RS-25-043, Enclosure 2: Dresden Nuclear Power Station, Units 2 and 3, Subsequent License Renewal Application Commitment List Update

Enclosure 2: Dresden Nuclear Power Station, Units 2 and 3, Subsequent License Renewal Application Commitment List Update

ML25072A156
Person / Time
Site:	Dresden
Issue date:	03/13/2025
From:	Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation
Shared Package
ML25072A153	List: ML25072A154 ML25072A155 RS-25-043, Enclosure 2: Dresden Nuclear Power Station, Units 2 and 3, Subsequent License Renewal Application Commitment List Update
References
RS-25-043
Download: ML25072A156 (1)

Text

March 13, 2025 Enclosure B Page 1 of 16 Enclosure B Dresden Nuclear Power Station, Units 2 and 3, Subsequent License Renewal Application Commitment List Update Introduction This enclosure identifies the commitments made in the document and serves as an update to the Dresden Nuclear Power Station SLRA Appendix A, Section A.5, Subsequent License Renewal Commitment List. Any other actions discussed in the submittal represent intended or planned actions. They are described to the NRC for informational purposes and do not constitute regulatory commitments.

The changes to the Dresden SLRA Appendix A, Section A.5, Subsequent License Renewal Commitment List, (Table A.5) are a result of this SLRA Supplement.

Previously submitted information is shown in normal font, while additions due to this submittal are highlighted with bolded italics for the inserted text, and strikethroughs for the deleted text.

March 13, 2025 Enclosure B Page 2 of 16 SLRA Table A.5, Subsequent License Renewal Commitment List, Item 27, Buried and Underground Piping and Tanks, on pages A-80 through A-83, is revised as shown below:

TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 27 Buried and Underground Piping and Tanks Buried and Underground Piping and Tanks is an existing program that will be enhanced to:

1. Perform direct visual inspections of one 10-linear foot section of buried stainless steel piping during each 10 year period beginning 10 years prior to the subsequent period of extended operation. Piping inspection location will be selected based on risk (i.e., susceptibility to degradation and consequences of failure). Inspections will utilize a method that has been demonstrated to be capable of detecting cracking, whenever coatings are removed exposing the base material.

2. Perform direct visual inspections of two 10-linear foot sections of buried polymeric carbon fiber reinforced polymer (CFRP) piping during each 10 year period beginning 10 years prior to the subsequent period of extended operation.

Piping inspection locations will be selected based on risk (i.e., susceptibility to degradation and consequences of failure).

3. Perform two direct visual inspections of 10 linear foot segments of buried carbon steel piping within the scope of license renewal during each 10 year period beginning 10 years prior to the subsequent period of extended operation. The number of inspections will be increased to nine 10 linear foot segments of buried carbon steel piping within the scope of license renewal if either of the following criteria are not met for the cathodic protection system protecting the buried steel piping within the scope of license renewal:

a. System is maintained operational at least 85 percent of the time since 10 years prior to the subsequent period of extended operation (excluding time periods in which the cathodic protection system is off-line for testing)

Program will be enhanced no later than six months prior to the subsequent period of extended operation.

Inspections that are required to be performed prior to the subsequent period of extended operation will be completed within the 10 years prior to the subsequent period of extended operation, and no later than the last refueling outage prior to the subsequent period of extended operation.

Section A.2.1.27 CEG Letter DNPS SLRA Supplement No. 2, dated March 13, 2025

March 13, 2025 Enclosure B Page 3 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 27 Buried and Underground Piping and Tanks (continued)

b. System has provided effective protection for buried steel piping as verified through acceptable annual system testing results 80% of the time since 10 years prior to the subsequent period of extended operation. Testing results for cathodic protection systems protecting steel piping is acceptable if instant off potential is -850 mV or more negative, relative to a copper/copper sulfate reference electrode.

4. Perform guided wave inspections of the common (Unit 2/3) nonsafety-related aluminum High Pressure Coolant Injection (HPCI) System suction line from the contaminated condensate storage tank to the Diesel Generator & HPCI Building.

Guided wave examinations will be performed during each 10 year period beginning 10 years prior to the subsequent period of extended operation from within the Diesel Generator & HPCI Building and from the B contaminated condensate storage tank. If examination results indicate active corrosion is occurring, then direct examination of suspect areas will be performed. If direct examination identifies loss of material that could result in a loss of pressure boundary function when extrapolated to the end of the subsequent period of extended operation, then an analysis will be conducted to determine the extent of condition and extent of cause. Additional corrective actions (e.g., repair, replacement, increased inspection sample size, increased inspection frequency) will be initiated in accordance with the corrective action program based on the extent of condition and extent of cause analysis.

