ML25085A276

Public - Enclosure - Terrapower, LLC - Final Safety Evaluation of Topical Report NAT-2695, Human Factors Engineering Program Plan and Methodologies, Rev 1

ML25085A276
Person / Time
Site:	99902100
Issue date:	04/18/2025
From:	NRC/NRR/DANU/UAL1
To:	TerraPower
References
NAT-2695 Rev. 1, EPID L-2023-TOP-0026
Download: ML25085A276 (1)

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OFFICIAL USE ONLY - PROPRIETARY INFORMATION TERRAPOWER, LLC. - FINAL SAFETY EVALUATION OF TOPICAL REPORT NAT-2965, NATRIUM HUMAN FACTORS ENGINEERING PROGRAM PLAN AND METHODOLOGIES, REVISION 1 (EPID L-2023-TOP-0026)

SPONSOR AND SUBMITTAL INFORMATION Sponsor:

TerraPower, LLC Sponsor Address:

15800 Northup Way Bellevue, WA 98008 Project No.:

99902100 Submittal Date:

September 17, 2024 Submittal Agencywide Documents Access and Management System Accession No.:

ML24261B925 Brief Description of the Topical Report: On April 26, 2023, TerraPower, LLC (TerraPower) submitted topical report (TR) NAT-2965, Natrium Human Factors Engineering Program Plan and Methodologies, Revision 0 [1], for review by the U.S. Nuclear Regulatory Commission (NRC) staff. The TR describes the Natrium Human Factors Engineering Program Plan (HFEPP), including related methodologies, and requests the NRC staff review and approval to support referencing of the report in licensing documentation.

By email dated June 21, 2023 [2], the NRC staff informed TerraPower that the TR provided sufficient information for the NRC staff to begin its detailed technical review [3].On May 28, 2024, the NRC staff transmitted an audit plan to TerraPower (ML24137A289), and subsequently conducted an audit of materials related to the TR from June 13, 2024, through August 6, 2024.

On September 17, 2024, TerraPower submitted revision 1 of TR NAT-2965 [4]. The NRC staff issued the audit summary on November 15, 2024 [5].

In section 2.0 of the TR, Requirements and Technical Basis, TerraPower states that the HFEPP creates a human factor engineering (HFE) program that is compliant with the requirements of Title 10 of the Code of Federal Regulations (10 CFR) 50.34(f)(2)(ii) and 10 CFR 50.34(f)(2)(iii). Additionally, TerraPower states that the HFEPP also considers relevant practices provided in both Institute of Electrical and Electronics Engineers (IEEE) 1023-2020, IEEE Recommended Practice for the Application of Human Factors Engineering to Systems, Equipment, and Facilities of Nuclear Power Generating Stations and Other Nuclear Facilities

[6], and NUREG-0711, Human Factors Engineering Program Review Model, revision 3 [7].

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION REGULATORY EVALUATION The NRC staff reviewed whether the HFEPP and related methodologies described in the TR were consistent with the relevant regulations and guidance. The key regulations, guidance, and standards discussed by TerraPower in the TR include:

10 CFR 50.34(f)(2)(ii), which states, in part, establish a program, to begin during construction and follow into operation, for integrating and expanding current efforts to improve plant procedures. The scope of the program shall include emergency procedures, reliability analyses, human factors engineering, crisis management, operator training 10 CFR 50.34(f)(2)(iii), which states, in part, provide, for Commission review, a control room design that reflects state-of-the-art human factor principles prior to committing to fabrication or revision of fabricated control room panels and layouts NUREG-0700, Human-System Interface Design Review Guidelines, revision 3 [8]

NUREG-0711, Human Factors Engineering Program Review Model, Revision 3 NUREG-1764, Guidance for the Review of Changes to Human Actions, revision 1 [9]

IEEE 1023-2020, IEEE Recommended Practice for the Application of Human Factors Engineering to Systems, Equipment, and Facilities of Nuclear Power Generating Stations and Other Nuclear Facilities Electric Power Research Institute, EPRI 3002004310, Human Factors Guidance for Control Room and Digital Human-System Interface Design and Modification [10]

Additionally, Kemmerer Power Station Unit 1 Preliminary Safety Analysis Report, revision 0,

[11], table 1.4-4, Applicability of TMI-Related Requirements, identifies, in part, the following regulations of 10 CFR 50.34(f) as having applicability to the proposed Natrium design.1 Multiple subsections of 10 CFR 50.34(f) apply to HFE, including:

10 CFR 50.34(f)(2)(ii) for procedures, 10 CFR 50.34(f)(2)(iii) for HFE in the control room, 10 CFR 50.34(f)(2)(iv) for safety parameters display system, 10 CFR 50.34(f)(2)(v) for status of safety systems, 10 CFR 50.34(f)(2)(xi) for relief and safety valve indication, 10 CFR 50.34(f)(2)(xvii) for containment related indications, 10 CFR 50.34(f)(2)(xviii) for core cooling indications, 10 CFR 50.34(f)(2)(xix) for instrumentation to monitor post-accident plant conditions, 10 CFR 50.34(f)(2)(xxvi) for leakage control and detection, 10 CFR 50.34(f)(2)(xxvii) for radiation monitoring, and 10 CFR 50.34(f)(3)(i) for operating experience.

Furthermore, in reviewing the HFEPP, the NRC staff also considered the following additional regulations:

10 CFR 50.54(k) through (m), which address licensed operator staffing requirements; 10 CFR 50.120, which addresses training requirements for various plant staff categories; 1 Combined Operating License (COL) applicants that wish to reference the topical report should describe how the content of the report has been assessed and, as needed, been supplemented in order to adapt its usage from the context of a Construction Permit/Operating License facility application process to that of a COL application process.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 10 CFR 55.4, which defines a systems approach to training and its associated elements; 10 CFR 55.45(b), which addresses the administration of operating tests; and 10 CFR 55.46, which addresses the requirements for simulation facilities.

Because TerraPower applied the licensing modernization project in the construction permit application for its proposed Natrium reactor, the NRC staff also reviewed the HFEPP against the applicable criteria in DANU-ISG-2022-05, Advanced Reactor Content of Application Project chapter 11, Organization and Human-System Considerations Interim Staff Guidance [12].2 TECHNICAL EVALUATION The NRC staff compared the TR to the relevant3 review criteria in NUREG-0711 to gain reasonable assurance that the HFEPP complies with the HFE regulations cited above. The HFE regulations include a requirement that the applicant provide a control room design that reflects state-of-the-art human factors (HF) principles so that the HFE design will support plant personnel in the safe operation of the plant.

NUREG-0711 describes a systematic method for developing a control room HFE design that complies with the HFE regulations. The method includes four general activities: (1) planning and analysis, (2) design, (3) verification and validation (V&V), and (4) implementation and operation.

These four general activities consist of 12 HFE program elements, which together provide for the successful integration of human characteristics and capabilities into nuclear power plant design, as shown below:

Planning and analysis: (1) HFE program management, (2) operating experience review (OER), (3) functional requirements analysis (FRA) and function allocation (FA), (4) task analysis (TA), (5) staffing and qualifications, and (6) treatment of important human actions (IHAs)

Design: (7) human-system interface (HSI) design, (8) procedure development, and (9) training program development V&V (10)

Implementation and operation: (11) design implementation and (12) human performance monitoring The evaluation in this SE is organized according to these 12 elements. The NRC staff conducted a bottom-up review by assessing the relevant review criteria associated with each of the 12 elements in NUREG-0711. In conducting this review, the NRC staff recognize that, while NRC review plans generally describe acceptable means of meeting the regulations, they 2 TerraPower, on behalf of US SFR Owner, LLC (USO), submitted a construction permit application on March 28, 2024 for a Natrium reactor plant (ML24088A059). The NRC staffs review of this application is ongoing.

