ML25059A093

Terrapower, LLC - Exemption Request and Application of Topical Report NATD-LIC-RPRT-0001-A for Construction of the Natrium Energy Island Kemmerer Unit 1

ML25059A093
Person / Time
Site:	Kemmerer File:TerraPower icon.png
Issue date:	02/28/2025
From:	George Wilson TerraPower
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
TP-LIC-LET-0382
Download: ML25059A093 (1)

Text

15800 Northup Way, Bellevue, WA 98008 www.TerraPower.com P. +1 (425) 324-2888 F. +1 (425) 324-2889 February 28, 2025 TP-LIC-LET-0382 Docket Number 50-613 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTN: Document Control Desk

Subject:

Exemption Request and Application of Topical Report NATD-LIC-RPRT-0001-A for Construction of the Natrium Energy Island at Kemmerer Unit 1

Reference:

1. TerraPower, LLC, TP-LIC-LET-0345, Exemption Request Associated with Construction of the Natrium Energy Island, September 9, 2024, ML24253A023

2. TerraPower, LLC, Submittal of Approved TerraPower, LLC Topical Report:

Regulatory Management of Natrium Nuclear Island and Energy Island Design Interfaces, NATD-LIC-RPRT-0001-A, Revision 0, January 11, 2024, ML24011A321

3. U.S. NRC, TerraPower, LLC - Final Safety Evaluation of Topical Report NATD-LIC-RPRT-0001, Regulatory Management Of Natrium Nuclear Island And Energy Island Design Interfaces, (EPID: L-2022-TOP-0045), Revision 0, October 4, 2023, ML23257A258.

TerraPower, LLC (TerraPower), on behalf of US SFR Owner, LLC (USO), a wholly owned subsidiary of TerraPower, submitted an exemption request from certain requirements of 10 CFR 50.10(a) and 10 CFR 51.4 as they apply to the Natrium Energy Island (EI)1(Reference 1). In response to audit discussions with the U.S. Nuclear Regulatory Commission (NRC) staff, TerraPower hereby supersedes the request in Reference 1 with this submittal.

TerraPower, on behalf of USO, requests exemption from the requirements of 10 CFR 50.10(a)(1)(iv) and 10 CFR 51.4 definition of construction (1)(i)(D) as they apply to the Natrium EI. This exemption request was discussed in the TerraPower Topical Report NATD-LIC-RPRT-0001 (Reference 2) and the NRC Safety Evaluation of Topical Report NATD-LIC-RPRT-0001 (Reference 3). The Natrium design incorporates independence of operation between the structures, systems, and components (SSCs) of the nuclear island (NI) and the SSCs of the EI.

1 Natrium is a TerraPower and GE-Hitachi technology.

Date: February 28, 2025 Page 2 of 2 provides the basis for the exemptions requested from 10 CFR 50.10(a)(1)(iv) and 10 CFR 51.4 definition of construction (1)(i)(D), in accordance with 10 CFR 50.12 and 10 CFR 51.6 respectively. USO is requesting that the NRC staff grant the exemption as stated in Enclosure 1 by April 5, 2025 to support timely construction of the Natrium EI and successful completion of the Natrium Demonstration Project.

This letter and Enclosure 1 maintain the regulatory commitment from Reference 1 as shown below in Table 1.

Table 1 Commitment #

Description Expected Completion Date REG-2024-01-00 Digital components or control systems identified as critical digital assets will not be installed or activated at the Kemmerer Unit 1 site prior to receipt of a construction permit.

Date of Kemmerer Unit 1 construction permit issuance provides an analysis of the application of Topical Report NATD-LIC-RPRT-0001-A to EI construction at Kemmerer Unit 1 prior to receiving a construction permit. Additional information is provided to support the non-applicability of certain criteria of 10 CFR 50.10(a)(1) to the EI, consistent with the Limitations and Conditions of the topical report. TerraPower requests NRC review and evaluate Enclosure 2 and provide feedback on the application of the topical report by April 5, 2025 to align with the exemption request in Enclosure 1.

If you have any questions regarding this submittal, please contact Nick Kellenberger at nkellenberger@terrapower.com or Ian Gifford at igifford@terrapower.com.

Sincerely, George Wilson Senior Vice President, Regulatory Affairs TerraPower, LLC Exemption Request Associated with Construction of the Natrium Energy Island Application of Topical Report NATD-LIC-RPRT-0001-A to Energy Island Construction at Kemmerer Unit 1 cc:

Mallecia Sutton, NRC Joshua Borromeo, NRC Nathan Howard, DOE Jeff Ciocco, DOE

ENCLOSURE 1 Exemption Request Associated with Construction of the Natrium Energy Island Page 1 of 10 Energy Island Construction Exemption Request Introduction The Natrium design incorporates independence of operation between the SSCs of the NI and the SSCs of the EI as described in the Topical Report NATD-LIC-RPRT-0001 (Reference 1).

This separation of functional areas allows the power production systems of the EI to be separate and independent from the NI with respect to site design and quality standards. This exemption request excludes EI SSCs classified as non-safety-related with no special treatment (NST) from the scope of limited work authorizations (LWAs), specifically 10 CFR 50.10(a)(1)(iv),

and the 10 CFR 51.4 definition of construction (1)(i)(D) environmental protection regulations.

This exemption request does not alter the underlying purpose of 10 CFR 50.10(a) or 10 CFR 51.4.

Regulatory Requirements The requirements of 10 CFR 50.10(a) define the scope of construction activities in the context of LWAs:

10 CFR 50.10(a) Definitions. As used in this section, construction means the activities in paragraph (a)(1) of this section, and does not mean the activities in paragraph (a)(2) of this section.