March 13, 2025 Enclosure B Page 4 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 27 Buried and Underground Piping and Tanks (continued)

5. Perform extent of condition inspections for steel and stainless steel piping as follows: When measured pipe wall thickness, projected to the end of the subsequent period of extended operation, does not meet the minimum pipe wall thickness requirements due to degradation of the external surface, the number of inspections within the affected piping categories will be doubled or increased by five, whichever is smaller. If adverse indications are found in the expanded sample, an analysis will be conducted to determine the extent of condition and extent of cause. The scope of the follow-up inspections will be determined based on the analysis. Timing of any additional inspections will be based on the severity of the identified degradation and the consequences of leakage or loss of function. Any additional inspections will be performed within the same 10 year inspection interval in which the original degradation was identified, or within four years after the end of the 10 year interval if the degradation was identified in the latter half of the 10 year interval. Expansion of sample size may be limited by the extent of piping subject to the observed degradation mechanism or if the piping system or portion of the system is replaced or otherwise mitigated within the same 10 year inspection interval in which the original degradation was identified or within four years after the end of the 10 year interval, if the degradation was identified in the latter half of the 10 year interval.

6. Perform annual system monitoring of the cathodic protection system to ensure effective protection of buried piping with a grace period of up to two months.

However, in each calendar year, system monitoring is conducted at least once.

7. Perform volumetric examination of a minimum of 25 percent of the internal tank surface of buried fuel oil tanks within the scope of license renewal during each 10 year period, beginning 10 years prior to the subsequent period of extended operation if either of the following criteria are not met for the cathodic protection system protecting the individual buried steel tank:

a. System is maintained operational at least 85 percent of the time since 10 years prior to the subsequent period of extended operation (excluding time periods in which the cathodic protection system is off-line for testing).

March 13, 2025 Enclosure B Page 5 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 27 Buried and Underground Piping and Tanks (continued)

b. System has provided effective protection for the buried steel tank as verified through acceptable annual system testing results 80% of the time since 10 years prior to the subsequent period of extended operation. Testing results for cathodic protection systems protecting the steel tanks is acceptable if instant off potential is -850 mV or more negative, relative to a copper/copper sulfate reference electrode.

8.

Perform direct visual inspection of one 10-linear foot section of underground steel pipe located in the condensate piping vault during each 10 year period beginning 10 years prior to the subsequent period of extended operation.

9. Utilize the 100 mV minimum polarization cathodic protection acceptance criterion for aluminum piping within the scope of the program.

10. Perform monthly monitoring of the makeup flow rate from the plant service water system to the fire protection system. The results will be trended to establish a baseline and indications of abnormal flows or increasing trends will be investigated in accordance with the corrective action program. If unexplained changes to the makeup rate to the fire protection system are identified, then a flow test will be performed by the end of the next refueling outage.

11. Perform monitoring of the volume of makeup water supplied to the 2/3 A(B)

Condensate Storage Tanks (CST) from the makeup demineralizer system.

The results will be trended to establish a baseline and indications of abnormal makeup requirements or increasing makeup trends will be investigated in accordance with the corrective action program. If unexplained changes to the volume of makeup water to the 2/3 A(B)

Condensate Storage Tanks (CST) are identified, then the source of water loss will be investigated to determine if water loss is occurring through the buried aluminum HPCI line within the scope of the program.

March 13, 2025 Enclosure B Page 6 of 16 SLRA Table A.5, Subsequent License Renewal Commitment List, Item 29, ASME Section XI, Subsection IWE, on pages A-84 is revised as shown below:

TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 29 ASME Section XI, Subsection IWE ASME Section XI, Subsection IWE is an existing program that will be enhanced to:

1.

Perform surface or enhanced visual examination (e.g., EVT-1) on accessible portions of a representative sample (i.e., 20 percent of population) of high-temperature one Main Steam System and one Feedwater System drywell penetrations subject to cyclic loading and stress corrosion cracking, to detect cracking, once per 10-year interval during the subsequent period of extended operation.

2.

