L-25-083, Containment Liner Random and Non-Random Examinations Report
| ML25111A185 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 04/21/2025 |
| From: | Blair B Vistra Operations Company |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-25-083 | |
| Download: ML25111A185 (1) | |
Text
L-25-083 April 21, 2025 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Subject Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 Containment Liner Random and Non-Random Examinations Report Beaver Valley Power Station Barry N. Blair Site Vice President P.O. Box 4 200 State Route 3016 Shippingport, PA 15077 724-682-5234 In accordance with license renewal commitment 35 listed in Beaver Valley Power Station, Unit No. 2 (BVPS-2),
Updated Final Safety Analysis Report (UFSAR) Table 19-1, enclosed is the containment liner random and non-random examinations report for examination activities performed in the BVPS-2 fall 2024 refueling outage (2R24).
This includes the consideration of additional statistical methods to gain insight into potential liner degradation in accordance with license renewal commitment 36.
By letter dated June 27, 2011 (Accession No. ML111790129), the containment liner random and non-random examinations report for the BVPS-2 spring 2011 refueling outage (2R15) was submitted to the Nuclear Regulatory Commission (NRC). Random and non-random containment liner examination activities performed during 2R15 and 2R24 that are associated with BVPS-2 license renewal commitments 33 and 34 listed in BVPS-2 UFSAR Table 19-1 have been satisfactorily completed and documented in correspondence to the NRC. Therefore, license renewal commitments 33, 34, 35, and 36 are considered closed.
There are no regulatory commitments contained in this submittal. If there are any questions, or if additional information is required, please contact Jack Hicks, Senior Manager, Licensing, at (254) 897-6725 or jack.hicks@vistracorp.com.
Enclosure:
Beaver Valley Power Station, Unit 2 Containment Liner Plate Random and Non-Random Examinations Report for Refueling Outage 2R24 I
I H, A 7 03 o
- 812 M
Beaver Valley Power Station, Unit No. 2 L-25-83 Page2 cc:
NRC Region I Administrator NRC Resident Inspector NRC Project Manager Director BRP /DEP Site BRP /DEP Representative
Enclosure L-25-083 Beaver Valley Power Station, Unit 2 Containment Liner Plate Random and Non-Random Examinations Report for Refueling Outage 2R24 (60 pages follow)
Beaver Valley Power Staon, Unit 2 Containment Liner Plate Random and Non-Random Examinaons Report for Refueling Outage 2R24 02/11/25 Daniel W. Lamond, GSE Solutions
Beaver Valley Power Staon, Unit 2 Containment Liner Plate Random and Non-Random Examinaons Report for Refueling Outage 2R24 Page 2 of 60 TABLE OF CONTENTS 1.0 EXAMINATION
SUMMARY
......................................................................................................................... 3 1.1 Introducon.............................................................................................................................................. 3 1.2 Results of Examinaons Performed During the Fall 2024 Refueling Outage 2R24................................... 6 1.3 Conclusions............................................................................................................................................... 7
2.0 REFERENCES
............................................................................................................................................... 8 Appendix I - Summary of Examinaons Performed During Refueling Outage 2R24 (Random Examinaon Areas)......................................................................................................... 9 Aachment 1 - Gecko Robocs Automated Ultrasonics Inspecon Report, Rev. 0, Gecko Job Number 2023-05204, approved November 1, 2024................................................ 11 Aachment 2 - Beaver Valley Power Staon, Engineering Evaluaon of Unit 2 Liner Locaon 2RN-063, dated December 9, 2024.......................................................................................................... 47
Beaver Valley Power Staon, Unit 2 Containment Liner Plate Random and Non-Random Examinaons Report for Refueling Outage 2R24 Page 3 of 60 1.0 EXAMINATION
SUMMARY
1.1 Introducon Vistra Operaons Company LLC (Vistra) performed supplemental volumetric examinaons on the Beaver Valley Power Staon, Unit No.2 (BVPS-2) containment liner during the Fall 2024 refueling outage (2R24) to sasfy BVPS-2 license renewal commitments 33 and 34, related to the ultrasonic thickness measurements of non-random areas and random areas, respecvely. These commitments are listed in BVPS-2 Updated Final Safety Analysis Report Table 19-1. A summary of the commitments are as follows:
1.1.1 Beaver Valley Power Staon, Unit 2 Renewed Facility Operang License (Reference 2.10), Secon 2.L contains the following requirements:
a)
If degradaon (greater than 10 percent of the nominal thickness not aributable to fabricaon/erecon pracces) is iden"ed in the non-random areas examined using ultrasonic tesng (UT) as described in Supplement 1 of NUREG-1929, UT examinaons shall be performed at addional non random areas, to be selected based on this operang experience. Should addional degradaon be iden"ed, addional non-random areas shall be UT examined unl no further degradaon (greater than 10 percent of the nominal thickness) is iden"ed. All areas with degradaon shall be reexamined over at least the next three successive inspecon periods to ensure that progression of the degradaon is not occurring.
b) If degradaon (greater than 10 percent of the nominal thickness not aributable to fabricaon/erecon pracces) is iden"ed in the random samples examined using ultrasonic tesng (UT) as described in Supplement 1 of NUREG-1929, UT examinaons shall be performed on addional random samples, to ensure a 95 percent con"dence that 95 percent of the unexamined accessible containment liner is not degraded.