3 Not all of the relevant review criteria in NUREG-0711 can be evaluated by the NRC staff at the construction permit application phase for Natrium that exists at the time of this evaluation. The information contained in the TR generally corresponds to implementation plans (IPs), as described under NUREG-0711 and describes the methods to be used, but not the resulting outputs and design stemming from implementation of those methods. A subsequent operating license application (OLA) is expected to be accompanied by the relevant results summary reports (RSRs) described under NUREG-0711 and a complete assessment of the HFE program for the purposes of determining compliance with 10 CFR 50.34(f)(2)(iii) may only occur at that point. Consistent with this, the evaluation of certain criteria is noted as being deferred until the OLA review when the necessary information will be available.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION do not necessarily describe the only means of doing so and, therefore, applications may deviate from the acceptance criteria of a review plan such as NUREG-0711. However, where such differences exist, the NRC staff expect that an application will discuss how the proposed alternative provides an acceptable method of complying with relevant regulations that underlie the corresponding review plan acceptance criteria. At the same time, the degree to which the NRC staff applies the methodology of a review plan will reflect the specific circumstances of individual applications, with the factors that are considered when determining the depth of a review including both risk importance and safety significance. Additionally, it should be noted that the criteria of NUREG-0711 generally do not make distinctions between whether IPs or RSRs are being reviewed. Consistent with that lack of distinction, staff judgement has been applied regarding what is reasonable for a review that is limited to the IP phase of the HFE process when development of RSRs has yet to occur (and, moreover, prior to the availability of detailed design information in an OLA).4 Furthermore, certain criteria of NUREG-0711 are relevant only within the context of the modification of existing plants and, as such, these criteria were excluded from the scope of this review.5 1.0 HFE PROGRAM MANAGEMENT The NRC staffs objective in the review of this element is to verify that the applicant has an HFE design team with the responsibility, authority, placement within the organization, and composition to reasonably assure that the plant design meets the commitment to HFE. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 2.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in sections 1.1 through 1.5. It should be noted that, per NUREG-0711, there is no associated RSR expected for this element.

1.1 General Human Factors Engineering Program Goals and Scope (Criteria 2.4.1(1) - (6))

1.1.1 HFE Program Goals (Criterion 2.4.1(1))

Criterion 2.4.1(1) identifies four general human-centered goals for an HFE program and states that, as the HFE program develops, the generic goals should be further defined and used as a basis for HFE tests and evaluations. The generic design goals provided by NUREG-0711 are:

1) personnel tasks can be accomplished within time and performance criteria

2) the HSIs, procedures, staffing/qualifications, training, and management and organizational arrangements support personnel situation awareness

3) the design will support personnel in maintaining vigilance over plant operations and provide acceptable workload levels, i.e., minimize periods of under-and over-load

4) the HSIs will minimize personnel error and will support error detection and recovery capability The HFEPP defines the following design goals in section 1.1, Purpose, of the TR:

4 The HFEPP described in the TR represents only HFE IPs for Natrium. Consistent with this, the need for applicants or licensees who reference the TR to make relevant RSRs available to support staff review of an OLA is addressed in the Limitations and Conditions section of this evaluation.

5 NUREG-0711 explicitly identifies which criteria apply only to plant modifications and, as such, discussion of those specific criteria is not reproduced within this evaluation because they are not applicable to this review.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION

1) personnel tasks are accomplished within the evaluated time frame and performance criteria

2) information systems support a high degree of situation awareness of the state of the plant and actions required

3) allocation of function (AOF) maintains human vigilance and provides acceptable workload levels that minimize periods of human underload and overload

4) HSI minimizes error and provides for error detection

5) HSI design supports the capability of the operating crew to recover from previous decisions and actions that did not achieve intended results

6) application of ergonomic principles to working areas and their environments ensures these areas are safe and designed for the human to perform operations, maintenance, inspection, surveillance, and test activities The NRC staff reviewed these goals described in the HFEPP and found they adequately address the four generic human-centered HFE design goals listed in criterion 2.4.1(1).

Additionally, the NRC staff notes that section 5 of the TR describes how individual HFE elements implement and verify these HFE design goals during the design process. For example, section 5.4, Staffing, of the TR discusses that staffing analysis is further confirmed through workload analysis and evaluated using mock-ups, modeling, or simulation, as appropriate. Additionally, section 5.10, Human Factors Verification and Validation, of the TR discusses integrated system validation (ISV), which includes both the validation that important personnel tasks can be accomplished within required time frames as well as the verification that crew situational awareness and workload levels remain acceptable. Separately, section 5.5, Treatment of Important Human Actions, of the TR discusses that human reliability analysis (HRA) is conducted as part of the development of a probabilistic risk analysis (PRA) and evaluates the potential for, and mechanisms of, human error that may affect plant safety with the HFE design (including HSIs) being used as an input to the definition of the performance shaping factors used in the HRA. Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management addresses definition of the general HFE program goals and will use these goals as a basis for HFE tests and evaluations to assess whether the general HFE program goals have been met. Therefore, the NRC staff concludes that criterion 2.4.1(1) is met.

1.1.2 Assumptions and Constraints (Criterion 2.4.1(2))

Criterion 2.4.1(2) states that the applicant should identify the design assumptions and constraints (i.e., aspects of the design that are inputs to the HFE program).

Section 1.3 of the TR discusses that the initial staffing assumption aligns with the staffing requirements of 10 CFR 50.54(m) and that this assumption will be confirmed via the staffing analysis described under appendix C, Human Factors Engineering Staffing Analysis Plan, of the TR. Additionally, section 1.3 of the TR states that no further assumptions have been identified with applicability to the overall HFE program and that any assumptions made during the design process when inputs are either not available or have not yet been confirmed will subsequently be confirmed by way of the design and testing program. Furthermore, section 1.3 of the TR states that no constraints have been identified that would apply to the HFE program in general. Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management adequately identifies both design assumptions and constraints and, therefore, concludes that criterion 2.4.1(2) is met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 1.1.3 Human Factors Engineering Program Duration (Criterion 2.4.1(3))

Criterion 2.4.1(3) states that the applicants HFE program should be in effect at least from the start of the design cycle through completion of the initial plant startup test program. Consistent with this, section 1.4 of the TR states that the HFE program will be in effect from the start of the conceptual design cycle though completion of the initial plant startup test program, with the Human Performance Monitoring Program specified and active before initial fuel loading. The NRC staff has determined that TerraPowers plan for HFE program management adequately addresses the duration of the program and, therefore, concludes that criterion 2.4.1(3) is met.

1.1.4 Human Factors Engineering Facilities (Criterion 2.4.1(4))

Criterion 2.4.1(4) states that the applicants HFE program should cover the main control room (MCR), remote shutdown facility, technical support center (TSC), emergency operations facility (EOF), and local control stations (LCSs). However, applicants may apply the elements of the HFE program in a graded fashion to facilities other than the MCR and remote shutdown facility, providing justification in the HFE program plan. The NRC staff notes that while this criterion discusses the TSC and EOF, the specific emergency facilities associated with Natrium will be defined within the emergency plan that will accompany an OLA.

Section 1.2, Scope, of the TR states that the HFEPP applies to Nuclear Island (NI)-related HSIs including those at the following locations:

1) MCR

2) Remote Shutdown Complex (RSC)

3) Local controls

4) Emergency support facilities TerraPower describes within section 1.2 of the TR that control and monitoring of both NI and Energy Island (EI) equipment is performed from HSIs in the MCR, with the layout and interface of both NI and EI workstations being of the same general design within an integrated overall MCR design. However, TerraPower states that the EI itself is not included within the scope of the HFEPP, with the justification being that no EI systems, structures, and components (SSC) are required to (1) respond to mitigate any events impacting the NI, (2) support safety-related, SSCs, or (3) ensure defense-in-depth adequacy. The NRC staff previously evaluated key implications of the separation of the NI and EI portions of the Natrium design, as documented under Final Safety Evaluation of Topical Report NATD-LICRPRT-0001, Regulatory Management of Natrium Nuclear Island and Energy Island Design Interfaces, [13]

and notes that TerraPowers characterization regarding the significance of EI operations to NI safety is generally consistent with those prior staff conclusions. Based upon that, the NRC staff determined that the application of HFE within the context of the EI is not of significance because human performance within that location is not reasonably expected to influence Natrium safety outcomes in an appreciable manner and, accordingly, that TerraPowers exclusion of the EI from the scope of the HFEPP is reasonable.

Section 1.2 of the TR further describes that the application of HFE is graded based on nuclear safety, personnel safety, and asset protection considerations to apply greater rigor to those human interactions that are of higher importance from a standpoint of safety or hazards. The NRC staff notes that this approach represents a difference from the criterion of NUREG-0711 in

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION that it involves grading HFE in a manner that is broader than what the criterion assumes. The NRC staff then considered whether this broader application of a graded HFE methodology was appropriate.