(1) Activities constituting construction are the driving of piles, subsurface preparation, placement of backfill, concrete, or permanent retaining walls within an excavation, installation of foundations, or in-place assembly, erection, fabrication, or testing, which are for:

(i) Safety-related structures, systems, or components (SSCs) of a facility, as defined in 10 CFR 50.2; (ii) SSCs relied upon to mitigate accidents or transients or used in plant emergency operating procedures; (iii) SSCs whose failure could prevent safety-related SSCs from fulfilling their safety-related function; (iv) SSCs whose failure could cause a reactor scram or actuation of a safety-related system; (v) SSCs necessary to comply with 10 CFR part 73; (vi) SSCs necessary to comply with 10 CFR 50.48 and criterion 3 of 10 CFR part 50, appendix A; and (vii) Onsite emergency facilities necessary to comply with either § 50.160 or § 50.47 and appendix E to this part, as applicable.

The regulations of 10 CFR 51.4 define the scope of construction activities in the context of environmental protection regulations:

Construction means:

(1) For production and utilization facilities, the activities in paragraph (1)(i) of this definition, and does not mean the activities in paragraph (1)(ii) of this definition.

(i) Activities constituting construction are the driving of piles, subsurface preparation, placement of backfill, concrete, or permanent retaining walls within an excavation, installation of foundations, or in-place assembly, erection, fabrication, or testing, which are for:

Page 2 of 10 (A) Safety-related structures, systems, or components (SSCs) of a facility, as defined in 10 CFR 50.2; (B) SSCs relied upon to mitigate accidents or transients or used in plant emergency operating procedures; (C) SSCs whose failure could prevent safety-related SSCs from fulfilling their safety-related function; (D) SSCs whose failure could cause a reactor scram or actuation of a safety-related system; (E) SSCs necessary to comply with 10 CFR part 73; (F) SSCs necessary to comply with 10 CFR 50.48 and criterion 3 of 10 CFR part 50, appendix A; and (G) Onsite emergency facilities (i.e., technical support and operations support centers), necessary to comply with 10 CFR 50.47 and 10 CFR part 50, appendix E.

Exemption Request Pursuant to 10 CFR 50.12, USO requests an exemption to exclude EI SSCs from the scope of the requirements of 10 CFR 50.10(a)(1)(iv). The requested exemption would result in the following 10 CFR 50.10(a)(1)(iv) requirement for the Natrium design within the LWA rule:

10 CFR 50.10(a) Definitions. As used in this section, construction means the activities in paragraph (a)(1) of this section, and does not mean the activities in paragraph (a)(2) of this section.

(1) Activities constituting construction are the driving of piles, subsurface preparation, placement of backfill, concrete, or permanent retaining walls within an excavation, installation of foundations, or in-place assembly, erection, fabrication, or testing, which are for:

(iv) SSCs whose failure could cause a reactor scram or actuation of a safety-related system, excluding Natrium Energy Island SSCs classified as non-safety-related with no special treatment (NST);

Pursuant to 10 CFR 51.6, USO requests an exemption to exclude EI SSCs from the scope of 10 CFR 51.4 definition of construction (1)(i)(D). The requested exemption would result in the following requirement of 10 CFR 51.4 definition of construction (1)(i)(D):

Construction means:

(1) For production and utilization facilities, the activities in paragraph (1)(i) of this definition, and does not mean the activities in paragraph (1)(ii) of this definition.

(i) Activities constituting construction are the driving of piles, subsurface preparation, placement of backfill, concrete, or permanent retaining walls within an excavation, installation of foundations, or in-place assembly, erection, fabrication, or testing, which are for:

(D) SSCs whose failure could cause a reactor scram or actuation of a safety-related system, excluding Natrium Energy Island SSCs classified as non-safety-related with no special treatment (NST);

Page 3 of 10 Basis for Exemption Consistent with the evaluation presented in the Final Safety Evaluation of Topical Report NATD-LIC-RPRT-0001, Regulatory Management Of Natrium Nuclear Island And Energy Island Design Interfaces, (Reference 2), the LWA rule is applicable to certain EI SSCs.

The basis for requesting an exemption from 10 CFR 50.10(a)(1)(iv) is the same as that for requesting an exemption from the 10 CFR 51.4 definition of construction (1)(i)(D). Discussion in the Limited Work Authorizations for Nuclear Power Plants Final Rule (Reference 3) states that the NRC chose to specifically align the 10 CFR 51.4 construction definition with 10 CFR 50.10(a) definition of construction:

Section 51.4 is revised by adding a new definition of construction. This makes applicable throughout Part 51 the definition of construction in proposed § 50.10(a) and has the effect of excluding from an EIS for any ESP, construction permit, combined license or an LWA, any discussion, evaluation or consideration of the environmental impacts or benefits associated with non-construction activities as set forth in § 50.10(a). This also removes the need for the NRC decision maker, including a presiding officer, to make a NEPA finding with respect to the environmental impacts or benefits associated with those non-construction activities.

Therefore, aligning the exemption requested for 10 CFR 50.10(a)(1)(iv) with the exemption requested for 10 CFR 51.4 definition of construction (1)(i)(D) also aligns with the intention of the regulations as stated in the LWA Final Rule (Reference 3).

Independence of NI and EI Systems TerraPower, on behalf of USO, submitted a Construction Permit Application (CPA) in March 2024 (Reference 6). CPA Enclosure 2, Preliminary Safety Analysis Report (PSAR),

Sections 1.1.3 and 1.1.4.4.9, describe the overall configuration of Kemmerer Unit 1 and the independence of the NI and EI in the Natrium design. The EI is physically separate from the NI as shown in PSAR Figure 1.2-1. The interface between the NI and EI occurs via the sodium-salt heat exchangers that transfer heat from the intermediate heat transport system to the thermal salt system. The isolation point for the thermal salt storage system (EI to NI isolation) is at the inlet valve (input from the cold salt storage tank) and outlet valve (output to the hot salt storage tank) of the sodium to salt heat exchangers.

