweld heat treatment of the Construction Code or ASME Section III provided the requirements of IWA4610 and IWA4630 are met. IWA4630 includes temper bead requirements applicable to the SMAW and the machine or automatic GTAW processes. As an alternative, SNC proposes to perform temper bead weld repairs using the ambient temperature temper bead technique described in Attachment 1. Only the machine or automatic GTAW process will be used when performing ambient temperature temper bead welding in accordance with Attachment 1.

2. IWA-4610(a) specifies that the weld area plus a band around the repair area of at least 1-1/2 times the component thickness or 5 inches, whichever is less, shall be preheated and maintained at a minimum temperature of 300'F for the GTAW process during welding; maximum interpass temperature shall be 450'F. As an alternative, SNC proposes that the weld area plus a band around the repair area of at least 1-1/2 times the component thickness or 5 inches, whichever is less, shall be preheated and maintained at a minimum temperature of 550 F for the GTAW process during welding; maximum interpass temperature shall be 1501F for the 1/8-inch butter thickness (first three weld layers as a minimum) and 350'F for the balance of welding.

3. IWA-4610(a) specifies that thermocouples and recording instruments shall be used to monitor process temperatures. As an alternative, SNC proposes to monitor preheat and interpass temperatures using an infrared thermometer as discussed in Attachment 1 (The infrared thermometer is described in Section IV.B.3.). Additionally, since thermocouples are not used with an infrared thermometer, the thermocouple attachment and removal requirements of IWA-4610(a) do not apply when an infrared thermometer is used.

4. IWA-4610(b)(1) establishes procedure technique requirements that apply when using the alternate temper bead welding methods but does not address joint design qualification of the repair cavity, except for included angle of the cavity. As an alternative, SNC proposes to qualify the joint design of the proposed repair cavity by requiring that the root width and included angle of the repair cavity in the test assembly be no greater than the minimum specified for the repair.

5. IWA-4633.2(c) specifies that the repair cavity shall be buttered with six layers of weld metal in which the heat input of each layer is controlled to within 10% of that used in the procedure qualification test, and heat input control for subsequent layers shall be deposited with a heat input equal to or less than that used for layers beyond the sixth in the procedure qualification. As an alternative, SNC proposes to butter the weld area with a minimum of three layers of weld metal to obtain a minimum butter thickness of 1/8-inch. The heat input of each weld layer in the 1/8-inch thick buttered section shall be controlled to within +10% of that used in the procedure qualification test. The heat input for subsequent weld layers shall not exceed the heat input used for layers beyond the 1/8-inch thick buttered section (first three weld layers) in the procedure qualification.

6. IWA-4633.2(c) specifies that the completed weld shall have at least one layer of weld reinforcement deposited and then this reinforcement shall be removed by mechanical means.

As an alternative, SNC's proposed ambient temperature temper bead technique does not include a reinforcement layer for nonferritic weld metal.

Enclosure 1 Page 15 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51

7. IWA-4633.2(d) specifies that, after at least 3/16-inch of weld metal has been deposited, the weld area shall be maintained at a temperature of 300 0 F for a minimum of four (4) hours (for P-No. 3 materials). As an alternative, SNC's proposed ambient temperature temper bead technique does not include a postweld soak.

8. IWA-4633.2(e) specifies that after depositing at least 3/16-inch of weld metal and performing a postweld soak at 3001F, the balance of welding shall be performed at a maximum interpass temperature of 350'F. As an alternative, SNC's proposes that a maximum interpass temperature of 350'F may be used after depositing at least 1/8-inch of weld metal without a postweld soak. i

9. IWA-4634 specifies liquid penetrant and volumetric examinations shall be performed after the completed repair weld has been at ambient temperature for at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. SNC will perform the liquid penetrant examination of the completed repair weld and preheated band as specified in IWA-4634. As an alternative to the volumetric examination of IWA-4634, SNC proposes to perform progressive liquid penetrant examinations in accordance with NB-5245 of ASME Section III. The liquid penetrant examinations will be performed in accordance with NB-5000. Acceptance criteria shall be in accordance with NB-5350.

This request for alternative is specific to localized weld repair of RVCH vent line penetration nozzle J-groove welds where 1/8-inch or less of nonferritic weld metal exists between the J-groove weld repair cavity and the ferritic base material of the RVCH. See Figure 1. Flaws in the J-groove weld will be removed prior to performing any temper bead repairs in accordance with this request.

VI. Justification for Granting Approval of Alternative: Pursuant to 10 CFR 50.55a(a)(3)(i), SNC requests approval to use the alternative ambient temperature temper bead welding requirements contained in Attachment 1 for repairs to pressure retaining partial penetration nozzle welds in the RVCH. The technical alternative is based on the requirements contained in ASME Section XI Code Case N-638, which has been proposed by the NRC in Draft Regulatory Guide DG-1091, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1", dated December 2001 as an acceptable alternative to applicable parts of ASME Section XI.

