ML100680517

From kanterella
Revision as of 03:34, 12 March 2020 by StriderTol (talk | contribs) (StriderTol Bot change)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
Response to January 28, 2020, Request for Additional Information (RAI) Regarding Reactor Internals, Half-Nozzle Repairs, Metal Fatigue, and Copper Alloy Piping, and Supplement to Balance
ML100680517
Person / Time
Site: Palo Verde  Arizona Public Service icon.png
Issue date: 03/01/2010
From: Hesser J
Arizona Public Service Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
102-06140-JHH/GAM
Download: ML100680517 (19)
v • d • e


Text

L A PS A subsidiaryof Pinnacle West CapitalCorporation John H. Hesser Mail Station 7605 Palo Verde Nuclear Vice President Tel: 623-393-5553 PO Box 52034 Generating Station Nuclear Engineering Fax: 623-393-6077 Phoenix, Arizona 85072-2034 102-06140-JHH/GAM March 01, 2010 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Dear Sirs:

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2, and 3 Docket Nos. STN 50-528, 50-529 and 50-530 Response to January 28, 2010, Request for Additional Information (RAI) Regarding Reactor Internals, Half-Nozzle Repairs, Metal Fatigue, and Copper Alloy Piping, and Supplement to Balance of Plant RAI response, for the Review of the PVNGS License Renewal Application By letter dated January 28, 2010, the NRC issued a request for additional information (RAI) regarding reactor internals, half-nozzle repairs, metal fatigue, and copper alloy piping related to~the PVNGS license renewal application (LRA). Enclosure 1 contains Arizona Public Service Company's (APS's) response to the January 28, 2010, RAI.

In addition, by letter dated December 3, 2009, the NRC issued a request for additional information (RAI) regarding balance of plant related to the PVNGS LRA. APS submitted a response to the December 3, 2009, RAI in letter no. 102-06122, dated January 18, 2010. It has been discovered that the response for the injector housings, one of the six components listed in RAI 2.3.3.21-01, was inadvertently omitted in the January 18, 2010, submittal. The response to the injector housings request in RAI 2.3.3.21-01 is provided in Enclosure 2.

APS makes no commitments in this letter. Should you need further information regarding this submittal, please contact Russell A. Stroud, Licensing Section Leader, at (623) 393-5111.

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

  • Comanche Peak
  • Diablo Canyon
  • Palo Verde - San Onofre
  • Wolf Creek 0 ?ý-jR

ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Response to January 28, 2010, Request for Additional Information for the Review of the Palo Verde Nuclear Generating Station License Renewal Application Page 2 I declare under penalty of perjury that the foregoing is true and correct.

Executed on 0 01 c2-)O (dale)

Sincerely, JHH/RAS/GAM

Enclosures:

1. Response to January 28 2010, Request for Additional Information Regarding Reactor Internals, Half-Nozzle Repairs, Metal Fatigue, and Copper Alloy Piping, for the Review of the PVNGS License Renewal Application
2. Response to the December 3, 2009, Injector Housings Request in RAI 2.3.3.21-01 cc: E. E. Collins Jr. NRC Region IV Regional Administrator J. R. Hall NRC NRR Project Manager R. I. Treadway NRC Senior Resident Inspector for PVNGS L. M. Regner NRC License Renewal Project Manager G. A. Pick NRC Region IV (electronic)

ENCLOSURE 1 Response to January 28, 2010, Request for Additional Information Regarding Reactor Internals, Half-Nozzle Repairs, Metal Fatigue, and Copper Alloy Piping, for the Review of the PVNGS License Renewal Application

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application NRC RAI 3.1.2.2.6-1 License renewal application (LRA) Table 3.1.2-1 lists the affected reactor pressure vessel (RPV) internals with the aging effect of loss of fracture toughness due to neutron irradiation embrittlement and void swelling (an aging effect discussed in LRA Section 3.1.2.2.6). These RPV internals are presented in the following with their corresponding Generic Aging Lessons Learned (GALL) Report Table IV.B3 line items: Reactor Vessel and Internals Core Support Structure (RVI CSS) Core Shroud Assembly (item IV.B3-12); RVI CSS Core Support Barrel Assembly (item IV.B3-16); and Core Support Barrel Snubber Assembly (nickel and stainless steel), RVI CSS Lower Support Structure Assembly, and RVI In-Core Instrumentation (ICI) Support Structure (item IV.B3-20).

However, the LRA table did not specifically list core shroud assembly bolts (item IV.B3-

10) and tie rods (item IV.B3-12) under this aging effect. Confirm that the unit core shroud assemblies are welded structures that do not have bolts and tie rods. Further, clarify why the LRA table did not specifically list the core support plate, fuel alignment pins, and core support column bolts as part of the GALL Report Table Item IV.B3-20 under this aging effect.