As discussed in Reference 1, and evaluated by NRC in Reference 2, the Natrium reactor design incorporates several features that support independence of the NI and EI. The fuel and core are designed to have substantial margin to safety limits, minimizing the probability of fuel failure and radiological releases. The primary and intermediate heat transport systems are designed such that adequate heat removal is achieved for various plant conditions and transients. Both sodium systems contain enough thermal inertia to reduce the effects of EI transients. The EI is not relied on for heat removal during NI transients. The intermediate air cooling system under force-flow mode is used for normal shutdown cooling via the sodium-air heat exchangers. Should the intermediate air cooling system be unavailable, the reactor air cooling system is capable of passively removing all decay heat. In addition, the sensors and SSCs as part of the reactor control and protection systems relied on to shut down the reactor are not located on the EI.

Additional information on these systems is contained in PSAR Chapter 7.

Page 4 of 10 As stated in the NRC Final Safety Evaluation for NATD-LIC-RPRT-0001 (Reference 2), the Natrium reactor design is fundamental to the transients that may occur at the facility, the response to transients, and the safety classification of the SSCs that prevent and mitigate transients. The NRC considered these aspects of the plant design and highlighted in Reference 2 those design features that are significant to the independence of the Natrium reactor NI and EI. Key aspects fundamental to the independence of the NI and EI include the licensing basis events (LBE) that may occur, the Natrium designs response to LBEs, and the SSC safety classification for those relied on to prevent and mitigate LBEs. Details on the LBEs considered and SSC response are described in PSAR Sections 3.5 through 3.9. EI transients are evaluated and determined not to be risk-significant. In addition, no radiological release occurs for EI transients as fuel integrity is maintained for the postulated events.

10 CFR 50.10(a)(1)(iv) and 10 CFR 51.4 Definition of Construction (1)(i)(D)

The underlying purpose for the scoping requirements of 10 CFR 50.10(a)(1)(iv) is described in the LWA Final Rule as those SSCs "that have a reasonable nexus to radiological health and safety and/or common defense and security." The requirements of 10 CFR 50.10(a)(1)(iv) deterministically define which SSCs have a reasonable nexus to radiological health and safety.

In contrast, the SSC classification process identified in Nuclear Energy Institute (NEI) 18-04 (Reference 4) and endorsed via Regulatory Guide 1.233 (Reference 5) uses a risk-informed performance-based process to determine the safety significance of SSCs. NEI 18-04 incorporates deterministic and PRA insights to classify which SSCs have a reasonable nexus to radiological health and safety (i.e., to classify which SSCs are safety-significant).

The Kemmerer Unit 1 CPA is based on the Natrium design and the methodology described in NEI 18-04 and Regulatory Guide 1.233 as described in CPA Enclosure 2, PSAR, Section 5.1.

The NEI 18-04 SSC classification categories are defined as follows:

Safety-Related (SR):

SSCs selected by the designer from the SSCs that are available to perform the required safety functions (RSFs) to mitigate the consequences of design basis events (DBEs) to within the license basis event (LBE) frequency-consequence (F-C) Target, and to mitigate design basis accidents (DBAs) that only rely on the SR SSCs to meet the dose limits of 10 CFR 50.34 using conservative assumptions.

SSCs selected by the designer and relied on to perform RSFs to prevent the frequency of beyond design basis events (BDBEs) with consequences greater than the 10 CFR 50.34 dose limits from increasing into the DBE region and beyond the F-C Target.

Non-Safety-Related with Special Treatment (NSRST):

Non-safety-related SSCs relied on to perform risk-significant functions. Risk-significant SSCs are those that perform functions that prevent or mitigate any LBE from exceeding the F-C Target or make significant contributions to the cumulative risk metrics selected for evaluating the total risk from all analyzed LBEs.

Non-safety-related SSCs relied on to perform functions requiring special treatment for defense in depth (DID) adequacy.

Page 5 of 10 Non-Safety-Related with No Special Treatment (NST):

All other SSCs (with no special treatment required).

Safety-significant SSCs include all those SSCs classified as SR or NSRST. None of the NST SSCs are classified as safety-significant.

To further define safety-significant SSCs, NEI 18-04 states:

The meaning of safety-significant SSC in this process is the same as that used in NRC regulations. The NRC glossary provides the following definition: When used to qualify an object, such as a system, structure, component, or accident sequence, this term identifies that object as having an impact on safety, whether determined through risk analysis or other means, that exceeds a predetermined significance criterion.

Based on this description, it can be concluded that SSCs which are classified as safety-significant via NEI 18-04 are those SSCs which have a reasonable nexus to radiological health and safety. Subsequently, NST SSCs do not have a reasonable nexus to radiological health and safety. As stated in the Topical Report NATD-LIC-RPRT-0001 and supported by the Kemmerer Unit 1 CPA, all EI SSCs would be classified as NST. Additionally, the SSCs included in the scope of this exemption do not meet the definition of SR per 10 CFR 50.2, nor were they classified as SR using the safety classification process defined in NEI 18-04. Therefore, USO can meet the underlying purpose of 10 CFR 50.10(a)(1)(iv) without including EI SSCs classified as NST within the scope of this regulation.

