ULNRC-05031, Response to NRC Bulletin 2004-01, Inspection of Alloy 82/182/600 Materials Used in the Fabrication of Pressurizer Penetrations and Steam Space Piping Connections at Pressurized-Water Reactors.

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Response to NRC Bulletin 2004-01, Inspection of Alloy 82/182/600 Materials Used in the Fabrication of Pressurizer Penetrations and Steam Space Piping Connections at Pressurized-Water Reactors.
ML042180192
Person / Time
Site: Callaway Ameren icon.png
Issue date: 07/27/2004
From: Keith Young
AmerenUE
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
BL-04-001, ULNRC-05031
Download: ML042180192 (13)
v • d • e


Text

AmerenUE PO Box 620 Callaway Plant Fulton, AlO 65251 July 27, 2004 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop P1-137 Washington, DC 20555-0001 ULNRC-0503 1 WAiierlei Ladies and Gentlemen:

U1F DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.

FACILITY OPERATING LICENSE NPF-30 RESPONSE TO NRC BULLETIN 2004-01, "INSPECTION OF ALLOY 82/182/600 MATERIALS USED IN THE FABRICATION OF PRESSURIZER PENETRATIONS AND STEAM SPACE PIPING CONNECTIONS AT PRESSURIZED-WATER REACTORS" Enclosed is the Callaway Plant 60-day response to NRC Bulletin 2004-01, "Inspection Of Alloy 82/182/600 Materials Used In The Fabrication Of Pressurizer Penetrations And Steam Space Piping Connections At Pressurized-Water Reactors,"

dated May 28, 2004. NRC Bulletin 2004-01 requested information related to the materials from which the pressurizer penetrations and steam space piping connections at Callaway were fabricated, and information related to the inspections that have been and those that will be performed to ensure that degradation of Alloy 82/182/600 materials used in the fabrication of pressurizer penetrations and steam space piping connections will be identified, adequately characterized, and repaired. Callaway Plant coordinated preparation of this response with the other participants in the Strategic Teaming and Resource Sharing (STARS) group.

Attachment III lists AmerenUE commitments contained in this correspondence.

4t rc a subsidiary olAmeren Corporation

ULNRC-0503 1 July 27, 2004 Page 2 If you have any questions regarding this submittal, please contact me at (573) 676-8659 or Mr. Dave Shafer, Superintendent - Licensing at (314) 554-3104.

Sincerely, Keith D. Young Manager - Regulatory Affairs Attachments: I - Affidavit II - RAI Responses III- List of Commitments

ULNRC-05031 July 27, 2004 Page 3 of 8 Mr. Bruce S. Mallett Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Jack N. Donohew (2 copies)

Licensing Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 7E1 Washington, DC 20555-2738 Missouri Public Service Commission Governor Office Building 200 Madison Street PO Box 360 Jefferson City, MO 65102-0360 Mr. Jerry B. Uhlmann Director Missouri State Emergency Management Agency P.O. Box 116 Jefferson City, MO 65102

ULNRC-0503 1 Attachment I Page 1 of I STATE OF MISSOURI

) SS COUNTY OF CALLAWAY Keith D. Young, of lawful age, being first duly sworn upon oath says that he is Manager, Regulatory Affairs for Union Electric Company; that he has read the foregoing document and knows the content thereof, that he has executed the same for and on behalf of said company with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.

By Keil- .

Manager, Regulatory Affairs SUBSCRIBED and sworn to before me this vY day of - , 2004.

0 TERRA fL CWOOK X.. orPb Notary Beod

  • OTATE OF MISSOURI tJotLj 6b &c Caltaway County My Commlsun Eiqis May 13. 2008

ULNRC-05031 Attachment It Page 1 of8 Response to NRC Bulletin 2004-01, "Inspection Of Alloy 82/1821600 Materials Used In The Fabrication Of Pressurizer Penetrations And Steam Space Piping Connections At Pressurized-Water Reactors" NRC Reauested Information (1) All subject PWJ? licensees are requestedto provide thefollowving information w'ithin 60 days of the date of this bulletin. [Forlines attacheddirectly to the pressurizer, with the exception of the surge line, the information requested in (1) and (2) above should be providedfor any locations, including those remotefrom the pressurizershell, which containAlloy 82/182/600 materialswhich are exposed to conditions similarto those of the pressurizerenvironment.]