The proposed technical alternative has been demonstrated by successful completion of welding procedure qualifications to provide sound welds with acceptable material properties meeting ASME Sections m and IX. The ambient temperature machine GTAW temper bead welding method in the proposed technical alternative has been previously evaluated by the NRC for repairs to RPV closure head penetrations at several plants, including North Anna, D. C. Cook, Arkansas Nuclear One, and Oconee.

Pursuant to 10 CFR 50.55a(a)(3)(i), the use of the alternative ambient temperature temper bead welding requirements contained in Attachment 1 provides an acceptable level of quality and safety.

VII. Implementation Schedule: This request for relief is applicable to the Third Ten-Year Interval, ending November 30, 2007.

VIII. Relief Request Status: This request for relief is awaiting NRC approval.

Enclosure 1 Page 16 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-5 1 Figure 1, RVCH Vent Line Penetration Nozzle Weld Original Configuration Enclosure 1 Page 17 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-5 1 ATTACHMENT 1 DISSIMILAR METAL WELDING USING AMBIENT TEMPERATURE MACHINE GTAW TEMPER BEAD TECHNIQUE Enclosure 1 Page 18 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-5 1 ATTACHMENT 1 1.0 GENERAL REQUIREMENTS:

(a) The maximum area of an individual weld based on the finished surface will be less than 100 square inches, and the depth of the weld will not be greater than one-half of the ferritic base metal thickness.

(b) Repair/replacement activities on a dissimilar-metal weld are limited to those along the fusion line of a nonferritic weld to ferritic base material on which 1/8-inch or less of nonferritic weld deposit exists above the original fusion line. Repair/replacement activities on nonferritic base materials where the repair cavity is within 1/8-inch of a ferritic base material may also be performed.

(c) If a defect penetrates into the ferritic base material, repair of the base material, using a nonferritic weld filler material, may be performed provided the depth of repair in the base material does not exceed 3/8-inch.

(d) Prior to welding, the temperature of the area to be welded and a band around the area of at least 0

1-1/2 times the component thickness (or 5 inches, whichever is less) will be at least 55 F.

(e) Welding materials will meet the Owner's Requirements and the Construction Code and Cases specified in the repair/replacement plan. Welding materials will be controlled so that they are identified as acceptable until consumed.

(f) The area prepared for welding shall be suitably prepared for welding in accordance with a written procedure.

2.0 WELDING QUALIFICATIONS The welding procedures and the welding operators shall be qualified in accordance with Section IX and the requirements of paragraphs 2.1 and 2.2.

2.1 Procedure Qualification:

(a) The base materials for the welding procedure qualification will be the same P-Number and Group Number as the materials to be welded. The materials shall be post weld heat treated to at least the time and temperature that was applied to the material being welded.

(b) Consideration will be given to the effects of irradiation on the properties of material, including weld material for applications in the core belt line region of the reactor vessel.

Special material requirements in the Design Specification will also apply to the test assembly materials for these applications. ,

(c) The root width and included angle of the cavity in the test assembly will be no greater than the minimum specified for the repair.

Enclosure 1 Page 19 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-5 1 ATTACHMENT 1 (d) The maximum interpass temperature for the first three layers or as required to achieve the 1/8-inch butter thickness in the test assembly will be 1500F. For the balance of the welding, the maximum interpass temperature shall be 3500 F.

(e) The test assembly cavity depth will be at least one-half the depth of the weld to be installed during the repair/replacement activity, and at least 1 inch. The test assembly thickness will be at least twice the test assembly cavity depth. The test assembly will be large enough to pennit removal of the required test specimens. The test assembly dimensions surrounding the cavity will be at least the test assembly thickness, and at least 6 inches. The qualification test plate will be prepared in accordance with Figure 1.

(f) Ferritic base material for the procedure qualification test will meet the impact test requirements of the Construction Code and Owner's Requirements. If such requirements are not in the Construction Code and Owner's Requirements, the impact properties shall be determined by Charpy V-notch impact tests of the procedure qualification base material at or below the lowest service temperature of the item to be repaired. The location and orientation of the test specimens shall be similar to those required in subparagraph (h) below, but shall be in the base metal.

(g) Charpy V-notch tests of the ferritic weld metal of the procedure qualification shall meet the requirements as determined in subparagraph (f) above.

(h) Charpy V-notch tests of the ferritic heat-affected zone (HAZ) will be performed at the same temperature as the base metal test of subparagraph (f) above. Number, location, and orientation of test specimens will be as follows:

1. The specimens will be removed from a location as near as practical to a depth of one-half the thickness of the deposited weld metal. The test coupons for HAZ impact specimens will be taken transverse to the axis of the weld and etched to define the HAZ. The notch of the Charpy V-notch specimens will be cut approximately normal to the material surface in such a manner as to include as much HAZ as possible in the resulting fracture. When the material thickness permits, the axis of a specimen will be inclined to allow the root of the notch to be aligned parallel to the fusion line.