Removing EI SSCs classified as NST from the scope of 10 CFR 50.10(a)(1)(iv) is consistent with the exemption request for 10 CFR 50.65(b) submitted by TerraPower, on behalf of USO, as CPA Enclosure 4, Regulatory Exemptions, (Reference 6) as it relates to the scope of SSCs falling within the definition of construction. As stated in Regulatory Guide 1.206, Revision 1, Applications for Nuclear Power Plants, Supplement to C.2.18, the LWA rule and maintenance rule both define a scope of SSCs that have some nexus to radiological health and safety. Based on the testing of already established guidance for selection of SSCs scoped into the maintenance rule, NRC decided the same definition can be applied to construction. Therefore, aligning the SSCs scoped for the definition of construction to the scope of SSCs that are included in the program for monitoring the effectiveness of maintenance at nuclear power plants defined in 10 CFR 50.65(b), is acceptable.

Eliminating EI SSCs classified as NST from the scope of SSCs that have a reasonable nexus to radiological health and safety is consistent with the 10 CFR Part 53 proposed rule (Reference 7 and Reference 8). Specifically, proposed 10 CFR 53.020 Definitions construction definition, proposed 10 CFR 53.610 Construction, proposed 10 CFR 53.1130 Limited work authorizations, and proposed 10 CFR 53.715 Maintenance, repair, and inspection programs, as follows:

The proposed 10 CFR 53.020 definitions do not include non-safety-significant (NSS)

SSCs within the scope of the construction definition (Note that proposed Part 53 classifications of SR, non-safety-related but safety-significant (NSRSS) and NSS are analogous to the NEI 18-04 classifications of SR, NSRST, and NST, respectively.) As such, NSS SSCs are not included in the proposed 10 CFR 53.610 construction scope, or the proposed 10 CFR 53.1130 limited work authorization scope. Therefore, under the 10 CFR Part 53 proposed rule, EI SSCs classified as NST are not included in the scope of SSCs for which LWAs are applicable.

Page 6 of 10 The proposed 10 CFR 53.715 requirements limit the scope of the Part 53 maintenance rule program to SR and NSRSS SSCs. As such, under the 10 CFR Part 53 proposed rule, NSS SSCs are not included in the scope of the maintenance rule. (Note that discussion in the LWA Final Rule states that the NRC chose to base the criteria in 10 CFR 50.10(a)(1)(iv) on the scoping criteria used in 10 CFR 50.65(b) which defines the Part 50 maintenance rule scope.)

Environmental Assessment Considerations The scope of the 10 CFR 50.10(a)(1)(iv) and 10 CFR 51.4 definition of construction (1)(i)(D) exemption requests specifically address EI SSCs instead of addressing all NST SSCs to apply the criteria of 10 CFR 50.12(b) and associated environmental assessments to the relevant scope of interest. The Department of Energy (DOE) had conducted a National Environmental Policy Act (NEPA) review of activities proposed at the Kemmerer Unit 1 site prior to issuance of the construction permit. Bechtel Power Corporation, on behalf of TerraPower, submitted a letter to DOE Office of Clean Energy Demonstrations (Reference 10) detailing the scope of work to support the DOE environmental assessment. Activities would include excavation and backfill for various areas of the EI and construction of several EI buildings and foundations. Additional activities to ready the site for construction (e.g., temporary parking areas, portable bathroom facilities, etc.) are also within the DOE environmental assessment review. Therefore, the environmental assessment for this exemption is bounded by the DOE environmental assessment.

Criteria of 10 CFR 50.12(a)

The exemption is authorized by law. The exemption would not violate the Atomic Energy Act of 1954 as amended or the Energy Reorganization Act of 1974 as amended. The language of the regulation was adopted at the discretion of the Nuclear Regulatory Commission, consistent with its statutory authority, and was not mandated by statute. The NRC has authority under 10 CFR 50.12 to grant exemptions from the requirements of this regulation.

The exemption will not present an undue risk to the public health and safety. EI SSCs classified as NST do not have a reasonable nexus to radiological health and safety, therefore, eliminating these SSCs from the scope of 10 CFR 50.10(a)(1)(iv) and 10 CFR 51.4 definition of construction (1)(i)(D) does not present an undue risk to the public health and safety.

The requested exemption is consistent with the common defense and security. This exemption does not affect the design, function, or operation of structures or plant equipment that are necessary to maintain the secure status of the plant. This exemption has no impact on plant security or safeguards procedures:

The requested exemption does not impact compliance with the requirements of 10 CFR 73 or 10 CFR 26, A fitness for duty program will be implemented prior to the commencement of construction of SR and security-related SSCs consistent with the requirements of 10 CFR 26 as described in the Kemmerer Unit 1 CPA, and A physical security plan, training and qualification plan, cyber security plan, and safeguards contingency plan will be provided with the application for an operating Page 7 of 10 license consistent with the requirements of 10 CFR 50.34(c) and 10 CFR 50.34(d) as described in the Kemmerer Unit 1 CPA.

This exemption affects only the timing of construction of the EI SSCs classified as NST, allowing construction to proceed in advance of construction permit issuance. This exemption does not authorize the possession of licensed material or affect NRC security requirements that will apply to Kemmerer Unit 1. Therefore, this exemption is consistent with the common defense and security.

Special circumstances are present per 10 CFR 50.12(a)(2)(ii) in that application of the regulation is not necessary to achieve the underlying purpose of 10 CFR 50.10(a)(1)(iv) and 10 CFR 51.4 definition of construction (1)(i)(D). The underlying purpose for the scoping requirements of 10 CFR 50.10(a)(1)(iv) is described in the LWA Final Rule (Reference 3) as those SSCs "that have a reasonable nexus to radiological health and safety and/or common defense and security." The Natrium reactor design described in the Kemmerer Unit 1 CPA uses the risk-informed performance-based SSC classification process to determine the safety significance of SSCs identified in NEI 18-04 (Reference 4) and endorsed via Regulatory Guide 1.233 (Reference 5). Based on the NEI 18-04 process, only safety-significant SSCs are those which have a reasonable nexus to radiological health and safety. EI SSCs classified as NST would not have a reasonable nexus to radiological health and safety. Therefore, the Natrium reactor design can meet the underlying purpose of 10 CFR 50.10(a)(1)(iv) and 10 CFR 51.4 definition of construction (1)(i)(D) without including EI SSCs classified as NST within the scope of these regulations.