(a) A descriptionof the pressurizerpenetrationsandsteam space piping connections at your plant. At a minimum, this descriptionshould include materialsof construction (e.g., stainlesssteelpipingand/orweld metal, Alloy 600 piping/sleeves, Alloy 82/182 wveld metal or buttering, etc.), joint design (e.g., partialpenetrationwelds, fill penetrationwelds, bolted connections, etc), and, in the case of weldedjoints, whether or not the weld was stress-relievedpriorto beingput into service. Additional information relevant with respect to determiningthe susceptibility of yourplant 's pressurizer penetrationsandsteam spacepipingconnections to PWSCC should also be included Callaway Plant Response:

The pressurizer at Callaway has 5 locations which contain Alloy 82/182/600 materials exposed to conditions similar to those of the pressurizer environment.

These locations are the pressurizer spray nozzle-to-pipe connection, and the four pressurizer safety and relief nozzle-to-safe end connections. The pressurizer heater penetrations do not contain Alloy 82/182/600 materials.

Materials of construction The Certified Material Test Reports (CMTRs) indicate that both Alloy 82 and Alloy 182 weld metals were used for all pressurizer nozzle to safe-end welds. Generally, the safe-end welds for the pressurizer were made of Alloy 182, with Alloy 82 used only for inprocess repairs.

Joint Design These pressurizer penetrations are carbon steel nozzles with Alloy 82/182 buttering and full penetration welds connecting to stainless steel safe ends which are then connected to stainless steel piping with stainless steel safe end-to-pipe welds. Figure

ULNRC-0503 1 July 27, 2004 Page 2 of 8 I below depicts the nozzle, nozzle-to-safe end and safe end configuration for these locations.

WEFY ?REUEF u4W.2LE Figure 1 The nozzle buttering was stress-relieved, but the buttering-to-safe end weld was not stress relieved prior to being put into service.

The operating temperature of the pressurizer at Callaway is approximately 653 degrees F.

ULNRC-0503 1 July 27, 2004 Page 3 of 8 (b) A description of the inspectionprogramfor Alloy 82/182/600pressurizer penetrationsand steam spacepiping connections that has been implemented at your plant. The descriptionshould include when the inspections were performed; the areas,penetrationsand steam spacepiping connections inspected; the extent (percentage) of coverage achievedfor each location which was inspected; the inspection methods used; the process used to resolve any inspectionfindings; the quality of the documentation of the inspections (e.g., written report, video record,photographs);and, the basisfor concluding thatyourplant satisfies applicableregulatoryrequirementsrelatedto the integrity ofpressurizerpenetrationsand steam spacepiping connections. If leakingpressurizerpenetrationsor steam spacepiping connections were found, indicate whatfollowup NDE was performed to characterizeflaws in the leakingpenetrations.

CallawaU Plant Response:

Volumetric examinations were performed utilizing .25" X .25" transducers with contoured wedges. Dual 45 degree shear wave axial scans were performed from the Safe end side. 60 degree dual L wave axial scans were performed from the Nozzle side. A dual 45 degree L wave scan was performed circumferentially from both sides. The table below summarizes the examinations for the locations of interest.

Weld Date of Examination NDE relevant resolution last coverage Method(s) indications of inspection achieved or (yes/no) indications, cited (%) if any 2-TBB03-2-W 04/15/1992 *100% UT/PT No N/A 2-TBB03-3-A-W 10/26/1996 *100% Surface UT/PT No N/A 88% Volumetric 2-TBB03-3-B-W 10/24/1996 *100% surface UT/PT No N/A 85% Volumetric 2-TBB03-3-C-W 10/13/1999 *100% Surface UT/PT No N/A 54% Volumetric 2-TBB034-W. 10/07/1999 *100% Surface UT/PT No N/A 54% Volumetric

  • Prior to appendix VIII coverage Notes: No rejectable indications were found.

All inspections documented by written record.

In Interval 1, all of the subject locations were examined according to ASME Section XI.

ULNRC-05031 July 27, 2004 Page 4 of 8 Callaway Plant implemented a Risk Informed ISI (RI-ISI) program in Period 2 of Interval 2. This was approved by the NRC in the safety evaluation contained in a letter dated January 30, 2002. The Callaway Plant RI-ISI program utilizes the methodology in EPRI TR-1 12657 Rev. B-A. Per this methodology these welds are Risk Category 4, which require 10% of the population to be selected for examination.

Weld 2-TBB03-03-A-W and 2-TBB03-04-W are selected for examination.

A review of the risk rankings of the RI-ISI program is to be performed prior to Refuel

14. If the subject welds are moved to Risk Category 2 per the above methodology, this will require 25% of the welds to be volumetrically examined. As 2 of the 5 subject welds are already being examined, this percentage is already met.

In addition to the NDE in the table above, a bare metal visual examination of all Alloy 82/182/600 locations, including the pressurizer connections was performed during Refuel 13 (Spring 2004) in conjunction with the boric acid walkdown performed at the beginning of the refueling outage. A pressure test (VT-2) at NOP was performed near the completion of each refueling outage in accordance with ASME pressure testing requirements. No indication of pressure boundary leakage was noted in any of the locations.