The staff notes that section 3.1, Risk Level Determination, of the TR describes that HFE is graded based upon three possible levels of application, ((

)) Section 3.2, Human Factors Engineering Application Level Determination, of the TR discusses that ((

))

The NRC staff notes that NUREG-1764 provides a review framework under which the NRC staff use a combination of risk-informed and deterministic criteria to establish a graded level of HFE review for a given application. The combination of quantitative and qualitative insights can result in a staff review that ranges from a very comprehensive and rigorous HFE review all the way to essentially no HFE review at all. While NUREG-1764 is guidance to the NRC staff, versus an applicant or licensee, used generally for its review of license amendment requests, versus construction permit or operating license applications, the NRC staff notes that the fundamental principles involved remain relevant in either context. That is, greater HFE focus should be placed on human actions (HAs) that are of higher risk importance and safety significance. Thus, the NRC staff has determined that the fundamental approach of grading the application of HFE based upon safety and risk insights is consistent with existing, accepted practices.

Based on the above, the NRC staff has determined that the scope of the HFEPP covers facilities equivalent to those described within the review criterion and that the described exception (i.e., the EI) is justified. Additionally, the NRC staff has determined that, while TerraPowers HFE grading approach is more extensive than that addressed by the criterion, the difference has been adequately justified and is consistent with practices that the NRC has found to be acceptable under NUREG-1764. Accordingly, the NRC staff concludes that the HFEPP meets criterion 2.4.1(4).

1.1.5 Human-System Interfaces, Procedures, and Training (Criterion 2.4.1(5))

Criterion 2.4.1(5) states that the applicants HFE program should address the design of HSIs and identify inputs to the development of procedures and training for all operations, accident management, maintenance, test, inspection, and surveillance tasks that operational personnel will perform or supervise. In addition, the HFE design process should identify training program

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION input for instrumentation and control (I&C) technicians, electrical maintenance personnel, mechanical maintenance personnel, radiological protection technicians, chemistry technicians, and engineering support personnel. Any other personnel who perform tasks directly related to plant safety also should be included.

TerraPower describes the HSI design element of the HFE program in section 5.7, Human-System Interface Design, of the TR. The NRC staff notes that this element is incorporated into a broader HFE process in a manner that is generally consistent with the structure described by NUREG-0711. Section 5.7.8, Human Factors Human-System interface Design Output, of the TR states that the detailed HSI design feeds into the development of the simulator for training and the validation of procedures. Section 5.8, Procedure Development, of the TR describes that the procedure development plan (PDP) addresses procedures for the operations, maintenance, and inspection/testing of the plant. TerraPower also states in section 5.9, Training and Qualification Program Development, of the TR that a training program development plan (TPDP) is established to specify a systems approach to training (SAT)-based training process, with the approach being applied to positions included in the minimum staff complement. Additionally, TerraPower states that the TPDP addresses the guidance provided in Regulatory Guide (RG) 1.8, Qualification and Training of Personnel for Nuclear Power Plants, revision 4 [14], which endorses American National Standards Institute (ANSI) /American Nuclear Society (ANS)-3.1-2014, Selection, Qualification, and Training of Personnel for Nuclear Power Plants [15]. The NRC staff notes that ANSI/ANS-3.1-2014, with certain exceptions identified under RG 1.8, generally addresses the categories of personnel included within this criterion.

Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management addresses the design of the HSIs and will input that design into the procedures and training programs. The NRC staff, therefore, concludes that criterion 2.4.1(5) is met.

1.1.6 Personnel (Criterion 2.4.1(6))

Criterion 2.4.1(6) states that the applicants HFE program should consider operations staffing and qualifications, including licensed control room operators as defined in 10 CFR Part 55, Operators Licenses; non-licensed operators; shift supervisors; and shift technical advisors.

TerraPower states in section 5.4 of the TR that a staffing analysis process systematically determines the minimum staff complement. Appendix C of the TR describes the HFE staffing analysis plan. ((

)) However, the NRC staff notes that the shift technical advisor position (STA) is not discussed within this appendix. During the audit, TerraPower clarified that they will request an exemption in conjunction with the OLA to omit the STA, with HFE program activities under the HFEPP serving to provide support for the justification of this requested exemption. The NRC staff makes no conclusions about the STA or the appropriateness of a potential exemption as part of this SE.

From a qualifications standpoint, TerraPower states in section 5.9 of the TR that the TPDP addresses the guidance provided in RG 1.8, which endorses ANSI/ANS-3.1-2014. The NRC staff notes that ANSI/ANS-3.1-2014, with certain exceptions identified in RG 1.8, generally

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION addresses the categories of personnel included within this criterion. Therefore, the NRC staff has determined that the HFEPP meets criterion 2.4.1(6), except for addressing STA staffing.

The NRC staff has determined that it will be necessary for a future OLA applicant to either address STA staffing or provide an adequate justification to support the omission of the STA from the staffing model, including any associated exemption request(s); this is addressed in the Limitations and Conditions section of this evaluation.

1.2 HFE Team and Organization (Criteria 2.4.2(1)-(4))

1.2.1 Responsibility of the Human Factors Engineering Team (Criterion 2.4.2(1))

Criterion 2.4.2(1) lists activities the applicants HFE team should be responsible for performing.

These activities include developing HFE plans, overseeing and reviewing all activities in HFE design, and assuring that all HFE activities comply with the HFE plans and procedures.

Section 4 of the TR describes the roles and responsibilities of the HFE organization. The NRC staff reviewed this section of HFEPP and determined that the responsibilities of the core HFE team, which broadly include establishing and performing the activities of the HFEPP, adequately address those listed in criterion 2.4.2(1). The NRC staff has determined that TerraPowers plan for HFE program management addresses the establishment of a specific entity to be responsible for the applicants HFE design and, therefore, concludes that criterion 2.4.2(1) is met.

1.2.2 Organizational Placement and Authority (Criterion 2.4.2(2))

Criterion 2.4.2(2) states that the applicant should describe the primary HFE organization(s) or function(s) within the engineering organization designing the plant. The organization should be illustrated to show organizational and functional relationships, reporting relationships, and lines of communication. The applicant also should address necessary transitions between responsible organizations and how the HFE team has the authority and appropriate organizational placement to reasonably assure that all its areas of responsibility are completed; to identify problems in establishing the overall plan; and to control further processing, delivery, installation, or use of HFE products until the disposition of a nonconformance, deficiency, or unsatisfactory condition is resolved.

Section 4.0 of the TR states that the HFE organization is comprised of both a core HFE team and an extended team, with the extended team including members from other disciplines within the engineering design team. Within the HFE core team, a technical lead is identified who, in part, acts as the contact point for schedule development, integration, and management. The extended team membership is distributed throughout the design organization and provides expertise to the core HFE team as needed.

Section 4.1.3 of the TR states that the TerraPower organization will use established processes and procedures for the identification and resolution of HFE-related issues. Regarding organizational structure, an HFE technical lead is described as coordinating design activities with a TerraPower HFE program owner who provides an oversight function. The HFE program owner has responsibly within the TerraPower design organization for ensuring that any HFE-related concerns are reported, processed, and resolved. The TerraPower HFE program owner, in turn, reports to a senior manager that acts as both the senior-level advocate for HFE and technical design authority. Additionally, it is described that while specific reporting

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION relationships are subject to change, the HFE program will continue to be represented by a TerraPower senior manager who would be the design authority.

During the audit, TerraPower clarified that GE Hitachi staffs the core HFE team (to include the HFE technical lead role), as well as related reporting relationships.

Because the HFE team has been given the responsibility for the HFE design as discussed under criterion 2.4.2(1) and because the HFE program owner has responsibly within the TerraPower design organization for ensuring that any HFE-related concerns are reported, processed, and resolved, the NRC staff has determined that the HFE team has adequate authority and organizational placement and, accordingly, concludes that criterion 2.4.2(2) is met.

1.2.3 Composition and Expertise (Criterion 2.4.2(3))

Criterion 2.4.2(3) states that the applicants HFE design team should include the expertise described in the appendix to NUREG-0711 (i.e., Composition of the HFE Design Team).

The NRC staff reviewed the HF organization description provided under section 4 of the TR, including the described roles, qualifications, and responsibilities. Section 4.1.1 of the TR describes that the HFE team is comprised of both a core team and an extended team.