2. If the test material is in the form of a plate or a forging, the axis of the weld will be oriented parallel to the principal direction of rolling or forging.

3. The Charpy V-notch test will be performed In accordance with SA-370. Specimens will be in accordance with SA-370. Figure 11, Type A. The test will consist of a set of three full-size 10 mm x 10 mm specimens. The lateral expansion, percent shear, absorbed energy, test temperature, orientation and location of all test specimens will be reported in the Procedure Qualification Record.

Enclosure 1 Page 20 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-5 1 ATTACHMENT 1 (i) The average values of the three HAZ impact tests will be equal to or greater than the average values of the three unaffected base metal tests.

2.2 Performance Qualification:

Welding operators will be qualified in accordance with ASME Section IX.

3.0 WELDING PROCEDURE REQUIREMENTS:

The welding procedure shall include the following requirements:

(a) The weld metal shall be deposited by the automatic or machine GTAW process using cold wire feed.

(b) Dissimilar metal welds shall be made using F-No. 43 weld metal (QW-432) for P-No. 43 to P-No. 3 weld joints.

(c) The area to be welded will be buttered with a deposit of at least three layers to achieve at least 1/8-inch butter thickness as shown in Figure 2, steps I through 3, with the heat input for each layer controlled to within +/- 10% of that used in the procedure qualification test. Particular care will be taken in placement of the weld layers at the weld toe area of the ferritic base material to ensure that the HAZ is tempered. Subsequent layers will be deposited with a heat input not exceeding that used for layers beyond the third layer (or as required to achieve the 1/8-inch butter thickness) in the procedure qualification.

(d) The maximum interpass temperature field applications will be 3501F regardless of the interpass temperature during qualification.

(e) Preheat and interpass temperatures will be continuously monitored using an infrared 0

thermometer. The preheat temperature will be verified to be 55 F (minimum) prior to depositing the first weld layer. Prior to depositing the second and third weld layers, the interpass temperature will be verified to be at least 550 F but less than 150'F. The interpass temperature of each remaining layer will be verified to be at least 551F but less than 350'F prior to depositing the subsequent weld layers. The initial preheat temperature and the interpass temperatures for each weld layer will be recorded in the weld documentation of the repair traveler for each repair weld. The weld documentation of the repair traveler will be maintained as a permanent plant record.

(f) Particular care will be given to ensure that the weld region is free of all potential sources of hydrogen. The surfaces to be welded, filler metal, and shielding gas shall be suitably controlled.

Enclosure 1 Page 21 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 ATTACHMENT 1

4.0 EXAMINATION

(a) Prior to welding, a surface examination will be performed on the area to be welded.

(b) Repair welds in RVCH penetration nozzle J-groove welds shall be progressively examined by the liquid penetrant method in accordance with NB-5245 of ASME Section III. After the completed repair weld has been at ambient temperature for at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, repair welds including the preheat band (1.5 times the component thickness or 5 inches, whichever is less) around the repair weld shall be examined by the liquid penetrant method. The liquid penetrant examinations will be performed in accordance with ASME Section m, NB-5000. Acceptance criteria shall be in accordance with NB-5350.

(c) NDE personnel performing liquid penetrant examination will be qualified and certified in accordance with NB-5500.

5.0 DOCUMENTATION Use of this technical alternative shall be documented on the NIS-2 or NIS-2A form, as applicable.

Enclosure 1 Page 22 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-5 1 ATTACHMENT 1 P-43 -- WELD -I---< P-3 - l DISCARD l SIDE BEND SPECIMENI REDUCED SECTION TENSILE PECIMEN SIDE BEND SPECIMEN

---Lnk--L----

l H-AZ ~CHARPY .VNOC lHAZ ,CHARPY _, 4 _V-NOTCH I IHAZ CHARPY V-NOTCH

-__ L SIDE BEND SPECIMEN REDUCED SECTION TENSILE PPECIMEN I SIDEBSEND SPECIMEN II DISCARD DISCARDI r----------

TOP VIEW HEAT AFFECTED ZONE (HAZ)

END VIEW GENERAL NOTE: Base Metal Charpy Impact specimens not shown.

Figure 1- QUALIFICATION TEST PLATE Enclosure 1 Page 23 of 24

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-51 ATTACHMENT 1 Step 1: Deposit layer one with first layer weld parameters used in qualification.

Step 2 Deposit layer two with second layer weld parameters used in qualification.

NOTE: Particular care shall be taken in application of the second layer at the weld toe to ensure that the weld metal and HAZ of the ferritic base metal are tempered.