The above satisfies the 10 CFR 50.55a requirements for inspection of the subject components.

(c) A descriptionof the Alloy 82/182/600 pressurizerpenetration andsteam space piping connection inspectionprogram that vill be implemented at your plant during the next andsubsequent refueling outages. The description should include the areas,penetrationsand steam space piping connections to be inspected; the extent (percentage) of coverage to be achievedfor each location; inspection methods to be Used; qualificationstandardsforthe inspection methods andpersonnel; the process Used to resolve any inspection indications;the inspection documentation to be generated,andthe basisfor concluding that your plant vill satisfy applicable regulatory requirements relatedto the structuraland leakage integrity ofpressurizerpenetrationsand steam space pipingconiections. If leakingpressurizerpenetrationsor steam spacepiping connections arefound indicate whatfollolvup NDE Vill be performed to characterizeflawvsin the leakingpenetrations. Provideyour plansfor expansion of the scope of NDE to be performed tfcircunmferential flavs arefound in any portionof the leakingpressurizerpenetrationsor steam space pipingconnections.

ULNRC-05031 July 27, 2004 Page 5 of 8 Callawav Plant Response:

The Alloy 82/182/600 pressurizer piping connections will receive a bare metal visual examination in the next refueling outage in accordance with MRP letter 2004-05.

The next refueling outage is RF14 (Fall 2005), which is the last refueling outage in ISI interval 2.

All of the locations of interest will continue to receive bare metal visual examinations near the beginning of each outage, as is required by the boric acid program, as well as the VT-2 examination at the end of each outage, as is required by the pressure testing program.

In ISI interval 3, as a minimum, the welds selected in the RI-ISI program will receive a volumetric examination. Callaway Plant continues to be involved in various industry groups associated with PWSCC of Alloy 82/182/600 Materials such as Alloy 600 Issue Task Group (ITG), the ASME Alloy 600 Task Group. Recommendation and requirements from these groups will be assessed, and if appropriate, changes to the Inservice Inspection Program will be made. Volumetric (UT) examinations will be qualified in accordance with Appendix VIII of ASME Section XI, as modified by 10 CFR 50.55a, to the extent possible. Currently, no Appendix VIII qualification exists which allows for examination of Dissimilar Metal (DM) welds when adjacent welds are included in the scan path as is the case at Callaway. Best industry practices will be utilized where formal qualifications are not feasible. Qualification or demonstration will include procedures, equipment, and personnel If examination volume composite coverage is not essentially 100% (i.e., > 90% of the exam volume shown in Figure IWB-2500-8 of ASME Section XI) relief pursuant to 10 CFR 50.55a(g)(5)(iii) will be requested.

If any cracking, leakage or degradation is detected during the inspection, corrective actions will be taken in accordance with the plant's corrective action program and procedures. Any RCPB leakage or degradation would be considered a significant condition adverse to quality and appropriate actions, including performing a cause analysis, will be taken Documentation will be commensurate with the requirements of the inspection. Visual examinations will have written records as a minimum and photographs as appropriate.

Manual ultrasonic exams will have written reports.

The regulatory requirements of 10 CFR 50.55a for the second ISI interval have been met. Callaway Plant will continue to meet the regulatory requirements of 10 CFR 50.55a in developing the 3rd ISI interval program plan.

Plant Technical Specifications do not allow for reactor coolant pressure boundary leakage. For a flaw with a through wall leak, sufficient NDE to facilitate the

ULNRC-05031 July 27, 2004 Page 6 of 8 appropriate repair will be performed. This would generally be a volumetric examination(s) sufficient to determine the length and direction of the flaw. As a minimum, the requirements of the ASME Code will be met.

Expansion of scope would be, as a minimum, in accordance with ASME Section XI.

(d) In light of the information discussedin this bulletin andyourunderstandingof the relevance of recent industry operatingexperience to yourfacility,explain wdhy the inspectionprogram identified in your response to item (J) (c) above is adequatefor the purpose of maintainingthe integrity ofyourfacility'sRCPB andfor meeting allapplicable regulatory requirementswthich pertain to your facility.

Callaway Plant Response:

The Callaway Plant inspection program is adequate to maintain the integrity of the Reactor Coolant Pressure Boundary (RCPB) in the area of pressurizer. To date, visual inspections have been the primary means of identification of through wall leakage associated with Alloy 82/182/600. The RCPB visual inspections conducted each refueling includes inspection of the Alloy 82/182 welds associated with the pressurizer as described in (1)(c) above. Volumetric examinations are also performed in accordance with the Callaway Plant ISI program. As Callaway Plant has implemented a Risk-Based program which complies with the guidelines of EPRI TR-112657, Revised Risk-Informed Inservice Inspection Evaluation Procedure, Rev B-A, the volumetric examination locations and frequency are based on a determination of the welds most susceptible to failure or whose failure has the most serious consequences.