Criteria of 10 CFR 50.12(b)

USO has considered 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. The exemption requested will not give rise to any adverse impact of large significance.

The Kemmerer Unit 1 CPA includes an Environmental Report (ER) in accordance with 10 CFR

51. The nature and extent of the environmental impacts associated with the construction of Kemmerer Unit 1, including the EI, is described in the CPA Enclosure 3, Environmental Report.

Consistent with the assessment presented in the ER and the summary in ER Chapter 10, only adverse impacts of small or moderate significance have been identified for activities that may be associated with the early construction of the EI, no adverse impacts of large significance have been identified which are attributable to the early construction of the EI.

The planned EI construction activities include, but are not limited to, excavation and backfill, laying foundations for SSCs used in electricity generation, and erecting support buildings. These activities do not prevent any anticipated future uses of the Kemmerer Unit 1 site. Removal of EI SSCs could be done using conventional construction methods for those not abandoned in place. Therefore, redress of any adverse environmental impact due to construction of the EI can be reasonably affected, and no anticipated future use of the site will be prevented.

The alternatives considered in ER Chapter 9 would not require any different use of the subsurface in the vicinity of the EI. Other sources of electricity generation could use the EI SSCs scoped into this exemption once constructed. Consequently, construction of the EI will not foreclose adoption of any alternatives.

Page 8 of 10 Delay of EI construction until issuance of the Kemmerer Unit 1 construction permit would impose significant costs and schedule delays for the Natrium Demonstration Project. The added costs and construction delays would not be in the public interest. In addition, the benefits, such as the need for power and reduced carbon emissions as described in the ER would not be realized.

The requested exemption would not preclude USO from obtaining the necessary approvals and permits from the state and local governments for the construction activities of the EI. These approvals and permits would be in place prior to construction or disturbance activities to ensure protection of the environment. The Wyoming Statute in Title 35, Chapter 12, Industrial Development and Siting, requires that USO obtain an industrial siting permit prior to commence to construct which is defined as:

Any clearing of land, excavation, construction, or other action that would affect the environment of the site of any facility, but does not include changes needed for temporary use of sites for less than ninety (90) days, changes required to conduct required studies and tests under this chapter, or any other state or federal act or regulation, or access roads and services associated with utilities, or routes for nonutility purposes or for uses in securing geological data but not limited to necessary borings or drillings to ascertain foundation conditions.

USO received approval for the industrial siting permit from the Wyoming Industrial Siting Council for the Kemmerer Unit 1 site on January 13, 2025 (Reference 11) and expects issuance of the industrial siting permit by February 27, 2025.

Activities associated with this exemption request will be carried out in such a manner as to minimize their environmental impact. USO plans to construct Kemmerer Unit 1 through a public-private partnership with the Department of Energy (DOE) Advanced Reactor Demonstration Program (ARDP). The DOE has completed a National Environmental Policy Act (NEPA) review and issued an environmental assessment (EA) for those activities that are planned to occur prior to issuance of NRC Environmental Impact Statement (EIS) for the Kemmerer Unit 1 CPA. The DOE EA requirements, as identified in 10 CFR 1021, address compliance with section 102(2) of the National Environmental Policy Act of 1969, as amended.

The criteria of 10 CFR 50.12(b) also address NEPA requirements, as such, the DOE EA addresses the criteria of 10 CFR 50.12(b).

Criteria of 10 CFR 51.6, Specific Exemptions As described in the LWA Final Rule (Reference 3), the 10 CFR 51.4 definition was intentionally aligned with the LWA rule:

Section 51.4 is revised by adding a new definition of construction. This makes applicable throughout Part 51 the definition of construction in proposed § 50.10(a) and has the effect of excluding from an EIS for any ESP, construction permit, combined license or an LWA, any discussion, evaluation or consideration of the environmental impacts or benefits associated with non-construction activities as set forth in § 50.10(a). This also removes the need for the NRC decision maker, including a presiding officer, to make a NEPA finding with respect to the environmental impacts or benefits associated with those non-construction activities.

Page 9 of 10 Therefore, aligning the exemption requested for 10 CFR 50.10(a)(1)(iv) with the exemption requested for 10 CFR 51.4 definition of construction (1)(i)(D) also aligns with the intention of the regulations as stated in the LWA Final Rule.

The exemption is authorized by law. The language of the regulation was adopted at the discretion of the Nuclear Regulatory Commission, consistent with its statutory authority, and was not mandated by statute. The NRC has authority under 10 CFR 51.6 to grant exemptions from the requirements of this regulation.

The exemption is in the public interest. As stated in ER Chapter 1 and Chapter 8, the purpose and need for Kemmerer Unit 1 is to demonstrate the Natrium advanced reactor design while replacing electricity generation capacity following planned retirement of existing coal-fired facilities with a zero-carbon emitting alternative. The Natrium design provides operational flexibility through energy storage that is ideal to support the Kemmerer Unit 1 region. Timely construction of Kemmerer Unit 1 supports the public interest by minimizing construction costs and by supporting a schedule amenable to the DOE ARDP timeline. Beginning construction early, specifically beginning construction of EI SSCs prior to receipt of a construction permit, allows flexibility to optimize construction timelines, which supports adherence to the challenging DOE ARDP schedule. Delay of construction activities of the EI and Kemmerer Unit 1, including potential delay costs, would not be in the public interest.

Conclusion The Natrium design can meet the underlying purpose of 10 CFR 50.10(a)(1)(iv) without incorporating EI SSCs classified as NST into the scope of this regulation because these SSCs are not safety-significant and do not have a reasonable nexus to radiological health and safety.