Step 3: Deposit layer three with third layer weld parameters used in qualification. NOTE: Particular care shall be taken in application of the third layer at the weld toe to ensure that the weld metal and HAZ of the ferritic base metal are tempered.

Step 4: Subsequent layers to be deposited as qualified, with heat Input less than or equal to that qualified in the test assembly. NOTE: Particular care

__ shall be taken in application of the fill layers to preserve the temper of the HAZ of the ferritic base metal.

GENERAL NOTE: For dissimilar-metal welding, only the ferritic base metal is required to be welded using Steps 1 through 3 of the temper bead welding technique.

Figure 2 - AUTOMATIC OR MACHINE GTAW TEMPER BEAD WELDING Enclosure 1 Page 24 of 24

ENCLOSURE 2 SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 UPDATED PROGRAM REQUEST FOR RELIEF RR-52

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-52 System/Component(s) for Which Alternative is Requested: Reactor Vessel Closure Head (RVCH), Base Material Repair Welds in Class 1 Penetration Nozzles, ASME Section XI, 1989 Edition.

II. Code Requirement: Farley Unit 1 is currently in the third inspection interval using the 1989 Edition of ASME Section XI with no Addenda. Augmented examinations of the RVCH penetration nozzles are planned, as committed to in response to NRC Bulletin 2002-02 and Order EA-03-009. In the event that defects are discovered in the nozzle base material that exceed the acceptable limits of IWA-3000, IWA-3132.2 requires that they either be removed or the component repaired to the extent necessary to meet the acceptance standards of IWB-3000.

IWB-3133 requires that repairs comply with the requirements of IWA-4000 and IWB4000.

1WA-4120 (a) requires that "Repairs shall be performed in accordance with the Owner's Design Specification and the original Construction Code of the system. Later editions and Addenda of the Construction Code or of Section III, either in their entirety or portions thereof, and Code Cases may be used." The latest Edition and Addenda of ASME Section m incorporated by reference in 10 CFR 50.55a (b) (1) is the 1998 Edition through the 2000 Addenda. IWA-4120 (c) permits that "Later Editions and Addenda of Section XI, either in their entirety or portions thereof, may be used for the repair program, provided these Editions and Addenda of Section XI at the time of the planned repair have been incorporated by reference in amended regulations of the regulatory authority having jurisdiction at the plant site." The latest Edition and Addenda of ASME Section XI incorporated by reference in 10 CFR 50.55a (b) (2) is the 1998 Edition through the 2000 Addenda.

The Construction Code of record for the Farley Unit 1 reactor vessel and closure head is the 1968 edition of ASME Section III with Addenda through Summer 1970.

III. Code Requirement for Which Alternative is Requested: Pursuant to 10 CFR 50.55a(a)(3)(i), the use of a technical alternative is requested in lieu of the rules in the 1989 Edition of ASME Section XI, IWA-4120(a) which require repairs to be performed in accordance with the Owner's Design Specification and the original Construction Code of the system. Augmented examinations of the RVCH penetration nozzles are planned, as committed to in response to NRC Bulletin 2002-02 and Order EA-03-009. In the event a flaw is found in a RVCH nozzle partial penetration weld, this technical alternative for examination of base metal repairs will be utilized in conjunction with defect removal and welding methods that otherwise comply with IWA-4120(a). This relief request will not be used for repairs that utilize temper bead welding methods.

As permitted by Subarticle IWA-4120(c) of ASME Section XI, 1989 Edition, repairs of the Farley Unit 1 RPV head penetration nozzle base materials will be performed in accordance with the later 1998 Edition through 2000 Addenda of ASME Section XI. ASME Section XI provides repair requirements that supplement, amend or supercede the repair rules of the Construction Code. Where applicable, compliance with these additional requirements is mandatory. With respect to localized repair welding of RPV head penetration nozzle base materials, the following requirements of the 1998 Edition through 2000 Addenda of ASME Section XI apply:

Enclosure 2 Page 1 of 9

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-52

• IWA-4421 - Construction Code and Owner's Requirements IWA-4421 establishes Construction Code and Owner's requirements for performing welding, brazing, defect removal, and installation activities. IWA4421 also requires that the requirements of IWA-4460 be used in lieu of Construction Code requirements for mechanical and thermal metal removal, and that the requirements of IWA4422 be used in lieu of Construction Code requirements for examination of defect removal areas. Supplementing the defect removal requirements in ASME Section III, the requirements of IWA-4421 apply to the performance of localized defect removal and repair welding of RPV head penetration nozzle base materials.

IWA-4421(a) states: "Welding, brazing, defect removal, and installation activities shall be performed in accordance with the Owner's Requirements and the Construction Code of the component or system, except as provided in (b) and (c) below. The requirements of IWA-4460 shall be used in lieu of Construction Code requirements for mechanical and thermal metal removal. The requirements of IWA-4422 shall be used in lieu of Construction Code requirements for examination of defect removal areas."

