NL-18-1480, Response to NRC Request for Additional Information on Alternative Request (HNP-ISI-ALT-05-04)

Response to NRC Request for Additional Information on Alternative Request (HNP-ISI-ALT-05-04)

ML18333A382
Person / Time
Site:	Hatch
Issue date:	11/29/2018
From:	Gayheart C Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
HNP-ISI-ALT-05-04, NL-18-1480
Download: ML18333A382 (19)

Text

Cheryl A. Gayheart 3535 Colonnade Parkway Regulatory Affairs Director Birmingham, AL 35243 205 992 5316 tel 205 992 7601 fax cagayhea@southernco.com November 29, 2018 Docket Nos.: 50-321 NL-18-1480 50-366 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Response to NRC Request for Additional Information on Alternative Request HNP-ISI-ALT-05-04 Ladies and Gentlemen:

By letter dated June 21, 2018 (Agencywide Documents Access and Management System Accession No. ML18172A281), Southern Nuclear Operating Company (SNC) submitted proposed Alternative Request No. HNP-ISI-ALT-05-04 (Proposed Alternative) to certain requirements of the American Society of Mechanical Engineers, Boiler and Pressure Vessel Code (ASME Code), for the fifth 10-year Inservice Inspection (ISI) Program for the Edwin I. Hatch Nuclear Plant, Units 1 and 2 (Hatch). Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) paragraph 50.55a(z)(1), SNC requested approval to implement alternative BWRVIP Guidelines in lieu of ASME Code Section XI Table IWB-2500-1 Examination Category B-N-1 and B-N-2 requirements. The proposed alternative applies to the fifth ISI interval for Hatch. SNC is requesting NRC authorization of this alternative on the basis that the proposed alternative will provide an acceptable level of quality and safety.

The NRC staff has reviewed the information provided by SNC and determined that additional information is needed to complete its evaluation. The enclosure provides the SNC response to the NRC request for additional information.

This letter contains no NRC commitments. If you have any questions, please contact Jamie Coleman at 205.992.6611.

Respectfully submitted, CAG/RMJ

Enclosure:

SNC Response to NRC Request for Additional Information Cc: Regional Administrator, Region ll NRR Project Manager - Hatch Senior Resident Inspector - Hatch RTYPE: CHA02.004

Edwin I. Hatch Nuclear Plant Response to NRC Request for Additional Information on Alternative Request HNP-ISI-ALT-05-04 Enclosure SNC Response to NRC Request for Additional Information

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information NRC Request for Additional Information 10 CFR 50.55a(g)(4) requires inservice inspection of ASME Code Class 1 components to be performed in accordance with Section XI of the ASME Code. The licensee has proposed an alternative to the inspection requirements of Section XI for ASME Code Class 1, Examination Category B-N-1 and B-N-2 components. Although the NRC has determined that BWRVIP alternatives may be used for inspection of Category B-N-1 and B-N-2 components, the NRC staff must review the inspection history of these components in order to determine that they are bounded by the proposed alternative. Therefore, NRC staff requests that the licensee submit an inspection history for the components for which an alternate inspection was requested.

SNC Response to NRC Request for Additional Information The following tables provide the requested inspection history:

E-1

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results Installed four Shroud Tie Rods in 1994 which exempts horizontal welds H-1 through NA NA H-8 from inspection.

Examined H-1 through H-7 to prove structural integrity due to cracked shroud tie rod Spring 2006 UT upper supports and one loose shroud tie rod. Significant cracking identified, but acceptable for one cycle.

Examined H-5, H6a, H6b, and H-7 to prove structural integrity due to the inability to Spring 2008 UT replace cracked shroud tie rod upper support at 225. Significant cracking identified, but acceptable for another cycle. Little growth in flaws from 2006 inspection.

Examined H4 from the OD and the ID from 65° to 115° for extent of condition due to Spring 2014 shroud vertical weld and weld intersection results. Several transverse indications identified originating from H4 upper and lower weld toes, some extending Core Shroud Spring 2016 EVT-1 beyond HAZ. Longest flaw 1.65". One at cell 50-35 (106°) verified through wall. Two Horizontal Welds flaws presumed through wall, for evaluation. All newly discovered flaws determined structurally acceptable and bounded by 1R26 structural and leakage evaluation.

Examined H4 from the OD and the ID from 235° to 245°. The 235° - 245° locations have several off-axis flaws that are extending above and below H4 from the ID ranging from < 0.5 to 1.09 in length at the 230°, 242°, 245°, and 247°. Two indications were noted on the OD at 228° and 232°, extending above H4, with a maximum length of Spring 2018 EVT-1 1.27. No flaws aligned on the OD and ID, and therefore none of the indications were through wall flaws. From the ID locations of the 335° - 345°, several off-axis flaws were noted above and below H4 ranging from 0.42 and 1.77 in length. No indications were observed from the OD. All newly discovered flaws determined structurally acceptable and bounded by latest structural and leakage evaluation.

Tightness checks to all four Tie Rods. One at 315° was again found to be less than Tightness, desirable load and was corrected. Two cracked upper supports at 135° & 225°, one at Spring 2006 EVT-1, VT-3 135° was replaced. Additional repairs and/or modifications to be performed next outage.

