Tennessee Valley Authority; Clinch River Nuclear Site; Exemption, 101643-101646 [2024-29564]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 89, Number 241 (Monday, December 16, 2024)]
[Notices]
[Pages 101643-101646]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-29564]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 99902056; NRC-2024-0146]


Tennessee Valley Authority; Clinch River Nuclear Site; Exemption

AGENCY: Nuclear Regulatory Commission.

ACTION: Notice; issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) has issued an 
exemption in response to a request dated November 30, 2023, from 
Tennessee Valley Authority for approval to conduct certain excavation 
support activities prior to the issuance of a construction permit 
application for the Clinch River Nuclear Site.

DATES: The exemption was issued on December 10, 2024.

ADDRESSES: Please refer to Docket ID NRC-2024-0146 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly available information related to this document 
using any of the following methods:
     Federal Rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2024-0146. Address 
questions about Docket IDs in Regulations.gov to Stacy Schumann; 
telephone: 301-415-0624; email: [email protected]. For technical 
questions, contact the individual listed in the FOR FURTHER INFORMATION 
CONTACT section of this document.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly available documents online in the 
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS 
Search.'' For problems with ADAMS, please contact the NRC's Public 
Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737, 
or by email to [email protected]. The ADAMS accession number for 
each document referenced (if it is available in ADAMS) is provided the 
first time that it is mentioned in this document.
     NRC's PDR: The PDR, where you may examine and order copies 
of publicly available documents, is open by appointment. To make an 
appointment to visit the PDR, please send an email to 
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8 
a.m. and 4 p.m. eastern time (ET), Monday through Friday, except 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: Allen Fetter, Office of Nuclear 
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001, telephone: 301-415-8556; email: [email protected].

SUPPLEMENTARY INFORMATION: The text of the exemption is attached.

    Dated: December 11, 2024.


[[Page 101644]]


    For the Nuclear Regulatory Commission.
Allen Fetter,
Senior Project Manager, Licensing and Regulatory Infrastructure Branch, 
Division of New and Renewed Licenses, Office of Nuclear Reactor 
Regulation.

Attachment--Exemption

NUCLEAR REGULATORY COMMISSION

[Docket No. 99902056; NRC-2024-0146]

Tennessee Valley Authority Clinch River Nuclear Site; Exemption

1.0 Background

    By letter dated November 30, 2023 (Agency wide Documents Access and 
Management System (ADAMS) Accession Number ML23335A100), Tennessee 
Valley Authority (TVA) submitted a request for an exemption from Title 
10 of the Code of Federal Regulations (10 CFR) Part 50, Section 
50.10(c). The U.S. Nuclear Regulatory Commission (NRC or the NRC staff) 
has reviewed this request for an exemption, pursuant to 10 CFR 50.12, 
as it relates to TVA's request to conduct certain excavation support 
activities that are otherwise prohibited by 10 CFR 50.10(c) prior to 
the issuance of a construction permit (CP) application for the Clinch 
River Nuclear (CRN) Site, which is expected to be submitted for NRC 
review in 2025. This exemption would authorize TVA to conduct certain 
excavation activities at the CRN Site and to abandon in place the 
initial ground support system, which may include rock bolts, wire mesh, 
horizontal gravity drains, and pressurized grout.
    Granting this exemption does not obviate the need for the applicant 
to meet the Permit Conditions or Action Items in the Early Site Permit 
for the CRN Site. Granting this exemption would also not constitute a 
commitment by the NRC to issue a CP for the CRN Site. TVA would conduct 
these excavation activities assuming the risk that its CP application 
may later be denied.