The Alloy 82/182 welds identified in NRC bulletin 2004-01 were included in the risk significant determinations made by PRA to support the current program. In addition, Callaway Plant has augmented these examinations as requested by NEI. As additional research and analysis provides more insight into the risk posed by the presence of Alloy 82/182 welds in pressurizer penetrations, the information will be incorporated into program risk assessments to ensure appropriate examination locations are selected to provide early identification of cracks before RCPB failure.

(2) WYithin 60 days ofplant restartfollowing the next inspection of the Alloy 82/182/600pressurizerpenetrationsandsteam spacepiping connections, the subject PWR licensees should either:

(a) submit to the NRC a statement indicatingthat the inspectionsdescribed in the licensee 's response to item (1)(c) of this bulletin wvere completed and a descriptionof the as-found condition of the pressurizershell, anyfindings of relevant indicationsof through-wallleakage,followrup NDE performed to characterizeflawvs in leakingpenetrationsor steam spacepiping connections,

ULNRC-05031 July 27, 2004 Page 7 of 8 a summary of all relevant indicationsfound by NDE, a summary of the disposition bf anyfindings of boric acid,andaihy Corrective actions taken and/or repairsmade as a result of the indicationsfound, or (b) if the licensee was unable to complete the inspectionsdescribed in response to item (1)(c) of this bulletin, submit to the NRC a summary of the inspections performed, the extent of the inspections,the methods used, a description of the as-found condition of the pressurizershell, anyfindings of relevant indicationsof through-wallleakage,followvup NDEperformed to characterize Jlaws in leakingpenetrationsor steam space pipingconnections, a summary of all relevant indicationsfoundby NDE, a summary of the disposition of any findings of boric acid,and any corrective actions taken and/orrepairsmade as a result of the indicationsfound In addition,supplement the answver which you providedto item (J)(d) above to explain why the inspections that you completed wvere adequatefor the purpose of maintainingthe integrity ofyour facility's RCPB andfor meeting all applicable regulatoryrequirements which pertain to yourfacility.

For lines attacheddirectly to the pressurizer,with the exception of the surge line, the information requestedin (1) and (2) above should be providedforany locations, includingthose remotefrom the pressurizershell, which containAlloy 82/182/600 materialswhich are exposed to conditions similar to those of the pressurizer environment.

Callaway Plant Response:

Callaway Plant will comply with the requirement described in (2) above within 60 days of plant restart following the next inspection of the Alloy 82/182/600 pressurizer penetrations and steam space piping connections.

As noted earlier, all Alloy 82/182/600 pressure boundary locations on the pressurizer were examined (bare metal visual) during Refuel 13 (Spring 2004). No leakage, boric acid residue due to leakage, or Carbon base metal wastage was noted. No followup NDE was required. This satisfies the 60 day reporting requirement for the current refueling (in progress at the time of issuance of this bulletin), however Callaway will, within 60 days of plant restart following the next inspection of the Alloy 82/182/600 pressurizer penetrations and steam space piping connections (Refuel 14, Fall 2005) submit to the NRC a statement indicating that the inspections described in Callaway Plant's response to item (1)(c) of this bulletin were completed and a description of the as-found condition of the pressurizer shell, any findings of relevant indications of through-wall leakage, followup NDE performed to characterize flaws in leaking penetrations or steam space piping connections, a summary of all relevant indications found byNDE, a summary of the disposition of

ULNRC-0503 1 July 27, 2004 Page 8 of 8 any findings of boric acid, and any corrective actions taken and/or repairs made as a result of the indications found.

ULNRC-0503 1 Attachment III Page 1 of I LIST OF COMMITMENTS The following tabie identifies those actions committed to by AmerenUE in this document. Any other statements in this document are provided for information purposes and are not considered commitments. Please direct questions regarding these commitments to Mr. Dave E. Shafer, Superintendent Licensing (314) 554-3104.

COMMITMENT Due Date/Event All of the locations of interest will continue to receive bare metal Each Refueling visual examinations near the beginning of each outage, as is Outage required by the boric acid program, as well as the VT-2 examination at the end of each outage, as is required by the pressure testing program.