Replaced two tie rod upper supports at 135° and 315°. Unsuccessful in detensioning Core Shroud Tightness, the Tie Rod nuts at 45° and 225°. 45° and 225° tie rod assemblies were restored to a Spring 2008 Tie Rods EVT-1, VT-3 condition acceptable for another cycle. Tie rod at 225° contains a flaw which grew at a rate less than predicted for the previous fuel cycle.

Tightness, Successfully replaced the remaining two tie rod assemblies 45° and 225°. Tightness Spring 2010 EVT-1, VT-3 checks performed at all four tie rods.

E-2

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results One-cycle post-installation re-inspection of all four tie rod assemblies, including post-VT-3 torque verifications and upper spring torsion arms/bolts. No recordable indications.

Spring 2012 Core Shroud EVT-1, VT-1 One-cycle post installation re-inspection of all four tie rod upper support corners. No Tie Rods recordable indications.

Conducted VT-3 exams of Tie Rod/Core Plate Wedges Assemblies at 45°, 135°, 225°,

Spring 2016 VT-3 and 315° with satisfactory results. No recordable indications.

No recordable indications - Performed examinations of all four (4) Torsion Arms &

Spring 2018 VT-3 Torsion Arm Bolts (45°, 135°, 225°, 315°).

Examined V1, V2, V3, V4, V7, V8 V9, V10, and V11. Short indications recorded on Spring 2008 EVT-1 the ID at the intersections of H4 with V4 and at the intersections of H5 with V7 and V8.

Examined 12 on either side of high fluence intersections from the ID, including V7/H5, V8/H5, V4/H4, V5/H5, V5/H4, V6/H4, and V6/H5 intersections. One new indication Spring 2010 EVT-1 reported at V5/H5, one less indication at V4/H4 compared to 2008 outage results.

Also examined V12, V13, and V14 from the shroud OD with no indications reported.

Examined V3, V4, V5, V6, V7, V8, V9, and V10, via UT. Indications noted at V4, V5, UT V6, V7 and V8. Re-examination of V6 revealed a portion of the longest V6 crack was through-wall. Another small indication near V5 above H4 not associated with a weld Core Shroud was sized via UT. All evaluated structurally and for leakage and found acceptable.

Vertical Welds Examined intersections of H4/V4, H5/V8, and H5/V7 via traditional or specialized UT UT to characterize previously reported off-axis indications. Four indications axial to H4 Spring 2014 near the V4 intersection were found to be through wall. All evaluated structurally and for leakage and found acceptable.

Intersections at H4/V4 and H5/V8 were also inspected via EVT-1 from the ID.

EVT-1 Additional small indications noted at both intersections evaluated as acceptable.

Additional coverage CCW of V4 at H4 revealed an additional axial indication (one of the four H4/V4 through-wall indications identified via UT). Examined V1, V2, and V11 via EVT-1 from the OD with no recordable indications. All evaluated as acceptable.

E-3

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results Conducted supplemental EVT-1 exam of V5 and V6 from the OD. Pre-existing IGSCC flaws at V5 and V6 showed no growth based on review of 1R26 UT. One 1.4" transverse flaw identified extending from V6 weld toe. All flaws determined Spring 2016 EVT-1 Core Shroud structurally acceptable. Examined V12, V13, V14 from the OD with no recordable Vertical Welds indications, re-examine in 6 years. See Shroud Horizontal Weld scope above for additional H4 inspection results.

No recordable Indications - Performed re-examinations from the OD surface of welds Spring 2018 EVT-1 V-12, V-13, and V-14 in accordance with Deviation 2017-01. Achieved 75% coverage for V12 and 85% coverage for V13, V14.

EVT-1 from OD of Top Guide RSW at 120°. No recordable indications. One of four Spring 2006 EVT-1 Top Guide RSW every 2 cycles, or 4 years.

EVT-1 from OD to Top Guide RSW at 240°. No recordable indications. One of four Core Shroud Spring 2010 EVT-1 Top Guide RSW every 2 cycles, or 4 years.

Ring Segment EVT-1 from OD of Top Guide RSW (R-12) at 300°. No recordable indications. One of Welds Spring 2014 EVT-1 four Top Guide RSW every 2 cycles, or 4 years.

Top Guide Support Ring Segment Weld at 60° R-8 from outside surface. No Spring 2018 EVT-1 recordable Indications.

EVT-1 EVT-1 of >15% of H-8 in order to establish redundancy to the degraded shroud repair (two cracked upper supports at 135°& 225°). No recordable indications.

Spring 2006 VT-3 ASME VT-3 of all shroud support plate gussets and attachment welds.

UT UT of approximately 20% of H-9 per BWRVIP-104. No recordable indications.

EVT-1 EVT-1 of Shroud Support Plate Gusset Welds at 30°, 45°, 90°, 135°, 210°, 225°, 300°,

Core Shroud 315°, 345° per BWRVIP-38 requirements.

Spring 2010 Support Ledge (H-9) VT-3 VT-3 of 30°, 90°, 210°, 300°, 345° for ASME requirements.

EVT-1 of Shroud Support Plate Gusset Welds at 60°, 120°, 150°, 240°, 330° per EVT-1 BWRVIP-38 requirements, and Tie Rod Anchorages/Gussets at 45°, 135°, 225°, and 315°.

