ML14056A196: Difference between revisions
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
||
| Line 14: | Line 14: | ||
| page count = 6 | | page count = 6 | ||
}} | }} | ||
=Text= | |||
{{#Wiki_filter:Technical Specification 5.6.8Palo VerdeNuclear Generating StationP.O. Box 52034Phoenix, AZ 85072Mail Station 7636Tel: (623) 393-5764Qaps102-06834-TNW/DHK February 20, 2014ATTN: Document Control DeskU.S. Nuclear Regulatory Commission Washington, DC 20555-0001 | |||
==Dear Sirs:== | |||
==Subject:== | |||
Palo Verde Nuclear Generating Station (PVNGS) Unit 1Docket No. STN 50-528License No. NPF-41Response to NRC Request for Additional Information 2013Steam Generator Tube Inspections By letter number 102-06781, dated October 16, 2013 (Agencywide Documents Access and Management Systems (ADAMS) Accession No. ML13294A021), | |||
ArizonaPublic Service Company (APS) submitted information summarizing the results ofthe 2013 steam generator (SG) tube inspections at Palo Verde Nuclear Generating Plant (PVNGS) Unit 1.The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the information provided by APS and determined that additional information was needed tocomplete its review of the SG tube inspections. | |||
On January 24, 2014, the NRC staffprovided a Request for Additional Information (RAI) to APS and requested that aresponse be submitted within 30 days. The APS response to the NRC RAI isprovided in the Enclosure to this letter.No commitments are being made to the NRC by this letter. Should you need furtherinformation regarding this submittal, please contact David H. Kelsey, Licensing Section Leader, at (623) 393-5730. | |||
Sincerely, | |||
ýýP' T Q ý WE 8 -ý p,_Thomas N. WeberDepartment Leader, Regulatory AffairsA member of the STARS (Strategic Teaming and Resource Sharing) | |||
AllianceCallaway 9 Comanche Peak 0 Diablo Canyon 0 Palo Verde 0 Wolf CreekADD( | |||
--ATTN: Document Control DeskU.S. Nuclear Regulatory Commission 102-06834-TNW/DHK Response to Request for Additional Information | |||
-Unit 1 2013 Steam Generator Tube Inspections Page 2TNW/DHK/CJS/hsc | |||
==Enclosure:== | |||
Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections cc: M. L. Dapas NRC Region IV Regional Administrator J. K. Rankin NRC NRR Project Manager (electronic and hard copy)A. E. George NRC NRR Project Manager (electronic and hard copy)M. A. Brown NRC Senior Resident Inspector for PVNGS Enclosure Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections Enclosure Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections Introduction By letter dated October 16, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13294A021), | |||
Arizona Public Service Company(APS) submitted information summarizing the results of the 2013 steam generator (SG) inspections at the Palo Verde Nuclear Generating Station (PVNGS), | |||
Unit 1.These inspections were performed during the seventeenth refueling outage (1R17)of Unit 1 which ended in April 2013.In order to complete its review of the documents listed above, the U.S. NuclearRegulatory Commission (NRC) staff requested additional information (RAI) in e-maildated January 24, 2014. This enclosure provides the APS response to the NRC RAI.Each NRC request is stated, followed by the APS response. | |||
NRC Request 1The report indicates that half of a castle nut from a feedwater heater was found inthe cold-leg annulus region of SG 12. Please discuss whether the other half of thenut was retrieved and/or assessed for possibly causing additional tube wear.APS ResponseDuring U1R17, extensive visual inspections were performed in the high flow areasof both SGs at the top of tubesheet level. No additional castle nut remnants werefound as a result of these inspections. | |||
The other half of the castle nut was not,therefore, retrieved. | |||