Regarding the expertise included within the HFE team, section 4.1.1 of the TR states the following:

The HFE team, as an entity, satisfies the professional experience qualifications described in this section. The satisfaction of these qualifications associated with a particular skill area may be realized through combining the professional experience of two or more members of the HFE team who individually satisfy other defined credentials of that particular skill area, but who do not possess all of the specified professional experience. The definition of roles is based on NUREG-0711.

Section 4.2 of the TR describes that the composition of the extended team is adapted from NUREG-0711 and states, in part, that:

The qualification and experience requirements for the individuals supporting as extended members of the HFE team are determined by the performers quality program and related procedures. Plant procedures and personnel training are developed in accordance with the licensees administrative procedures, therefore, these roles are not summarized herein.

During the audit, TerraPower provided clarifications regarding the differences between the composition, qualifications, and experience of their HFE team versus that of the generic approach described by NUREG-0711.

The NRC staff notes that the TR describes a scope of roles, qualifications, and responsibilities for the HFE team that is generally consistent with the generic model presented under NUREG-0711 and that the differences between the approach described under the TR and that discussed within NUREG-0711 are reasonable. Based on the above, the NRC staff has determined that the applicants HFE team includes adequate expertise and that the application conforms to this criterion. Therefore, the NRC staff concludes that criterion 2.4.2(3) is met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 1.2.4 Human Factors Engineering Team Staffing (Criterion 2.4.2(4))

Criterion 2.4.2(4) states that the applicant should describe team staffing in terms of job descriptions and assignments of team personnel. The NRC staff reviewed the HF organization description provided under section 4 of the TR (including the overall roles and responsibilities of team members) as part of the evaluation of criterion 2.4.2(3). Under that evaluation, the NRC staff determined that the applicants overall plan for HFE team composition is adequate because the HFE team, as described in the TR, will include sufficient expertise. During the audit, TerraPower further clarified that GE Hitachi staffs the core HFE team, to include the HFE technical lead role. This HFE technical lead coordinates design activities with the TerraPower HFE program owner who, in turn, provides oversight. The NRC staff has determined that the applicant has addressed team staffing in terms of job descriptions and assignments of team personnel and, therefore, concludes that criterion 2.4.2(4) is met.

1.3 HFE Processes and Procedures (Criteria 2.4.3(1)-(6))

1.3.1 General Process Procedures (Criterion 2.4.3(1))

Criterion 2.4.3(1) states that the applicant should identify the process through which the team will execute its responsibilities and include procedures for governing the internal management of the team, making decisions on managing the HFE program, making HFE design decisions, controlling changes in the design of equipment, and reviewing HFE products.

Section 4.1.1 of the TR describes that the HFE technical lead provides both technical and programmatic oversight and review, in addition to acting as the contact point for schedule development, integration, and management. Additionally, section 4.1.2 states that the HFE team guides and oversees the design activities and ensures that the execution and documentation of steps in the activities are carried out in accordance with the established program and procedures. Section 4.1.3 of the TR states that the HFE technical lead coordinates design activities with a TerraPower HFE program owner who, in turn, provides an oversight function. The TerraPower HFE program owner reports to a senior manager that acts as the technical design authority. Additionally, it is stated that while specific reporting relationships are subject to change, the HFE program will continue to be represented by a TerraPower senior manager who will be the design authority. During the audit, TerraPower clarified that GE Hitachi staffs the core HFE team, to include the HFE technical lead role. This HFE technical lead coordinates design activities with the TerraPower HFE program owner who, in turn, provides oversight.

Section 6.1 of the TR describes that the HFE program will be executed in accordance with procedures that include processes for HFE-related design and project decisions, acceptance of engineering products from suppliers, and design change control. It also states that the companies supporting Natrium HFE will work under their respective programs, plans, and procedures. Specifically, the procedures utilized by GE Hitachi in implementing HFE-related work are governed by NEDO-11209-A, GE Hitachi Nuclear Energy Quality Assurance Program Description, revision 17 [16], and includes those procedures related to the design, review, and retention of engineering products, as well as for workforce planning, scheduling, and project management. Additionally, the TR states that supporting procedures related to personnel qualification, technical training, and proficiency that support making resource assignments are included within this scope as well.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION During the audit, TerraPower clarified that they will generate the procedures for execution of the Natrium design for Kemmerer, Unit 1, and that these procedures are governed by TP-QA-PD-0001, TerraPower QA Program Description, revision 14-A [17]. Additionally, TerraPower further clarified that the HFE core team members will also work under their respective company procedures for workforce planning, scheduling, and project management.

Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management identifies the processes through which the HFE team will execute its responsibilities and will include procedures for HFE team activities. Therefore, the NRC staff concludes that criterion 2.4.3(1) is met.

1.3.2 Process Management Tools (Criterion 2.4.3(2))

Criterion 2.4.3(2) states that the applicant should identify the tools and techniques the team members use to verify that they fulfill their responsibilities. The TR identifies the following tools and techniques the HFE team members use for this verification:

HFE Databases: Appendix A, Human Factors Engineering Allocation of Function and Task Grading Methodology, of the TR contains an example of a Allocation of Function and Task Grading Data Sheet, ((

)) Appendix B, Human Factors Engineering Task Analysis and Human-System Interface Design Methodology, of the TR contains an example of the data collection forms ((

)) Additionally, examples were also provided of a task-level support, job design, workload, and workplace block template, as well as an HSI task support inventory template and trade-off evaluation form (i.e., Pugh Matrix).

Verification Checklists: Appendix B of the TR contains examples of an HFE performance test methods and measures form, a usability questionnaire form, and a HF engineer observation form. Additionally, examples are also provided of a HF design evaluation checklist and a HF task support evaluation checklist. Appendix C of the TR contains an example of a timeline analysis chart and also discusses the development of both an expert panel staffing report and an expert panel staffing review report. Appendix D, Human Factors Engineering Verification and Validation Plan, of the TR ((

))

Human factors engineering issue tracking system (HFEITS) records: Section 8, Human Factors Engineering Issue and Human Engineering Discrepancy Identification and Disposition, of the TR describes ((

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION

))

Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management addresses identification of the tools and techniques the HFE team members use to verify that they have fulfilled their responsibilities and, therefore, concludes that criterion 2.4.3(2) is met.

1.3.3 Integration of HFE and Other Plant Design Activities (Criterion 2.4.3(3))

Criterion 2.4.3(3) states that the applicant should describe the process for integrating the inputs from other design work to the HFE program, and the outputs from the HFE program to other plant design activities. The applicant should also discuss the iterative aspects of the HFE design process.

The NRC staff notes that section 4.1 of the TR states that the HF Operations/Maintenance role of the HFE core team provides knowledge of operations, maintenance, and testing activities including technical requirements related to operational activities. Section 4.2 states that the mechanical and electrical system engineering discipline of the extended HFE team provides knowledge of the purpose, operating characteristics, and technical specifications of major plant systems. Section 4.2 also describes the civil/structural engineering discipline of the extended HFE team provides knowledge of the overall structure of the plant and design characteristics of locations that include the MCR and RSC. Additionally, this section also describes the risk and reliability engineering discipline of the extended HFE team as providing knowledge of plant component and system reliability/availability, plus assessment methodologies, to the HSI development activities.

The NRC staff further notes that in section 5 of the TR, TerraPower provides an overview of the elements that comprise the HFEPP and how they interrelate. The introduction to section 5 of the TR states that these HFE activities are iterative and progressive, such that results from analysis and activities later in the program, for example staffing analysis or procedure validation, are used for feedback and to refine the AOF, TA, HSI design, and procedure development.

Plant and system inputs are described, in part, as informing the FRA and FA (referred to as the AOF within the HFEPP), which section 5.2, Functional Requirements Analysis, of the TR describes as then informing TA and HSI design activities. The HFE elements of the HFEPP are also described as being integrated with wider plant design processes. Section 5.11 of the TR, which addresses the design implementation element, includes the evaluation of deviations from the design during implementation and the resolution HEDs.

Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management addresses the process for integrating the design activities (i.e., the inputs from other design work to the HFE program, and the outputs from the HFE program to other plant design activities) and discussed the iterative aspects of the HFE design process. Therefore, the NRC staff concludes that criterion 2.4.3(3) is met.