Spring 2016 VT-3 VT-3 of Shroud Support Plate Gusset Welds at 15°, 45°, 60°, 75°, 105°, 120°, 135°,

150°, 165°, 195°, 225°, 240°, 255°, 270°, 285°, 315°, 330° for ASME requirements.

E-4

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results UT UT examination of approximately 15% of H-9 was conducted. No recordable indications.

Core Shroud Spring 2006 VT-1 & VT-3 Examine each period. Examined 0° and 180 Evidence of expected leakage.

Support Ledge Examine once per 8 years per BWRVIP-180. Examined AHCs at 0 and 180.

Access Hole Spring 2014 VT-1 & VT-3 Evidence of expected leakage. No changes noted.

Covers Spring 2006 EVT-1 No indications.

Spring 2008 EVT-1 No indications.

Spring 2010 EVT-1 No indications.

Spring 2012 EVT-1 No indications.

Core Spray Spring 2014 EVT-1 No indications.

Internal Piping Spring 2016 EVT-1 No indications.

No recordable indications. Transitioned to BWRVIP-18 Rev 2A Inspection Spring 2018 EVT-1 Requirements. Performed inspections of the P4a, P4b, P4c, and P4d welds at 350°.

Discovered Core Spray Pipe draw beads near P4b.

EVT-1 & No recordable indications.

Spring 2006 VT-3 Spring 2008 EVT-1 No recordable indications.

EVT-1, Spring 2010 VT-1(89) & No recordable indications.

VT-3 EVT-1 &

Spring 2012 No recordable indications.

Core Spray VT-1(89)

Sparger EVT-1 &

Spring 2014 No recordable indications.

VT-1(89)

No recordable Indications - Transitioned to BWRVIP-18 Rev. 2-A Inspection VT-1(89) Requirements. Inspected Core Spray Sparger Repair Clamp (Bolting and Tack Welds) at 350°.

Spring 2018 VT-3 No recordable Indications - All (A-D) Sparger Nozzles (S3a/b) and Sparger D Drain Connections (S3c).

VT-1, two of four Top Guide Hold-downs, 180° apart every other outage. Also Spring 2006 VT-1 Top Guide performed VT-1 of two cells from the underside. No recordable indications.

Spring 2008 EVT-1 Grid beams in 14 cells per BWRVIP-183. No recordable indications.

E-5

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results EVT-1 & EVT-1 of grid beams in 21 cells per BWRVIP-183. VT-1 on two of four top guide hold-Spring 2010 VT-1 downs, 180° apart, every other outage. No recordable indications.

VT-1, two of four Top Guide Hold-downs, 180° apart every other outage. Minor wear Spring 2014 VT-1 noted on 176 assembly at pin area. Evaluated as acceptable.

VT-1, Reinspection of Top Guide Hold-down at 176. No noted changes in wear, Spring 2016 VT-1 acceptable.

Performed examinations of the Top Guide Hold Down Bracket and Attachment Welds to the Shroud at 86°, 176°, and 266°. A previously undocumented indication (from the Spring 2010 Refueling Outage (1R24)) was noted on the 086° top guide hold down Top Guide assembly. The indication will be reinspected during 1R29 to reassess the growth rate.

Performed examinations of the Top Guide Beam Connection. Two indications were Spring 2018 VT-1 found on the top guide beam connection at cell 46-11. Based on these findings, expanded scope to all accessible top guide beam connection locations. Cumulative inspections resulted in newly discovered indications on the top guide bottom support ring at 30°, 40°, 50°, 130°, 140°, 220°, 310°, and 320° locations, and on the bottom collars at 50°, 130°, 220°, 230°, and 310° locations. All indications evaluated as acceptable for one cycle of operation. 1R29 top collars are to be inspected to ensure evaluation assumptions remain bounded.

Two cell locations during CRB exchange. Also four Core Plate By-pass Flow Hole Spring 2006 VT-3 Plugs. No recordable indications. Examinations scheduled when CRBs are exchanged.

Spring 2008 VT-3 Examined 10 Core Plate Bypass Plugs.

Core Plate Spring 2010 VT-3 Examined 21 Core Plate Bypass Plugs. No recordable indications reported.

Spring 2014 VT-3 Examined 34 Core Plate Bypass Plugs. No recordable indications or leak by reported.

Spring 2016 VT-3 Examined 17 Core Plate Bypass Plugs. No recordable indications reported.

Spring 2018 VT-3 Examined 17 Core Plate Bypass Plugs. No recordable indications reported.

Direct VT-2 Performed direct VT-2 during leakage test. Access not suitable for UT. No recordable Spring 2006 or UT indications.

SLC Direct VT-2 Performed direct VT-2 during leakage test. Access not suitable for UT. No recordable Spring 2008 or UT indications.

Performed UT using newly developed tooling allowing access. No recordable Spring 2010 UT indications.

E-6

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results EVT-1 was performed on 50% of the RS-1, RS-2, RS-3 welds. Indications on the two EVT -1 thermal sleeve to elbow welds (RS-1s) that were first reported in 1997 and re-examined in 1999, 2000 and 2004 had no significant changes since 1997.

Spring 2006 VT-1 Re-baseline all 20 restrainer wedge bearing surfaces (WD-1) - No recordable indications.

Spring 2006 EVT-1 & Re-examined all wedges. Completed baseline of medium priority locations. Re-VT-1 examined 50% of RB-1 locations. No recordable indications.