It is very likely that the half of a castle nut that was discovered in the cold leg annulus region of SG12 was the only remnant that entered the SG(from the feedwater train).PVNGS operating history indicates numerous castle nuts and remnants were foundin the original Steam Generators in all 3 PVNGS units and the remnants did notresult in measured tube wear. The composition of the castle nuts is aluminum-bronze.NRC Reauest 2Please provide the effective full power years of operation for the last severalrefueling outages/SG inspection outages.APS ResponseThe steam generators have been replaced at each of the PVNGS units. Thefollowing table provides the respective refueling outages when the steamgenerators were replaced and the effective full power years (EFPY) of operation forcycles 12 through 17, for each unit.I Enclosure Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections SG Replacement Outages for PVNGS UnitsU1R12 U2R11 U3R13Refueling Outages Unit 1 (EFPY) Unit 2 (EFPY) Unit 3 (EFPY)Cycle 12 1.28 1.21 1.14Cycle 13 0.83 1.29 1.26Cycle 14 1.14 1.31 1.18Cycle 15 1.32 1.25 1.32Cycle 16 1.34 1.31 1.32Cycle 17 1.32 1.41 1.42Replacement SGAccumulated EFPY 5.95 7.78 5.24NRC Reauest 3The SG Inspection Report indicated that no severe erosion or corrosion was foundduring the visual inspection of the wet layup recirculation piping. With respect tothe secondary side visual inspections (including the inspections of the wet layuprecirculation piping), | |||
please discuss whether any erosion or corrosion wasidentified. | |||
If so, please discuss the nature/severity of the degradation. | |||
APS ResponseA visual inspection was performed on the upper internals of both steam generators. | |||
The examinations provided visual documentation of the overall condition of thecomponents in the accessible areas above the primary separator deck, below theprimary separator deck (inside the shroud) and the internal feed ring piping(outside the shroud). | |||
The upper hand hole (HH#5) was opened and a camera wasinserted into the no-tube lane to inspect the top of the 7th egg-crate tube support,the bottom of the 8th egg-crate tube support and the center stay opening.Specific areas visually examined during the inspection above the primary separator deck included 194 steam separators, the dryer deck drain lines, the bottom of thedryer deck, the bottom of the dryers and accessible nozzles.Specific areas visually examined below the primary separator deck included I-Beamattachments, recirculation piping and nozzles, recirculation pipe stanchions, U-boltattachments and vanes underneath the primary separators. | |||
The square bend regionwas visually inspected including the tube bundle in this area, diagonal supports andvertical supports. | |||
The square bend region showed evidence of scale deposits, asexpected, and is being monitored. | |||
No anomalies were noted.2 Enclosure Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections The downcomer feedwater ring was also inspected visually. | |||
No anomalies, corrosion or erosion were noted. The PVNGS replacement steam generator downcomer feedwater ring is constructed of chrome-moly carbon steel and erosion/corrosion isnot considered relevant for this component of the PVNGS replacement steamgenerators at the current accumulated EFPY.No erosion or corrosion was documented in the inspection report on any of thecomponents that were visually inspected. | |||
NRC Request 4Please discuss the scope and results of any primary channel head inspections, if anywere performed. | |||
APS ResponseDuring U1R17, a Steam Generator primary channel head inspection was performed in each SG. This inspection involved a complete video scan of the SG channel head(tubesheet, walls, bottom of the channel head) in accordance with the SteamGenerator Channel Head Video Inspection procedure (MRS-GEN-1214). | |||
The intentof this video inspection is to make a record of items such as debris or tools left inthe SG, damage to the tube sheet; any tube plug discrepancies, tube locations thathave water dripping from them, or any other unexplained anomalies of interest. | |||
Furthermore, in response to Westinghouse Engineering Nuclear Safety AdvisoryLetter (NSAL) 12-1, an enhanced inspection was performed in accordance with FieldChange Request 1 to the Steam Generator Channel Head Video Inspection procedure. | |||
The enhanced inspection was limited to the lower portion of the channelhead, approximately 36 inches radially away from the lowest point of the bowl oneach side of the divider plate (72 inches total), centered on the bottom of the bowl.The inspection took video or digital photographs (i.e., stills) on a "macro" level, nota "micro" level. The inspection looked for the following conditions: | |||