2.0 Request/action

    The proposed action, as described in TVA's request for an exemption 
from 10 CFR 50.10(c), would allow TVA to conduct certain excavation 
activities which would otherwise be prohibited prior to issuance of a 
CP. This exemption would authorize TVA to abandon in place the initial 
ground support system for conducting certain excavation activities at 
the CRN Site. According to TVA, the initial ground support system for 
the reactor will serve no function in the completed reactor building 
(RB). As such, TVA's interpretation of NRC regulations is that this 
proposed construction does not have a reasonable nexus to nuclear 
safety or security and therefore does not meet the definition of 
``construction,'' as defined in 10 CFR 50.10(a). However, NRC 
regulations clearly require that the activities described by TVA that 
involve the placement/installation of permanent parts of the overall 
facility are considered ``construction'' as defined in 10 CFR 50.10(a) 
(see 72 FR 57416, pp. 57416-57447). Therefore, an exemption from the 
requirements of 10 CFR 50.10(c) is needed for TVA's request.
    TVA states that the initial ground support system includes the 
following activities:
     rock bolts to secure unstable rock blocks, as required;
     wire mesh and a 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, as required.
    TVA also states that additional components of the initial ground 
support system, depending on the excavation method selected, may 
include items such as the following or similar:
     steel soldier beams with timber lagging through the soil 
overburden and weathered rock;
     rock bolts to secure soldier beams; and
     reinforced concrete compression rings to provide lateral 
support for the soldier beams.
    As construction of the permanent plant structures proceeds, TVA 
states that the initial ground support system is infeasible to remove 
and would be abandoned in place. After abandonment, the initial ground 
support system would have no function in the completed RB construction.
    In its exemption request, TVA stated that the proposed exemption is 
needed to allow excavation to proceed in advance of the issuance of the 
CP for the CRN Site. The initial ground support system would allow TVA 
to complete certain on-site activities in parallel with the licensing 
process, so that it can begin construction promptly upon issuance of 
the CP. The on-site activities will ensure worker safety as the 
excavation activities proceed.

3.0 Discussion

    Pursuant to 10 CFR 50.12(a), the Commission may, upon application 
by any interested person or upon its own initiative, grant exemptions 
from the requirements of 10 CFR part 50 when (1) the exemption is 
authorized by law, will not present an undue risk to public health or 
safety, and is consistent with the common defense and security; and
    (2) when special circumstances are present.
    Under 10 CFR 50.12(b), to issue an exemption from 10 CFR 50.10 that 
would allow for the conduct of activities prior to the issuance of a 
construction permit, the Commission may grant such an exemption upon 
considering and balancing the following factors: (1) whether conduct of 
the proposed activities will give rise to a significant adverse impact 
on the environment and the nature and extent of such impact, if any; 
(2) whether redress of any adverse environment impact from conduct of 
the proposed activities can reasonably be effected should such redress 
be necessary; (3) whether conduct of the proposed activities would 
foreclose subsequent adoption of alternatives; and (4) the effect of 
delay in conducting such activities on the public interest, including 
the power needs to be used by the proposed facility, the availability 
of alternative sources, if any, to meet those needs on a timely basis 
and delay costs to the applicant and to consumers.

10 CFR 50.12(a)(1): Authorized by Law

    This exemption would authorize the applicant to abandon in place 
the initial ground support system prior to issuance of a CP for the CRN 
Site. Granting of the applicant's proposed exemption will not otherwise 
result in a violation of the Atomic Energy Act of 1954, as amended, or 
the Commission's regulations. Therefore, the NRC staff finds that the 
exemption is authorized by law.

10 CFR 50.12(a)(1): No Undue Risk to Public Health and Safety

    In determining that the proposed exemption would not pose an undue 
risk to public health and safety and that the applicant could be 
exempted from the prohibition on construction for the limited purpose 
of the installation and subsequent abandonment of the initial ground 
support system to ensure worker safety during the onsite excavation 
activities, the NRC staff evaluated the safety aspects of the exemption 
in the areas of Geology and Geotechnical Engineering because the 
excavation activities described by TVA are specific to those technical 
review areas.
Geology
    The NRC staff reviewed geologic information in the CRN Site 
exemption request using the criteria in NUREG-0800, Standard Review 
Plan (SRP), Chapter 2.5.1, ``Geological Characterization Information'' 
and Chapter 2.5.3, ``Surface Deformation.''

