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{{#Wiki_filter:9/11/2023 NRC Public Meeting TVA Clinch River Project CRN-1 Reactor Building Excavation September 13, 2023 1
{{#Wiki_filter:9/11/2023
Agenda           Introductions               Clinch River Nuclear (CRN) Site
 
NRC Public Meeting
 
TVA Clinch River Project
 
CRN-1 Reactor Building Excavation
 
September 13, 2023
 
1
 
Agenda Introductions Clinch River Nuclear (CRN) Site


===Background===
===Background===
Expected Activities/Benefits Exemption Request Schedule Conclusion Questions/Comments 2
Expected Activities/Benefits Exemption Request Schedule Conclusion Questions/Comments
2 1
 
2


9/11/2023
2
 
1 9/11/2023


===Background===
===Background===
* In preparing the CRN-1 site for nuclear construction, TVA intends to excavate for the BWRX-300 Reactor Building in advance of receiving the Construction Permit (CP).
* InpreparingtheCRN-1sitefornuclearconstruction,TVAintendstoexcavateforthe BWRX-300ReactorBuildinginadvanceofreceivingtheConstructionPermit(CP).
* Per 10 CFR 50.10(a)(2)(v), excavation on its own is not considered to fall into the definition of construction.
* Per10CFR50.10(a)(2)(v),excavationonitsownisnotconsideredtofallintothe definitionofconstruction.
* To ensure worker safety during excavation and facilitate construction activities, an initial ground support system is expected to be installed for erosion control prior to and during excavation.
* Toensureworkersafetyduringexcavationandfacilitateconstructionactivities,an initialgroundsupportsystemisexpectedtobeinstalledforerosioncontrolpriorto andduringexcavation.
* Initial ground support system serves no function in the completed construction.
* Initialgroundsupportsystemservesnofunctioninthecompletedconstruction.
* Proposed initial ground support features are infeasible to remove and are planned to be abandoned in place.
* Proposedinitialgroundsupportfeaturesareinfeasibletoremoveandareplannedto beabandonedinplace.
* TVA has not yet authorized the deployment of an SMR. Nonetheless, these discussions and efforts regarding excavation activities will enable TVA to move forward in a timely manner, if and when a decision is made to build an SMR.
* TVAhasnotyetauthorizedthedeploymentofanSMR.Nonetheless,thesediscussions andeffortsregardingexcavationactivitieswillenableTVAtomoveforwardinatimely manner,ifandwhenadecisionismadetobuildanSMR.
3 3
 
Initial Ground Support System The following items may be installed as part of the initial ground support system:
3
secant piles or steel piles through the soil overburden and weathered rock, if required, rock bolts to secure unstable rock blocks and create a safe and stable excavation, as required, wire mesh and a thin, non-structural sprayed-gunite lining to stabilize and protect exposed rock walls, horizontal gravity drains to manage groundwater, as required, pressurized grout to seal any notable areas of water entry.
 
4 4
3
2
 
Initial Ground Support System
 
The following items may be installed as part of theinitial ground support system:
secant piles or steel piles through the soil overburden and weathered rock, if required, rock bolts to secure unstable rock blocks and create a safe and stable excavation, as required, wire mesh and a thin, non-structural sprayed-gunitelining to stabilize and protect exposed rock walls, horizontal gravity drains to manage groundwater, as required, pressurized grout to seal any notable areas of water entry.
 