APS Response to RAI 3.1.2.2.6-1 Request 1 The LRA Table 3.1.2-1 did not specifically list Core Shroud Assembly Bolts (Item IV.B3-

10) and Tie Rods (Item IV.B3-12) under this aging effect. Confirm that the Palo Verde Nuclear Generating Station (PVNGS) unit Core Shroud Assemblies are welded structures that do not have bolts and tie rods.

Response to Request 1 The PVNGS unit Core Shroud Assemblies are welded structures that do not have bolts and tie rods.

As described in PVNGS UFSAR 3.9.5.1.1.3, the Core Shroud consists of a welded vertical assembly of plates designed to channel the coolant through the core. The Core Shroud Circumferential Rings are attached to the vertical plates by means of welded ribs which extend the full length of the Core Shroud. Therefore, LRA Table 3.1.2-1 does not specifically include evaluation of Core Shroud Assembly Bolts (GALL line item IV.B3-10) and Core Shroud Assembly Tie Rods (GALL line Item IV.B3-12).

The following PVNGS components of the Core Shroud Assembly were evaluated to be consistent with GALL line item IV.B3-12 for the aging effect of loss of fracture toughness due to neutron irradiation embrittlement and void swelling: (1) Core Shroud Vertical Plate, End Plate and Channel; and (2) Core Shroud Circumferential Ring and Ring Rib.

1

Enclosure I Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application Request 2 Further, clarify why the LRA Table 3.1.2-1 did not specifically list the core support plate, fuel alignment pins, and core support column bolts as part of the GALL Report Table Item IV.B3-20 under this aging effect.

Response to Request 2 Palo Verde Units 1, 2, and 3 do not have a Core Support Plate. The functions of a Core Support Plate in other plants are to position and support the reactor core and provide control of the reactor coolant flow into each fuel assembly. These functions are provided in the Palo Verde units by the Core Shroud Assembly and Core Shroud End Plate. As described in UFSAR 3.9.5.1.1.2, the Lower Support Structure is a welded assembly that includes the Core Shroud End Plate as part of Core Shroud Assembly.

Therefore, LRA Table 3.1.2-1 does not include evaluation of Core Support Plate and Core Support Column Bolts that are identified as part of the Lower Internal Assembly in GALL line item IV.B3-20. The Core Shroud Assembly including the Core Shroud End Plate are evaluated to be consistent with GALL line item IV.B3-12 for the aging effect of loss of fracture toughness due to neutron irradiation embrittlement and void swelling.

Fuel Alignment Pins are identified as part of the Lower Internal Assembly in GALL line item IV.B3-20 and are evaluated as Lower Support Structure Fuel Locating Pins included as part of the PVNGS RVI CSS Lower Support Structure Assembly component type.

NRC RAI 3.1.2.2.12-1 LRA Table 3.1.2-1 identified the following GALL Report Table IV.B3 items under cracking due to stress corrosion cracking (SCC) and irradiation-assisted SCC (IASCC):

IV.B3-2, IV.B3-11, IV.B3-15, IV.B3-21, and IV.B3-28. However, for this aging mechanism, the LRA table does not cover all RPV internals listed under the GALL Report Table IV.B3 items listed above. Clarify the disposition of the core support plate and core support column of the lower internal assembly (IV.B3-21) and the fuel alignment plate, the fuel alignment plate guide lugs, and guide lug inserts of the upper internals assembly (IV.B3-28).

APS Response to RAI 3.1.2.2.12-1 Request 1 LRA Table 3.1.2-1 identified the following GALL Report Table IV.B3 items under cracking due to stress corrosion cracking (SCC) and irradiation-assisted SCC (IASCC):

IV.B3-2, IV.B3-11, IV.B3-15, IV.B3-21, and IV.B3-28. However, for this aging mechanism, the LRA table does not cover all RPV internals listed under the GALL 2

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application Report Table IV.B3 items listed above. Clarify the disposition of the core support plate and core support column of the lower internal assembly (IV.B3-21).

Response to Request 1 The PVNGS reactor internals Component Types that use these GALL reference lines in evaluations for the aging effect of cracking due to SCC and IASCC are:

GALL Line PVNGS ComponentType in LRA Table 3.1.2-1 IV.B3-2 RVI UGS CEA Shroud Assembly IV.B3-11 RVI CSS Core Shroud Assembly IV.B3-15 RVI CSS Core Support Barrel Assembly IV.B3-21 RVI CSS Core Support Barrel Snubber Assembly (Stainless Steel portions)

IV.B3-21 RVI CSS Lower Support Structure Assembly IV.B3-21 RVI ICI Support Structure IV.B3-28 RVI UGS Holddown Ring IV.B3-28 RVI UGS Support Barrel Assembly The following paragraphs demonstrate that the LRA Table 3.1.2-1 covers all the applicable RPV internals listed under the GALL Report Table IV.B3 items listed above.