1.3.4 HFE Program Milestones (Criterion 2.4.3(4))

Criterion 2.4.3(4) states that the applicant should identify HFE milestones that show the relationship of the elements of the HFE program to the integrated plant design, development,

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION and licensing schedule, as well as that a relative program schedule of HFE tasks should be available for review. The NRC staff notes that the TR describes an HFE program (i.e., the HFEPP) that is intended to be incorporated by reference into a subsequent facility licensing application (e.g., a construction permit and/or operating license application) and that specific dates for activities are not included within the TR itself. The NRC staff has determined that this represents an incomplete aspect of the NUREG-0711 review methodology and is addressed in the Limitations and Conditions section of this evaluation.

1.3.5 HFE Documentation (Criterion 2.4.3(5))

Criterion 2.4.3(5) states that the applicant should identify the HFE documentation items, such as RSRs and their supporting materials, and briefly describe them, along with the procedures for their retention and for making them available to the NRC staff for review.

The NRC staff notes that the TR contains IPs that address the methods that will be used to implement the HFEPPs elements of OER, FRA, AOF, staffing, treatment of important HAs, TA, HSI Design, procedures, training and qualification, HF V&V, design implementation, and human performance monitoring. In general, these IPs provide a description of the methods to be used and the documentation to be generated. NUREG-0711 explains that IPs and RSRs are the two primary types of applicant submittals that the NRC staff reviews. The NRC staff notes that no corresponding RSRs for the discussed IPs are available currently, which is addressed in the Limitations and Conditions section of this evaluation.

Section 6.1 of the TR describes that the companies supporting Natrium HFE will work under their respective programs, plans, and procedures. Specifically, the procedures utilized by GE Hitachi in implementing HFE-related work are governed by NEDO-11209-A and includes those procedures related to the retention of engineering products. Section 6.5, Results, of the TR further discusses that RSRs and supporting documentation will be retained as required by the performers quality assurance program, with TerraPower providing the RSRs for the NRC staff review. During the audit, TerraPower further clarified the specific details on their plans for retention of engineering documentation for HFE.

Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management addresses procedures for the retention of HFE documentation items (specifically RSRs and their supporting materials) and that the review of the RSRs can be deferred until the review of an OLA. Therefore, the NRC staff concludes that criterion 2.4.3(5) is met.

1.3.6 Subcontractor Efforts (Criterion 2.4.3(6))

Criterion 2.4.3(6) states that the applicant should include HFE requirements in each subcontract contributing to the HFE program, periodically verify the subcontractors compliance with HFE requirements, and describe milestones and the methods used for this verification. Section 5.7.4, Human Factors Design Requirements Document and Human-Systems Interface Style Guide, of the TR states that the HFE design requirements document (DRD), or DRD source requirements, and the style specification are passed along to contractor suppliers for NI HSIs via the procurement process. In instances where there are commercial-off-the-shelf considerations the HFE team will work with the designer to comply with the HFE DRD or style specification or, alternatively, develop a justification for acceptability. Furthermore, section 5.7.4 of the TR states that the implementation of HFE requirements by suppliers is confirmed by means of the V&V process. Section D.4, Sampling of Operational Conditions, of the TR

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION discusses, in part, this aspect of the V&V process and states that the sampling process includes equipment and interfaces provided by suppliers and sub-contractors as part of the sampling population.

During the audit, TerraPower clarified the various means by which the contractors and sub-contractors doing HFE-related work are tied into the Natrium HFE program.

Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management addresses the methods by which HFE requirements will be provided to contractors, sub-contractors, and suppliers contributing to the HFE program, as well as the milestones and the methods that will be used to verify compliance with HFE requirements, and, therefore, concludes that criterion 2.4.3(6) is met.

1.4 Tracking HFE Issues (Criteria 2.4.4(1)-(4))

1.4.1 Availability (Criterion 2.4.4(1))

Criterion 2.4.4(1) states that the applicant should have a tracking system to address human factors issues that are known to the industry; identified throughout the life cycle of the HFE aspects of design, development, and evaluation; and deemed by the HFE program as HEDs.

Section 8 of the TR states that the HFEITS is used to address HFE issues, including those issues specifically listed in criterion 2.4.4(1). The NRC staff has determined that the applicant has established a tracking system for HFE issues and, therefore, concludes that criterion 2.4.4(1) is met because.

1.4.2 Method (Criterion 2.4.4(2))

Criterion 2.4.4(2) states that the applicant should establish criteria for entering issues into the system and tracking issues until the potential for negative effects on human performance are reduced to an acceptable level. Section 8.1, How to Identify Human Factors Engineering Issues and Human Engineering Discrepancy, of the TR describes that HFE issues are placed into the HFEITS when issues cannot be currently resolved through the normal HFE process and require tracking until the can be resolved. HEDs are described as being placed into HFEITS when a deviation from a human factors DRD requirement is discovered during design verification, when information and control requirements identified by TA have not been met by an HSI during task support verification (TSV), when HSIs are identified during TSV as not being needed to support personnel tasks, or when acceptance criteria are not met during ISV. Thus, the NRC staff has determined that the applicant established criteria for entering issues into the tracking system.

Section 8.2 of the TR discusses the methodology for prioritizing HFE issues and HEDs. ((

)). Three priority levels are described as follows:

Priority 1 (highest) corresponds to safety consequences and is associated with conditions (e.g., equipment, HSI, procedure, training, or staffing deviation, deficiency, or nonconformance) or adverse trends that have the potential to affect ((

)).

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Priority 2 (high) corresponds to plant or personnel performance effects and is associated with conditions or adverse trend that have the potential to affect ((

)).

Priority 3 (low) corresponds to enhancements (of a nature neither involving safety consequences nor affecting performance) and is associated with conditions or adverse trends that deviate from the HFE DRD or HFE principles but do not involve safety or risk consequences.

Section 8.4 states that all HEDs that have been rated as Priority 1 or Priority 2 must be dispositioned through design change to correct the discrepancy and to address the human factors concern, as well as that resolution of Priority 1 and 2 HEDs may not be deferred.

Milestones before which Priority 1 and 2 HEDs must be dispositioned are also described (e.g.,

prior to ISV or design implementation). Beyond this, Priority 3 HEDs may instead be dispositioned through design change, deferment, or by means of a HF-justified exception, as determined by the HFE team.

NUREG-0711, section 11.4.4, Human Engineering Discrepancy Review Criteria, contains guidance for determining which HEDs to correct such that possible negative impacts on human performance are reduced to an acceptable level. The NRC staff found the applicants plan to track and resolve Priority 1 and 2 HEDs to be consistent with this guidance; therefore, the applicant will track HEDs that could have negative impacts on human performance until they have been resolved. Priority 3 HEDs do not have direct or indirect impacts on plant safety, plant performance or operability, so the NRC staff does not consider these types of issues to require resolution. Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management addresses the establishment of criteria for tracking issues until the potential for negative effects on human performance is reduced to an acceptable level and, therefore, concludes that criterion 2.4.4(2) is met.

1.4.3 Documentation (Criterion 2.4.4(3))

Criterion 2.4.4(3) states that the applicant should document the actions taken to address each issue in the system, and if no action is required, this should be justified. Section 8 of the TR states that HFE issues and HEDs are placed into the HFEITS when specified criteria are met.

The information that is documented includes the associated priority of the issue or HED. This section also describes the general types of information that is documented with regard to the resolution of issues and HEDs. This documentation is described as including, as applicable, justifications, verification results and methodology, test reports, acceptability conclusions, newly identified HEDs, and deferred resolutions. The NRC staff has determined that the applicants method is acceptable because the actions taken to address issues and descriptions of the resolutions will be documented. Therefore, the NRC staff concludes that criterion 2.4.4(3) is met.

1.4.4 Responsibility (Criterion 2.4.4(4))

Criterion 2.4.4(4) states that the applicants tracking procedures should describe individual responsibilities for logging, tracking, and resolving issues, along with the acceptance of the outcome.

Section 8 of the TR describes individual responsibilities for tracking issues. This sections states that HFEITS information is initially populated by the originator and updated by the issue owner.