4
 
4
 
2 9/11/2023


9/11/2023 Benefits of Excavation prior to CP Issuance Reduces risk and improves schedule by completing excavation prior to CP issuance and commencement of construction activities:
Benefits of Excavation prior to CP Issuance Reduces risk and improves schedule by completing excavation prior to CP issuance and commencement of construction activities:
Additional subsurface information can be provided to the NRC to consider before the CP is issued.
Additional subsurface information can be provided to the NRC to consider before the CP is issued.
Allows the extensive geotechnical mapping and surveys to be performed on a more controlled schedule when it is separated from the primary construction schedule.
Allows the extensive geotechnical mapping and surveys to be performed on a more controlled schedule when it is separated from the primary construction schedule.
Identification of any critical features like discontinuities, shear zones, faults, karst features, or potentially unstable blocks will help improve the design of the permanent ground support system prior to construction.
Identification of any critical features like discontinuities, shear zones, faults, karst features, or potentially unstable blocks will help improve the design of the permanent ground support system prior to construction.
Optimizing the schedule for demonstration of new nuclear plants is imperative to enabling TVA to consider SMRs throughout the TVA Power Service Areas to support TVAs carbon emission reduction aspirations (e.g. net-zero by 2050).
Optimizing the schedule for demonstrationof new nuclear plants is imperative to enabling TVA to consider SMRs throughout the TVA Power Service Areas to support TVAs carbon emission reduction aspirations (e.g. net-zero by 2050).
5 5
 
5
 
5
 
Expected Excavation Activities
: 1. Sitepreparationactivities
: 2. Installationoffieldinstrumentation
: 3. Excavationthroughthesoiloverburdenandweatheredrock.
* 1)slopedexcavationusingconventionalearthmoving equipment,
* 2)secantpilesorsteelpilesinstalledandkeyedintothe bedrock1.
: 4. Constructionoftemporarycranepads.
: 5. Linedrillingaroundtheperimeteroftheshaftexcavation.
 
1If installed will be abandoned in place.
 
6
 
6
 
3 9/11/2023
 
Expected Excavation Activities
 
6.Excavatingthroughthebedrockwillbecompletedin8-12deeplifts.
* 1)Controlleddrillingandblasting,
* 2)Expandingchemicalgrouting,and
* 3) Rock Hammer 7.Temporaryde-wateringsystems,suchaspumpsand sumpsandtemporarywellsorwellpoints,willbe employedduringshaftexcavation. Areasofnotable waterentrywillbesealedviaanengineeredpressure groutingprocessorlocalizedwatercollectionsystem1.
 
1If installed will be abandoned in place.
 
7
 
7
 
Expected Excavation Activities
Expected Excavation Activities
: 1. Site preparation activities
: 2. Installation of field instrumentation
: 3. Excavation through the soil overburden and weathered rock.
* 1) sloped excavation using conventional earthmoving equipment,
* 2) secant piles or steel piles installed and keyed into the bedrock1.
: 4. Construction of temporary crane pads.
: 5. Line drilling around the perimeter of the shaft excavation.
1 If installed will be abandoned in place.
6 6
3


9/11/2023 Expected Excavation Activities
8.Geologicalmappingoftherockwallswillbecompleted duringtheexcavationmeetingtherequirementsof NRCInspectionManual88131.Theinspectionofthe shaftwallswillbeperformedastheshaftprogressesin lifts.
: 6. Excavating through the bedrock will be completed in 8-12 deep lifts.
9.Naturalvoidsorpoorqualityrockidentifiedduring theexcavationprocessorexposedinthewallsoflifts willbeevaluatedand,whenrequired,stabilized.This stabilizationmayincluderockreinforcement(i.e.rock bolts)ortreatmentwithgrout1.
* 1) Controlled drilling and blasting,
 
* 2) Expanding chemical grouting, and
1If installed will be abandoned in place.
* 3) Rock Hammer
 
: 7. Temporary de-watering systems, such as pumps and sumps and temporary wells or well points, will be employed during shaft excavation. Areas of notable water entry will be sealed via an engineered pressure grouting process or localized water collection system1.
8
1 If installed will be abandoned in place.
 