Note the components of GALL line IV.B3-28 are addressed in the response to Request 2.

The GALL line item IV.B3-2 The GALL line IV.B3-2 for CEA Shroud Assemblies does not include details of subcomponent items for the Palo Verde UGS CEA Shroud assembly. The following PVNGS subcomponents of the UGS CEA Shroud Assembly are evaluated to be consistent with GALL line item IV.B3-2 for the aging effect of cracking due to SCC and IASCC: (1) CEA Shroud Tube; (2) Shroud Support Web with Welds; (3) Tie Rods with Nuts; and (4) CEA Shroud Snubber Block.

The GALL line item IV.B3-11 The GALL line IV.B3-11 for the Core Shroud Assembly includes a subcomponent for Core Shroud Assembly Tie Rods. As described in PVNGS UFSAR 3.9.5.1.1.3, the Core Shroud consists of a welded vertical assembly of plates designed to channel the coolant through the core. The Core Shroud Circumferential Rings are attached to the vertical plates by means of welded ribs which extend the full length of the Core Shroud. Therefore, LRA Table 3.1.2-1 does not include evaluation of Core Shroud Assembly Tie Rods.

3

Enclosure I Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application However, the following PVNGS components of the Core Shroud Assembly are evaluated to be consistent with GALL line item IV.B3-11 for the aging effect of cracking due to SCC and IASCC: (1) Core Shroud Vertical Plate, End Plate and Channel and (2) Core Shroud Circumferential Ring and Ring Rib.

The GALL line item IV.B3-15 The GALL line IV.B3-15 for the Core Support Barrel only includes a subcomponent for the Core Support Barrel Upper Flange. The following PVNGS components of the RVI CSS Core Support Barrel Assembly are evaluated to be consistent with GALL line item IV.B3-15 for the aging effect of cracking due to SCC and IASCC: (1) Core Support Barrel Cylinder; (2) Upper Flange; (3) Lower Flange; and (4) Core Support Barrel Outlet Nozzle.

The GALL line item IV.B3-21 The GALL line item IV.B3-21 for the Lower Internal Assembly includes subcomponents for (1) Core Support Plate, (2) Lower Support Structure Beam Assemblies, (3) Core Support Column, and (4) Core Support Barrel Snubber Assemblies.

The following PVNGS components of the component types listed above are evaluated to be consistent with GALL line item IV.B3-21 for the aging effect of cracking due to SCC and IASCC: (1) Core Support Barrel Snubber Lug (attached to the Core Support Barrel); (2) Lower Support Structure Support Beam; (3)

Lower Support Structure Fuel Locating Pins; (4) Lower Support Structure Cylinder and Bottom Plate; (5) ICI Support Columns and Plates; and (6) ICI Nozzles.

Palo Verde Units 1, 2, and 3 do not have a Core Support Plate. The functions of a Core Support Plate in other plants are to position and support the reactor core and provide control of the reactor coolant flow into each fuel assembly. Core Support Columns support the Core Support Plate and transfer the loads to the Lower Support Structure Beam Assemblies. These functions are provided in the Palo Verde units by the Core Shroud Assembly and Core Shroud End Plate.

Palo Verde has a Core Shroud End Plate that is evaluated as an integral part of Core Shroud Assembly. Therefore, items (1), Core support plate, and (3), Core support column, listed in GALL IV.B3-21, are not applicable to Palo Verde Units 1, 2, and 3.

Request 2 Clarify the disposition of the fuel alignment plate, the fuel alignment plate guide lugs, and guide lug inserts of the upper internals assembly (IV.B3-28).

4

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application Response to Request 2 The GALL line item IV.B3-28 for the Upper Internal Assembly includes subcomponent items for (1) Upper Guide Structure Support Plate, (2) Fuel Alignment Plate, (3) Fuel Alignment Plate Guide Lugs and Guide Lug Inserts.

The following PVNGS components of the component types listed above are evaluated to be consistent with GALL line item IV.B3-28 for the aging effect of cracking due to SCC and IASCC: (1) Holddown Ring; (2) Upper Guide Structure (UGS) Cylinder, Flange and Base Plate; (3) UGS Control Element Shroud Tube; (4) UGS Fuel Alignment Plate; (5) UGS and Core Support Barrel Alignment Key; and (6) UGS Guide Structure Support System (GSSS).