If addional degradaon is iden"ed, the sample size for UT examinaons shall be further expanded unl the stascal sampling has achieved the 95 percent con"dence goal described previously. All areas with degradaon shall be reexamined over at least the next three successive inspecon periods to ensure that progression of the degradaon is not occurring.
Beaver Valley Power Staon, Unit 2 Containment Liner Plate Random and Non-Random Examinaons Report for Refueling Outage 2R24 Page 4 of 60 1.1.2 Beaver Valley Power Staon, Unit 2 UFSAR (Reference 2.11), Table 19-1 contains the following commitments related to examinaon of the Unit 2 containment liner:
License Renewal Commitment 33:
Supplemental volumetric examinaons will be performed on the Unit 2 containment liner prior to the period of extended operaon. A minimum of seventy-"ve (one foot square) randomly selected (as described in FENOC Leer L-09-205) sample locaons will be examined (as described in FENOC Leer L-09-243). If degradaon is iden"ed, it will be addressed through the correcve acon program (as described in FENOC Leer L-09-243).
These examinaons are required to be completed by May 27, 2027.
FENOC Leer L-09-243 contains the following informaon:
FENOC characterizes a stascal failure at the concrete to liner interface as a random locaon with greater than 10% loss of material, displaying measurable breadth and shape; unless through engineering evaluaon it is determined that indicaons are aributed to fabricaon/erecon pracces or locaons not indicave of corrosion. If a stascal failure is iden"ed, it will be placed into the correcve acon program and evaluated in accordance with 10 CFR 50, Appendix B, Criterion XVI. The random sample plan will assure a con"dence level of 95% that 95% of the accessible ultrasonically untested containment liner is not experiencing localized ping corrosion degradaon of concern.
Stascal failures will be re-examined during subsequent outages unl disposioned. Locaons with iden"ed loss of material less than 10% but with a breadth and shape will be entered into the correcve acon program and tracked as a point of interest for monitoring during subsequent outages unl disposioned.
The random sampling plan includes 100% UT of a minimum of 75 1-x 1-square areas randomly selected on the accessible ultrasonically untested poron of the containment liner per unit.
The compleon of the random sample plan, with a minimum of 75 samples, will provide a con"dence level of 95% that 95% of the accessible ultrasonically untested liner is not experiencing localized ping corrosion of concern with greater than 10% loss of material.
Beaver Valley Power Staon, Unit 2 Containment Liner Plate Random and Non-Random Examinaons Report for Refueling Outage 2R24 Page 5 of 60 License Renewal Commitment 34:
Supplemental volumetric examinaons will be performed on the Unit 2 containment liner. A minimum of 8 non-randomly selected locaons will be examined, focusing on areas most likely to experience degradaon based on past operang experience (as described in FENOC Leer L 242). If degradaon is iden"ed, it will be addressed through the correcve acon program.
These examinaons are required to be completed by May 27, 2027.
FENOC Leer L-09-242 contains the following informaon:
Locaons with iden"ed loss of material less than 10% but with a breadth and shape that potenally indicates the presence of foreign material will be entered into the correcve acon program and tracked as a point of interest for monitoring during subsequent outages unl disposioned by trending.
FENOC intends to characterize locaons with greater than 10% loss of material and displaying breadth and shape as stascal failures unless through engineering evaluaon it is determined that indicaons are aributed to fabricaon/erecon pracces. Samples with greater than 10% loss of material would be entered into the correcve acon program and re-examined during subsequent outages unl disposioned by trending.
The following criteria will be considered for selecon of the Unit 2 non-random sample populaon:
- 1. Locaons that have required re-painng more than once. These are areas where the inside liner topcoat has required rework.
The primer coat was intact at these locaons.
- 2. Locaons that have irregular contour.
- 3. The containment liner surface between Elevaons 725' and 735'
("nal grade level). External surface of the concrete in this area has a greater potenal for exposure to moisture. The liner surface area with adjoining buildings will not be considered for non-random sampling.
License Renewal Commitment 35:
A summary of results for each phase of volumetric tesng (described in Unit 2 Commitments No. 33 and No. 34) will be documented in a leer to the NRC.
A summary of all examinaons required for Commitments 33 and 34 is required to be completed by May 27, 2027.
Beaver Valley Power Staon, Unit 2 Containment Liner Plate Random and Non-Random Examinaons Report for Refueling Outage 2R24 Page 6 of 60 License Renewal Commitment 36:
FENOC will evaluate if an appropriate/applicable stascal method exists to gain addional insight into potenal liner degradaon. Data gathered will be evaluated and used to determine the general state of the liner.
This commitment is required to be completed by May 27, 2027.
1.2 Results of Examinaons Performed During the Fall 2024 Refueling Outage 2R24 1.2.1 The results of ultrasonic thickness measurements performed on non-random areas were previously documented and reported to the NRC in 2011 (Reference 2.3)
All of the required (8) UT thickness measurements were performed in 2011 and were found to exceed the nominal plate thickness of 3/8.
1.2.2 The results of ultrasonic thickness measurements performed on random areas are documented in Appendix I Examinaons of Grids 2RN-001 through 2RN-014 were performed in 2024 using roboc UT examinaon equipment that scanned the enre surface of each 12 x 12 UT grid (Reference 2.1).