Issue owners also conduct any related cumulative effects analysis and determine if a change to

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION the priority of the affected HEDs is warranted. ((

)). Issue owners also determine the means to check the adequacy of revision or disposition actions completed by assignees. Additionally, issue owners also assign and brief the individuals who implement HED resolution reviews, verifications, and validations. Individual roles are explained as they relate to the various HED resolution approaches. ((

)). For HEDs that emerge during ISV, issue owners determine appropriate validation strategies using a graded approach, with the HF verifiers acting as the lead on retesting activities and documenting acceptability.

((

)). For deferrals, issue owners update HFEITS accordingly and ensure the HEDs are tracked to resolution.

Based on the above, the NRC staff has determined that TerraPowers plan for HFE program management addresses individual responsibilities for logging, tracking, and resolving HFE issues, as well as for determining the acceptability of outcomes, and, therefore, concludes that criterion 2.4.4(4) is met.

1.5 Technical Program (Criteria 2.4.5(1)-(5))

1.5.1 Status (Criterion 2.4.5(1)) and Schedule (Criterion 2.4.5(2))

Criterion 2.4.5(1) states that the applicant should describe the applicability and status of each of the HFE elements, and criterion 2.4.5(2) states that the applicant should provide a schedule for completing HFE activities that are unfinished at the time of application. The NRC staff found that the HFEPP describes programmatic activities associated with all the HFE elements described under criterion 2.4.5(1) and that no elements are identified as being non-applicable.

Accordingly, the NRC staff concludes that the HFEPP meets criterion 2.4.5(1).

However, the NRC staff notes that the TR describes an HFE program (i.e., the HFEPP) that is intended to be incorporated by reference into a subsequent facility licensing application (e.g., a construction permit and/or operating license application) and that specific dates for HFE activities are not included within the TR itself. The NRC staff has determined that criterion 2.4.5(2) represents an incomplete aspect of the NUREG-0711 review methodology that is addressed in the Limitations and Conditions section of this evaluation.

1.5.2 Standards and Specifications (Criterion 2.4.5(3))

Criterion 2.4.5(3) states that the applicants plan should identify and describe the standards and specifications that are sources of the HFE requirements.

In section 2.0 of the TR, Requirements and Technical Basis, TerraPower describes the process requirements and technical basis inputs applicable to the creation, implementation, and maintenance of an HFE program. Section 2.0 of the TR states that the HFEPP considers relevant practices provided in both NUREG-0711, revision 3, and IEEE 1023-2020. Section 2.0 of the TR also states that specific HFE design and element areas also have other requirement and technical basis documents associated with them in the applicable sections of the TR. The NRC staff notes that a number of other guidance documents are referenced in conjunction with the various HFEPP elements described in the HFEPP, including ones produced by the NRC staff, International Atomic Energy Agency, U.S. Department of Energy, IEEE, and International

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Electrotechnical Commission (IEC). The NRC staff has determined that the HFEPP identifies the references for the design-specific HFE requirements established by TerraPower for the HFE design. Accordingly, the NRC staff concludes that the HFEPP meets criterion 2.4.5(3).

1.5.3 Facilities, Equipment, Tools, and Techniques (Criterion 2.4.5(4))

Criterion 2.4.5(4) states that the applicants plan should specify HFE facilities, equipment, tools, and techniques (such as laboratories, simulators, and rapid prototyping software) that the HFE program will employ. The applicant described the following HFE facilities, equipment, tools, and techniques used in the HFE program:

HFE facilities and equipment: Section 5.7.6, Human-System Interface Tests and Evaluations, of the TR states that a generic plant simulation model may be used for HSI development and usability testing until a site-specific system model becomes available, at which point tests and evaluations will be conducted using site-specific models. It is also stated that dynamic simulation will be used as a HF design tool for validation testing. Simulations are designed as either being conducted using a user interface through a computer-based workstation, a glass-top simulator, or a hardware-based simulator. Section 5.10 of the TR states that testing is iterative in nature and that once the design reaches a sufficient level of maturity, validation work can be conducted on a part-task simulator. The subsequent ISV is described as being performed on a high-fidelity simulator of the control area.

Tools: Section 8 of the TR discusses that the HFEITS is used to capture both HFE issues and HEDs for the purposes of tracking and resolution. Appendix A of the TR describes the use of a workbook for documenting the results of AOF, task grading, and TA activities, while appendix B discusses the use of a workbook for TA and HSI design activities as well. ((

)). Appendix D, section D.6.1, Human Factors Engineering Validation Inputs, discusses the use of a variety of tools for developing validations, including, in part, task narratives, timeline analyses, and workload analyses. Section D.6.3.2, Human Factors Engineering Validation Data Collection Tools, describes the use of various observation tools and data collection forms for use during ISV, ((

)).

Techniques: Section 3 of the TR describes an assessment methodology for use grading the application of HFE under certain elements addressed by the HFEPP. In section 5.7.6, TerraPower describes that iterative testing is to find and correct issues immediately in lieu of waiting for subsequent V&V activities. HSI test and evaluation employs techniques ranging from simple user questionnaire responses and comments to empirical, performance-based techniques. Other design techniques that are described include, in part, using drawings, physical or virtual mock-ups, and software-based 3D models.

The NRC staff has determined that the HFEPP describes equipment, tools, and techniques that represent an acceptable means of gaining user feedback that can be incorporated into the design as it evolves and, therefore, concludes that criterion 2.4.5(4) is met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 1.6 Overall Conclusion for the HFE Program Management Element The NRC staff concludes that, subject to the limitations and conditions contained in this evaluation, TerraPowers plan for HFE program management, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711.

2.0 OPERATING EXPEREIENCE REVIEW The NRC staffs objective in the review of this element is to verify that the applicant will identify and analyze HFE-related problems and issues encountered in previous designs so that these problems and issues may be avoided in the development of the new design. This review also considers whether the applicant will retain the positive features of previous designs. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 3.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in sections 2.1 through 2.2. The subsections below document the results of the NRC staffs evaluation. The NRC staff notes that, per NUREG-0711, an associated RSR is expected for this element, however, RSRs are not included as part of this HFEPP and will need to be submitted and reviewed as part of an OLA.

2.1 Scope (Criteria 3.4.1(1) - (5))

2.1.1 Predecessor/Related Plants and Systems (Criterion 3.4.1(1))

Criterion 3.4.1(1) states that the applicants OER should include information about HF issues in the predecessor plant(s) or highly similar plants, systems, and HSIs. Section 5.1 of the TR states that the objective of the OER is to identify and analyze issues in earlier designs that are similar to the current ones in order to facilitate negative features associated with those predecessor designs being avoided while positive features are retained. Section 5.1 of the TR also describes that the OER report will include an HFE-focused literature review that covers prior deployments of similar reactor technologies. The NRC staff has determined that TerraPowers plan for OER addresses predecessor/related plants and systems and, therefore, concludes that criterion 3.4.1(1) is met.

2.1.2 Recognized Industry HFE Issues (Criterion 3.4.1(2))

Criterion 3.4.1(2) states that the applicant should address the HFE issues identified in NUREG/CR-6400, Human Factors Engineering (HFE) Insights for Advanced Reactors Based Upon Operating Experience, [18]. Section 5.1 of the TR states that the OER report will address HFE issues identified in NUREG/CR-6400. The NRC staff has determined that TerraPowers plan for OER will include the HFE issues identified in NUREG/CR-6400 within its scope and, therefore, concludes that criterion 3.4.1(2) is met.

2.1.3 Related HSI Technology (Criterion 3.4.1(3))

Criterion 3.4.1(3) states that the applicants OER should cover operating experience (OE) with the proposed HSI technology in the applicants design. Section 5.1 of the TR states that the OER report will address OE related to the HSI technology that will be used to support those HAs included in both the safety analysis and in the PRA. The NRC staff has determined that TerraPowers plan for OER addresses related HSI technology and, therefore, concludes that criterion 3.4.1(3) is met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 2.1.4 Issues Identified by Plant Personnel (Criterion 3.4.1(4))

Criterion 3.4.1(4) states that applicants OER should discuss issues identified through interviews with plant personnel based on their operating experience with plants or systems applicable to the new design. Section 5.1 of the TR states that the OER report will incorporate HFE-focused personnel interviews or questionnaires on previous deployments of the same reactor technology. The NRC staff has determined that TerraPowers plan for OER addresses the inclusion of issues identified by plant personnel and, therefore, concludes that criterion 3.4.1(4) is met.