As shown above, item (1), Upper Guide Structure Support Plate, and (2), Fuel Alignment Plate, of GALL line item IV.B3-28 are included in LRA Table 3.1.2-1 for the aging effect of cracking due to SCC and IASCC.

Item (3), Fuel Alignment Plate Guide Lugs and Guide Lug Inserts, is not included in PVNGS detail component list. Based on UFSAR Figure 3.9.5-5 and the description in UFSAR Section 3.9.5.1.2, the Fuel Alignment Plate Guide Lugs and Guide Lug Inserts are integral parts of the Core Shroud Assembly instead of the Upper Guide Structure Assembly. A subcomponent of Fuel Alignment Plate Guide Lugs and Guide Lug Inserts has been added to PVNGS Core Shroud Assembly. The GALL reference of IV.B3-11 is used for evaluation of the aging effect of Cracking due to SCC and IASCC for Fuel Alignment Plate Guide Lugs and Guide Lug Inserts as part of the Core Shroud Assembly instead of IV.B3-28 for the Upper Guide Structure Assembly. LRA Table 3.1.2-1 is not affected by this addition of the Fuel Alignment Plate Guide Lugs and Guide Inserts to the Core Shroud Assembly.

NRC RAI 3.1.2.2.15-1 LRA Table 3.1.2-1 identified the following GALL Report Table IV.B3 items under changes in dimension due to void swelling for stainless steel and nickel alloy RPV internals exposed to reactor coolant: IV.B3-4, IV.B3-13, IV.B3-14, IV.B3-19, and IV.B3-

27. However, for this aging mechanism, the LRA table does not cover all RPV internals listed under the GALL Table IV.B3 items listed above. Clarify the disposition of the core support plate, fuel alignment pins, and core support column bolts of the lower internal assembly (IV.B3-19) and the fuel alignment plate, the fuel alignment plate guide lugs, and guide lug inserts of the upper internals assembly (IV.B3-27). Further, discuss the relationship between RVI ICI Support Structures (identified in LRA Table 3.1.2-1) and the core support plate, fuel alignment pins, and core support column bolts of the lower internal assembly (listed in the GALL Table IV.B3).

5

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application APS Response to RAI 3.1.2.2.15-1 Request 1 LRA Table 3.1.2-1 identified the following GALL Report Table IV.B3 items under changes in dimension due to void swelling for stainless steel and nickel alloy RPV internals exposed to reactor coolant: IV.B3-4, IV.B3-13, IV.B3-14, IV.B3-19, and IV.B3-

27. However, for this aging mechanism, the LRA table does not cover all RPV internals listed under the GALL Table IV.B3 items listed above. Clarify the disposition of the core support plate, fuel alignment pins, and core support column bolts of the lower internal assembly (IV.B3-19).

Response to Request 1 The PVNGS reactor internals Component Types that use these GALL reference lines in evaluations for the aging effect of changes in dimension due to void swelling are:

GALL Line PVNGS Component Tvpe in LRA Table 3.1.2-1 IV.B3-4 RVI UGS CEA Shroud Assembly IV.B3-13 RVI CSS Core Shroud Assembly IV.B3-14 RVI CSS Core Support Barrel Assembly IV.B3-19 RVI CSS Core Support Barrel Snubber Assembly IV.B3-19 RVI CSS Lower Support Structure Assembly IV.B3-19 RVI In-Core Instrumentation (ICI) Support Structure IV.B3-27 RVI UGS Holddown Ring IV.B3-27 RVI UGS Support Barrel Assembly The following paragraphs demonstrate that the LRA Table 3.1.2-1 covers all the applicable RPV internals listed under the GALL Report Table IV.B3 items listed above.

Note the subcomponents of GALL line IV.B3-27 are addressed in the response of Request 2.

The GALL line item IV.B3-4 The GALL line item IV.B3-4 for the CEA Shroud Assemblies includes a subcomponent item for the CEA Shroud Bolts. The following PVNGS components of the UGS CEA Shroud Assembly are evaluated to be consistent with GALL line item IV.B3-4 for the aging effect of changes in dimension due to void swelling: (1) CEA Shroud Tube; (2) Shroud Support Web with welds; (3) Tie Rods with Nuts; Snubber Blocks; and RVLMS Shroud/Tube. The tie rods are threaded into the UGS base plate and pretensioned with the nuts.

6

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application The GALL line item IV.B3-13 The GALL line item IV.B3-13 for the Core Shroud Assembly includes a subcomponent for the Core Shroud Assembly Tie Rods. As described in PVNGS UFSAR 3.9.5.1.1.3, the Core Shroud consists of a welded vertical assembly of plates designed to channel the coolant through the core and does not use tie rods. The Core Shroud Circumferential Rings are attached to the vertical plates by means of welded ribs which extend the full length of the Core Shroud.