[[Page 101645]]

The related excavation support activities requested in the exemption 
request would result in covering the excavation floor and walls; 
therefore, the purpose of staff's review was to determine whether the 
proposed activities to be completed under the exemption request would 
affect TVA's ability to meet the terms of the Clinch River Site early 
site permit (ESP-006), issued on December 19, 2019 (ML19352D868), with 
respect to geologic mapping of the foundation-bearing rock unit, to 
include the floor and walls of the open excavation. ESP-006 included 
permit condition #3, which requires TVA to perform detailed geologic 
mapping of excavations for safety-related engineered structures, 
examine and evaluate geologic features discovered in those excavations, 
and notify the staff once excavations for safety related structures are 
open for examination. The geologic mapping of the foundation-bearing 
unit in the open excavation required under permit condition #3 would 
not be implementable once the excavations support activities proposed 
in this exemption request are complete. Therefore, the staff considered 
how this permit condition can be met under this exemption request.
    For this exemption request, staff planned and conducted a virtual 
regulatory audit between March 5, 2024, and May 3, 2024. Audit 
information needs were provided to TVA in an audit plan (ML24060A069) 
and through a supplemental additional information request from the NRC 
staff (ML24075A322).
    During the virtual audit (see NRC Audit Summary Report, 
ML24145A107), the applicant summarized how it would perform the 
geologic mapping of the excavation as required in permit condition #3 
of ESP-006 (Early Site Permit for the Clinch River Nuclear Site, 
ML1935D868). The applicant clarified that during the excavation 
activities requested in the exemption, geologic mapping will be 
conducted for each lift before the excavation walls are covered by any 
stabilization methods and the subsequent lift commences. The applicant 
further clarified that the data obtained from mapping each lift will be 
available as it is recovered during the excavation activities.
    The staff reviewed the applicant's response to audit questions 
about how the applicant intends to perform the necessary geologic 
mapping to obtain the required information to address permit condition 
#3 in ESP-006 related to geologic mapping of the excavation. The staff 
concludes that because the applicant will perform the geologic mapping 
as the requested early excavation activities proceed and that 
information will be made available before the subsequent lifts 
commence, these early excavation activities will not affect the 
satisfactory addressing of permit condition #3 in ESP-006. Because the 
applicant will obtain the information necessary to meet the terms of 
the geologic mapping permit condition to ensure the foundation-bearing 
geologic unit meets the criteria reviewed and approved in the ESP, the 
staff concludes that there is no undue risk to public health and safety 
in approving this exemption request.
Geotechnical Engineering
    The NRC staff evaluated geotechnical engineering information in the 
CRN Site exemption request using the criteria in NUREG-0800, Standard 
Review Plan (SRP), Chapter 2.5.4, ``Stability of Subsurface Materials 
and Foundations''. The guidance that applies to aspects of the early 
excavation exemption request includes specific criteria from:
    1. RG 1.132, ``Site Investigations for Foundations of Nuclear Power 
Plants.''
    2. RG 1.138 ``Laboratory Investigations of Soils and Rocks for 
Engineering Analysis and Design of Nuclear Power Plants.''
    For this exemption request, staff conducted a virtual regulatory 
audit between March 5, 2024, and May 3, 2024. Audit information needs 
were provided to TVA in an audit plan (ML24060A069) and through a 
supplemental additional information request from the NRC staff 
(ML24075A322). In response to the staff's information needs, the 
applicant provided a summary of disposition regarding Early Site Permit 
(ESP) permit condition #4 that relate to geotechnical engineering 
(Audit Summary Report ML24145A107).
    ESP-006 permit condition #4 requires TVA to remove the material 
above El. 225.9 m (741 ft) NAVD88 in the areas where safety-related 
structures will be located to minimize adverse effects of 
discontinuities, weathered and shear-fracture sones, and karst features 
on the stability of the subsurface materials and foundations. Permit 
condition #4 also requires TVA to perform additional investigations at 
the excavation level to identify any potential geologic features that 
may adversely impact the stability of subsurface materials and 
foundations. The staff considered how this permit condition can be met 
under this exemption request.
    The applicant intends to address the ESP-006 permit condition #4 to 
ensure that compliance with relevant terms and conditions of the early 
site permit will not be affected by the excavation performed pursuant 
to the exemption request. Specifically, the applicant stated that the 
proposed BWRX-300 RB foundation elevation is located below the required 
permit condition excavation elevation and the applicant will remove the 
material above Elevation 225.9m (741 ft) NAVD 88 in the RB area as part 
of the early excavation. In addition, the applicant stated that it will 
provide details of its supplemental site investigation program at the 
center and perimeter of the RB shaft as part of a future CP 
application. The applicant will perform additional investigations in 
accordance with RG 1.132 at the foundation level if any significant 
anomalous issues are discovered while performing the excavation and 
geologic mapping of the RB shaft. In addition, the applicant stated 
that the activities related to this early excavation exemption request 
should not affect addressing the permit conditions and CP or COL action 
items in a future application.
    The staff reviewed the applicant's summary of dispositions 
clarifying how the applicant intends to address permit condition #4. 
Given that the applicant will gather all necessary data during the 
activities that involve this early excavation exemption request and 
will utilize it to address regulatory requirements in a subsequent 
application, the staff finds that this early excavation activities 
would not pose an undue risk to public health and safety and would not 
affect addressing permit condition #4 in ESP-006.
    The applicant states that it plans to use a combination of 
stabilization methods as the initial ground support system for erosion 
control to ensure the safety of their employees and to facilitate 
construction activities. The applicant stated that the initial ground 
support system serves no function in the completed RB construction, but 
that its components are not feasible to remove and will remain in 
place. The applicant indicated that the initial ground support system 
is expected to be composed of rock bolts, wire mesh and non-structural 
sprayed-gunite, horizontal gravity drains, and pressurized grout. 
Depending on the final excavation method, the applicant stated that the 
initial ground support system could also include steel soldier beams 
and reinforced concrete compression rings. In addition, the applicant 
stated that no part of the RB walls or foundations will be installed 
before a CP is approved.
    During the virtual audit, the applicant provided a conceptual 
excavation plan describing its planning efforts for the excavation, 
such as site preparation