Examinaons of Grids 2RN-015 through 2RN-075 were performed in 2011 (Reference 2.3)
- 1. The UT thickness measurements of Grids 2RN-001 through 2RN-062, and 2RN-064 through 2RN-075 revealed no locaons where the minimum wall thickness was less than or equal to 90% of the nominal wall thickness, and none of the minimum wall thickness measurements within these grids detected condions that exhibited breadth and shape consistent with presence of foreign material behind the liner plate.
- 2. Grid 2RN-063 was examined in 2011 during refueling outage 2R15. The inial UT examinaon detected a minimum wall thickness of 0.310. The liner plate in this area has a nominal wall thickness of 0.375, and the measured minimum wall thickness was lower than 90% of the nominal wall thickness (0.337). As such, License Renewal Commitment #34 required that Samples with greater than 10% loss of material would be entered into the correcve acon program and re-examined during subsequent outages unl disposioned by trending. Subsequent examinaons were performed in refueling outages 16, 17, 18, and 22.
An Engineering Evaluaon, dated December 9, 2024 analyzed the examinaon results and concluded that indicaons of local wall thinning within this grid were the product of the fabricaon/erecon process, since there was essenally no change in the measured wall thickness between measurements taken in refueling outage 2R15 and 2R22.
Beaver Valley Power Staon, Unit 2 Containment Liner Plate Random and Non-Random Examinaons Report for Refueling Outage 2R24 Page 7 of 60 Further details of this Engineering Evaluaon are documented in Reference 2.2. As a result of this conclusion, the examinaon result in 2011 for Grid 2R-063 is not considered to be a stascal failure that would require addional UT examinaons.
1.3 Conclusions 1.3.1 The non-random UT examinaons, performed in 2011, were all acceptable, and no further acon or addional examinaons are required to sasfy the regulatory commitments for the non-random UT Grids.
1.3.2 The random UT examinaons, completed in refueling outage 2R15 and 2R24, did not idenfy any stascal failures. Therefore, the 75 random examinaons completed to-date sasfy the stascal sampling plan that provides a con"dence level of 95% that 95% of the accessible ultrasonically untested liner is not experiencing localized ping corrosion of concern with greater than 10% loss of material.
1.3.3 None of the random and non-random examinaons detected any condions that exhibited breadth and shape that would be consistent with corrosion or ping due to the presence of foreign material behind the liner plate.
1.3.4 Addional stascal methods were considered (as required by Commitment 36), but were not required as a result of meeng License Renewal Commitments 33 and 34. Various modi"ed sampling plans were considered, based on the possible detecon of one or more stascal failures in the inial random sample. If one or more stascal failures had been detected in any of the 75 random examinaons, use of a modi"ed sampling plan (requiring addional UT examinaons) would have been necessary in order to demonstrate compliance with the stascal con"dence level requirement of Commitment 33.
1.3.5 This report concludes that the License Renewal Commitments 33, 34, 35, and 36 will have been met upon submial of this report to the NRC, as required by Commitment 35. No further UT examinaons of the Unit 2 containment liner plate are necessary in order to comply with these license renewal commitments.
Beaver Valley Power Staon, Unit 2 Containment Liner Plate Random and Non-Random Examinaons Report for Refueling Outage 2R24 Page 8 of 60
2.0 REFERENCES
2.1 Gecko Robocs Automated Ultrasonics Inspecon Report, Rev. 0, Gecko Job Number 2023-05204, approved November 1, 2024 (Aachment 1) 2.2 Beaver Valley Power Staon, Engineering Evaluaon of Unit 2 Liner Locaon 2RN-063, dated December 9, 2024, documented in Beaver Valley SAP No"caon 601474100 (Aachment 2).
2.3 First Energy Nuclear Operang Company Leer L-11-181, Containment Liner Random and Non-Random Examinaons Report, dated June 27, 2011 (ML111790129) 2.4 First Energy Nuclear Operang Company Leer L-09-205, "Supplemental Informaon for the Review of the Beaver Valley Power Staon, Units 1 and 2, License Renewal Applicaon (TAC Nos. MD6593 and MD6594), and License Renewal Applicaon Amendment No. 39", dated July 28, 2009 (ML092110117) 2.5 First Energy Nuclear Operang Company Leer L-09-242, "Supplemental Informaon for the Review of the Beaver Valley Power Staon, Units 1 and 2, License Renewal Applicaon (TAC Nos. MD6593 and MD6594), and License Renewal Applicaon Amendment No. 40", dated September 2,2009 (ML092510168) 2.6 First Energy Nuclear Operang Company Leer L-09-243, "Supplemental Informaon for the Review of the Beaver Valley Power Staon, Units 1 and 2, License Renewal Applicaon (TAC Nos. MD6593 and MD6594), and License Renewal Applicaon Amendment No. 41", dated September 4,2009 (ML092530241) 2.7 First Energy Nuclear Operang Company Leer L-09-244, Supplemental Informaon for the Review of the Beaver Valley Power Staon, Units 1 and 2, License Renewal Applicaon (TAC Nos. MD6593 and MD6594), and License Renewal Applicaon Amendment No. 42, dated September 8, 2009 (ML092530242) 2.8 First Energy Nuclear Operang Company Leer L-09-245, Supplemental Informaon for the Review of the Beaver Valley Power Staon, Units 1 and 2, License Renewal Applicaon (TAC Nos. MD6593 and MD6594), and License Renewal Applicaon Amendment No. 43, dated September 14, 2009 (ML092590047) 2.9 NUREG-1929, Volumes 1 and 2, Safety Evaluaon Report Related to the License Renewal of Beaver Valley Power Staon, Units 1 and 2, Docket Nos. 50-334 and 50-412, October 2009 2.10 Beaver Valley Power Staon, Unit 2 Renewed Operang License, License No. NPF-73 (Amendment No. 194) 2.11 Beaver Valley Power Staon, Unit 2 Updated Final Safety Analysis Report, Revision 18
Page 9 of 60 Appendix I - Summary of Examinaons Performed During Refueling Outage 2R24 (Random Examinaon Areas)
Page 10 of 60 Unit 2 Dome Liner Plate Random UT Examinaon Results (Performed 10/22/2024 - 10/24/2024)
Component ID (Grid No.)