Therefore, LRA Table 3.1.2-1 does not include evaluation of Core Shroud Assembly Tie Rods.

However, the following PVNGS components of the Core Shroud assembly are evaluated to be consistent with GALL line item IV.B3-13 for the aging effect of changes in dimension due to void swelling: (1) Core Shroud Vertical Plate; End Plate and Channel; and (2) Core Shroud Circumferential Ring and Ring Rib.

The GALL line item IV.B3-14 The GALL line item IV.B3-14 for the Core Support Barrel only includes a subcomponent item for the Core Support Barrel Upper Flange. The following PVNGS components of RVI CSS Core Support Barrel Assembly are evaluated to be consistent with GALL line item IV.B3-14 for the aging effect of changes in dimension due to void swelling: (1) Core Support Barrel Cylinder; (2) Upper Flange; (3) Lower Flange; and (4) Core Support Barrel Outlet Nozzle.

The GALL line item IV.B3-19 The GALL line item IV.B3-19 for the Lower Internal Assembly includes subcomponent items of (1) Core Support Plate, (2) Fuel Alignment Pins, (3)

Lower Support Structure Beam Assemblies, (4) Core Support Column Bolts, and (5) Core Support Barrel Snubber Assemblies.

The following PVNGS components of the component types listed above are evaluated to be consistent with GALL line item IV.B3-19 for the aging effect of changes in dimension due to void swelling: (1) Core Support Barrel Snubber Lug (attached to 'the Core Support Barrel); (2) Lower Support Structure Support Beam; (3) Lower Support Structure Fuel Locating Pins; (4) Lower Support Structure Cylinder and Bottom Plate; (5) ICI Support Columns and Plates; and ICI Nozzles.

Palo Verde Units 1, 2, and 3 do not have a Core Support Plate. The functions of a Core Support Plate in other plants are to position and support the reactor core and provide control of the reactor coolant flow into each fuel assembly. These functions are provided in the Palo Verde units by the Core Shroud Assembly and Core Shroud End Plate. Palo Verde has a Core Shroud End Plate that is 7

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application evaluated as an integral part of the Core Shroud Assembly. As described in UFSAR 3.9.5.1.1.2, the lower support structure is a welded assembly.

Therefore, items (1), Core Support Plate, and (4), Core Support Column Bolts, listed in GALL line item IV.B3-19, are not applicable to Palo Verde Units 1, 2, and 3.

Item (2) listed in GALL IV.B3-19, Fuel Alignment Pins, is evaluated as PVNGS component item (3), Lower Support Structure Fuel Locating Pins, listed above for the aging effect of changes in dimension due to void swelling.

Request 2 Clarify the disposition the fuel alignment plate, the fuel alignment plate guide lugs, and guide lug inserts of the upper internals assembly (IV.B3-27).

Response to Request 2 The GALL line item IV.B3-27 for the Upper Internals Assembly includes subcomponent items of (1) Upper Guide Structure Support Plate, (2) Fuel Alignment Plate, (3) Fuel Alignment Plate Guide Lugs and Guide Lug Inserts.

The following PVNGS components of the component types listed above are evaluated to be consistent with GALL line item IV.B3-27 for the aging effect of changes in dimension due to void swelling: (1) Holddown Ring, (2) UGS Cylinder, Flange and Base Plate, (3) UGS Control Element Shroud Tube, (4) UGS Fuel Alignment Plate, (5) UGS and Core Support Barrel Alignment Key and (6) UGS Guide Structure Support System (GSSS).

As shown above, item (1), Upper Guide Structure Support Plate, and (2), Fuel Alignment Plate, of GALL line item IV.B3-27 are included in LRA Table 3.1.2-1 for the aging effect of changes in dimension due to void swelling.

Item (3), Fuel Alignment Plate Guide Lugs and Guide Lug Inserts, of GALL line item IV.B3-27 is not included in PVNGS Upper Guide Structure Assembly subcomponent list.

Based on UFSAR Figure 3.9.5-5 and the description in UFSAR Section 3.9.5.1.2, the Fuel Alignment Plate Guide Lugs and Guide Lug Inserts are integral parts of the Core Shroud Assembly instead of the Upper Guide Structure Assembly. A subcomponent of Fuel Alignment Plate Guide Lugs and Guide Lug Inserts has been added to PVNGS Core Shroud Assembly. The GALL reference of IV.B3-13 is used for evaluation of the aging effect of changes in dimension due to void swelling for Fuel Alignment Plate Guide Lugs and Guide Lug Inserts as part of the Core Shroud Assembly instead of IV.B3-27 for the Upper Guide Structure Assembly. LRA Table 3.1.2-1 is not affected by this addition of the Fuel Alignment Plate Guide Lugs and Guide Lug Inserts to the Core Shroud Assembly.