7 7
8
 
4 9/11/2023
 
Expected Excavation Activities
Expected Excavation Activities
: 8. Geological mapping of the rock walls will be completed during the excavation meeting the requirements of NRC Inspection Manual 88131. The inspection of the shaft walls will be performed as the shaft progresses in lifts.
: 9. Natural voids or poor quality rock identified during the excavation process or exposed in the walls of lifts will be evaluated and, when required, stabilized. This stabilization may include rock reinforcement (i.e. rock bolts) or treatment with grout1.
1 If installed will be abandoned in place.
8 8
4


9/11/2023 Expected Excavation Activities 10.Wire mesh reinforcement, in combination with a non-structural sprayed-gunite lining will be installed on the rock face1. In cases where seepage is noted in the bedrock, horizontal gravity drains1 and/or weep holes will be installed so that the water does not deteriorate the sprayed-gunite lining.
10.Wiremeshreinforcement,incombinationwitha non-structuralsprayed-guniteliningwillbeinstalled ontherockface1.Incaseswhereseepageisnotedin thebedrock,horizontalgravitydrains1 and/orweep holeswillbeinstalledsothatthewaterdoesnot deterioratethesprayed-gunitelining.
11.The final foundation level at the base of the excavation will be cleaned and mapped in addition to the walls of the final lift. If any anomalous issues are discovered, additional geotechnical investigations will be performed in accordance with RG 1.132.
11.Thefinalfoundationlevelatthebaseoftheexcavation willbecleanedandmappedinadditiontothewallsof thefinallift.Ifanyanomalousissuesarediscovered, additionalgeotechnicalinvestigationswillbe performedinaccordancewithRG1.132.
1 If installed will be abandoned in place.
 
9 9
1If installed will be abandoned in place.
Exemption Request TVA is considering submitting an exemption request to provide regulatory certainty in moving forward with excavation prior to CP Issuance.
9
 
9
 
Exemption Request
 
TVA is considering submitting an exemption request to provide regulatory certainty in moving forward with excavation prior to CP Issuance.
* 10 CFR 50.12 (a)
* 10 CFR 50.12 (a)
* 10 CFR 50.12 (b)
* 10 CFR 50.12 (b)
It is not expected that an NRC environmental impact statement or environmental assessment will be required for approval of an exemption request as it would meet the criteria of 10 CFR 51.22(c)(25).
It is not expected that an NRC environmental impact statement or environmental assessment will be required for approval of an exemption request as it would meet the criteria of 10 CFR 51.22(c)(25).
10 10 5


9/11/2023 Construction Permit Issuance 2022                      2023                            2024            2025                          2026 Q1     Q2      Q3  Q4    Q1    Q2      Q3      Q4    Q1      Q2      Q3 Q4 Q1 Q2      Q3      Q4    Q1    Q2      Q3 Q4 Prepare CPA                                             NRC Review CPA NRC Acceptance                         CPA Approval Review Prepare ER                                             NRC Review ER Submit               NRC Approval of Exemption             Exemption Request Request Prepare         NRC Review Excavation TVA NEPA TVA SEIS Issued
10
* As communicated previously, TVA has not yet authorized the deployment of an SMR. Nonetheless, receiving an exemption from 10 CFR 50.10(c) will provide regulatory certainty from NRC moving forward for excavation activities which would enable TVA to move forward in a timely manner, if and when a decision is made to build an SMR.
 
11 11 Conclusion
10
 
5 9/11/2023
 
Construction Permit Issuance
 
20222023202420252026 Q1Q2Q3Q4Q1 Q2Q3Q4Q1Q2Q3 Q2Q3Q4Q4Q1Q2Q3Q4 Q1
 
Prepare CPA NRCReview CPA
 
NRC Acceptance CPA Approval Review
 
Prepare ER NRCReview ER
 
Submit NRC Approval of Exemption Exemption Request Request Prepare NRC Review Excavation TVA NEPA
 
TVA SEIS Issued
* As communicated previously, TVA has not yet authorized the deployment of an SMR. Nonetheless, receiving an exemption from 10 CFR 50.10(c) will provide regulatory certainty from NRC moving forward for excavation activities which would enable TVA to move forward in a timely manner, if and whena decision is made to build an SMR.
 