EVT-1 Re-examined RS-1 indications on JP 3/4 and 7/8 with no change in length.

VT-1 Examined sensing lines on JPs 7 and 17. No recordable indications.

Spring 2008 UT UT was performed on 50% (10 Jet Pumps) of AD-1, AD-2, & DF-2 in accordance with BWRVIP-41 Rev. 2. No recordable indications.

Jet Pump EVT -1 Re-examined RS-1 indications on JP 3/4 and 7/8 with no change in length. Examined Assembly RS-8 and RS-9 welds for Jet Pumps 1-10. No recordable indications.

Spring 2010 EVT-1 & Examined RB-1, riser braced to vessel welds, for Jet Pumps 5/6 and Jet Pumps 9 VT-1 through 18. No recordable indications.

Examined RS-1, RS-2, RS-3 riser welds for JP 11-20. Re-examined RS-1 indications EVT-1 on JP 3/4 and 7/8 with no change in length.

Spring 2012 Examined all 20 JP restrainer bracket wedges.

VT-1 Examined sensing lines on JP 7 and 17. No recordable indications.

Re-examined RS-1 indications on JP 3/4 and 7/8 with no change in length. Re-examined 25% (five Jet Pumps) of MX-2, IN-4, RS-6 and RS-7, and DF-1 welds Spring 2014 EVT-1 according to BWRVIP-41 Rev 3, with no indications noted. Also examined Riser brace to yoke (RB-2) welds for four jet pumps with no indications noted.

Re-examined RS-1 indications on JP 3/4 and 7/8 with no change in length.

Examined RS-8 and RS-9 welds for Jet Pumps 11-16. Expanded scope to RS-8/9 on Spring 2016 EVT-1 JP riser 5/6 due to large set screw gap and wedge rod wear at JP 5 and 6 respectively. No recordable indications.

E-7

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results Re-examined WD-1 for Jet Pumps 1-20, slight wedge rod wear (less than 1%) found at VT-1 WD-1 for Jet Pump 6 and was evaluated as acceptable for plant operation. Expanded scope to WD-2 and AS-2a/b for Jet Pump 5 & 6 due to large set screw gap and wedge rod wear at JP 5 and 6 respectively. No other recordable indications.

Examined 100% AS-1 locations. Restrainer bracket set screw gaps identified at nine Spring 2016 VT-1 jet pumps. The largest gaps noted at Jet Pumps 5 & 15 (23 and 18 mils respectively) were eliminated via wedge tapping. The as-left condition of all gaps were evaluated and determined acceptable for continued plant operation.

Jet Pump Assembly In accordance with BWRVIP-41, UT was performed on 50% (10 Jet Pumps) of AD-1, UT AD-2, & DF-2 and 100% (20 Jet Pumps) of BB-1, BB-2, & BB-3. No recordable indications.

Performed re-inspections of 40% of the RB-1 welds (4/10 locations). Performed re-inspections (EVT-1) on 50% of the RS-1, RS-2, and RS-3 Welds. No changes to previous indications at JP-3/4 and JP-7/8 RS-1 welds. Performed AS-1a (Vessel EVT-1 Side), AS-1b (Shroud Side) for JP-5, 10, and 15. Restrainer bracket set screw gaps identified at three jet pumps. The largest gaps noted at Jet Pumps 5 & 10 (14 mils at Spring 2018 both locations). The as-left condition of all gaps were evaluated and determined acceptable for continued plant operation.

No recordable indications - Performed re-inspections of five (5) Jet Pump WD-1 VT-1 locations (25%) and two (2) Jet Pump Sensing Line Brackets.

No Indications - Inspected six (6) Fuel Support / Guide Tube Anti-Rotation Pins from CRD the top of core plate during core plate plug exams.

Spring 2018 VT-3 Guide Tubes Note - CRGT-1, and anti-rotation pin welds are inspected via VT-3, and CRGT-2, 3 are inspected via VT-1 (10% sample) if made accessible during maintenance.

Spring 2006 N/A Replaced 6 (50%) dry tubes.

Dry Tubes Spring 2008 N/A Replaced 6 (50%) dry tubes.

Spring 2006 EVT-1 Three Lower Surveillance Specimen brackets to RPV.

EVT-1 & Four FW Sparger Bracket Welds to RPV. No indications.

Spring 2008 RPV Interior VT-3 Attachments EVT-1 & One Core Spray Bracket to RPV weld at 330°. No indications.

Spring 2010 VT-3 E-8

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results One Upper guide rod bracket to RPV at 180°, and two Guide Rod & Lower guide rod Spring 2012 VT-3 attachment welds to Shroud at 0° and 180°. No recordable indications.

EVT-1 & Steam Dryer Support Bracket & Attachment welds (4). No indications.

Spring 2012 VT-3 Core Spray Piping Bracket at 210° also inspected. No indications.

VT-3 Steam Dryer Hold Down Brackets (4). No recordable indications.

Spring 2014 EVT-1 & Core Spray Bracket & Attachment welds at 30°. No recordable indications.

Spring 2014 VT-3 RPV Interior EVT-1 & Examined one Core Spray Bracket & Attachment weld at 150°, and four FW Sparger Attachments Spring 2016 VT-3 Bracket Welds to RPV. No recordable indications.