• IWA-4422.1 -Defect Removal IWA-4422.1 establishes requirements for defect removal processes and extent of defect removal. IWA-4422.1 (a) requires defects to be removed or reduced to an acceptable size.

IWA-4422.1(b) provides an alternative that the defect removal area and any remaining portion of the defect may be evaluated and accepted in accordance with the flaw evaluation rules of ASME Section XI.

IWA-4422.1 states:

"(a) The defect removal process shall be in accordance with IWA-4421, except that thermal removal processes shall be in accordance with IWA-4460. A defect is considered removed when it has been reduced to an acceptable size. The component shall be acceptable for continued service if the resulting section thickness created by the cavity is at least the minimum required thickness. If the resulting section thickness is less than the minimum required thickness, the component shall be corrected by repair/replacement activities in accordance with this Article.

(b) Alternatively, the defect removal area and any remaining portion of the defect may be evaluated and the component accepted in accordance with appropriate flaw evaluation provisions of Section XI, or the design provisions of the Owner's Requirements and either the Construction Code or Section III."

Enclosure 2 Page 2 of 9

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-52

• IWA-4422.2 - Nondestructive Examination of Defect Removal Areas IWA-4422.2 establishes nondestructive examination requirements that are applicable to defect removal areas. IWA-4422.2.1 addresses examination of defect removal areas with no subsequent welding and IWA-4422.2.2 addresses examination of defect removal areas to be followed by welding. IWA-4422.2.2(a) states in part: "Surface examination of the defect removal area is required prior to welding, except as provided below." The exceptions are listed in IWA-4422.2.2(a)(1), (2) and (3). As required by IWA-4421(a), the requirements of IWA-4422 apply in lieu of the requirements of ASME Section III for examination of defect removal areas in RPV head penetration nozzle base materials.

IWA-4422.2.2(a)(3) states: "If final volumetric examination will be performed on the completed repair, the final volumetric examination method is the same as the method used to detect the defect, and the volume to be examined includes the location of the original defect, surface examination of the defect removal area is not required."

IWA-4422.2.2(e) states: "Examination following welding or brazing shall be in accordance with IWA-4520."

• IWA-4520 - Examination of Repair Welds IWA-4520 requires that welded areas be examined in accordance with the Construction Code identified in the Repair/Replacement Plan. For repair welds to the Farley Unit 1 RPV head penetration nozzle base materials, the Construction Code identified in the Repair/Replacement Plan will be ASME Section III, 1998 Edition through 2000 Addenda.

IWA-4520 applies to examination of the final weld surface.

Subarticle IWA-4120(a) of ASME Section XI, 1989 Edition states in part: "Repairs shall be performed in accordance with the Owner's Design Specification and the original Construction Code of the component or system. Later Editions and Addenda of the Construction Code or of Section III, either in their entirety or portions thereof, and Code Cases may be used."

The original Construction Code for the Farley Unit 1 reactor vessel and closure head is the 1968 edition of ASME Section III with Addenda through Summer 1970. As permitted by Subarticle IWA-4120(a) of ASME Section XI, 1989 Edition, localized weld repairs of the Farley Unit 1 RPV head penetration nozzle base materials will be performed in accordance with the later 1998 Edition through 2000 Addenda of ASME Section III. With respect to localized repair welding of RPV head penetration nozzle base materials, the following requirements of the 1998 Edition through 2000 Addenda of ASME Section III apply:

Enclosure 2 Page 3 of 9

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-52 NB-4000 NB4000 establishes fabrication, installation, and repair requirements for ASME Class 1 components. According to NB-4131, when defects are identified in materials during fabrication and installation that exceed the limits of NB-2500, then the condition must be corrected in accordance with the requirements of NB-2500 for the applicable product form, with the exception that the limitation on depth of weld repair does not apply. The Farley Unit 1 RPV head penetration nozzles are manufactured from SB-167 nickel alloy tube materials.

Based on the product form, the requirements of NB-2550 apply to all of the RPV head penetration nozzles.

• NB-2550 NB-2550 establishes examination and repair requirements that are applicable to ASME Class 1 tubular products, such as the Farley Unit 1 RPV head penetration nozzles. NB-2559 establishes requirements for performing localized repairs by welding. NB-2559 states:

"Repair of defects shall be in accordance with NB-2539, except repair by welding is not permitted on copper-nickel alloy and nickel alloy heat exchanger tubes." The SB-167 nickel alloy RPV head penetration nozzles are not heat exchanger tubes, therefore repair welding of RPV head penetration nozzle base materials is permitted and must be performed in accordance with NB-2539.