[[Page 101646]]

activities, installation of field instrumentation, methods of 
excavation, construction of temporary crane pads, temporary dewatering 
systems, a finite element model to assess the impact of dewatering and 
construction stages on excavation support and foundation, geologic 
mapping, and stabilization methods. In a CP application, the applicant 
plans to quantify and incorporate the impacts of rock excavation on the 
mechanical properties in a numerical simulation for the assessment of 
the foundations. The applicant stated that it will also develop an 
instrumentation and monitoring program consistent with Chapter 3.4 of 
the approved Licensing Topical Report (LTR) NEDO-33914-A to meet 
regulatory requirements. The applicant stated that it plans to monitor 
lateral and vertical displacement during excavation and construction. 
In addition, during the excavation the applicant plans to monitor slope 
movement, heave, changes in pore pressures and dewatering, and 
settlement.
    During the virtual audit, the applicant clarified that neither the 
annulus filled with lean concrete nor the steel plate composite RB 
walls, as shown in Figure 1 ``Conceptual Layout of Excavation utilizing 
Soldier Beams and Compression Rings'' of the exemption request, are 
considered part of this early excavation exemption request. 
Furthermore, the applicant stated that the emplacement of the annulus 
will occur after CP issuance and that it will be approximately 5 feet 
wide around the RB shaft, thus separating the RB from the excavation 
and any abandoned initial ground support system.
    The staff reviewed the description of the design methodology for 
the BWRX-300 as approved in the LTR NEDO-33914-A Section 5.0, Revision 
1, and notes that the BWRX-300 design does not rely on the resistance 
provided by initial ground support system. However, the staff noted 
that in accordance with the design methodology, the applicant must 
consider the effects of the initial ground support system in its 
seismic sensitivity analysis for a future application. Therefore, in 
the event that, during early excavation, the applicant needs additional 
retaining measures as part of the initial ground support system, the 
potential effects of all retaining measures on the RB structure shall 
be included as part of the SSI sensitivity analysis in a future CP 
licensing application.
    Based on the foregoing and in accordance with 10 CFR 50.12(a)(1), 
the staff finds that the proposed exemption that would permit the 
installation of an initial ground support system for erosion control 
measures and subsequently abandon it in place prior to the issuance of 
a CP, would not pose an undue risk to public health and safety because 
(1) the applicant will gather all necessary data during the activities 
that involve this early excavation exemption request and will utilize 
it to address regulatory requirements and relevant ESP-006 permit 
conditions; (2) the applicant will include demonstration of the 
structural integrity of the RB prior to the presence or use of 
radiological materials on the CRN Site to provide adequate protection 
of the public health and safety; (3) the initial ground support system 
will not perform a support function of the RB since the BWRX-300 design 
does not rely on the resistance provided by initial ground support 
system; (4) the annulus filled with lean concrete will separate the RB 
from the excavation and any abandoned initial ground support system, 
and (5) the applicant will consider the potential effects of all 
retaining measures (including the initial ground support system) on the 
RB structure as part of the Soil-Structure Interaction (SSI) 
sensitivity analysis in a future licensing application.