No recordable Indications - Guide Rod and Lower Guide Rod Bracket Attachment Weld to RPV at 0°. Upper and Lower surveillance specimen bracket attachment welds VT-3 to the RPV (30°, 120°, & 300°). Interim inspection guidance within BWRVIP Letter 2018-045 was completed for 120° upper, lower surveillance specimen brackets, Spring 2018 basket, rod, etc. This is the only location with a capsule remaining in vessel.

EVT-1 No recordable Indications - Core Spray Piping Bracket and Attachment Welds to RPV at 330° location.

LPCI Coupling N/A N/A Not applicable to Edwin I. Hatch Nuclear Plant Unit 1.

Sparger Arms, Flow Holes, Brackets, Tees, Welds. Unusual wear on end brackets to Spring 2006 VT-1 & VT-3 pins. Probable repair next outage. Schedule two of four every other outage beginning 1R20.

New FW Sparger end bracket repair assemblies installed at four locations (185°, 265°,

Spring 2008 VT-3 275°, & 355°) due to wear.

FW Sparger end pins/brackets at 5°, 85°, 95°, 175° inspected. Minor wear discovered on locations at 95° and 175°. Scope expanded to examine repaired locations at 185°,

Spring 2010 VT-3 Feedwater 265°, 275°, 355°. No further wear noted from additional exams. Re-examine Spargers locations at 5°, 85°, 95°, and 175° next outage with contingency planning in place.

VT-1 & VT-3 FW Sparger end pins/brackets at 5°, 85°, 95°, 175° re-inspected. No further wear noted from reinspection. Re-examine or repair next outage.

Spring 2012 EVT-1 & Previously repaired FW sparger end pin brackets at 265°, 185°, 355°, 275° also VT-3 inspected with no indications noted.

E-9

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results VT-3 Sparger Arms, Flow Holes, Brackets, Tees, Welds. One flow nozzle discovered slightly out of round. Evaluated as acceptable. No other recordable indications EVT-1 & Modified FW Sparger end pins/brackets at 185°, 265°, 275°, 355° re-inspected. No Spring 2014 VT-3 recordable indications.

EVT-1 & FW Sparger end pins/brackets at 5°, 85°, 95°, 175° re-inspected. No further wear VT-3 noted from reinspection. Re-examine or repair next outage.

VT-3 Sparger Arms, Flow Holes, Brackets, Tees, Welds. Flow nozzle at 315° re-inspected.

No recordable changes.

VT-1 & VT-3 FW Sparger end pins/brackets at 5°, 85°, 95°, 175° re-inspected. No further wear Spring 2016 Feedwater noted from reinspection.

Spargers EVT-1 & End bracket attachment welds at 185°, 265°, 275°, 355° re-inspected. No recordable VT-3 changes.

Sparger Arms, Flow Holes, Brackets, Tees, Welds. Flow nozzle at 45° & 135° re-VT-3 inspected. No recordable changes.

FW Sparger End Pins/Brackets at 85°, 95°, 175° re-inspected. The inspections Spring 2018 resulted in: (1) minor new wear being identified on the 085° pin, (2) no discernible change in previously identified (during the Spring 2010 Refueling Outage (1R24)) wear VT-1 & VT-3 on the 095° pin, and (3) a slight change in previously identified (during 1R24) wear on 175° pin. All indications evaluated for continued operation with re-inspection per NUREG 0619.

Upper support ring @ 0°-360° top and vertical surfaces VT-3. Lower & Upper Guide at 1800 (10) Tie Bars TB1 - TB10, Vertical welds - Various Hood (8) Drain Channels DC1 - DC8 (5) Lower horizontal welds (2) Upper horizontal welds. One tie bar was Steam Dryer Spring 2006 VT-1 & VT-3 cracked on one side on the middle span and was repaired (re-welded). Minor indications on DC-1 & Upper Support Ring were evaluated as acceptable. BWRVIP examinations are performed every other cycle until the BWRVIP determines an examination frequency. Other owner designated examinations are performed every 6 years.

E-10

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 1 Component Inspection Date Type Inspection Results Upper support ring top and vertical surfaces 0-360°. Monitoring previously identified small indications. Flaws exhibited little discernable change.

Spring 2008 VT-1 (89) Lower support ring and guide 24 on either side of lower guide at 0°. Drain channel #1.

Monitoring previously identified small indications. Flaws exhibited little discernable change. Repaired tie bar #6 inspected with no indications.

Upper support ring top and vertical surfaces 0-360°. Previously identified indications Spring 2010 VT-1 (89) were determined to be non-relevant during 1R24. Flaws exhibited little discernable change.

Examined steam dryer tie bars 3-7, various horizontal welds (4), vertical partition Spring 2012 VT-1 (89) welds (4), Vertical hood welds (9), and drain channels (4). No indications.

Lower support ring 24 on either side of lower guide at 0°. Upper guide and lower guide at 0°. Seismic Brackets (4). Lifting Eye, Rod and Attachment welds at 215° and Spring 2014 VT-1 (89) 325°. No indications.

Vertical partition weld (1) - no change to historical/legacy indications.

Steam Dryer Inspected Upper Support Ring top and vertical surfaces 0°-360°, Lower support ring 24 on either side of lower guide at 180°, Vertical Partition Welds (3), Various Horizontal Welds (3), Vertical Hood Welds (10), with no indications.