Implement a one-time supplemental volumetric examination of the containment metal shell surfaces that are inaccessible from one side, if triggered by plant-specific OE. The trigger for this supplemental examination is plant-specific occurrence or recurrence of metal shell corrosion (base metal material loss exceeding 10 percent of nominal plate thickness over a local area as defined by ASME Section III 1965, Section N-513.3), initiated on the inaccessible side or areas, identified since the date of issuance of the first renewed license. For the purposes of this enhancement, a local area is defined as a circular area with a radius defined by 1/2 of the square root of the product of the drywell shell diameter times the shell thickness at the location in question. This supplemental volumetric examination consists of a sample of one-foot square locations that include both randomly-selected and focused areas most likely to experience degradation based on plant-specific OE and/or other relevant considerations such as environment. The sample size, locations, and any needed scope expansion (based on findings) for this one-time set of volumetric examinations should be determined on a plant-specific basis to demonstrate statistically with 95 percent confidence that 95 percent of the accessible portion of the containment liner is not experiencing corrosion degradation with greater than 10 percent loss of nominal thickness. If required, the corrective action program will be used to determine the timing of the supplemental volumetric Program will be enhanced no later than six months prior to the subsequent period of extended operation.

If required, the supplemental one-time examinations will be performed in accordance with the schedule identified in the commitment.

Section A.2.1.29 CEG Letter DNPS SLRA Supplement No. 2, dated March 13, 2025

March 13, 2025 Enclosure B Page 7 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 29 ASME Section XI, Subsection IWE (continued) examinations will be completed within two refueling outages of identification of the triggering metal shell corrosion or sooner, as determined by the corrective action program based on the severity of the identified degradation. Additionally, the corrective action program will be used to assess the results of the one-time inspection and determine the extent of examinations for the other unit.

3.

Provide guidance for proper selection of bolting material and lubricants, and appropriate installation torque or tension to prevent or minimize loss of bolting preload and cracking of high-strength bolting consistent with EPRI NP-5067 and TR-104213. Also, provide guidance for storage, lubricant selection, and bolting and coating material selection consistent with Section 2 of Research Council on Structural Connections (RCSC) publication Specification for Structural Joints Using High-Strength Bolts.

March 13, 2025 Enclosure B Page 8 of 16 SLRA Table A.5, Subsequent License Renewal Commitment List, Item 30, ASME Section XI, Subsection IWF, on pages A-85 and A-86, is revised as shown below:

TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 30 ASME Section XI, Subsection IWF ASME Section XI, Subsection IWF is an existing program that will be enhanced to:

1.

Perform periodic evaluations of the acceptability of inaccessible areas of supports (e.g., portions of supports encased in concrete, buried underground, or encapsulated by guard pipe), when conditions exist in accessible areas that could indicate the presence of, or result in, degradation to inaccessible areas of supports. Perform these evaluations once every 10 years during the subsequent period of extended operation.

2.

Perform a one-time inspection of an additional five percent of the currently inspected sample size specified in Table IWF-2500-1 for Class 1, 2, and 3 piping supports. The one-time inspection will be conducted within five years prior to entering the subsequent period of extended operation. The additional supports will be selected from the remaining population of IWF piping supports not already included in the current inspection sample. The expanded sample locations will be selected to include components that are more susceptible to age-related degradation (i.e., based on factors such as time in service, material, and aggressiveness of the environment) than those not in the sample.

3.

Revise procedures to require volumetric examination of high-strength bolting (actual measured yield strength greater than or equal to 150 ksi) in sizes greater than 1-inch nominal diameter (including ASTM A490 and equivalent ASTM F2280), if additional high-strength bolting is installed during the subsequent period of extended operation. The examination shall be comparable to that of ASME Code Section XI, Table IWB-2500-1, Examination Category B-G-1 and performed at least once per 10-year interval to detect cracking, in addition to the VT-3 examination required by ASME Section XI.

4.

Provide guidance regarding the selection of supports to be examined in subsequent inspection intervals when a support that is acceptable for continued service, as defined in IWF-3400, is restored in accordance with the corrective action program. The enhanced guidance will ensure that the successive inspection is increased or modified to include another support, of the same type and function, that has not been restored to correct the observed condition.

Program will be enhanced no later than six months prior to the subsequent period of extended operation.

One-Time inspections will be completed within the five years prior to the subsequent period of extended operation and no later than the last refueling outage prior to the subsequent period of extended operation.