Data Source (Reference No.)
Nominal Plate Thickness (in.)
Minimum Measured UT Thickness (in.)
Minimum Thickness
(% of Nominal)
Maximum Measured UT Thickness (in.)
Average Measured UT Thickness Within Grid (in.)
Comments RN-001 2.1 1/2 0.463 92.6 0.488 0.486 See Note 1 RN-002 2.1 1/2 0.479 95.8 0.499 0.498 See Note 1 RN-003 2.1 1/2 0.500 100 0.508 0.507 See Note 1 RN-004 2.1 1/2 0.473 94.6 0.500 0.496 See Note 1 RN-005 2.1 1/2 0.496 99.2 0.502 0.501 See Note 1 RN-006 2.1 1/2 0.477 95.4 0.500 0.497 See Note 1 RN-007 2.1 1/2 0.488 97.6 0.499 0.498 See Note 1 RN-008 2.1 1/2 0.489 97.8 0.516 0.513 See Note 1 RN-009 2.1 1/2 0.497 99.4 0.510 0.509 See Note 1 RN-010 2.1 1/2 0.489 97.8 0.507 0.504 See Note 1 RN-011 2.1 1/2 0.515 103 0.520 0.519 See Note 1 RN-012 2.1 1/2 0.500 100 0.515 0.513 See Note 1 RN-013 2.1 1/2 0.463 92.6 0.504 0.500 See Note 1 RN-014 2.1 1/2 0.489 97.8 0.518 0.510 See Note 1 Note 1: The UT examinaon report indicated that there were no areas of localized or general wall loss, plate variaons in thickness are normal and consistent with expected nominal thickness, and 100% scan was achieved with no loss of back wall signal.
Page 11 of 60 Aachment 1 Gecko Robocs Automated Ultrasonics Inspecon Report, Rev. 0, Gecko Job Number 2023-05204, approved November 1, 2024
Customer:
Method:
Asset:
Containment Liner - Dome Unit 2 Gecko Job Number:
2023-05204 Date of Inspection:
10/22/2024 - 10/24/2024 Field Technician Certification Date Signature Date Signature 11/1/2024 Alexey Gusarenko PCN UT Level II 10/24/2024 Alexey Gusarenko Data Analyst Certification Robert Moran Brad Hastings Certification Report Revision: 0 Automated Ultrasonics Inspection Report Rapid Ultrasonic Gridding (RUG) Examination Vistra, Beaver Valley Shippingport PA 15001 Project Manager ASNT UT Level III Date Signature 11/1/2024 Reviewed by
Gecko Job Number: 2023-05204 Table of Contents RUG Data Images....................................................................................
21 5.0 Intro to Rapid Ultrasonic Gridding (RUG)..................................................................
35 4.0 6
3.1
- Images...........................................................................................
20 2.0 Inspection Data Sheet.................................................................................
5 3.0 Section Page 1.0 Inspection Summary.................................................................................
3 1.1
- Inspection Scope...................................................................................
3 1.2
- Inspection Summary................................................................................
3 Data Overview......................................................................................
Report Revision: 0 Page 2 of 36
Gecko Job Number: 2023-05204 Inspection Summary Inspection Scope:
Inspection Summary:
Gecko Robotics was contracted to perform a Rapid Ultrasonic Gridding (RUG) Examination on the Dome Unit 2 (Containment Liner) at the Vistra, Beaver Valley facility in Shippingport PA 15001.
Vistra, Beaver Valley identified 1' X 1' Random locations for the RUG Inspection. The inspection resolution is 1" x 1" and the deliverable resolution is 3" x 3".
The material for the Dome Unit 2 is carbon steel with a nominal thickness of 0.500". The surface temperature was 71° at the time of inspection.
RN-001 The minimum thickness detected was 0.463" with an average thickness of 0.486".
RN-002 The minimum thickness detected was 0.479" with an average thickness of 0.498".
RN-003 The minimum thickness detected was 0.500" with an average thickness of 0.507".
RN-004 The minimum thickness detected was 0.473" with an average thickness of 0.496".
RN-005 The minimum thickness detected was 0.496" with an average thickness of 0.501".
RN-006 The minimum thickness detected was 0.477" with an average thickness of 0.497".
RN-007 The minimum thickness detected was 0.488" with an average thickness of 0.498".
RN-008 The minimum thickness detected was 0.489" with an average thickness of 0.513".