• NB-2539 - Repair of Base Materials by Welding NB-2539 establishes requirements for performing repairs by welding. These requirements address defect removal, qualification of welding procedures and welders, blending of repaired areas, and examination of repair welds. As invoked by NB-2559, these requirements apply to localized welded repairs of RPV head penetration nozzles. Examination requirements for completed repair welds are specified in NB-2539.4 as follows: "Each repair weld shall be examined by the magnetic particle or liquid penetrant method. In addition, when the depth of the repair cavity exceeds the lesser of 3/8-inch or 10% of the section thickness, the repair weld shall be radiographed after repair in accordance with NB-5 110 and to the acceptance standards of NB-5320." The section thickness for the RPV head penetration nozzle base material is nominally 5/8-inch. It is anticipated that repair cavities as deep as 3/8-inch will be required, which is greater than 10% of the section thickness. Therefore, radiography of the completed repair weld would be required to meet NB-2539.

• NB-5279 - Special Exceptions for Examinations NB-5279 permits ultrasonic plus liquid penetrant or magnetic particle examination to be performed when the weld joint detail does not permit radiographic examination. This provision applies to the RPV head penetration nozzles since the configuration of the installed nozzles does not permit access to the outside diameter of the nozzle base material for placement of radiographic film.

Enclosure 2 Page 4 of 9

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-52 NB-5279 states: "When the joint detail does not permit radiographic examination to be performed in accordance with this article, ultrasonic examination plus liquid penetrant or magnetic particle examination of the completed weld may be substituted for the radiographic examination. The absence of suitable radiographic equipment shall not be justification for such substitution. The substitution of ultrasonic examination can be made provided the examination is performed using a detailed written procedure which has been proven by actual demonstration to the satisfaction of the Inspector as capable of detecting and locating defects described in this Subsection. The nondestructive examinations shall be in accordance with NB-5 110 and meet the acceptance standards of NB-5300.

IV. Basis for Alternative: Augmented examinations of the RVCH penetration nozzles are planned, as committed to in response to NRC Bulletin 2002-02 and Order EA-03-009. If inspection of the RPV head penetration nozzles reveals flaws in the nozzle base material such that defect removal and repair welding is required, the weld joint detail does not permit the radiographic examination required by the Construction Code paragraph NB-2539 to be performed due to the geometry of the nozzle. As an alternative, the ultrasonic examination method of ASME Section V and acceptance criteria of NB-5330 of ASME Section mII, 1998 Edition through 2000 Addenda is proposed. Additionally, the eddy current examination method of IWA-2223 of ASME Section XI, 1998 Edition through 2000 Addenda is proposed as an alternative to the magnetic particle or liquid penetrant examination requirements of NB-2539 of ASME Section III, 1998 Edition through 2000 Addenda for the completed weld. This relief request will not be used for repairs that utilize temper bead welding methods.

A. Surface Examination of Repair Cavity lWA-4422.2.2(a) of ASME Section XI requires a surface examination of all defect removal areas (i.e., repair cavities) prior to repair welding, except that IWA-4422.2.2(a)(3) provides that "If final volumetric examination will be performed on the completed repair, the final volumetric examination method is the same as the method used to detect the defect, and the volume to be examined includes the location of the original defect, surface examination of the defect removal area is not required."

RPV head penetration nozzles will be examined by the ultrasonic and eddy current examination methods as described below to characterize all flaws prior to defect excavation.

Identified flaws will be evaluated for acceptance in accordance with IWB-3600. Flaws that exceed the acceptance limits of the IWB-3600 flaw evaluation will be removed or reduced to an acceptable size prior to welding. Upon completion of repair welding, the location of the original defect and repair weld region will be re-examined using the same ultrasonic and eddy current examination methods to verify that the as-left flaw dimensions are still within the acceptance limits of the IWB-3600 flaw evaluation. The volume to be examined after the repair will be the same as the volume examined in the detection and characterization of the original defect. Therefore, surface examination of the defect removal area is not required prior to welding, as permitted by IWA-4422.2.2(a)(3).

Enclosure 2 Page 5 of 9

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-52 B. Surface Examination of Repair Welds NB-2539.4 of ASME Section III requires a magnetic particle or liquid penetrant examination of all repair welds. However, a magnetic particle examination of repair welds in RPV head penetration nozzles cannot be performed. Magnetic particle testing is a nondestructive examination method used to detect surface and near-surface discontinuities in ferromagnetic materials. The basic principle of magnetic particle inspection is that when a ferromagnetic material contains one or more discontinuities in the path of the magnetic flux, minute poles are set up at the discontinuities. These poles have a stronger attraction for the magnetic particles than the surrounding surface of the material. However, the Farley Unit 1 RPV head penetration nozzles are manufactured from SB-167 nickel Alloy 600, which is not magnetic.