Section A.2.1.30 CEG Letter DNPS SLRA Supplement No. 2, dated March 13, 2025

March 13, 2025 Enclosure B Page 9 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 30 ASME Section XI, Subsection IWF (continued)

5.

Perform volumetric examination comparable to that of ASME Code Section XI, Table IWB-2500-1, Examination Category B-G-1, of twelve high strength bolts at each of the reactor vessel support skirts, one time per 10-year interval during the subsequent period of extended operation. The selection of the samples will consider susceptibility to stress corrosion cracking (e.g., actual measured yield strength) and ALARA principles. If the volumetric examination of these bolts reveals conditions that do not meet acceptance criteria, then the results will be entered into the corrective action program and the inspection will be expanded to include additional high strength bolts used at the reactor vessel support skirt to ring girder, which is comparable to the methodology used by the ASME Code, Section IWF-2430 for IWF component supports.

March 13, 2025 Enclosure B Page 10 of 16 SLRA Table A.5, Subsequent License Renewal Commitment List, Item 33, Structures Monitoring, on pages A-86 through A-89, is revised as shown below:

TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 33 Structures Monitoring

1. Add the following structures to the scope of the program.

a. Bridge over the Units 2 and 3 intake canal

b. Radwaste Solidification Building

c. Reactor Building Interlock (Unit 3)

d. Turbine Building (Unit 1)

2. Clarify that the 138 kV Control Building and the 345 kV Control Building are within the scope of the program.

3. Shorten frequency for inspecting non-segregated bus ducts supports and the ring girder for the Reactor Vessel support skirt ring girder to an interval not to exceed five years.

4. Explicitly include the following components and commodities within the scope of the program:

a. Manholes

b. Sliding Surfaces

c. Trash Racks

5. Implement preventive actions to emphasize proper selection of bolting material and lubricants, and appropriate installation torque or tension to prevent or minimize loss of bolting preload and cracking of high-strength bolting. For ASTM A325 or ASTM A490 bolts, the preventive actions for storage, lubricant selection, and bolting and coating material selection discussed in will be in accordance with Section 2 of Research Council for Structural Connection publication Specification for Structural Joints Using High-Strength Bolts for structural bolting fabricated from ASTM A325 and ASTM A490.

6.

Clarify procedures to state that evidence of cracking, spalling, scaling, discoloration, and leaching could indicate the presence of increased porosity and permeability due to mechanisms of aggressive chemical attack or leaching of calcium hydroxide and carbonation.

Program will be enhanced and the initial engineering evaluation will be completed no later than six months prior to the subsequent period of extended operation.

Baseline inspections will be completed no later the last refueling outage prior to the subsequent period of extended operation.

Section A.2.1.33 CEG Letter DNPS SLRA Supplement No. 2, dated March 13, 2025

March 13, 2025 Enclosure B Page 11 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 33 Structures Monitoring (continued)

7. Expand the program to monitor accessible sliding surfaces for indications of significant loss of material due to wear or corrosion, and for accumulation of debris or dirt. Establish acceptance criteria for sliding surfaces as no significant loss of material due to wear or corrosion, and no debris or dirt that could restrict or prevent sliding of the surfaces, as required by design.

8. Expand the program to monitor elastomeric structural sealants, seismic joint fillers, vibration isolators, and bearing pads for cracking, loss of material, and hardening. Supplement visual inspection of elastomeric elements with tactile inspection to detect hardening if the intended function is suspect. Establish acceptance criteria for elastomeric structural sealants, seismic joint fillers, bearing pads, and vibration isolation elements as no loss of material, cracking, or hardening that can lead to loss of intended function.

9. Develop a new implementing procedure or revise an existing implementing procedure to address aging management of inaccessible areas exposed to raw water and groundwater/soil environments that will include the following:

a. Monitor raw water and groundwater chemistry, for pH, chlorides, and sulfates, on a frequency not to exceed five years that accounts for seasonal variations (e.g., quarterly monitoring every fifth year). Increase sampling locations to ensure that the results are representative of the groundwater in contact with structures within the scope of subsequent license renewal. Enter adverse results, which exceed water chemistry criteria, into the corrective action program.

b. Develop engineering evaluations to evaluate the water chemistry results to assess the impact, if any, on below-grade concrete, including the potential for degradation due to the aggressive water chemistry, as well as consideration of current conditions. As part of the engineering evaluations, determine if additional actions are warranted, which might include enhanced inspection techniques and/or increased frequency, destructive testing, and focused inspections of representative accessible (leading indicator) or below grade, inaccessible concrete structural elements exposed to the potentially aggressive environment.

c. Develop the initial engineering evaluations prior to the subsequent period of extended operation. Develop follow-up engineering evaluations on an interval not to exceed five years.