RN-009 The minimum thickness detected was 0.497" with an average thickness of 0.509".
RN-010 The minimum thickness detected was 0.489" with an average thickness of 0.504".
Section: 1.0 l Report Revision: 0 A total of 183,662 UT readings were collected on the Dome Unit 2 (Containment Liner) with RUG. The maximum difference from nominal detected was 7.40%.
Page 3 of 36
Inspection Summary Gecko Job Number: 2023-05204 Inspection Summary (continued):
RN-011 The minimum thickness detected was 0.515" with an average thickness of 0.519".
RN-012 The minimum thickness detected was 0.500" with an average thickness of 0.513".
RN-013 The minimum thickness detected was 0.463" with an average thickness of 0.500".
RN-014 The minimum thickness detected was 0.489" with an average thickness of 0.510".
Notes:
No areas examined are below the site engineering stated minimum thickness of 0.450. No areas of localized or general wall loss.
Section: 1.0 l Report Revision: 0 Page 4 of 36
Asset Information Inspection Procedure Inspection Equipment Calibration Standard Calibration Calibration Verification Sensor Payload:
Sensor #
Sensor #
Sensor #
Sensor #
1 7
13 19 2
8 14 20 3
9 15 21 4
10 16 22 5
11 17 23 6
12 18 24 Gecko Job Number: 2023-05204 Measurement Mode:
Mode 3 (BW2-BW1)
Procedure Title GR-TOKA-001-PRC Rev.0 General Rapid Ultrasonic Gridding Using TOKA Robots
- of Robots:
Robot/DAC Model(s):
SD-Thin Angle:
0° 80% +/-6dB 80% +/-6dB Type:
5-Step Block (0.100"-0.500")
Thin Step:
0.100
Material:
Carbon Steel Thick Step:
0.500
10/22/2024 1:20 PM 10/23/2024 Amplitude 10/24/2024 9:15 AM 1
TOKA 4.1 Robot/DAC S/N(s):
Inspection Software:
Analysis Software:
Couplant Type:
U11RAA U11SB6 N/A N/A U11RB9 U11SAQ N/A N/A Sensor Frequency:
10 MHz Sensor S/N Sensor S/N Sensor S/N Payload #1 Payload Type:
Coating:
Yes Temperature:
71°F Procedure:
U11SBF N/A N/A U119TQ U11S9R N/A N/A U11GI4 U11SAK N/A N/A Wave Mode:
Longitudinal Inspection Data Sheet Asset:
Material:
Nominal:
Dimensions:
Containment Liner - Dome Unit 2 Carbon Steel 0.500" Diameter: 1' l Height 1' Inspection Surface:
Service Side Surface Condition:
Clean Sensor Diameter:
0.125" U11OOF U11SAX N/A N/A U11RA3 Water Sensor S/N Distance 1:00 PM Date Time 80% +/-6dB S/N:
3097-20 Verification Step:
0.400
Section: 2.0 l Report Revision: 0 CB400000032 RC 6.9.3 IDA Tools Page 5 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" Gecko Job Number: 2023-05204 1'
0
Reference:
0 l 0 Client Provided Drawing Plate B02, Location 001 1'
Section: 3.0 l
Report Revision: 0 Page 6 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Section: 3.0 l
Report Revision: 0 Client Provided Drawing Plate B04, Location 002 Page 7 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate B12, Location 003 Section: 3.0 l
Report Revision: 0 Page 8 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate B17, Location 004 Section: 3.0 l
Report Revision: 0 Page 9 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate B18, Location 005 Section: 3.0 l
Report Revision: 0 Page 10 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate C04, Location 006 Section: 3.0 l
Report Revision: 0 Page 11 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate C14, Location 007 Section: 3.0 l
Report Revision: 0 Page 12 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate C17, Plate 008 Section: 3.0 l
Report Revision: 0 Page 13 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate C22, Location 009 Section: 3.0 l
Report Revision: 0 Page 14 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Section: 3.0 l
Report Revision: 0 Client Provided Drawing Plate 34, Location 010 Page 15 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate D02, Location 011 Section: 3.0 l
Report Revision: 0 Page 16 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate D03, Location 012 Section: 3.0 l Report Revision: 0 Page 17 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Client Provided Drawing Plate D08, Location 013 Section: 3.0 l
Report Revision: 0 Page 18 of 36
Data Overview Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Section: 3.0 l
Report Revision: 0 Client Provided Drawing Plate D20, Location 014 Page 19 of 36
Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" Gecko Job Number: 2023-05204 1'
0
Reference:
0 l 0 Robot Deployment Paste Right Image Here Use CTRL+q to fit & center your image in the cell.
Digital Image Section: 3.1 l
Report Revision: 0 1'
Liner Manufactiing Flaws Paste Left Image Here Use CTRL+q to fit & center your image in the cell.