Submit to the NRC a report indicating that the inspections Within 60 days of described in Callaway Plant's response to item (1)(c) of this plant restart bulletin were completed and a description of the as-found following the next condition of the pressurizer shell, any findings of relevant inspection of the indications of through-wall leakage, followup NDE performed to Alloy 82/182/600 characterize flaws in leaking penetrations or steam space piping pressurizer connections, a summary of all relevant indications found by NDE, penetrations and a summary of the disposition of any findings of boric acid, and steam space any corrective actions taken and/or repairs made as a result of the piping indications found. connections

Text

AmerenUE PO Box 620 Callaway Plant Fulton, AlO 65251 July 27, 2004 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop P1-137 Washington, DC 20555-0001 ULNRC-0503 1 WAiierlei Ladies and Gentlemen:

U1F DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.

FACILITY OPERATING LICENSE NPF-30 RESPONSE TO NRC BULLETIN 2004-01, "INSPECTION OF ALLOY 82/182/600 MATERIALS USED IN THE FABRICATION OF PRESSURIZER PENETRATIONS AND STEAM SPACE PIPING CONNECTIONS AT PRESSURIZED-WATER REACTORS" Enclosed is the Callaway Plant 60-day response to NRC Bulletin 2004-01, "Inspection Of Alloy 82/182/600 Materials Used In The Fabrication Of Pressurizer Penetrations And Steam Space Piping Connections At Pressurized-Water Reactors,"

dated May 28, 2004. NRC Bulletin 2004-01 requested information related to the materials from which the pressurizer penetrations and steam space piping connections at Callaway were fabricated, and information related to the inspections that have been and those that will be performed to ensure that degradation of Alloy 82/182/600 materials used in the fabrication of pressurizer penetrations and steam space piping connections will be identified, adequately characterized, and repaired. Callaway Plant coordinated preparation of this response with the other participants in the Strategic Teaming and Resource Sharing (STARS) group.

Attachment III lists AmerenUE commitments contained in this correspondence.

4t rc a subsidiary olAmeren Corporation

ULNRC-0503 1 July 27, 2004 Page 2 If you have any questions regarding this submittal, please contact me at (573) 676-8659 or Mr. Dave Shafer, Superintendent - Licensing at (314) 554-3104.

Sincerely, Keith D. Young Manager - Regulatory Affairs Attachments: I - Affidavit II - RAI Responses III- List of Commitments

ULNRC-05031 July 27, 2004 Page 3 of 8 Mr. Bruce S. Mallett Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Jack N. Donohew (2 copies)

Licensing Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 7E1 Washington, DC 20555-2738 Missouri Public Service Commission Governor Office Building 200 Madison Street PO Box 360 Jefferson City, MO 65102-0360 Mr. Jerry B. Uhlmann Director Missouri State Emergency Management Agency P.O. Box 116 Jefferson City, MO 65102

ULNRC-0503 1 Attachment I Page 1 of I STATE OF MISSOURI

) SS COUNTY OF CALLAWAY Keith D. Young, of lawful age, being first duly sworn upon oath says that he is Manager, Regulatory Affairs for Union Electric Company; that he has read the foregoing document and knows the content thereof, that he has executed the same for and on behalf of said company with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.

By Keil- .

Manager, Regulatory Affairs SUBSCRIBED and sworn to before me this vY day of - , 2004.

0 TERRA fL CWOOK X.. orPb Notary Beod

  • OTATE OF MISSOURI tJotLj 6b &c Caltaway County My Commlsun Eiqis May 13. 2008

ULNRC-05031 Attachment It Page 1 of8 Response to NRC Bulletin 2004-01, "Inspection Of Alloy 82/1821600 Materials Used In The Fabrication Of Pressurizer Penetrations And Steam Space Piping Connections At Pressurized-Water Reactors" NRC Reauested Information (1) All subject PWJ? licensees are requestedto provide thefollowving information w'ithin 60 days of the date of this bulletin. [Forlines attacheddirectly to the pressurizer, with the exception of the surge line, the information requested in (1) and (2) above should be providedfor any locations, including those remotefrom the pressurizershell, which containAlloy 82/182/600 materialswhich are exposed to conditions similarto those of the pressurizerenvironment.]

(a) A descriptionof the pressurizerpenetrationsandsteam space piping connections at your plant. At a minimum, this descriptionshould include materialsof construction (e.g., stainlesssteelpipingand/orweld metal, Alloy 600 piping/sleeves, Alloy 82/182 wveld metal or buttering, etc.), joint design (e.g., partialpenetrationwelds, fill penetrationwelds, bolted connections, etc), and, in the case of weldedjoints, whether or not the weld was stress-relievedpriorto beingput into service. Additional information relevant with respect to determiningthe susceptibility of yourplant 's pressurizer penetrationsandsteam spacepipingconnections to PWSCC should also be included Callaway Plant Response:

The pressurizer at Callaway has 5 locations which contain Alloy 82/182/600 materials exposed to conditions similar to those of the pressurizer environment.