Upper and Lower Guides at 0° and 180° inspected. No change to pre-existing gouges and areas of raised metal at 180° Lower Guide. Acceptable for continued operation.

Spring 2016 VT-1 (89)

Drain Channel welds 1-7 inspected. No change to pre-existing indications at Drain Channel #1. No other indications reported.

Seven Tie Bars inspected. Tie Bar #6 repairs showed no change. Tie Bars 7 & 8 show crack-like indications. Evaluated as acceptable for 1-cycle of operation. Repairs to be planned next outage.

Tie Bars 3, 4, 5, 6, 7, and 8 were inspected. There were no new indications noted on Tie Bars 3-8 or changes to existing indications on Tie Bars 7 and 8.

Two newly identified indications at vertical partition weld on the end plate base Spring 2018 VT-1 (89) material of the Steam Dryer (beginning in the heat affected zone (HAZ) of the Steam Dryer Vertical Partition Plate (VP) 3/2-4 Weld) were evaluated as acceptable.

Repaired Items - Upper and Lower Guides at 0° and Tie Bars 7 and 8.

E-11

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 2 Component Inspection Date Type Inspection Results Core Shroud Note: Installed four Shroud Tie Rods in 1995 which exempts horizontal welds H-1 N/A N/A Horizontal Welds through H-8 from inspection.

Performed EVT-1 examinations from the outside surface for welds V-1, V-2, V-9, V-10, & V-11. No recordable Indications. V-6 Inside surface indication was found in Spring 2007 EVT-1 2005 on at the upper intersection (H-4) which parallels H-4. Was re-examined to determine if this indication had changed. No changes were recorded.

Performed EVT-1 examinations from the outside surface for welds V-12, V-13, and Spring 2011 EVT-1 V-14. No recordable indications.

Performed EVT-1 examinations from the outside surface for welds V-1, V-2, V-9, Spring 2013 EVT-1 V-10, & V-11. No recordable Indications.

Performed EVT-1 examinations from ID and OD on V3, V4, V5, V6, V7, V8. Several recordable indications noted near V3 and V6. Corresponding outside diameter Core Shroud locations were examined with no recordable indications. All indications evaluated as Vertical Welds EVT-1 acceptable for return to service per BWRVIP-76 guidance and ASME SCXI rules as applicable.

Spring 2015 Performed ASME SCXI VT-3 shroud inside surface exams from shroud flange to support ledge for approximately 270 degrees, and from top guide support ring to shroud flange for 90 degrees. Several recordable indications noted at three additional VT-3 locations from the inside diameter. Corresponding outside diameter inspections revealed no recordable indications. All indications evaluated as acceptable for return to service per BWRVIP-76 guidance and ASME SCXI rules as applicable.

Performed examinations from the OD surface of welds V-12, V-13, and V-14. No Spring 2017 EVT-1 recordable indications.

Core Shroud Ring Segment N/A N/A Edwin I. Hatch Nuclear Plant (Unit 2) does NOT have Ring Segment Welds Welds EVT-1 & All Tie Rods - No indications. Upper Supports & Tie Rod Nuts have been determined Spring 2007 VT-3 to be susceptible to IGSCC. This will make corrective action necessary by next Core Shroud (Tightness) outage.

Tie Rods All four tie rod assemblies modified with replacement component items designed to EVT-1 &

Spring 2009 not be susceptible to IGSCC. All component items replaced with the exception of the VT-3 lower collet and clevis pin.

E-12

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 2 Component Inspection Date Type Inspection Results EVT-1 & Post tie-rod modification inspections on all four tie rods were successfully performed Spring 2011 Core Shroud VT-3 with no indications noted.

Tie Rods Performed examinations on all four Core Plate Seismic Wedges associated with the Spring 2017 VT-3 Shroud Tie Rods (45°, 135°, 225°, and 315°). No recordable indications.

VT-3 H-9: Examined 100% of accessible surfaces from top per BWRVIP-38. No indications.

Spring 2007 Core Shroud EVT-1 H-8: EVT-1 of accessible weld surface from the top side of H8. No indications.

Support VT-1 & VT-3 AHC: VT-3 of 0° and 360° access hole covers with VT-1 of tack welds. No indications.

Spring 2015 VT-1 & VT-3 AHC: VT-3 of 0° and 360° access hole covers with VT-1 of tack welds. No indications.

H-9: Performed examinations on 70% of all accessible surfaces (from top) per Spring 2017 VT-3 BWRVIP-38. No recordable indications.

New sparger bracket-to-shroud indication at 272°. Previous sparger bracket-to-EVT-1 &

Spring 2009 shroud indications tracked since 1994 remain unchanged. New indication recorded is VT-1 acceptable and similar to previous indications.

Reinspection of sparger bracket-to-shroud indication at 272°. Additional indications noted in the same area, similar to previous indications. This indication is thought to be Spring 2011 VT-1 older and revealed due to more efficient cleaning methods used for the first time in this area. All other bracket locations were inspected in 2009 with no changes since 1994.

Core Spray EVT-1 of all sparger major piping welds (S1, S2, & S4). VT-1 (89) of all sparger Sparger bracket (SB) locations and 50% of sparger nozzle welds. Newly discovered indication EVT-1 & at 330° sparger bracket (weld 50), bounded by previous evaluations, and similar to Spring 2013 VT-1(89) findings Spring 2011, thought to be older and revealed due to more efficient cleaning methods used for the first time in this area. No changes noted for any other previous indications.