Page 20 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" Gecko Job Number: 2023-05204 Location:
RN-001 Comments Nominal Thickness:
0.488
7.40%
0.486
1' 0
Reference:
0 l 0 No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Measurements Maximum Thickness:
Difference From Nominal (%):
Average Thickness:
Section: 4.0 l
Report Revision: 0 Minimum Thickness:
0.500
0.463
1' Page 21 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Location:
RN-002 Nominal Thickness:
Average Thickness:
Minimum Thickness:
0.500
0.479
0.499
4.20%
0.498
Difference From Nominal (%):
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Measurements Comments Maximum Thickness:
Section: 4.0 l
Report Revision: 0 Page 22 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 0.500
0.508
0.00%
0.507
Average Thickness:
Location:
RN-003 0.500
Measurements Nominal Thickness:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Difference From Nominal (%):
Minimum Thickness:
Maximum Thickness:
Section: 4.0 l
Report Revision: 0 Comments Page 23 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 0.500
0.473
0.500
5.40%
0.496
Location:
Minimum Thickness:
Measurements Average Thickness:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Comments Maximum Thickness:
Nominal Thickness:
RN-004 Difference From Nominal (%):
Section: 4.0 l
Report Revision: 0 Page 24 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Section: 4.0 l
Report Revision: 0 0.500
0.496
0.502
0.80%
0.501
Minimum Thickness:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Nominal Thickness:
Average Thickness:
Location:
RN-005 Comments Measurements Maximum Thickness:
Difference From Nominal (%):
Page 25 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Minimum Thickness:
Maximum Thickness:
Difference From Nominal (%):
0.500
0.500
4.60%
0.497
Section: 4.0 l
Report Revision: 0 Comments Measurements Average Thickness:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Nominal Thickness:
0.477
Location:
RN-006 Page 26 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 0.500
0.488
0.499
2.40%
0.498
Average Thickness:
Difference From Nominal (%):
RN-007 Maximum Thickness:
Nominal Thickness:
Minimum Thickness:
Comments Measurements Location:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Section: 4.0 l
Report Revision: 0 Page 27 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Nominal Thickness:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Average Thickness:
Minimum Thickness:
Maximum Thickness:
Difference From Nominal (%):
0.513
0.500
0.489
0.516
2.20%
Location:
RN-008 Measurements Comments Section: 4.0 l
Report Revision: 0 Page 28 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Nominal Thickness:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Minimum Thickness:
Difference From Nominal (%):
Average Thickness:
0.500
0.497
0.510
0.60%
0.509
Maximum Thickness:
Location:
RN-009 Measurements Comments Section: 4.0 l
Report Revision: 0 Page 29 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Location:
RN-010 Measurements Comments Nominal Thickness:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Minimum Thickness:
Difference From Nominal (%):
Average Thickness:
0.500
0.489
0.507
2.20%
0.504
Maximum Thickness:
Section: 4.0 l
Report Revision: 0 Page 30 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Location:
RN-011 Measurements Comments Maximum Thickness:
Section: 4.0 l
Report Revision: 0 No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Minimum Thickness:
Difference From Nominal (%):
Average Thickness:
Nominal Thickness:
0.500
0.515
0.520
0.00%
0.519
Page 31 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Location:
RN-012 Measurements Comments Maximum Thickness:
Section: 4.0 l
Report Revision: 0 No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Minimum Thickness:
Difference From Nominal (%):
Average Thickness:
Nominal Thickness:
0.500
0.500
0.515' 0.00%
0.513
Page 32 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Location:
RN-013 Measurements Comments Nominal Thickness:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Minimum Thickness:
Difference From Nominal (%):
Average Thickness:
0.463
0.504
7.40%
0.500
0.500
Maximum Thickness:
Section: 4.0 l
Report Revision: 0 Page 33 of 35
RUG Data Images Client:
Vistra, Beaver Valley Asset:
Diameter(ft):
Height(ft):
Nominal:
Location:
Shippingport PA 15001 Containment Liner - Dome Unit 2 0.500" 1'
0
Reference:
0 l 0 1'
Gecko Job Number: 2023-05204 Location:
RN-014 Maximum Thickness:
Section: 4.0 l
Report Revision: 0 Measurements Comments Nominal Thickness:
No areas of localized or general wall loss. Plate variations in thickness are normal and consistent with expected nominal thickness. 100% scan achieved with no loss of back wall signal.
Minimum Thickness:
Difference From Nominal (%):
Average Thickness:
0.500
0.489
0.518
2.20%
0.510
Page 34 of 35
Gecko Job Number: 2023-05204 Intro to Rapid Ultrasonic Gridding (RUG)
The image above illustrates the final binned data output in Gecko Robotics software, on the left side, and a view of the original unbinned data within each data point on the right. This unbinned view is an internal function for data validation and localization.
Section: 6.0 l Report Revision: 0 A RUG inspection is a robot-enabled ultrasonic inspection that produces thickness grid maps to identify areas where corrosion and other damage mechanisms have caused wall-thinning. RUG is a replacement for traditional hand-held gridding with variable grid sizes from 12 x 12 to 1 x 1.
Typically, data collection occurs on a 1" x 1" grid (referred to as inspection resolution) and is then presented on a 3" x 3" grid (known as deliverable resolution).
The procedure that transitions the inspection resolution of 1" x 1" to the deliverable resolution of 3" x 3" is commonly known as binning. The act of binning involves identifying the lowest thickness measurement within a specific 3" x 3" area, which consists of nine data points.