8

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application Request 3 Further, discuss the relationship between RVI ICI Support Structures (identified in LRA Table 3.1.2-1) and the core support plate, fuel alignment pins, and core support column bolts of the lower internal assembly (listed in the GALL Table IV.B3).

Response to Request 3 As indicated above in the response to Request 1, the Core Support Plate and Core Support Column Bolts listed in GALL line IV.B3-19 for the Lower Internal Assembly are not applicable to Palo Verde Units 1, 2, and 3. Palo Verde Units 1, 2 and 3 do not have a Core Support Plate. Palo Verde has a Core Shroud End Plate that is evaluated as an integral part of Core Shroud Assembly. As described in UFSAR 3.9.5.1.1.2, the Lower Support Structure is a welded assembly.

The response to Request 1 notes that item (2) listed in GALL IV.B3-19, Fuel Alignment Pins, is evaluated in PVNGS as the component Lower Support Structure Fuel Locating Pins for the aging effect of changes in dimension due to void swelling.

The RVI ICI Support Structures identified in LRA Table 3.1.2-1 includes subcomponents of (1) ICI Nozzle Support Plate, (2) ICI Nozzle Support Column, and (3) (ICI) Nozzles.

Based on the descriptions in UFSAR Section 3.9.5.1.1.2, UFSAR Figure 3.9.5-1 and UFSAR Figure 3.9.5-4, the components of RVI ICI Support Structures are evaluated as part of the Lower Support Structure assembly. The following aging effects apply to the RVI ICI Support Structures:

  • Changes in dimensions due to void swelling (IV.B3-19).

" Loss of fracture toughness due to neutron irradiation embrittlement and void swelling (IV.B3-20).

  • Loss of material due to wear (IV.B3-22).
  • Loss of material due to pitting and crevice corrosion (IV.B3-25).

NRC RAI 4.7.5-1 LRA Section 4.7.5 references WCAP-15973-P, "Low Alloy Steel Component Analysis Supporting Small Diameter Alloy 600/690 Nozzle Repair/Replacement Program," and concludes, "[t]he bounding case for general corrosion in pressurizer heater sleeves in WCAP-15973-P gives an estimated repair life of 194 years; therefore the analysis is not a time-limited aging analysis (TLAA), and is valid for the period of extended operation."

The staff's evaluation of the general corrosion analysis supporting half-nozzle repairs of small-diameter Alloy 600/690 nozzles was documented in the safety evaluation (SE) 9

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application dated January 12, 2005, for the WCAP-1 5973-P report. Please identify the plant-specific submittal addressing the general corrosion in support of the half-nozzle repairs installed in the pressurizer heater sleeves. Since the corrosion results are time dependent, unless they were evaluated and approved in an SE for a period of time covering the period of extended operation, they should be evaluated now as a TLAA.

Please also provide the Updated Final Safety Analyses Report Supplement for this TLAA.

APS Response to RAI 4.7.5-1 The plant-specific submittal addressing general corrosion in support of the half-nozzle repairs installed in the pressurizer heater sleeves for all three PVNGS units is Relief Request 29. It was filed by APS letter no. 102-05112, dated June 15, 2004 (ADAMS Accession No. ML041750296), clarified by RAI responses in letter no. 102-05141, dated August 24, 2004 (ADAMS Accession No. ML042450041), and approved by the NRC in their letter and safety evaluation dated November 5, 2004 (ADAMS Accession No. ML043130170). This approval, therefore, preceded the January 12, 2005, safety evaluation approving WCAP-1 5973-P, Revision 1 (ADAMS Accession No. ML050180528). For general corrosion, the APS relief request cited the results of WCAP 15973 P Revision 1, the same revision approved by the January 12, 2005, safety evaluation.

(Note: Relief Request 29 is for relief from inspection requirements of the sleeve and Alloy 82/182 weld remnant at the inner clad. It is explicitly applicable to the repair method, and applies to all three units.)

The corrosion results are time-dependent but they were evaluated by APS, and approved in the NRC safety evaluation (SE) of November 5, 2004, for a period of time covering the period of extended operation, and are therefore not a TLAA. The APS evaluation and NRC SE concluded that corrosion would not cause unacceptable damage for 194 years.

Since the corrosion analyses are not supported by a TLAA and will not change with a change in the licensed operating period, no revision to the Updated Final Safety Analysis Report Supplement (LRA Appendix A) is required.

NRC RAI 3.1.2-1

Background

The Generic Aging Lessons Learned (GALL) Report,Section X.M1, recommends the Metal Fatigue of Reactor Coolant Pressure Boundary Aging Management Program (AMP) for managing the aging of selected reactor coolant system components.