VT-1 (89) Reinspection of core spray sparger bracket to shroud welds at 272° and Spring 2015 VT-1(89) 330°. No changes to indications at 272°. Evaluated as acceptable. No indications reported at 330°.

Transitioned to BWRVIP-18 Rev. 2-A Inspection Requirements. Reinspection of Core Spray Sparger Bracket to Shroud Welds at 272° and 330° and the remaining sparger Spring 2017 VT-1(89) bracket locations with previous Indications. No discernible changes were noted. New indications were found at 60° (Weld 8), 240° (Weld 36), and 330° (Weld 51), and all E-13

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 2 Component Inspection Date Type Inspection Results were evaluated as acceptable. The new indications will be reinspected during the next two refueling outages (2R25 and 2R26).

Spring 2007 EVT-1 Reinspection per BWRVIP-18. No Indications.

Spring 2009 EVT-1 Reinspection per BWRVIP-18. No Indications.

Spring 2011 EVT-1 Reinspection per BWRVIP-18-A. No Indications.

Spring 2013 EVT-1 Reinspection per BWRVIP-18 Rev. 1-A. No indications.

Core Spray Spring 2015 EVT-1 Reinspection per BWRVIP-18 Rev. 1-A. No indications.

Internal Piping Transitioned to BWRVIP-18 Rev. 2-A Inspection Requirements. Performed inspections (EVT-1 and VT-3) of the Core Spray Piping Bracket to RPV Welds at 30° Spring 2017 EVT-1 and 210° and inspections (EVT-1) of P4a, P4b, P4c, and P4d Welds at 170°. No recordable indications.

Core Plate N/A N/A No BWRVIP inspections are required. Core Plate wedges installed in 1995.

SLC Spring 2015 UT N10 Safe-end & Extension exam per ASME Supplement 10. No indications.

CRD Note - CRGT-1, and anti-rotation pin welds are inspected via VT-3, and CRGT-2, 3 NA NA Guide Tubes are inspected via VT-1 (10% sample) if made accessible during maintenance.

Spring 2007 N/A Replaced six (50%) dry tubes.

Dry Tubes Spring 2009 N/A Replaced six (50%) dry tubes.

Spring 2007 VT-1 Grid/beams: SIL-554, Examined bottom surfaces of 14 cells. No indications.

Hold Downs and Attachments to the shroud (two of four) 180° apart every other Spring 2009 VT-1 outage. No recordable indications.

Grid/Beams: BWRVIP-183. Examined bottom 2 from sides and grid beam Spring 2011 EVT-1 intersections of eight cells. No indications.

Top Guide Hold Downs and Attachments to the shroud (two of four) 180° apart every other (U2 has Wedges) Spring 2013 VT-1 outage. No recordable indications.

Grid/Beams: BWRVIP-183. Examined bottom 2 from sides and grid beam Spring 2015 EVT-1 intersections of 8 cells. No indications.

Recordable Indication - Performed examinations of the Top Guide Hold Down Bracket and Attachment Welds to the Shroud at 86° and 266°. A new indication was found at Spring 2017 VT-1 the 86° azimuth and was evaluated as acceptable for continued operation.

The indication will be reinspected during 2R25 to reassess the growth rate.

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Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 2 Component Inspection Date Type Inspection Results LPCI Coupling N/A N/A N/A - Not Applicable to Edwin I. Hatch Nuclear Plant Unit 2.

Performed VT-1 100% of the WD-1s. Performed 100% UT of BB-1, BB2, & BB-3.

EVT-1, VT-1 Spring 2007 Performed EVT-1 50% of RS-8 to RS-9s, IN-4s, MX-2s, DF-1s, RS-6s & RS-7s. No

& UT indications.

EVT-1 & Performed second 50% reinspection of RS-1, RS-2, RS-3, DF-2, AD-1, & AD-2.

Spring 2009 VT-1 Inspected two RB-1 locations. No indications.

Performed VT-1 of 100% of the WD-1 population. Performed EVT-1 of 100% of RS-8 EVT-1 & to RS-9 welds. Performed EVT-1 of four total RB-1 weld locations and three total RB-2 Spring 2011 VT-1 weld locations. Performed VT-1 of two jet pump sensing line brackets. No recordable indications.

Jet Pump EVT-1 & Performed EVT-1 re-inspection of 25% of IN-4s, MX-2s, DF-1s, RS-6s & RS-7s. No Assembly Spring 2013 VT-1 indications.

Performed EVT-1 re-inspection of 50% of RS-1, RS-2, RS-3, DF-2, AD-1 and AD-2 EVT-1 & welds, as well as 25% of RB-1 welds. Performed VT-1 of 100% of WD-1 population.

Spring 2015 VT-1 No indications. Also performed VT-1 of 100% of AS-1 population, with minor set screw gaps noted at six Jet Pumps evaluated as acceptable.

Performed re-inspections (VT-1) of five Jet Pump WD-1 Locations (25%) and two Jet Pump Sensing Line Brackets. Additionally, performed re-inspections (EVT-1) of 25%

EVT-1, VT-1 Spring 2017 of the RS-8/9 Welds and the RB-2a, RB-2b, RB-2c, & RB-2d Welds. Finally,

& UT performed re-inspections (UT) on 100% of the BB-1, BB-2, and BB-3 Welds. No recordable indications.