Aligning the exemption requested for 10 CFR 50.10(a)(1)(iv) with the exemption requested for 10 CFR 51.4 definition of construction (1)(i)(D) is consistent with the intention of the regulations.

On this basis, and the details discussed above, USO requests an exemption from 10 CFR 50.10(a)(1)(iv) and 10 CFR 51.4 definition of construction (1)(i)(D) to remove EI SSCs classified as NST from the scope these regulations.

Page 10 of 10 References

1. TerraPower, Regulatory Management of Natrium Nuclear Island and Energy Island Design Interfaces, Topical Report NATD-LIC-RPRT-0001, Revision 0, October 3, 2023, ML22277A824.

2. U.S. NRC, TerraPower, LLC - Final Safety Evaluation of Topical Report NATD-LIC-RPRT-0001, Regulatory Management Of Natrium Nuclear Island And Energy Island Design Interfaces, (EPID: L-2022-TOP-0045), Revision 0, October 4, 2023, ML23257A258.

3. U.S. NRC, Limited Work Authorizations for Nuclear Power Plants Final Rule, 72 FR 57441, October 9, 2007.

4. Nuclear Energy Institute, Risk-Informed Performance-Based Technology Inclusive Guidance for Non-Light Water Reactor Licensing Basis Development, Technical Report NEI 18-04, Revision 1, August 2019, ML19241A336.

5. U.S. NRC, Guidance for a Technology-Inclusive, Risk-Informed, and Performance-Based Methodology to Inform the Licensing Basis and Content of Applications for Licenses, Certifications, and Approvals for Non-Light-Water Reactors, Regulatory Guide 1.233, Revision 0, June 2020, ML20091L620.

6. TerraPower, LLC on behalf of US SFR Owner, LLC, Submittal of the Construction Permit Application for the Natrium Reactor Plant, Kemmerer Power Station, Unit 1, March 28, 2024, ML24088A060.

7. U.S. NRC, Proposed Rule: Risk-Informed, Technology-Inclusive Regulatory Framework for Advanced Reactors (RIN 3150-AK31)," SECY 23-0021, March 1, 2023, ML21162A093.

8. U.S. NRC, Proposed Rule: Risk-Informed, Technology-Inclusive Regulatory Framework for Advanced Reactors (RIN 3150-AK31)," SRM-SECY 23-0021, March 4, 2024, ML2064A047.

9. TerraPower, Principal Design Criteria for the Natrium Advanced Reactor, Topical Report NATD-LIC-RPRT-0002, Revision 0, January 24, 2023, ML23024A281

10. Letter from Bechtel Power Corporation, on behalf of TerraPower, LLC, to U.S.

Department of Energy, Office of Clean Energy Demonstrations, General Scope Description of Pre-NRC Construction Permit Activities for Kemmerer Power Station Unit 1, June 13, 2024.

11. Wyoming Department of Environmental Quality - Industrial Siting - Permitting.

https://deq.wyoming.gov/industrial-siting-2/permitting/. Accessed January 30, 2025.

ENCLOSURE 2 Application of Topical Report NATD-LIC-RPRT-0001-A to Energy Island Construction at Kemmerer Unit 1 Page 1 of 6 Application of NATD-LIC-RPRT-0001-A Introduction The requirements of 10 CFR 50.10(a) define the scope of construction activities in the context of LWAs. Demonstrating the requirements of 10 CFR 50.10(a)(1) are not applicable to the Natrium EI SSCs having no reasonable nexus to radiological health and safety, or receiving an exemption from one or more requirements of 10 CFR 50.10(a)(1), is essential to beginning construction of the EI prior to receiving a construction permit.

The Final Safety Evaluation to TerraPower Topical Report NATD-LIC-RPRT-0001-A, Regulatory Management of Natrium Nuclear Island and Energy Island Design Interfaces, (Reference 1) acknowledges the non-applicability of several criteria of 10 CFR 50.10(a)(1) to the EI based on EI SSCs safety classification being NST. Criteria described in 10 CFR 50.10(a)(1)(ii), apart from SSCs used in emergency operating procedures (EOP), (iii),

and (vi) are all not applicable as described in Reference 1. An exemption request from the requirements of 10 CFR 50.10(a)(1)(iv) is provided in Enclosure 1 of this submittal. The remaining criteria require additional information be provided to demonstrate their non-applicability as described in this enclosure.

Evaluation of NATD-LIC-RPRT-0001-A Limitations and Conditions Related to Construction Limitation and Condition 3 The TR does not address differences between the 10 CFR 50.2 and NEI 18-04 definitions of safety-related SSCs and does not discuss whether TerraPower plans to demonstrate compliance with the 10 CFR 50.2 definition or seek an exemption. Applicants or licensees referencing this TR must comply with the 10 CFR 50.2 definition or propose an exemption. If an applicant or licensee referencing this TR proposes an exemption from 10 CFR 50.2, an exemption to 10 CFR 50.10(a)(1)(i) must also be proposed, since that regulation references the 10 CFR 50.2 definition.

The requirements of 10 CFR 50.10(a)(1)(i) deterministically define which SSCs have a reasonable nexus to radiological health and safety. In contrast, the SSC classification process identified in NEI 18-04 (Reference 2) and endorsed via Regulatory Guide 1.233 (Reference 3) uses a risk-informed performance-based process to determine the safety significance of SSCs.

NEI 18-04 incorporates deterministic and PRA insights to classify which SSCs have a reasonable nexus to radiological health and safety (i.e., to classify which SSCs are safety-significant).