10 CFR 50.12(a): Consistent With Common Defense and Security

    The proposed exemption would allow the applicant to pursue 
excavation of the CRN Site and install the initial ground support 
system to ensure worker safety during excavation activities. Because 
the exemption would allow for early excavation and excavation wall 
support only, the exemption has no relation to defense and security 
issues. Therefore, the common defense and security is not impacted by 
this exemption.

10 CFR 50.12(a)(2): Special Circumstances

    Special circumstances, in accordance with 10 CFR 50.12(a)(2)(iii), 
are present whenever ``compliance [with a regulation] would result in 
undue hardship or other costs that are significantly in excess of those 
contemplated when the regulation was adopted, or that are significantly 
in excess of those incurred by others similarly situated''. The 
applicant cited undue hardship or other costs as a special circumstance 
that would warrant granting this exemption. The applicant stated that 
removal of the initial ground support system, which would make the 
system temporary and therefore not ``construction,'' as defined in 10 
CFR 50.10(a), is infeasible because the initial ground support system 
is necessary for personnel safety and removal of these items could 
potentially destabilize the rock walls. The applicant stated that the 
delay in excavation for the RB at the CRN Site until receipt of the CP 
will result in substantial costs due to delays to the construction 
schedule and commercial operation of CRN Unit 1, hence delaying the 
deployment of carbon-free electricity generation.

10 CFR 50.12(b): Environmental Considerations

    The applicant has also provided information on this proposed action 
pursuant to 10 CFR 50.12(b) which states any person may request an 
exemption permitting the conduct of activities prior to the issuance of 
the construction permit prohibited by 10 CFR 50.10. The NRC staff 
considered the balancing factors for granting such an exemption and its 
evaluation is documented in the environmental assessment (EA) that is 
attached to this package. The ADAMS Accession number for this 
associated EA is ML24310A024. The staff made a finding of no 
significant impact.

4.0 Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a) and 10 CFR 50.12 (b), the exemption is authorized by law, will 
not present an undue risk to the public health and safety, and is 
consistent with the common defense and security. Also, special 
circumstances are present.
    Therefore, the Commission hereby grants Tennessee Valley Authority 
an exemption from the requirements in 10 CFR 50.10(c) for the 
installation of initial ground support system prior to and during 
excavation activities.
    Pursuant to 10 CFR 51.32, the Commission has determined that the 
granting of this exemption will not have a significant effect on the 
quality of the human environment (89 FR 90319).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 10th day of December 2024.

    For the Commission

/RA/

Michele Sampson,
Director Division of New and Renewed Licenses Office of New 
Reactors.

[FR Doc. 2024-29564 Filed 12-13-24; 8:45 am]
BILLING CODE 7590-01-P