Through-holes or breaches in either the divider plate bar-to-clad weld orin the cladding itself that would expose the carbon steel base materialunderneath the cladding. | |||
Classic "rust-colored" discoloration or stains clearly visible on the cladsurface caused by contact of primary water with the carbon steel basematerial underneath the cladding. | |||
No discrepancies were identified as a result of the inspections. | |||
3}} | |||
Revision as of 15:31, 2 July 2018
| ML14056A196 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 02/20/2014 |
| From: | Weber T N Arizona Public Service Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 102-06834-TNW/DHK | |
| Download: ML14056A196 (6) | |
Text
Technical Specification 5.6.8Palo VerdeNuclear Generating StationP.O. Box 52034Phoenix, AZ 85072Mail Station 7636Tel: (623) 393-5764Qaps102-06834-TNW/DHK February 20, 2014ATTN: Document Control DeskU.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS) Unit 1Docket No. STN 50-528License No. NPF-41Response to NRC Request for Additional Information 2013Steam Generator Tube Inspections By letter number 102-06781, dated October 16, 2013 (Agencywide Documents Access and Management Systems (ADAMS) Accession No. ML13294A021),
ArizonaPublic Service Company (APS) submitted information summarizing the results ofthe 2013 steam generator (SG) tube inspections at Palo Verde Nuclear Generating Plant (PVNGS) Unit 1.The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the information provided by APS and determined that additional information was needed tocomplete its review of the SG tube inspections.
On January 24, 2014, the NRC staffprovided a Request for Additional Information (RAI) to APS and requested that aresponse be submitted within 30 days. The APS response to the NRC RAI isprovided in the Enclosure to this letter.No commitments are being made to the NRC by this letter. Should you need furtherinformation regarding this submittal, please contact David H. Kelsey, Licensing Section Leader, at (623) 393-5730.
Sincerely,
ýýP' T Q ý WE 8 -ý p,_Thomas N. WeberDepartment Leader, Regulatory AffairsA member of the STARS (Strategic Teaming and Resource Sharing)
AllianceCallaway 9 Comanche Peak 0 Diablo Canyon 0 Palo Verde 0 Wolf CreekADD(
--ATTN: Document Control DeskU.S. Nuclear Regulatory Commission 102-06834-TNW/DHK Response to Request for Additional Information
-Unit 1 2013 Steam Generator Tube Inspections Page 2TNW/DHK/CJS/hsc
Enclosure:
Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections cc: M. L. Dapas NRC Region IV Regional Administrator J. K. Rankin NRC NRR Project Manager (electronic and hard copy)A. E. George NRC NRR Project Manager (electronic and hard copy)M. A. Brown NRC Senior Resident Inspector for PVNGS Enclosure Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections Enclosure Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections Introduction By letter dated October 16, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13294A021),
Arizona Public Service Company(APS) submitted information summarizing the results of the 2013 steam generator (SG) inspections at the Palo Verde Nuclear Generating Station (PVNGS),
Unit 1.These inspections were performed during the seventeenth refueling outage (1R17)of Unit 1 which ended in April 2013.In order to complete its review of the documents listed above, the U.S. NuclearRegulatory Commission (NRC) staff requested additional information (RAI) in e-maildated January 24, 2014. This enclosure provides the APS response to the NRC RAI.Each NRC request is stated, followed by the APS response.
NRC Request 1The report indicates that half of a castle nut from a feedwater heater was found inthe cold-leg annulus region of SG 12. Please discuss whether the other half of thenut was retrieved and/or assessed for possibly causing additional tube wear.APS ResponseDuring U1R17, extensive visual inspections were performed in the high flow areasof both SGs at the top of tubesheet level. No additional castle nut remnants werefound as a result of these inspections.
The other half of the castle nut was not,therefore, retrieved.