The Kemmerer Unit 1 CPA for Kemmerer Unit 1 is based on the Natrium design and the methodology described in NEI 18-04 and Regulatory Guide 1.233 as described in CPA, PSAR, Section 5.1 (Reference 4). EI SSCs do not meet the definition of SR in 10 CFR 50.2, nor were they classified as SR via the safety classification process defined in NEI 18-04.

No additional exemption request for 10 CFR 50.2 definitions is necessary and the criteria of 10 CFR 50.10(a)(1)(i) is not applicable. Limitation and Condition 3 is therefore met.

Page 2 of 6 Limitation and Condition 4 The NRC staffs review of what constitutes construction is limited to the provisions of 10 CFR 50.10 and does not address other definitions of construction (e.g., those in the environmental regulations in 10 CFR Part 51 or other non-NRC regulations).

Discussion in the Limited Work Authorizations for Nuclear Power Plants Final Rule (Reference 5) states that the NRC chose to specifically align the 10 CFR 51.4 construction definition with 10 CFR 50.10(a) definition of construction:

Section 51.4 is revised by adding a new definition of construction. This makes applicable throughout Part 51 the definition of construction in proposed § 50.10(a) and has the effect of excluding from an EIS for any ESP, construction permit, combined license or an LWA, any discussion, evaluation or consideration of the environmental impacts or benefits associated with non-construction activities as set forth in § 50.10(a). This also removes the need for the NRC decision maker, including a presiding officer, to make a NEPA finding with respect to the environmental impacts or benefits associated with those non-construction activities.

Table 1 provides a comparison of the definition of construction between 10 CFR 50.10 and 10 CFR 51.4.

Table 1 Comparison of 10 CFR 50.10 and 10 CFR 51.4 Definition of Construction 10 CFR 50.10(a) 10 CFR 51.4 definition of construction (a) Definitions. As used in this section, construction means the activities in paragraph (a)(1) of this section, and does not mean the activities in paragraph (a)(2) of this section.

(1) Activities constituting construction are the driving of piles, subsurface preparation, placement of backfill, concrete, or permanent retaining walls within an excavation, installation of foundations, or in-place assembly, erection, fabrication, or testing, which are for:

(i) Safety-related structures, systems, or components (SSCs) of a facility, as defined in 10 CFR 50.2; (ii) SSCs relied upon to mitigate accidents or transients or used in plant emergency operating procedures; (iii) SSCs whose failure could prevent safety-related SSCs from fulfilling their safety-related function; Construction means:

(1) For production and utilization facilities, the activities in paragraph (1)(i) of this definition, and does not mean the activities in paragraph (1)(ii) of this definition.

(i) Activities constituting construction are the driving of piles, subsurface preparation, placement of backfill, concrete, or permanent retaining walls within an excavation, installation of foundations, or in-place assembly, erection, fabrication, or testing, which are for:

(A) Safety-related structures, systems, or components (SSCs) of a facility, as defined in 10 CFR 50.2; (B) SSCs relied upon to mitigate accidents or transients or used in plant emergency operating procedures; (C) SSCs whose failure could prevent safety-related SSCs from fulfilling their safety-related function; Page 3 of 6 (iv) SSCs whose failure could cause a reactor scram or actuation of a safety-related system; (v) SSCs necessary to comply with 10 CFR part 73; (vi) SSCs necessary to comply with 10 CFR 50.48 and criterion 3 of 10 CFR part 50, appendix A; and (vii) Onsite emergency facilities necessary to comply with either § 50.160 or § 50.47 and appendix E to this part, as applicable.

(D) SSCs whose failure could cause a reactor scram or actuation of a safety-related system; (E) SSCs necessary to comply with 10 CFR part 73; (F) SSCs necessary to comply with 10 CFR 50.48 and criterion 3 of 10 CFR part 50, appendix A; and (G) Onsite emergency facilities (i.e.,

technical support and operations support centers), necessary to comply with 10 CFR 50.47 and 10 CFR part 50, appendix E.

The definitions are functionally the same as intended by the LWA Final Rule (Reference 5). The main difference is between 10 CFR 50.10(a)(1)(vii) and 10 CFR 51.4 definition of construction (1)(i)(G). The 50.10 definition refers to 10 CFR 50.160 while the 51.4 definition does not.

10 CFR 51.4 was not revised with the promulgation of 10 CFR 50.160. However, the requirements described in 10 CFR 50.160 are the risk-informed and performance-based alternatives to 10 CFR 50 Appendix E for non-light-water reactors. As such, construction of the EI prior to receiving a construction permit will achieve the underlying purpose of 10 CFR 51.4 definition of construction (1)(i)(G) by complying with 10 CFR 50.160.

Application of NATD-LIC-RPRT-0001-A does not create a conflict between 10 CFR 50.10(a)(1) and 10 CFR 51.4 definition of construction (1)(i)(D). Therefore, Limitation and Condition 4 is met.

Limitation and Condition 5 Applicants or licensees using this TR as a basis for non-applicability of 10 CFR 50.10(a)(1)(ii) or 10 CFR 50.65(b)(2)(i) to the EI must provide additional information demonstrating that EI SSCs are not used in the EOPs.

NUREG-0899, Guidelines for the Preparation of Emergency Operating Procedures, Section 2.2, defines EOPs as:

EOPs are plant procedures that direct operators' actions necessary to mitigate the consequences of transients and accidents that have caused plant parameters to exceed reactor protection system set points or engineered safety feature set points, or other established limits.