These locations are the pressurizer spray nozzle-to-pipe connection, and the four pressurizer safety and relief nozzle-to-safe end connections. The pressurizer heater penetrations do not contain Alloy 82/182/600 materials.

Materials of construction The Certified Material Test Reports (CMTRs) indicate that both Alloy 82 and Alloy 182 weld metals were used for all pressurizer nozzle to safe-end welds. Generally, the safe-end welds for the pressurizer were made of Alloy 182, with Alloy 82 used only for inprocess repairs.

Joint Design These pressurizer penetrations are carbon steel nozzles with Alloy 82/182 buttering and full penetration welds connecting to stainless steel safe ends which are then connected to stainless steel piping with stainless steel safe end-to-pipe welds. Figure

ULNRC-0503 1 July 27, 2004 Page 2 of 8 I below depicts the nozzle, nozzle-to-safe end and safe end configuration for these locations.

WEFY ?REUEF u4W.2LE Figure 1 The nozzle buttering was stress-relieved, but the buttering-to-safe end weld was not stress relieved prior to being put into service.

The operating temperature of the pressurizer at Callaway is approximately 653 degrees F.

ULNRC-0503 1 July 27, 2004 Page 3 of 8 (b) A description of the inspectionprogramfor Alloy 82/182/600pressurizer penetrationsand steam spacepiping connections that has been implemented at your plant. The descriptionshould include when the inspections were performed; the areas,penetrationsand steam spacepiping connections inspected; the extent (percentage) of coverage achievedfor each location which was inspected; the inspection methods used; the process used to resolve any inspectionfindings; the quality of the documentation of the inspections (e.g., written report, video record,photographs);and, the basisfor concluding thatyourplant satisfies applicableregulatoryrequirementsrelatedto the integrity ofpressurizerpenetrationsand steam spacepiping connections. If leakingpressurizerpenetrationsor steam spacepiping connections were found, indicate whatfollowup NDE was performed to characterizeflaws in the leakingpenetrations.

CallawaU Plant Response:

Volumetric examinations were performed utilizing .25" X .25" transducers with contoured wedges. Dual 45 degree shear wave axial scans were performed from the Safe end side. 60 degree dual L wave axial scans were performed from the Nozzle side. A dual 45 degree L wave scan was performed circumferentially from both sides. The table below summarizes the examinations for the locations of interest.

Weld Date of Examination NDE relevant resolution last coverage Method(s) indications of inspection achieved or (yes/no) indications, cited (%) if any 2-TBB03-2-W 04/15/1992 *100% UT/PT No N/A 2-TBB03-3-A-W 10/26/1996 *100% Surface UT/PT No N/A 88% Volumetric 2-TBB03-3-B-W 10/24/1996 *100% surface UT/PT No N/A 85% Volumetric 2-TBB03-3-C-W 10/13/1999 *100% Surface UT/PT No N/A 54% Volumetric 2-TBB034-W. 10/07/1999 *100% Surface UT/PT No N/A 54% Volumetric

  • Prior to appendix VIII coverage Notes: No rejectable indications were found.

All inspections documented by written record.

In Interval 1, all of the subject locations were examined according to ASME Section XI.

ULNRC-05031 July 27, 2004 Page 4 of 8 Callaway Plant implemented a Risk Informed ISI (RI-ISI) program in Period 2 of Interval 2. This was approved by the NRC in the safety evaluation contained in a letter dated January 30, 2002. The Callaway Plant RI-ISI program utilizes the methodology in EPRI TR-1 12657 Rev. B-A. Per this methodology these welds are Risk Category 4, which require 10% of the population to be selected for examination.

Weld 2-TBB03-03-A-W and 2-TBB03-04-W are selected for examination.

A review of the risk rankings of the RI-ISI program is to be performed prior to Refuel

14. If the subject welds are moved to Risk Category 2 per the above methodology, this will require 25% of the welds to be volumetrically examined. As 2 of the 5 subject welds are already being examined, this percentage is already met.

In addition to the NDE in the table above, a bare metal visual examination of all Alloy 82/182/600 locations, including the pressurizer connections was performed during Refuel 13 (Spring 2004) in conjunction with the boric acid walkdown performed at the beginning of the refueling outage. A pressure test (VT-2) at NOP was performed near the completion of each refueling outage in accordance with ASME pressure testing requirements. No indication of pressure boundary leakage was noted in any of the locations.

The above satisfies the 10 CFR 50.55a requirements for inspection of the subject components.