All Guide Rod Brackets: VT-3. 30° Upper Surveillance Specimen Brackets: VT-3.

Spring 2007 VT-3 30° Lower Surveillance Specimen Brackets: EVT-1. All Steam Dryer Support Brackets: EVT-1. No Indications.

RPV Interior EVT-1, Inspected two Jet Pump RB-1 locations, two Core Spray PB locations, eight FW Attachments Spring 2009 VT-1, Sparger End Bracket Attachment Welds, and Upper & Lower Surveillance Specimen

& VT-3 at 300° location. No indications.

EVT-1, Inspected one of three Surveillance Specimen Brackets at 120° location, and four Jet Spring 2011 VT-1, Pump Riser Brace (RB-1) locations. No recordable indications.

& VT-3 E-15

Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 2 Component Inspection Date Type Inspection Results Steam Dryer Hold Down Brackets: Inspected all four locations. No indications.

EVT-1 &

Spring 2013 Steam Dryer Support Brackets: Inspected two locations. Repairs made 2R18 (2005).

VT-3 No changes noted.

EVT-1 &

Spring 2015 Core Spray Bracket and Attachment Welds to RPV at 330° location. No indications.

VT-3 Performed re-examinations of: (1) the RPV Clad punch mark-like indication at 300°,

which was first identified and measured in depth in 2011 and assessed not to penetrate the clad, and (2) Steam Dryer Support Lug Attachment Weld to RPV at RPV Interior 326°. Found no changes in the previously identified indications.

Attachments Performed examinations of the: Upper Guide Rod Bracket Attachment Weld to the EVT-1 & RPV (0° & 180°), Guide Rod and Lower Guide Rod Bracket Attachment Weld to the Spring 2017 VT-3 RPV (0° & 180°), Upper and Lower Surveillance Specimen Bracket Attachment Weld to the RPV (30°), Steam Dryer Support Lug Attachment Weld to the RPV (34° & 326°), and the Core Spray Piping Bracket to the RPV (30° & 210°). Minor service related indications were found at the Upper Guide Rod and were evaluated as acceptable for continued operation. No other recordable indications.

Additionally, the Surveillance Specimen at 120° was removed.

BWRVIP-139 2 - Steam Dryer Cover Plate Horizontal Welds at 0° & 180° - No indications 2 - Steam Dryer Upper Hood Horizontal Welds - No indications 2 - Steam Dryer Radial Cover Plate Welds at 90° & 270° - No indications 8 - Steam Dryer Drain Channel Welds - No indications 1 - Steam Dryer Manway Cover Weld at 270 degrees - No indications Steam Dryer Spring 2007 VT-1 49 - Steam Dryer Vertical End Plate & Partition Welds - No indications.

28 - Steam Dryer Tie Bars & Welds - No indications.

1 - Steam Dryer Upper Support Ring 0-360° (Top & Vert Surfaces) Minor indications on upper support ring side are monitored for change.

4 - Steam Dryer Lifting Eye and Attachment Welds. No indications.

Asset Management 4 - Steam Dryer Seismic Brackets - Minor indications on upper support ring side are monitored for change with no discernable changes.

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Enclosure to NL-18-1480 SNC Response to NRC Request for Additional Information Hatch Unit 2 Component Inspection Date Type Inspection Results 2 - Steam Dryer Lower Support Ring (24 either side of guides at 0° & 180°) - No indications.

1 - Steam dryer Upper Guide at 180° - No indications.

Inspected all four steam dryer seismic brackets and upper support ring top and vertical Spring 2009 VT-1 (89) surfaces 0-360° - Minor indications on upper support ring side were being tracked for changes. No discernable changes.

Inspected steam dryer upper support ring top and vertical surfaces (0-360°). Minor Spring 2011 VT-1 (89) indications on upper support ring side were being tracked for changes. No discernable changes.

Inspected four steam dryer lifting eye, rod, & attachment welds, two steam dryer seismic brackets & attachment welds to support ring, one manway cover weld and Steam Dryer three other horizontal hood welds, the lower support ring and upper and lower guides Spring 2013 VT-1 (89) at 0 deg, 9 vertical partition welds, 12 vertical hood welds, 4 drain channels, and 14 tie bars. Damage due to steam dryer removal or installation at 0 deg upper guide was evaluated acceptable as-is. No other recordable indications.

Inspected steam dryer upper and lower guides at 180°. No indications.

Reinspected steam dyer seismic brackets at 214° and 146°. No changes to existing indications.

Spring 2015 VT-1 (89)

Minor changes to wear pattern on contact surfaces of at both locations. Evaluated as acceptable.

Performed examinations on the Upper Support Ring Vertical and Top Surfaces (from 0°-360°). There were no changes to existing indications.

Performed examinations on the Steam Dryer: Lifting Eyes (two), Rod and Attachment Spring 2017 VT-1 (89)

Welds (two each), Tie Bar and Attachment Welds (14 each), Vertical Hood Welds (ten), Vertical Hood Support Welds (eight), Vertical Partition Welds (seven), Drain Channel Welds (one - DC-8), Horizontal Welds (three), and the Lower Support Ring (180°). No recordable indications.

E-17