In addition, Regulatory Guide 1.206, Revision 1, Applications for Nuclear Power Plants, Section C.I.17, further clarifies the definition for SSCs used in EOPs within the context of 10 CFR 50.65(b) as:

Page 4 of 6 SSCs used in the EOPs that are required to be in the scope of the Maintenance Rule program are those that are directly used to mitigate the accident or transient (explicitly mentioned in the EOPs or in steps of referenced procedures needed to accomplish the EOP step) and those whose use is implied and that provide a significant portion of the mitigating function. For the purposes of this definition, significant proportion of the mitigating function means that the implied-use SSC is essential to the performance of one or more EOP steps and there are no reliable and consistently readily available (under EOP conditions) alternatives. SSCs that do not provide or support a mitigating function, but are included in the EOPs for other reasons, for example, operator convenience or simplifying EOP compliance, equipment protection, etc., are not necessarily required to be in the Maintenance Rule scope under 10 CFR 50.65(b)(2)(i).

EI SSCs classified as NST using the methodology described in NEI 18-04 are not directly relied upon to mitigate accidents or transients and do not have a reasonable nexus to radiological health and safety. EI SSCs do not provide a significant proportion of the mitigating function and would not be used in plant EOPs for direct accident mitigation. Therefore, Limitation and Condition 5 is met.

Limitation and Condition 6 Applicants or licensees using this TR as a basis for non-applicability of 10 CFR 50.10(a)(1)(v) to the EI must provide detailed information demonstrating that the physical and cyber security programs would be implemented in such a way that the EI would not include any SSCs that meet the 10 CFR 50.10(a)(1)(v) criterion (i.e., not include any SSCs necessary to comply with 10 CFR part 73, or otherwise not construct the EI SSCs necessary to comply with 10 CFR Part 73 until a CP has been issued).

The Kemmerer Unit 1 EI does not contain SSCs necessary to comply with the physical security program of 10 CFR 73, including physical barriers and structures and associated hardware and detection systems. The EI will contain critical digital assets (CDAs) to support the cyber security program of 10 CFR 73. As such, no digital components or control systems identified as CDAs will be installed or activated at the Kemmerer Unit 1 site prior to receipt of a construction permit.

This commitment is made to address Limitation and Condition 6.

Limitation and Condition 7 TerraPower asserted in the TR that onsite emergency facilities necessary to comply with 10 CFR 50.47 or 10 CFR Part 50 Appendix E and facilities for providing onsite emergency first aid and decontamination are not located on the EI. Applicants or licensees using this TR as a basis for non-applicability of 10 CFR 50.10(a)(1)(vii) must provide detailed information to demonstrate this assertion.

The Kemmerer Unit 1 PSAR Section 11.3 (Reference 4) describes preliminary plans for coping with emergencies. The emergency preparedness program will be developed using the requirements in 10 CFR 50.160 and the guidance in Regulatory Guide 1.242, Performance Based Emergency Preparedness for Small Modular Reactors, Non-Light-Water Reactors, and Non-Power Production or Utilization Facilities, Revision 0. Kemmerer Unit 1 PSAR Figure 1.2-1 shows the buildings on the EI consist of the Turbine Facility Building, Steam Generator Building, and Water Treatment Building.

Page 5 of 6 Onsite emergency first aid is initially performed at the location of injury. Personnel would then be transported offsite, as needed, for additional medical care. Routine decontamination of personnel will occur at the exit of the radiation control area located in the Fuel Auxiliary Building on the Nuclear Island. Decontamination of injured personnel will also occur in the Fuel Auxiliary Building if the severity of the injury allows. For severe injuries to contaminated personnel, the Radiation Protection Program and implementing procedures will describe the protocol for contamination control.

The EI does not contain buildings with onsite emergency facilities to meet the requirements of 10 CFR 50.160 and does not provide facilities to support onsite emergency first aid nor decontamination of personnel. Therefore, Limitation and Condition 7 is met.

Conclusion Application of TerraPower Topical Report NATD-LIC-RPRT-0001-A (Reference 1), when combined with the additional information provided here and the exemption request provided in to this submittal provides the justification necessary to begin construction of the Kemmerer Unit 1 EI prior to issuance of a construction permit. EI SSCs classified as NST do not have a reasonable nexus to radiological health and safety, resulting in criteria of 10 CFR 50.10(a)(1)(ii) (except SSCs used in EOPs), (iii), and (vi) being not applicable. An exemption request from 10 CFR 50.10(a)(1)(iv) and 10 CFR 51.4(1)(i)(D) is included in Enclosure 1 to this submittal. Additional information is provided here for the remaining criteria in 10 CFR 50.10(a)(1)(i), (ii) for SSCs used in EOPs, (v), and (vii). In addition, the analysis shows the 10 CFR 50.10(a) and 10 CFR 51.4 definition of construction are functionally the same. On this basis, and the details discussed above, USO concludes the Limitations and Conditions of NATD-LIC-RPRT-0001-A related to construction have been met.

Page 6 of 6 References

1. U.S. NRC, TerraPower, LLC - Final Safety Evaluation of Topical Report NATD-LIC-RPRT-0001, Regulatory Management Of Natrium Nuclear Island And Energy Island Design Interfaces, (EPID: L-2022-TOP-0045), Revision 0, October 4, 2023, ML23257A258.

2. Nuclear Energy Institute, Risk-Informed Performance-Based Technology Inclusive Guidance for Non-Light Water Reactor Licensing Basis Development, Technical Report NEI 18-04, Revision 1, August 2019, ML19241A336.

3. U.S. NRC, Guidance for a Technology-Inclusive, Risk-Informed, and Performance-Based Methodology to Inform the Licensing Basis and Content of Applications for Licenses, Certifications, and Approvals for Non-Light-Water Reactors, Regulatory Guide 1.233, Revision 0, June 2020, ML20091L620.

4. TerraPower, LLC on behalf of US SFR Owner, LLC, Submittal of the Construction Permit Application for the Natrium Reactor Plant, Kemmerer Power Station, Unit 1, March 28, 2024, ML24088A060.

5. U.S. NRC, Limited Work Authorizations for Nuclear Power Plants Final Rule, 72 FR 57441, October 9, 2007.