March 13, 2025 Enclosure B Page 12 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 33 Structures Monitoring (continued)

d. If warranted based on the engineering evaluations, perform focused inspections of representative, accessible (leading indicator) structural elements, or if accessible areas will not be leading indicators for the potential aging mechanisms, excavate and inspect buried concrete elements exposed to potentially aggressive groundwater/soil.

e. If degraded concrete is identified, as part of the focused inspections of leading indicators (representative, accessible or exposed inaccessible concrete), enter adverse results that exceed ACI 349.3R-02 tier 2 criteria into the corrective action program, and expose inaccessible concrete so that the extent of the condition can be determined, baseline conditions documented, and additional actions identified such as repairs, new preventive actions, additional evaluations, and future inspections.

10. Monitor and trend indications of groundwater infiltration or through-wall concrete groundwater leakage infiltration volumes. If leakage volumes allow, procedures will be revised to clarify that water chemistry analysis should be considered for parameters including pH, as well as mineral, chloride, sulfate and iron content in the water to assess for potential impact on age-related degradation of concrete or steel reinforcement. This assessment may include engineering evaluation, more frequent inspections, or destructive testing of affected concrete to validate existing concrete properties, including concrete pH levels.

11. Require that personnel performing inspections and evaluations meet the qualifications specified within ACI 349.3R-02 with respect to knowledge of inservice inspection of concrete and visual acuity requirements.

12. Evaluate the acceptability of inaccessible areas when conditions exist in accessible areas that could indicate the presence of, or result in, degradation to such inaccessible areas.

March 13, 2025 Enclosure B Page 13 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 33 Structures Monitoring (continued)

13. Perform inspections to establish quantitative baseline inspection data prior to the subsequent period of extended operation for structures in which prior inspection results are inadequate to establish a quantitative baseline to allow for effective monitoring and trending.

13. Quantitative baseline inspection data will be established against acceptance criteria provided in the enhanced Structures Monitoring program prior to the subsequent period of extended operation.

Previously performed inspections that were conducted using comparable acceptance criteria are acceptable in lieu of performing a new baseline inspection.

14. Provide evaluation criteria for structural concrete using quantitative second tier criteria of Chapter 5 in ACI 349.3R-02.

15. Clarify that loose bolts and nuts and cracked bolts are not acceptable unless accepted by engineering evaluations.

16. Provide additional guidance on visual indications such as exudations, surface staining, expansion causing structural deformation, relative movement or displacement, misalignment or distortion of attached components for detection of expansion due to alkali-aggregate reactivity in concrete.

17. Locations of degraded steel structural components due to water in-leakage in the Unit 2 torus basement will be inspected on a two-year frequency.

March 13, 2025 Enclosure B Page 14 of 16 SLRA Table A.5, Subsequent License Renewal Commitment List, Item 34, Inspection of Water-Control Structures Associated with Nuclear Power Plants, on pages A-89 through A-91, is revised as shown below:

TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 34 Inspection of Water--Control Structures Associated with Nuclear Power Plants Inspection of Water-Control Structures Associated with Nuclear Power Plants is an existing program that will be enhanced to:

1.

Add the following structures to the scope of the program:

a.

Bridge over the Units 2 and 3 intake canal

b.

Deicing Line

c.

Circulating Water Inlet Tunnel

d.

Embankments of the Unit 1 intake canal

e.

Embankments of the Units 2 and 3 intake canal

2.

Explicitly include the following components within the scope of the program:

a.

Stop logs

b.

Trash racks

c.

Traveling screen foundations

3.

Implement preventive actions to emphasize proper selection of bolting material and lubricants, and appropriate installation torque or tension to prevent or minimize loss of bolting preload and cracking of high-strength bolting. For ASTM A325 or ASTM A490 bolts, the preventive actions for storage, lubricant selection, and bolting and coating material selection discussed in will be in accordance with Section 2 of Research Council for Structural Connection publication Specification for Structural Joints Using High-Strength Bolts for structural bolting fabricated from ASTM A325 and ASTM A490.

4.

Perform above the waterline inspections of the discharge outfall structure every five years.