10

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application Issue In the license renewal application (LRA), Section 3.1.2.2.1, the applicant states that the pressurizer relief tank is not an ASME Section III Class 1 component, nor is it designated to other fatigue or cycle design rules, and therefore has no fatigue time-limited aging analysis. However, the GALL Report,Section IV, Subsection C2, item IV.C2-23 states that a time-limited aging analysis is needed to evaluate metal fatigue of the pressurizer relief tank for the period of extended operation.

Request Provide additional information how metal fatigue of the pressurizer relief tank will be evaluated and managed for the period of extended operation.

APS Response to RAI 3.1.2-1 Palo Verde UFSAR Section 5.4.11 states "The reactor drain tank is used as the pressurizer relief tank." The reactor drain tank at Palo Verde is designed to receive and quench the discharge from the pressurizer safety valves. UFSAR Table 3.2-1, Principal Component 3, identifies the reactor drain tank as a non-safety related component in the Chemical and Volume Control System.

A fatigue analysis is not part of the design basis of the reactor drain tank (pressurizer relief tank), nor does a fatigue analysis support a safety determination for any of its functions. Neither a fatigue evaluation nor fatigue management of this component is required for the period of extended operation.

Column 6 of GALL Section IV, Subsection C2 lists the "Aging Effect/Mechanism" that requires evaluation, including the question of whether the effect exists. The "Further Evaluation" column indicates that the further evaluation required for this item is of the type "TLAA," meaning that the design and licensing bases analyses and evaluations for these components are, first, screened against the six criteria of 10 CFR 54.3(a) to determine whether a TLAA exists. (10 CFR 54.21(c)(1): "A list of time-limited aging analyses, as defined in § 54.3, must be provided....") The reactor drain tank (pressurizer relief tank) design and licensing basis analyses and evaluations do not meet these six criteria. That is, the design of the reactor drain tank (pressurizer relief tank) is not supported by a time dependent fatigue analysis in support of a safety determination, and therefore GALL Report,Section IV, Subsection C2, item IV.C2-23 does not apply (no fatigue TLAA exists).

11

4 Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application NRC RAI 3.2.2-1

Background

The GALL Report, Table V.C, item V.C-4, indicates that stainless steel containment isolation piping and component internal surfaces exposed to treated water are subject to loss of material/pitting and crevice corrosion as an aging effect/mechanism. The GALL Report states that the aging effect/mechanism can be managed by the Water Chemistry and One-time Inspection Programs. The GALL Report further states that a further evaluation should be conducted on these components.

Issue Section 3.2.2.2.8 of the LRA indicates that the further evaluation associated with this component is not applicable because the containment isolation components were "evaluated in the systems in which the components were found to have the function of containment integrity." Staff is unclear why the applicant indicates that this further evaluation for steel containment isolation piping is not applicable.

Request Provide additional information what is meant by the containment isolation components were evaluated in the system in which the components were found to have the function of containment integrity. In addition, if a further evaluation is conducted for these components in a different system, provide the location of the further evaluation. If further evaluations were not conducted for these components, provide additional justification.

APS Response to RAI 3.2.2-1 LRA Table 2.2-1 presents the list of systems containing SSCs evaluated as within the scope of license renewal. This list was developed using information contained in the plant equipment list. The Palo Verde plant equipment list does not contain a separate system for mechanical containment isolation components. Therefore mechanical containment isolation components are evaluated as part of the plant equipment list system to which they are assigned.

Auxiliary Feedwater System containment isolation components and Demineralized Water system containment isolation components were evaluated with Chapter VIII GALL Report lines that are consistent with GALL Report, Table V.C, item V.C-4. The GALL Report, Table V.C, item V.C-4, is applicable to loss of material due to pitting and crevice corrosion of stainless steel containment isolation piping and component internal surfaces exposed to treated water that are managed by M2 Water Chemistry and XI.M32 One Time Inspection. The further evaluation associated with this line recommends XI.M32 One Time Inspection to verify the effectiveness of the Chemistry 12

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application program at locations of stagnant flow conditions to ensure that the aging effect will not cause a loss of the component's intended function. The material, environment, aging effects, and aging management program (MEAP) for the mechanical containment isolation components noted in GALL line item V.C-4 is summarized in GALL Summary Table 3.2-1 item 3 for Engineered Safeguards Features (ESF) Systems. MEAPs and further evaluations consistent with GALL Summary Table 3.2-1 item 3 for Engineered Safeguards Features (ESF) Systems are noted in GALL Summary Table 3.3-1 item 24 for Auxiliary Systems (BWR systems only - not applicable to Palo Verde) and GALL Summary Table 3.4-1 item 16 for Steam and Power Conversion systems. Mechanical containment isolation component MEAPs evaluated consistent with GALL Summary Table 3.4-1 item 16 for Steam and Power Conversion systems include Auxiliary Feedwater System containment isolation components and Demineralized' Water system containment isolation components.