11
 
11
 
Conclusion
* The RB excavation is of critical importance to the CRN-1 construction schedule and cannot be conducted without installation of the initial ground support system.
* The RB excavation is of critical importance to the CRN-1 construction schedule and cannot be conducted without installation of the initial ground support system.
* If excavation for CRN-1 is delayed until issuance of the CP, it is anticipated the demonstration of constructing and licensing an SMR would be delayed over one year, hence delaying the availability of carbon-free electricity generation.
* If excavation for CRN-1 is delayed until issuance of the CP, it is anticipated the demonstration of constructing and licensing an SMRwould be delayed over one year, hence delaying the availability of carbon-free electricity generation.
* An exemption request would satisfy the necessary elements of 10 CFR 50.12(a) and 10 CFR 50.12(b), as well as satisfy the requirements for a categorical exclusion in accordance with 10 CFR 51.22(c)(25).
* Anexemption request would satisfy the necessary elements of 10 CFR 50.12(a) and 10 CFR 50.12(b), as well as satisfy the requirements for a categorical exclusion in accordance with 10 CFR 51.22(c)(25).
12 12 6
 
12
 
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6 9/11/2023
 
13
 
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9/11/2023 13 13 7}}
7}}

Revision as of 12:10, 13 November 2024

20230913 NRC Public Meeting Slides TVA CRN-1 RB Excavation
ML23255A005
Person / Time
Site: Clinch River, 99902056
Issue date: 09/13/2023
From: Allen Fetter
Tennessee Valley Authority
To:
Office of Nuclear Reactor Regulation
References
Download: ML23255A005 (1)
v • d • e


Text

9/11/2023

NRC Public Meeting

TVA Clinch River Project

CRN-1 Reactor Building Excavation

September 13, 2023

1

Agenda Introductions Clinch River Nuclear (CRN) Site

Background

Expected Activities/Benefits Exemption Request Schedule Conclusion Questions/Comments

2

2

1 9/11/2023

Background

  • InpreparingtheCRN-1sitefornuclearconstruction,TVAintendstoexcavateforthe BWRX-300ReactorBuildinginadvanceofreceivingtheConstructionPermit(CP).
  • Per10CFR50.10(a)(2)(v),excavationonitsownisnotconsideredtofallintothe definitionofconstruction.
  • Toensureworkersafetyduringexcavationandfacilitateconstructionactivities,an initialgroundsupportsystemisexpectedtobeinstalledforerosioncontrolpriorto andduringexcavation.
  • Initialgroundsupportsystemservesnofunctioninthecompletedconstruction.
  • Proposedinitialgroundsupportfeaturesareinfeasibletoremoveandareplannedto beabandonedinplace.
  • TVAhasnotyetauthorizedthedeploymentofanSMR.Nonetheless,thesediscussions andeffortsregardingexcavationactivitieswillenableTVAtomoveforwardinatimely manner,ifandwhenadecisionismadetobuildanSMR.

3

3

Initial Ground Support System

The following items may be installed as part of theinitial ground support system:

secant piles or steel piles through the soil overburden and weathered rock, if required, rock bolts to secure unstable rock blocks and create a safe and stable excavation, as required, wire mesh and a thin, non-structural sprayed-gunitelining to stabilize and protect exposed rock walls, horizontal gravity drains to manage groundwater, as required, pressurized grout to seal any notable areas of water entry.

4

4

2 9/11/2023

Benefits of Excavation prior to CP Issuance Reduces risk and improves schedule by completing excavation prior to CP issuance and commencement of construction activities:

Additional subsurface information can be provided to the NRC to consider before the CP is issued.

Allows the extensive geotechnical mapping and surveys to be performed on a more controlled schedule when it is separated from the primary construction schedule.

Identification of any critical features like discontinuities, shear zones, faults, karst features, or potentially unstable blocks will help improve the design of the permanent ground support system prior to construction.