Page 35 of 35
Page 47 of 60 Aachment 2 Beaver Valley Power Staon, Engineering Evaluaon of Unit 2 Liner Locaon 2RN-063, dated December 9, 2024
ISi Memorandum To:
File Date: December 9, 2024 From:
Nick Libonati L/LIJ,,.-
2024.12.09
/v-f~
15:52:10-05'00' Peer Review:
Tom Westbrook f!Tonv <J}f~-c,,(per telecon)
Subject:
Engineering Evaluation of Unit 2 Liner Location 2RN-063
==
Introduction:==
The purpose of this memorandum is to provide an Engineering Evaluation of a specific area of the Unit 2 Containment Building steel liner. The specific area of the liner, designated as 2RN-063, was examined using Non-Destructive Testing (NDE) ultrasonic testing {UT) techniques during refueling outage 2R15 in October of 2011. The purpose of the exam was to determine if the liner area had evidence of degradation, thinning, external corrosion or other detectable conditions that would affect the integrity or fitness for the intended design function of the liner. Thei one-foot by 1-foot area was one of 75 areas randomly selected for examination as a Unit 2 License Renewal Commitment. Since the initial UT examination of 2RN-063 during 2R15, additional UT examinations were performed during subsequent refueling outages to monitor the area for any observable changes in thickness, length, width or appearance. This memorandum focuses on the review and evaluation of the documentation pertinent to the characterization of the identified areas of interest in order to determine if the expansion of scope is necessary pursuant to NRC Letter, L-09-242 (Reference 7).
Data Collection and Analysis:
For initial UT examinations, the qualified UT examiner manually scanned the 12" by 12" marked area by slowly moving the transducer across the area and observing the displayed digital thickness value and the instrument A-scan display for thickness fluctuations. During the manual UT examination of Location 2RN-063, an indication, having a general thickness of 0.292" was observed.
To further characterize the signal responses, the FE NOC Level Ill recommended performing an auto-scan to obtain a digital record of the examination, as well as to allow subsequent analysis of the signal responses using the data analysis featurns of the auto-scan software. The scanning parameters were selected to obtain and digitize UT signal responses every 0.050" in both stroke (Y) axis and travel (X) axis.
This scanning increment results in 400 captured signal responses in every square inch of the scanned areas.
The auto-scan of the Location 2RN-063 verified the presence of the Nelson studs and the original indication measuring 0.300" in the horizontal axis by 0.250" in the vertical axis. An area of lower thickness than the surrounding area was also observed beginning near the original isolated indication and continuing beyond the 12" by 12" examination area. Field analysis of the auto-scan led to a decision to expand the scan to the right of the original examination area. The expanded area identified a broader area having lower than expected thickness. This area measured approximately 2" (vertical) by 10" (horizontal}.
The statistical screening criterion for the liner examination is 90% of the nominal plate thickness. The nominal plate thickness at Location 2RN--063 is 0.375", making the criteria 0.338". However, the minimum
design thickness for the general wall of the liner at this location is 0.213". For a pit having the dimensions noted above, the minimum required thickness is 0.032". Therefore, the corrosion observed at Location 2RN-063 does not challenge the structural integrity of the liner but does fall below the statistical screening criterion.
Comparison of initial and subsequent ultrasonic data The speci"c areas of concern (including the additional scan areas adjacent to the original 12-inch by 12-inch area) have been designated as Indications 1 through 3. Refer to Ultrasonic Examination Report UT 1007 attachments for images of the initial 2RN-063 scan area and UT C-scan (plan view) UT analysis images that graphically illustrate the overall UT data analysis. It should be noted that the color palate has been adjusted to provide color change in the analysis image to re"ect very small dierences in thickness for illustrative purposes. This adjustment of palate is one of the UT analysis techniques employed during evaluation of automated scanning data. Report UT-14-1007 was selected as the best overview and graphic presentation of the scanned areas and results for those with limited experience or understanding of ultrasonic NDT. It should also be noted that the UT monitoring examination performed in 2014 and identi"ed an additional area (designated as indication #4) that was.001 under the screening criterion of 0.337. The table below summarizes the initial and subsequent UT examination results:
BVPS Unit 2 Containment Liner area 2RN-063 Indication 2R15 2R16 2R17 2R18 2R21 Technique 1
.310
.309
.308
.307
.308 Auto-scan 2
.302
.303
.309
.314
.301 Auto-scan 3
.267
.266
.275
.282
.265 Auto-scan 4
N/A N/A
.336
.341
.335 Manual Ultrasonic Testing accuracy, limitations and observed variations The accuracy of UT techniques applied for the initial and subsequent examinations have been demonstrated to be repeatable, accurate and consistent, which is a testament to the individuals who performed the examinations, and the quality of the instrumentation used. The initial examination was performed manually with hand-held dual-element search units and UT instrumentation monitoring the screen presentation while manually moving the search unit. The subsequent use of automated scanning equipment allowed the capture of the signal response of a motor-driven UT scanner which pulsed, received and recorded a signal response every.050 as the scanner traveled over the surface of the designated area.
The automated system was used for the initial automated investigation and subsequent monitoring examinations in 2011, 2012, 2014, and 2015. The "nal monitoring examination in 2021 was performed manually due to the unavailability of the automated scanner due to UT circuit board failure. In all cases, the results were nearly identical, but the manual examinations obviously do not allow the graphic post-examination and analysis of results. From the data available the following data sensitivity review was performed:
Considering the plate did not gain additional thickness (shown in green boxes above) and the UT probes
+/-0.005. measurement error, this data review indicates there is no evidence conclude there was any actual wall loss during the monitoring period.