It is very likely that the half of a castle nut that was discovered in the cold leg annulus region of SG12 was the only remnant that entered the SG(from the feedwater train).PVNGS operating history indicates numerous castle nuts and remnants were foundin the original Steam Generators in all 3 PVNGS units and the remnants did notresult in measured tube wear. The composition of the castle nuts is aluminum-bronze.NRC Reauest 2Please provide the effective full power years of operation for the last severalrefueling outages/SG inspection outages.APS ResponseThe steam generators have been replaced at each of the PVNGS units. Thefollowing table provides the respective refueling outages when the steamgenerators were replaced and the effective full power years (EFPY) of operation forcycles 12 through 17, for each unit.I Enclosure Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections SG Replacement Outages for PVNGS UnitsU1R12 U2R11 U3R13Refueling Outages Unit 1 (EFPY) Unit 2 (EFPY) Unit 3 (EFPY)Cycle 12 1.28 1.21 1.14Cycle 13 0.83 1.29 1.26Cycle 14 1.14 1.31 1.18Cycle 15 1.32 1.25 1.32Cycle 16 1.34 1.31 1.32Cycle 17 1.32 1.41 1.42Replacement SGAccumulated EFPY 5.95 7.78 5.24NRC Reauest 3The SG Inspection Report indicated that no severe erosion or corrosion was foundduring the visual inspection of the wet layup recirculation piping. With respect tothe secondary side visual inspections (including the inspections of the wet layuprecirculation piping),
please discuss whether any erosion or corrosion wasidentified.
If so, please discuss the nature/severity of the degradation.
APS ResponseA visual inspection was performed on the upper internals of both steam generators.
The examinations provided visual documentation of the overall condition of thecomponents in the accessible areas above the primary separator deck, below theprimary separator deck (inside the shroud) and the internal feed ring piping(outside the shroud).
The upper hand hole (HH#5) was opened and a camera wasinserted into the no-tube lane to inspect the top of the 7th egg-crate tube support,the bottom of the 8th egg-crate tube support and the center stay opening.Specific areas visually examined during the inspection above the primary separator deck included 194 steam separators, the dryer deck drain lines, the bottom of thedryer deck, the bottom of the dryers and accessible nozzles.Specific areas visually examined below the primary separator deck included I-Beamattachments, recirculation piping and nozzles, recirculation pipe stanchions, U-boltattachments and vanes underneath the primary separators.
The square bend regionwas visually inspected including the tube bundle in this area, diagonal supports andvertical supports.
The square bend region showed evidence of scale deposits, asexpected, and is being monitored.
No anomalies were noted.2 Enclosure Response to Request for Additional Information Unit 1 2013 Steam Generator Tube Inspections The downcomer feedwater ring was also inspected visually.
No anomalies, corrosion or erosion were noted. The PVNGS replacement steam generator downcomer feedwater ring is constructed of chrome-moly carbon steel and erosion/corrosion isnot considered relevant for this component of the PVNGS replacement steamgenerators at the current accumulated EFPY.No erosion or corrosion was documented in the inspection report on any of thecomponents that were visually inspected.
NRC Request 4Please discuss the scope and results of any primary channel head inspections, if anywere performed.
APS ResponseDuring U1R17, a Steam Generator primary channel head inspection was performed in each SG. This inspection involved a complete video scan of the SG channel head(tubesheet, walls, bottom of the channel head) in accordance with the SteamGenerator Channel Head Video Inspection procedure (MRS-GEN-1214).
The intentof this video inspection is to make a record of items such as debris or tools left inthe SG, damage to the tube sheet; any tube plug discrepancies, tube locations thathave water dripping from them, or any other unexplained anomalies of interest.
Furthermore, in response to Westinghouse Engineering Nuclear Safety AdvisoryLetter (NSAL) 12-1, an enhanced inspection was performed in accordance with FieldChange Request 1 to the Steam Generator Channel Head Video Inspection procedure.
The enhanced inspection was limited to the lower portion of the channelhead, approximately 36 inches radially away from the lowest point of the bowl oneach side of the divider plate (72 inches total), centered on the bottom of the bowl.The inspection took video or digital photographs (i.e., stills) on a "macro" level, nota "micro" level. The inspection looked for the following conditions:
Through-holes or breaches in either the divider plate bar-to-clad weld orin the cladding itself that would expose the carbon steel base materialunderneath the cladding.
Classic "rust-colored" discoloration or stains clearly visible on the cladsurface caused by contact of primary water with the carbon steel basematerial underneath the cladding.
No discrepancies were identified as a result of the inspections.
3