Repair welds will be performed using nickel Alloy 52 filler metals that are also non-magnetic. Therefore, examination of repair welds in RPV head penetration nozzles by the magnetic particle method is not possible and liquid penetrant examination is the applicable examination method.

Suitability of Proposed Alternative The eddy current examination method of IWA-2223 of ASME Section XI, 1998 Edition through 2000 Addenda is proposed as an alternative to the magnetic particle or liquid penetrant examination requirements of NB-2539 for the completed weld. The eddy current examination complements the ultrasonic examination by providing sensitivity to surface and subsurface flaws along the inspection surface. The eddy current approach utilizes a 5-mm diameter, "cross wound" probe design, which is capable of operating frequencies between 75 and 500 kHz. This technique is primarily responsible for detection and length sizing of defects, which are open to the inside diameter surface of the penetration tube. Since this particular probe design produces eddy currents that penetrate to approximately 0.030 inch into the inside diameter surface, it will also aid in the evaluation of very shallow surface defects. For post-repair inspection purposes, this eddy current examination technique will provide the necessary surface examination of the repair weld area. Identified flaws will be evaluated for acceptance in accordance with the flaw evaluation rules of IWB-3600. The proposed eddy current technique will be used in the initial examinations for flaw characterization and in the post-repair examinations. In the event that an eddy current examination cannot be performed on a repair weld due to the surface profile or some other prohibitive condition, then a liquid penetrant examination will be performed.

Several demonstrations of the proposed eddy current examination techniques have been performed to determine effectiveness to detect and size axial and circumferential primary water stress corrosion cracking (PWSCC)-type defects in the nozzle material, utilizing cracked nozzle samples. These demonstration efforts include the EPRI-sponsored demonstrations associated with NRC Generic Letter 97-01 and NRC Bulletin 2001-01, as well as Westinghouse internal demonstrations. The results of these demonstrations are discussed in Westinghouse technical report WCAP-15987 Revision 1, which was submitted to the NRC staff for generic review by Westinghouse on December 16, 2002. Entergy also submitted a detailed summary of demonstrations to the NRC staff via a letter dated June 17, 2002 in support of repairs performed at Arkansas Nuclear One, Unit 2.

Enclosure 2 Page 6 of 9

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-52 C. Radiographic Examination of Repair Welds NB-2539.4 requires a radiographic examination of base material repair welds when the depth of the repair cavity exceeds the lesser of 3/8-inch or 10% of the section thickness. However, a radiographic examination of the repair weld cannot be performed.

Radiographic examination of weldments employs x-rays or gamma rays to penetrate an object and detect discontinuities by the resulting image on a recording or a viewing medium such as photographic film. When a weld is exposed to radiation, some of the radiation is absorbed, some scattered, and some transmitted through the weldment to the film. The variations in amount of radiation transmitted through the weld depend on (1) relative densities of the material and any inclusions, (2) through-thickness variations, and (3) the characteristic of the radiation itself. Nonmetallic inclusions, pores, aligned cracks, and other discontinuities result in more or less radiation reaching the recording film. The variations in transmitted radiation produce optically contrasting areas on the recording film.

Radiography is not appropriate for base material weld repairs of RPV head penetration nozzles. Radiographic techniques require that the source of radiation be placed as near normal to the item being examined as possible, with the film in intimate contact with the item on the opposite surface. An attempt to radiograph repair welds in the RPV head penetration nozzles would have the radiation source being placed at various angles other than normal, penetrating from fractions of an inch of material thickness up to multiple inches of material thickness. Image quality indicators (penetrameters) would have to be placed on the inside bores of the RPV head penetration nozzles. Multiple exposures would be required, and the image distortion would increase as the repair weld moved up the nozzle bore. The required radiographic sensitivity and geometric unsharpness would also not be obtainable with generally used radiographic techniques. Depending on the location of the repair weld, access to both surfaces of the RPV nozzle may not be available to allow radiographic examinations.

In other cases, clearances between the RPV nozzles and the RPV head would make radiography of a repair weld impossible. Multiple exposures, complex geometry and thickness, and the adverse radiological environment make radiographic examination of RPV head penetration nozzle repair welds impractical.

Suitabilitv of Proposed Alternative Meaningful radiographic examination of repair welds in RPV head penetration nozzle base materials cannot be performed. NB-5279 permits ultrasonic plus liquid penetrant examination of the completed weld to be substituted when the weld joint detail does not permit radiographic examination. Southern Nuclear Operating Company (SNC) proposes to utilize the ultrasonic and eddy current examination methods.

The ultrasonic examination will be performed using a combination of Time of Flight Diffraction (TOFD) and standard 00 pulse-echo techniques. The TOFD approach utilizes two pairs of 1/4-inch diameter, 550 refracted-longitudinal wave transducers pointed at each other.