The further evaluation for GALL Summary Table 3.4-1 item 16 is consistent with the further evaluation for GALL Summary Table 3.2-1 item 3.

NRC RAI 3.3.2-1

Background

The GALL Report, Table VIII, item VIII.A-5 is for copper piping exposed to treated water in the steam turbine system. The GALL Report suggests' the use of the Water Chemistry Program augmented with the One-Time Inspection Program to manage loss of material and selective leaching in this system. However, the'GALL Report in Table VII, item VII.C2-7 is for copper piping (zinc > 15 percent) exposed to treated water in the Closed-Cycle Cooling Water System. The GALL Report suggests that loss of material and selective leaching for this component and system be managed by the Selective Leaching of Materials Program. One of the main differences between these two programs as described in the GALL Report is that hardness measurements are incorporated into the Selective Leaching of Materials Program, not in the Water Chemistry Program.

Issue The LRA indicates in Table 3.3.2-4 that a copper alloy (zinc > 15 percent) piping exposed to demineralized water is consistent with GALL Report item VIII.A-5. However, LRA Table 3.3.2-4 is a closed-cycle cooling water system. As such it seems that the GALL Report item VII.C2-7 may be more appropriate for this material. It is not clear to the staff how the Water Chemistry Program augmented with the One-Time Inspection Program is sufficient to manage the loss of material for the LRA closed-cycle cooling water component since these programs do not require hardness testing.

13

Enclosure 1 Response to January 28, 2010, Request for Additional Information for the Review of the PVNGS License Renewal Application Request Provide additional explanation on how the Water Chemistry Program (B2.1.2) and the One-Time Inspection (B2.1.16) will address the aging effect for loss of material for the copper alloy piping exposed to demineralized water in a Closed-Cycle Cooling Water System.

APS Response to RAI 3.3.2-1 The copper alloy (zinc > 15%) piping component in LRA Table 3.3.2-4 is a brass fire hose connection used as an emergency source of make-up water to the safety-related Essential Chilled Water system that has been evaluated as susceptible to loss of material due to selective leaching and also susceptible to loss of material due to general, pitting and crevice corrosion. The following GALL line items were identified to manage aging of the component:

" VII.C2-7 to manage loss of material due to selective leaching with AMP B2.1.17, Selective Leaching of Materials, and

" VIII.A-5 to manage loss of material due to general, pitting and crevice corrosion with AMP B2.1.2 Water Chemistry Program and AMP B2.1.16 One-Time Inspection.

These aging management reviews are depicted in LRA Table 3.3.2-4 in vertically adjacent lines on page 3.3-94.

14

ENCLOSURE 2 Response to the December 3, 2009, Injector Housings Request in RAI 2.3.3.21-01

NRC RAI 2.3.3.21-01 (Iniector Housinas)

Background:

In LRA Section 2.3.3.21 portions of the diesel generator system are in-scope based on criteria 10 CFR 54.4(a)(1) and 10 CFR 54.4(a)(2). License renewal rule 10 CFR 54.21(a) requires applicants to list all component types subject to an AMR.

Issue:

The following license renewal drawing locations show components that are within the scope of license renewal for criteria 10 CFR 54.4(a)(1) or 10 CFR 54.4(a)(2) and not included in Table 2.3.3-21. The components and their drawing locations follow:

Injector housings in the Fuel Oil Subsystem at location F-I, F-2, F-5, and F-6 on drawing LR-PVNGS-DG-01-M-DGP-001-07.

Request:

Provide additional information explaining why the components identified above are not included as component types subject to an AMR in LRA Table 2.3.3-21.

APS Response to RAI 2.3.3.21-01 (Injector Housings)

Injector housings in the Fuel Oil Subsystem on drawing LR-PVNGS-DG-01-M-DGP-001-07 at location F-i, F-2, F-5, and F-6 are shown symbolically, do not have unique component identification numbers and, therefore, are evaluated as within scope of license renewal as integral parts of the Emergency Diesel Generator. NEI 95-10 Appendix B, line 56, identifies the Emergency Diesel Generator as not subject to aging management review (AMR) per 10 CFR 54.21(a)(1). LRA Table 2.3.3-21 presents the component types that are subject to AMR together with the license renewal intended functions evaluated. Since these components are not subject to AMR, they are not presented in Table 2.3.3-21.

Retrieved from "https://kanterella.com/w/index.php?title=ML100680517&oldid=2559252"