5.

Develop a new implementing procedure or revise an existing implementing procedure to address aging management of inaccessible areas exposed to raw water and groundwater/soil environments that will include the following:

Program will be enhanced and the initial engineering evaluation will be completed no later than six months prior to the subsequent period of extended operation.

Baseline inspections will be completed no later than the last refueling outage prior to the subsequent period of extended operation.

Section A.2.1.34 CEG Letter DNPS SLRA Supplement No. 2, dated March 13, 2025

March 13, 2025 Enclosure B Page 15 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 34 Inspection of Water--Control Structures Associated with Nuclear Power Plants (continued)

a.

Monitor raw water and groundwater chemistry, for pH, chlorides, and sulfates, on a frequency not to exceed five years that accounts for seasonal variations (e.g., quarterly monitoring every fifth year). Increase sampling locations to ensure that the results are representative of the groundwater in contact with structures within the scope of subsequent license renewal. Enter adverse results, which exceed water chemistry criteria, into the corrective action program.

b.

Develop engineering evaluations to evaluate the water chemistry results to assess the impact, if any, on below-grade concrete, including the potential for degradation due to the aggressive water chemistry, as well as consideration of current conditions. As part of the engineering evaluations, determine if additional actions are warranted, which might include enhanced inspection techniques and/or increased frequency, destructive testing, and focused inspections of representative accessible (leading indicator) or below grade, inaccessible concrete structural elements exposed to the potentially aggressive environment.

c.

Develop the initial engineering evaluations prior to the subsequent period of extended operation. Develop follow-up engineering evaluations on an interval not to exceed five years.

d.

If warranted based on the engineering evaluations, perform focused inspections of representative, accessible (leading indicator) structural elements, or if accessible areas will not be leading indicators for the potential aging mechanisms, excavate and inspect buried concrete elements exposed to potentially aggressive groundwater/soil.

e.

If degraded concrete is identified, as part of the focused inspections of leading indicators (representative, accessible or exposed inaccessible concrete), enter adverse results that exceed ACI 349.3R-02 tier 2 criteria into the corrective action program, and expose inaccessible concrete so that the extent of the condition can be determined, baseline conditions documented, and additional actions identified such as repairs, new preventive actions, additional evaluations, and future inspections.

f.

Monitor and trend indications of groundwater infiltration or through-wall concrete groundwater leakage infiltration volumes. If leakage volumes allow, procedures will be revised to clarify that water chemistry analysis

March 13, 2025 Enclosure B Page 16 of 16 TABLE A.5 - SUBSEQUENT LICENSE RENEWAL COMMITMENT LIST NO.

PROGRAM OR TOPIC COMMITMENT IMPLEMENTATION SCHEDULE SOURCE 34 Inspection of Water--Control Structures Associated with Nuclear Power Plants (continued) should be considered for parameters including pH, as well as mineral, chloride, sulfate and iron content in the water to assess for potential impact on age-related degradation of concrete or steel reinforcement. This assessment may include engineering evaluation, more frequent inspections, or destructive testing of affected concrete to validate existing concrete properties, including concrete pH levels.

6.

Evaluate the acceptability of inaccessible areas when conditions exist in accessible areas that could indicate the presence of, or result in, degradation to such inaccessible areas.

7.

Perform inspections to establish quantitative baseline inspection data prior to the subsequent period of extended operation for structures in which prior inspection results are inadequate to establish a quantitative baseline to allow for effective monitoring and trending. Quantitative baseline inspection data will be established against acceptance criteria provided in the enhanced Inspection of Water-Control Structures Associated with Nuclear Power Plants program prior to the subsequent period of extended operation.

Previously performed inspections that were conducted using comparable acceptance criteria are acceptable in lieu of performing a new baseline inspection.

8.

Provide evaluation criteria for structural concrete using quantitative second tier criteria of Chapter 5 in ACI 349.3R-02.

9.

Require that personnel performing inspections and evaluations meet the qualifications specified within ACI 349.3R-02 with respect to knowledge of inservice inspection of concrete and visual acuity requirements.

10. Clarify that loose bolts and nuts and cracked bolts are not acceptable unless accepted by engineering evaluations.

11. Perform below the waterline inspections of the discharge outfall structure every three refueling cycles.

12. Require visual inspections of submerged concrete structural components by dewatering a structure or by a diver or remote imaging equipment if the structure is not dewatered at least once every five (5) years.