(c) A descriptionof the Alloy 82/182/600 pressurizerpenetration andsteam space piping connection inspectionprogram that vill be implemented at your plant during the next andsubsequent refueling outages. The description should include the areas,penetrationsand steam space piping connections to be inspected; the extent (percentage) of coverage to be achievedfor each location; inspection methods to be Used; qualificationstandardsforthe inspection methods andpersonnel; the process Used to resolve any inspection indications;the inspection documentation to be generated,andthe basisfor concluding that your plant vill satisfy applicable regulatory requirements relatedto the structuraland leakage integrity ofpressurizerpenetrationsand steam space pipingconiections. If leakingpressurizerpenetrationsor steam spacepiping connections arefound indicate whatfollolvup NDE Vill be performed to characterizeflawvsin the leakingpenetrations. Provideyour plansfor expansion of the scope of NDE to be performed tfcircunmferential flavs arefound in any portionof the leakingpressurizerpenetrationsor steam space pipingconnections.

ULNRC-05031 July 27, 2004 Page 5 of 8 Callawav Plant Response:

The Alloy 82/182/600 pressurizer piping connections will receive a bare metal visual examination in the next refueling outage in accordance with MRP letter 2004-05.

The next refueling outage is RF14 (Fall 2005), which is the last refueling outage in ISI interval 2.

All of the locations of interest will continue to receive bare metal visual examinations near the beginning of each outage, as is required by the boric acid program, as well as the VT-2 examination at the end of each outage, as is required by the pressure testing program.

In ISI interval 3, as a minimum, the welds selected in the RI-ISI program will receive a volumetric examination. Callaway Plant continues to be involved in various industry groups associated with PWSCC of Alloy 82/182/600 Materials such as Alloy 600 Issue Task Group (ITG), the ASME Alloy 600 Task Group. Recommendation and requirements from these groups will be assessed, and if appropriate, changes to the Inservice Inspection Program will be made. Volumetric (UT) examinations will be qualified in accordance with Appendix VIII of ASME Section XI, as modified by 10 CFR 50.55a, to the extent possible. Currently, no Appendix VIII qualification exists which allows for examination of Dissimilar Metal (DM) welds when adjacent welds are included in the scan path as is the case at Callaway. Best industry practices will be utilized where formal qualifications are not feasible. Qualification or demonstration will include procedures, equipment, and personnel If examination volume composite coverage is not essentially 100% (i.e., > 90% of the exam volume shown in Figure IWB-2500-8 of ASME Section XI) relief pursuant to 10 CFR 50.55a(g)(5)(iii) will be requested.

If any cracking, leakage or degradation is detected during the inspection, corrective actions will be taken in accordance with the plant's corrective action program and procedures. Any RCPB leakage or degradation would be considered a significant condition adverse to quality and appropriate actions, including performing a cause analysis, will be taken Documentation will be commensurate with the requirements of the inspection. Visual examinations will have written records as a minimum and photographs as appropriate.

Manual ultrasonic exams will have written reports.

The regulatory requirements of 10 CFR 50.55a for the second ISI interval have been met. Callaway Plant will continue to meet the regulatory requirements of 10 CFR 50.55a in developing the 3rd ISI interval program plan.

Plant Technical Specifications do not allow for reactor coolant pressure boundary leakage. For a flaw with a through wall leak, sufficient NDE to facilitate the

ULNRC-05031 July 27, 2004 Page 6 of 8 appropriate repair will be performed. This would generally be a volumetric examination(s) sufficient to determine the length and direction of the flaw. As a minimum, the requirements of the ASME Code will be met.

Expansion of scope would be, as a minimum, in accordance with ASME Section XI.

(d) In light of the information discussedin this bulletin andyourunderstandingof the relevance of recent industry operatingexperience to yourfacility,explain wdhy the inspectionprogram identified in your response to item (J) (c) above is adequatefor the purpose of maintainingthe integrity ofyourfacility'sRCPB andfor meeting allapplicable regulatory requirementswthich pertain to your facility.

Callaway Plant Response:

The Callaway Plant inspection program is adequate to maintain the integrity of the Reactor Coolant Pressure Boundary (RCPB) in the area of pressurizer. To date, visual inspections have been the primary means of identification of through wall leakage associated with Alloy 82/182/600. The RCPB visual inspections conducted each refueling includes inspection of the Alloy 82/182 welds associated with the pressurizer as described in (1)(c) above. Volumetric examinations are also performed in accordance with the Callaway Plant ISI program. As Callaway Plant has implemented a Risk-Based program which complies with the guidelines of EPRI TR-112657, Revised Risk-Informed Inservice Inspection Evaluation Procedure, Rev B-A, the volumetric examination locations and frequency are based on a determination of the welds most susceptible to failure or whose failure has the most serious consequences.