2.1.5 Important Human Actions (Criterion 3.4.1(5))

Criterion 3.4.1(5) states that the applicants OER should identify important HAs in the predecessor plants or systems and determine whether they remain important in the applicants design. Section 5.1 of the TR states that the OER report will include the review of HAs from predecessor designs that are similar to HAs included in both the safety analysis and PRA. The NRC staff has determined that TerraPowers plan for OER addresses IHA and, therefore, concludes that criterion 3.4.1(5) is met.

2.2 Issue Analysis, Tracking, and Review (Criteria 3.4.2(1) - (4))

2.2.1 Operating Experience Review Process (Criterion 3.4.2(1))

Criterion 3.4.2(1) states that the applicant should discuss the administrative procedures for evaluating the operating, design, and construction experience, and for ensuring that applicable important industry experiences will be provided in a timely manner to those designing and constructing the plant.

Section 5.1 of the TR states that an OER report will be developed and that the objective will be to identify HFE issues to provide a basis for improving the plant design at the beginning of the design process. This includes the identification and analysis of issues from similar past designs to facilitate both the avoidance of negative features and the retention of positive ones.

Additionally, it is also stated that OER outputs to the other HFE elements may influence the design process and design itself. During the audit, TerraPower stated that the OE gathered to support the Natrium HFE design was collected over many years of new nuclear design efforts and will also be updated with new sodium reactor OE at the start of HFE design activities.

Section 6.5 of the TR states that RSRs addressing at least the minimum information stipulated in NUREG-0711 will be developed and that TerraPower will make these RSRs available for review by the NRC staff. The NRC staff notes that this RSR scope would be inclusive of the OER report.

Based on the above, the NRC staff has determined that TerraPowers plan for OER addresses the evaluation of relevant issues and operating experience to inform the design and, furthermore, that the details of how this review was conducted and its results can be evaluated by the NRC staff when the associated OER RSR is submitted in conjunction with an OLA.

2.2.2 Analysis Content (Criterion 3.4.2(2))

Criterion 3.4.2(2) states that the applicant should analyze issues to identify human performance issues and sources of human error, as well as design elements supporting and enhancing

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION human performance. Section 5.7.4 of the TR states that, HFE findings from the OER relating to HSI design are allocated to HFE DRD to provide input identifying positive HSI features to be included and negative HSI features to be avoided. Section B.2.2.1, Review of System Relevant Operating Experience, of the TR describes the TA process as being informed by the review of OE. Section B.2.2.5.5, Operating Experience Associated with Task, of the TR discusses ((

)) Additionally, section C.4, Inputs, of the TR discusses that the staffing analysis uses input information from the OER, with focus on specific OE that is related to human performance issues. The NRC staff has determined that TerraPowers plan for OER addresses the analysis of human performance related issues and, therefore, concludes that criterion 3.4.2(2) is met.

2.2.3 Documentation (Criterion 3.4.2(3))

Criterion 3.4.2(3) states that the applicant should document the analysis of OE. Section 5.1 of the TR states that an OER report will be developed and that lessons learned from OE will provide a basis for design improvements. The NRC staff has determined that TerraPowers plan for OER addresses documentation of the analysis of OE and, therefore, concludes that criterion 3.4.2(3) is met.

2.2.4 Incorporation into the Tracking System (Criterion 3.4.2(4))

Criterion 3.4.2(4) states that the applicant should document each issue determined to be relevant to the design, but yet to be addressed, in the issue tracking system. Section 5.1 of the TR states that operating experience issues relevant to the HFE design but not yet addressed are documented in the HFEITS. The NRC staff has determined that TerraPowers plan for OER addresses the documentation of unresolved issues within an issue tracking system and, therefore, concludes that criterion 3.4.2(4) is met.

2.3 Overall Conclusion for the Operating Experience Review Element The NRC staff concludes that TerraPowers plan for OER, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff when a future OER RSR is provided.

3.0 FUNCTIONAL REQUIREMENTS ANALYSIS AND FUNCTION ALLOCATION Functional Requirements Analysis (FRA) is the identification of functions that must be performed to satisfy plant overall goals (e.g., safe operation, power generation). Function Allocation (FA) is the analysis of requirements for plant control and the assignment of control functions to personnel, system elements, and combinations of personnel and system elements.

The NRC staffs objective in the review of this element is to verify that the plants functions that must be performed to satisfy plant safety objectives will be defined, and the allocation of those functions to human and system resources will result in a role for personnel that takes advantage of human strengths and avoids human limitations. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 4.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in sections 3.1 through 3.2. It should be noted that, per NUREG-0711, an associated RSR is expected for this element, however, RSRs are not included as part of this HFEPP and will need to be submitted and reviewed as part of an OLA.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 3.1 Methodology (Criteria 4.4(1) - (2))

In NUREG-0711, section 4.4, criteria 4.4(1) - (2) address the methodology used for the FRA/FA processes. Criterion 4.4(1) focuses on ensuring a structured and documented methodology that reflects HFE principles and criterion 4.4(2) says that the processes should be performed iteratively.

Section 5.2 of the TR states that FRA defines functions that are traced to the principal design requirements of the plant. The overall process is described as including activities for elicitation, analysis, allocation, and documentation. This process yields an output document containing a complete list of functions, including their relevance to HFE, which are then input into the AOF process. Section 5.3 of the TR describes the AOF as establishing a plant control scheme that enhances plant safety and reliability by taking advantage of human and machine strengths and avoiding human and machine limitations. Objectives of the AOF process include establishing a design conducive to situational awareness and providing acceptable workload levels. The AOF process is described as first establishing an initial allocation based on expert input. The possible allocations are described to include human-only, machine-only, shared (i.e., human and machine), or backup (e.g., a human providing backup to a machine). The initial AOF is described as being iterated upon as the design process and testing progresses until the point at which a final AOF is established for ISV.

Appendix A of the TR details specifics of the AOF process. Section A.2.1, Allocation of Function Definition, discusses that the AOF definition process incorporates both OE and subject-matter experts to consider how similar applications were allocated, as well as what performance resulted from those allocations. Section A.2.2, Allocation of Function Definition, describes that the AOF evaluation process involves examining function and task groupings to assess allocations collectively and in an integrated environment via scenario development.

Evaluations are then conducted to determine acceptability based on task performance, workload, and situation awareness. During the audit, TerraPower clarified how the AOF is iterated upon, as needed, as the design progresses. TerraPower also confirmed that, once the plant is turned over to the licensee, any evaluations or changes in the AOF would be implemented using the administrative procedures described in the Kemmerer Power Station Unit 1 Preliminary Safety Analysis Report (PSAR) [19].

Based on the above, the NRC staff has determined that TerraPowers plan for FRA and AOF describes a structured, documented methodology that will be performed iteratively and, therefore, concludes that criteria 4.4(1) - (2) are met. The evaluation of measures to ensure that the FRA and FA are updated, as needed, during the operations phase can reasonably be deferred until the review of an OLA.

3.2 Functional Requirements Analysis and Function Allocation Results (Criteria 4.4(3) - (8))

In NUREG-0711, section 4.4, criteria 4.4(3) - (4) focus on ensuring that the results of the FRA analysis are adequate, criteria 4.4(5) - (7) address the results of the FA, and criterion 4.4(8) addresses verification of completion. Specifically, criterion 4.4(3) provides specific properties that the plants functional hierarchy should address. Criterion 4.4(4) focuses on identifying design requirements associated with the high-level plant functions identified in the plants functional hierarchy. Criterion 4.4(5) states that the FA should identify the level of automation for each function as well as the technical bases for the allocation. Criterion 4.4(6) states that the FA should address primary actions taken by the operator as well as other operator actions, such as

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION monitoring automation, detecting degradations/failures, and assuming manual control. Criterion 4.4(7) addresses the overall role of the operators while considering all functions allocated to them. Finally, criterion 4.4(8) focuses on verifying that the results of the FRA/FA are complete and have accomplished the objectives.