Optimizing the schedule for demonstrationof new nuclear plants is imperative to enabling TVA to consider SMRs throughout the TVA Power Service Areas to support TVAs carbon emission reduction aspirations (e.g. net-zero by 2050).

5

5

Expected Excavation Activities

1. Sitepreparationactivities
2. Installationoffieldinstrumentation
3. Excavationthroughthesoiloverburdenandweatheredrock.
  • 1)slopedexcavationusingconventionalearthmoving equipment,
  • 2)secantpilesorsteelpilesinstalledandkeyedintothe bedrock1.
4. Constructionoftemporarycranepads.
5. Linedrillingaroundtheperimeteroftheshaftexcavation.

1If installed will be abandoned in place.

6

6

3 9/11/2023

Expected Excavation Activities

6.Excavatingthroughthebedrockwillbecompletedin8-12deeplifts.

  • 1)Controlleddrillingandblasting,
  • 2)Expandingchemicalgrouting,and
  • 3) Rock Hammer 7.Temporaryde-wateringsystems,suchaspumpsand sumpsandtemporarywellsorwellpoints,willbe employedduringshaftexcavation. Areasofnotable waterentrywillbesealedviaanengineeredpressure groutingprocessorlocalizedwatercollectionsystem1.

1If installed will be abandoned in place.

7

7

Expected Excavation Activities

8.Geologicalmappingoftherockwallswillbecompleted duringtheexcavationmeetingtherequirementsof NRCInspectionManual88131.Theinspectionofthe shaftwallswillbeperformedastheshaftprogressesin lifts.

9.Naturalvoidsorpoorqualityrockidentifiedduring theexcavationprocessorexposedinthewallsoflifts willbeevaluatedand,whenrequired,stabilized.This stabilizationmayincluderockreinforcement(i.e.rock bolts)ortreatmentwithgrout1.

1If installed will be abandoned in place.

8

8

4 9/11/2023

Expected Excavation Activities

10.Wiremeshreinforcement,incombinationwitha non-structuralsprayed-guniteliningwillbeinstalled ontherockface1.Incaseswhereseepageisnotedin thebedrock,horizontalgravitydrains1 and/orweep holeswillbeinstalledsothatthewaterdoesnot deterioratethesprayed-gunitelining.

11.Thefinalfoundationlevelatthebaseoftheexcavation willbecleanedandmappedinadditiontothewallsof thefinallift.Ifanyanomalousissuesarediscovered, additionalgeotechnicalinvestigationswillbe performedinaccordancewithRG1.132.

1If installed will be abandoned in place.

9

9

Exemption Request

TVA is considering submitting an exemption request to provide regulatory certainty in moving forward with excavation prior to CP Issuance.

It is not expected that an NRC environmental impact statement or environmental assessment will be required for approval of an exemption request as it would meet the criteria of 10 CFR 51.22(c)(25).

10

10

5 9/11/2023

Construction Permit Issuance

20222023202420252026 Q1Q2Q3Q4Q1 Q2Q3Q4Q1Q2Q3 Q2Q3Q4Q4Q1Q2Q3Q4 Q1

Prepare CPA NRCReview CPA

NRC Acceptance CPA Approval Review

Prepare ER NRCReview ER

Submit NRC Approval of Exemption Exemption Request Request Prepare NRC Review Excavation TVA NEPA

TVA SEIS Issued

  • As communicated previously, TVA has not yet authorized the deployment of an SMR. Nonetheless, receiving an exemption from 10 CFR 50.10(c) will provide regulatory certainty from NRC moving forward for excavation activities which would enable TVA to move forward in a timely manner, if and whena decision is made to build an SMR.

11

11

Conclusion

  • The RB excavation is of critical importance to the CRN-1 construction schedule and cannot be conducted without installation of the initial ground support system.
  • If excavation for CRN-1 is delayed until issuance of the CP, it is anticipated the demonstration of constructing and licensing an SMRwould be delayed over one year, hence delaying the availability of carbon-free electricity generation.

12

12

6 9/11/2023

13

13

7

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