The Alloy 82/182 welds identified in NRC bulletin 2004-01 were included in the risk significant determinations made by PRA to support the current program. In addition, Callaway Plant has augmented these examinations as requested by NEI. As additional research and analysis provides more insight into the risk posed by the presence of Alloy 82/182 welds in pressurizer penetrations, the information will be incorporated into program risk assessments to ensure appropriate examination locations are selected to provide early identification of cracks before RCPB failure.

(2) WYithin 60 days ofplant restartfollowing the next inspection of the Alloy 82/182/600pressurizerpenetrationsandsteam spacepiping connections, the subject PWR licensees should either:

(a) submit to the NRC a statement indicatingthat the inspectionsdescribed in the licensee 's response to item (1)(c) of this bulletin wvere completed and a descriptionof the as-found condition of the pressurizershell, anyfindings of relevant indicationsof through-wallleakage,followrup NDE performed to characterizeflawvs in leakingpenetrationsor steam spacepiping connections,

ULNRC-05031 July 27, 2004 Page 7 of 8 a summary of all relevant indicationsfound by NDE, a summary of the disposition bf anyfindings of boric acid,andaihy Corrective actions taken and/or repairsmade as a result of the indicationsfound, or (b) if the licensee was unable to complete the inspectionsdescribed in response to item (1)(c) of this bulletin, submit to the NRC a summary of the inspections performed, the extent of the inspections,the methods used, a description of the as-found condition of the pressurizershell, anyfindings of relevant indicationsof through-wallleakage,followvup NDEperformed to characterize Jlaws in leakingpenetrationsor steam space pipingconnections, a summary of all relevant indicationsfoundby NDE, a summary of the disposition of any findings of boric acid,and any corrective actions taken and/orrepairsmade as a result of the indicationsfound In addition,supplement the answver which you providedto item (J)(d) above to explain why the inspections that you completed wvere adequatefor the purpose of maintainingthe integrity ofyour facility's RCPB andfor meeting all applicable regulatoryrequirements which pertain to yourfacility.

For lines attacheddirectly to the pressurizer,with the exception of the surge line, the information requestedin (1) and (2) above should be providedforany locations, includingthose remotefrom the pressurizershell, which containAlloy 82/182/600 materialswhich are exposed to conditions similar to those of the pressurizer environment.

Callaway Plant Response:

Callaway Plant will comply with the requirement described in (2) above within 60 days of plant restart following the next inspection of the Alloy 82/182/600 pressurizer penetrations and steam space piping connections.

As noted earlier, all Alloy 82/182/600 pressure boundary locations on the pressurizer were examined (bare metal visual) during Refuel 13 (Spring 2004). No leakage, boric acid residue due to leakage, or Carbon base metal wastage was noted. No followup NDE was required. This satisfies the 60 day reporting requirement for the current refueling (in progress at the time of issuance of this bulletin), however Callaway will, within 60 days of plant restart following the next inspection of the Alloy 82/182/600 pressurizer penetrations and steam space piping connections (Refuel 14, Fall 2005) submit to the NRC a statement indicating that the inspections described in Callaway Plant's response to item (1)(c) of this bulletin were completed and a description of the as-found condition of the pressurizer shell, any findings of relevant indications of through-wall leakage, followup NDE performed to characterize flaws in leaking penetrations or steam space piping connections, a summary of all relevant indications found byNDE, a summary of the disposition of

ULNRC-0503 1 July 27, 2004 Page 8 of 8 any findings of boric acid, and any corrective actions taken and/or repairs made as a result of the indications found.

ULNRC-0503 1 Attachment III Page 1 of I LIST OF COMMITMENTS The following tabie identifies those actions committed to by AmerenUE in this document. Any other statements in this document are provided for information purposes and are not considered commitments. Please direct questions regarding these commitments to Mr. Dave E. Shafer, Superintendent Licensing (314) 554-3104.

COMMITMENT Due Date/Event All of the locations of interest will continue to receive bare metal Each Refueling visual examinations near the beginning of each outage, as is Outage required by the boric acid program, as well as the VT-2 examination at the end of each outage, as is required by the pressure testing program.

Submit to the NRC a report indicating that the inspections Within 60 days of described in Callaway Plant's response to item (1)(c) of this plant restart bulletin were completed and a description of the as-found following the next condition of the pressurizer shell, any findings of relevant inspection of the indications of through-wall leakage, followup NDE performed to Alloy 82/182/600 characterize flaws in leaking penetrations or steam space piping pressurizer connections, a summary of all relevant indications found by NDE, penetrations and a summary of the disposition of any findings of boric acid, and steam space any corrective actions taken and/or repairs made as a result of the piping indications found. connections

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