One of the transducers sends sound into the inspection volume, and the other transducer receives the reflected and diffracted signals, as they interact with the material. There will be one TOFD pair looking in the axial direction of the penetration tube, and one TOFD pair will Enclosure 2 Page 7 of 9

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-52 be looking in the circumferential direction of the penetration tube. The TOFD technique is primarily responsible for detecting and characterizing planer-type defects within the full volume of the penetration tube. This TOFD ultrasonic technique will be used in the initial inspections for flaw characterization and in the post-repair inspections.

The standard 00 pulse-echo ultrasonic approach utilizes two 1/4-inch diameter straight beam transducers. One transducer uses a center frequency of 2.25 MHz while the other uses a frequency of 5.0 MHz. The 00 technique is primarily responsible for plotting the penetration tube outside diameter location and the J-groove attachment weld location, which will aid in defect orientation and sizing information. Additionally, the O0technique will be capable of locating and sizing any laminar-type defects that may be encountered. These transducers will interrogate the weld repair area for lack of fusion and other laminar-type defects. This ultrasonic technique will be used in the initial inspections for flaw characterization and in the post-repair inspections.

Several demonstrations of the proposed ultrasonic and eddy current examination techniques have been performed to determine effectiveness to detect and size axial and circumferential PWSCC-type defects in the nozzle material, utilizing cracked nozzle samples. These demonstration efforts include the EPRI-sponsored demonstrations associated with NRC Generic Letter 97-01 and NRC Bulletin 2001-01, as well as Westinghouse internal demonstrations. The results of these demonstrations are discussed in Westinghouse technical report WCAP-15987 Revision 1, which was submitted to the NRC staff for generic review by Westinghouse on December 16, 2002. Entergy also submitted a detailed summary of demonstrations to the NRC staff via a letter dated June 17, 2002 in support of repairs performed at Arkansas Nuclear One, Unit 2. Please refer to those reports for detailed descriptions of examination demonstrations.

V. Alternative Requirements: Pursuant to the provisions of 10 CFR 50.55a(a)(3)(i), SNC proposes alternatives to examination requirements applicable to localized repair welds in RPV head penetration nozzle base materials specified in ASME Section In as imposed by the 1989 Edition of ASME Section XI.

As an alternative to a magnetic particle or liquid penetrant examination of the completed repair weld in accordance with NB-2539.4 of ASME Section III, SNC proposes to perform an eddy current examination. When an eddy current examination cannot be performed due to the surface profile of the repair weld or other prohibitive conditions, then a liquid penetrant examination will be performed.

• Eddy current examinations will be performed in accordance with IWA-2223 of ASME Section XI, 1998 Edition through 2000 Addenda, and as described in Section IV.B above.

Identified flaws will be evaluated for acceptance in accordance with the flaw evaluation rules of IWB-3600.

• The liquid penetrant examination and acceptance criteria will be in accordance with NB-2546 of ASME Section III.

As an alternative to a radiographic examination of the completed repair weld in accordance with NB-2539.4 of ASME Section III, SNC proposes to perform ultrasonic and eddy current examination as follows:

Enclosure 2 Page 8 of 9

SOUTHERN NUCLEAR OPERATING COMPANY FARLEY UNIT 1 THIRD INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF NO. RR-52

• Ultrasonic examinations will be performed in accordance with ASME Section V and as described in item IV.C above. Acceptance criteria shall be in accordance with NB-5330.

Any remaining portions of flaws not completely removed shall be evaluated to ensure their size continues to be acceptable in accordance with the flaw evaluation rules of IWB-3600.

• Eddy current examinations will be performed in accordance with IWA-2223 of ASME Section XI, 1998 Edition through 2000 Addenda, and as described in item IV.B above.

Identified flaws will be evaluated for acceptance in accordance with the flaw evaluation rules of IWB-3600.

Successive examinations of repaired areas where defects were reduced to an acceptable size but not removed completely will be performed for three consecutive periods, as addressed in IWB-2420(b) of ASME Section XI, or until such time as the RPV head may be replaced.

VI. Justification for Granting Approval of Alternative: Pursuant to 10 CFR 50.55a(a)(3)(i), if inspection of the RVCH penetrations reveals flaws affecting the nozzle base material, the proposed alternative would provide an acceptable level of quality and safety. SNC believes that the proposed alternatives identified in item V above, and discussed in items IV.B and IV.C above, provide an acceptable level of quality and safety to the repair rules of ASME Section XI, 1989 Edition and as described in Section m above of this request. Therefore, we request that the proposed alternative be authorized pursuant to 10CFR50.55a(a)(3)(i).

VII. Implementation Schedule: This request for relief is applicable to the Third Ten-Year Interval, ending November 30, 2007.

VIII. Request for Relief Status: This request for relief is awaiting NRC approval.

Enclosure 2 Page 9 of 9