Outage, 2R 1
2 3
4 15 0.310 0.302 0.267 16 0.309 0.303 0.266 17 0.308 0.309 0.275 0.336 18 0.307 0.314 0.282 0.341 22 0.308 0.301 0.265 0.335 T avg-error 0.303 0.301 0.266 0.332 Tmeasured.min 0.307 0.301 0.265 0.335 T avg 0.308 0.306 0.271 0.337 Tmeasured.max 0.310 0.314 0.282 0.341 T avg+error 0.313 0.311 0.276 0.342 Dmax-min 0.003 0.013 0.017 0.006 Indication Number Data Sensitivity Review 0.200 0.220 0.240 0.260 0.280 0.300 0.320 0.340 0.360 0.380 0.400 15 16 17 18 19 20 21 22 Liner Thickness (in.)
Refueling Outage Number Liner Thickness Trend 1
2 3
4
Evaluation of Operating Experience There is no operating experience (OE) for containment liner through-wall degradation for Unit 2, however,
for Unit 1, two condition reports were identi"ed. Using this OE, the following evaluation was compiled:
Based on this evaluation, the postulated wall losses for the periods of erection to discovery, erection to 2R22 (end of monitoring period), and during the monitoring period far exceed the results of all UT measurements captured pertaining to 2RN-063. Thus, if these indications were consistent with Unit 1 OE, the expected wall thickness at the time of discovery would have been 0.070 and would have propagated through-wall prior to 2R22.
Potential Causes of Observed exterior containment liner Plate thickness variations Since the discovery of the indications a number of possible causes have been evaluated and considered.
Since the exterior of the plate is inaccessible, there are no additional NDE methods available to further investigate the condition. Potential causes include plate laminations during the forming process, subsequent handling and forming when the plate was processed to achieve the required curvature of the containment structure. Storage or exposure to moisture during transit, storage or rigging and "tting problems when the steel plates were being welded together during the erection of the containment liner.
Heavy grinding or hammering to achieve the desired spacing between the adjacent plates during welding.
Finally, it may have been caused by improper grinding in preparation for installation of the Nelson studs on the exterior of the liner plate. Occurrences of related fabrication de"ciencies are identi"ed in Reference 6, the Speci"cation for the Containment Liner. Attachment 1 includes pictures of the Unit 2 containment building fabrication which show the complexity of the rebar reinforcement structure and exposure to the elements during erection, indicating potential for rainwater to have been dripping at this location during fabrication, prior to concrete pour.
Conclusion In summary, based on all available data/information and with consideration to plant operating experience and potential causes, the indications are believed to be a product of the fabrication/erection process, since there no evidence of in-service degradation. Pursuant to NRC Letter, L-09-242 attachment Supplemental Jun-1972 Jun-1979 Apr-2009 Mar-2011 Oct-2013 Oct-2021 36.9 yr.
31.8 yr.
41.4 yr.
42.4 yr.
0.375 in.
10.6 yr.
0.010 in./yr.
0.375 in.
0.009 in./yr.
0.010 in./yr.
0.010 in./yr.
0.305 in.
0.407 in.
0.102 in.
Est. Unit 2 Shell Pour 2RN-063 Discovery 2R22 Exam Time to Discovery Time to 2R22 Monitoring Period Tnom Plate U1 OE Average Rate PWL(1) to Discovery Time to OE #1 thru-wall Time to OE #2 thru-wall Est. Unit 1 Shell Pour OE#1: CR-2009-57762 OE#2: CR-2013-15843 Unit 1 Operating Experience Evaluation Unit 2 Discovery Timeline Evaluation OE #2 Degredation Rate PWL to 2R22 PWL Monitoring (1) Postulated Wall Loss (based on OE)
Tnom Plate Average Rate OE #1 Degredation Rate
Information Regarding Beaver Valley Power Station, Units 1 and 2, License Renewal Application, Section B.2.3, which, the response to question 1:
Describe the failure criteria for volumetric (UT) examination which will trigger the UT scanning at additional locations. In establishing the criteria, distinguish between the criteria used; (1) if the metal thinning is attributed to degradation on the inside surface of the liner, and (2) if the metal thinning is attributable to the exterior surface (in contact with the containment concrete) of the liner.
states:
FENOC intends to characterize locations with greater than 10% loss of material and displaying breadth and shape as statistical failures unless through engineering evaluation it is determined that indications are attributed to fabrication/erection practices.
Therefore, expanded scope is not required.
References:
- 1. CR-2011-90997
- 2. CR-2011-91213
- 3. Report UT-14-1007
- 4. CR-2009-57762
- 5. CR-2013-15843
- 6. 2BVS-0065, Speci"cation for Reactor Containment Liner and Embedments
- 7. NRC Letter, L-09-242
- 8. NRC Letter, L-09-245 Unit 2 Construction Page 1 of 8 Unit 2 Construction Page 2 of 8 Unit 2 Construction Page 3 of 8 Unit 2 Construction Page 4 of 8 Unit 2 Construction Page 5 of 8 Unit 2 Construction Page 6 of 8 The use of tarps and scaolding on the Containment shell during fabrication and erection processes presents potential for rainwater drain paths.
Unit 2 Construction Page 7 of 8 Containment dome exposed to the elements prior to lift and installation.
Unit 2 Construction Page 8 of 8