The NRC staffs evaluation of criteria 4.4(1) - (2) is also applicable for the evaluation of criteria 4.4(3)-(8) in that TerraPowers plan for FRA and AOF describes a structured, documented FRA/FA methodology that will be performed iteratively. For criteria 4.4(3)-(4),

section 5.2 of the TR describes that the FRA defines functions that are based upon the principal design requirements of the plant and provides inputs into the AOF process. For criteria 4.4(5)-(6), section 5.3 of the TR describes that the AOF establishes how the plant will be controlled (e.g., allocations of human-only, machine-only, shared, or backup control) and is iterated upon as the design process and testing progresses. For criteria 4.4(7)-(8), section A.2.2 of the TR details how the AOF evaluation process involves examining task groupings to collectively assess allocations in an integrated, scenario environment, with evaluations being conducted to determine acceptability based on task performance. The NRC staff has determined that the HFEPP includes plans for developing a functional hierarchy, identifying related requirements, allocating functions, accounting for human roles in backing up functions allocated to machines, describing the overall role of personnel, and for completing FRA/FA processes. Therefore, the NRC staff concludes that criteria 4.4(3) - (8) are met.

3.3 Overall Conclusion for the FRA/FA Element The NRC staff concludes that TerraPowers plan for FRA/FA, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff when a future FRA/FA RSR is provided.

4.0 TASK ANALYSIS Task analysis (TA) identifies the tasks that plant personnel must perform to accomplish the functions that are allocated to HAs. TA also identifies the alarms, information, controls, and task support that must be available for plant personnel to successfully perform these tasks. TA generates input to several program elements: staffing and qualifications, HSI design, procedure development, training program development, and V&V. The NRC staffs objective in the review of this element is to verify that the TA will be adequate to address these needs. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 5.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in sections 4.1 through 4.4. The NRC staff notes that, per NUREG-0711, an associated RSR is expected for this element, however, RSRs are not included as part of this HFEPP and will need to be submitted and reviewed as part of an OLA.

4.1 Scope (Criterion 5.4(1))

Criterion 5.4(1) lists tasks that should be part of the scope of the applicants TA, including (1) all important HAs (determined by probabilistic and deterministic means), (2) tasks that represent the full range of plant operating modes, and (3) eight specific types of tasks listed in criterion 5.4(1) (e.g., tasks that are new compared to those in predecessor plants). As discussed in section 3.1 of this evaluation, the FRA defines those functions linked to the plants principal design requirements and yields the complete list of functions for input into the AOF process.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION The AOF is described in the HFEPP as allocating those plant functions to humans, machines, or combinations thereof (e.g., shared human-machine operation or a human providing backup to a machine) via an iterative process. Section 5.6, Task Analysis, of the TR states that the TA identifies task requirements to accomplish those functions that are allocated to humans (including any partial allocations made to humans).

Appendix B of the TR describes the methodology used in systematically conducting the TA. In section B.1.2, Scope, the TA process is stated to address human interactions with NI plant systems. Section B.2.1.1, System Design Inputs, discusses that system design inputs to include, in part, ((

)), relevant OE, and those tasks allocated during the AOF process. Section B.2.1.2, Plant Information, further explains that the TA process also incorporates narratives that describe how the plant functions through its modes of operation and an HFE concept of operations (COO), in addition to both

((

))

The NRC staff notes that the described scope of the HFEPP TA is not as specific as that that described by criterion 5.4(1) and that the plan instead presents a more generalized methodology that reflects a top-down approach to identifying tasks. The HFEPP discusses certain aspects of criterion 5.4(1), such as the inclusion of HAs that were identified by deterministic means, the consideration of functions throughout various modes of plant operation, and backup functions in the event of automation (i.e., machine allocated task) failures. However, not all aspects of the specific types of tasks described by the criterion 5.4(1) are explicitly addressed. The NRC staff notes that the described FRA and AOF processes that input into the TA (i.e., a top-down HFE approach) should reasonably result in a TA scope that is consistent with the underlying objective of criterion 5.4(1). Furthermore, the NRC staff notes that since the TA process discussed in the HFEPP only reflects the IP stage, the TA RSR, when completed, will provide the NRC staff an opportunity to confirm the adequacy of the completed TA process scope.

As previously discussed in the evaluation of the HFE program management element of the HFEPP, section 1.2 of the TR describes that control and monitoring of both NI and EI equipment is performed from HSIs in the MCR, with the layout and interface of both NI and EI workstations being of the same general design within an integrated overall MCR design. However, TerraPower states that the EI itself is not included within the scope of the HFEPP, with the justification being that no EI SSCs are required to (1) respond to mitigate any events impacting the NI, (2) support safety-related, SSCs, or (3) endure defense-in-depth adequacy.

The NRC staff previously evaluated key implications of the separation of the NI and EI portions of the Natrium design, as documented under, Final Safety Evaluation of Topical Report NATD-LICRPRT-0001, Regulatory Management of Natrium Nuclear Island and Energy Island Design Interfaces and note that TerraPowers characterization of the significance of EI operations to NI safety is consistent with prior staff conclusions. Based upon that, the NRC staff determined that exclusion of the EI from the scope of the TA and HSI design elements is reasonable because human performance within that location is not reasonably expected to influence Natrium safety outcomes in an appreciable manner. The NRC staff has determined that TerraPowers plan for TA has an adequate scope and, therefore, concludes that criterion 5.4(1) is met.

4.2 Screening Methodology (Criterion 5.4(2))

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Criterion 5.4(2) states that the applicant should describe the screening methodology used to select the tasks for analysis, based on criteria specifically established to determine whether analyzing a particular task is necessary. ((

))

Section 3.2 of the TR discusses that ((

))

Based on the above, the NRC staff has determined that TerraPowers plan for TA includes a screening methodology for selecting tasks for analysis and, therefore, concludes that criterion 5.4(2) is met.

4.3 Task Attributes and Iterative Process (Criteria 5.4(3) - (8))

NUREG-0711, Criteria 5.4(3) - (7), state that the applicant should (3) begin TA with detailed narratives of what personnel have to do, along with specifying the alarms, information, controls, and task support needed to accomplish the task, (4) identify the relationships among tasks, (5) estimate the time required to perform tasks, (6) identify the number of people required to perform each task, and (7) identify the knowledge and abilities required to perform each task.

Criterion 5.4(8) states that the applicants TA should be iterative and updated as the design is better defined.

Section 5.6 of the TR discusses that the TA identifies task requirements to accomplish plant functions that have been allocated to humans, with appendix B describing the methodology used in systematically conducting the TA. As noted by the staff in section 4.2 of this evaluation,

((

))

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Section 5.6 of the TR describes the following information as being documented, in part, for tasks associated with ((

)):

Descriptive narrative of the task Time available versus time required to complete Action to be taken Information needed Controls needed Alarms needed Location and access considerations Workspace needed Job aids, tools, or equipment needs Environmental considerations and potential hazards Special or protective clothing needs The NRC staff notes that the items above generally address the scope of considerations included under Criterion 5.4(3) for task narratives and Criterion 5.4(5) for time estimates.

Table B.2-1, Task Step Sequence Narrative Definition Process, of the TR includes ((

)) Additionally, section C.4 of the TR describes that the TA process identifies all plant personnel involved to complete a task. Furthermore, section 5.9 of the TR discusses that tasks which support plant functions are identified as part of TA and that those tasks that are selected for training under the SAT are then analyzed to determine the required skills, knowledge, and abilities. Finally, section B.1.1, Purpose, describes that the TA process as being repeated through the iterative design process and if needed for design modifications. The NRC staff has determined that this is generally consistent with the identification of the relationships among tasks, the identification of the number of people required to perform each task, the identification of the knowledge and abilities required to perform tasks, and the use of an iterative TA process as covered under criteria 5.4(4), 5.4(6),

5.4(7) and 5.4(8).

((

)) The NRC staff has determined that TerraPowers plan for TA accounts for detailed narratives, task relationships, time estimates, numbers of people required, identification of knowledge and abilities, and iterations during the design process.

Therefore, the NRC staff concludes that criteria 5.4(3) - (7) are met.

4.4 Reliability and Feasibility (Criterion 5.4(9))

NUREG-0711, criterion 5.4(9), states that the applicant should analyze the feasibility and reliability of important HAs and lists topics that should be considered in doing so.

Table A.2-1, Initial Allocation of Function Definition Steps, of the TR addresses initial allocations of functions to humans. This table includes feasibility considerations for human

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION agents that consist of the following: ability to detect, response time limits, reliability of response, acceptable cognitive workload, and acceptable physical workload. As discussed in section 4.1 of this evaluation, the output of the AOF process serves as the input into the TA. Section 5.5 of the TR states that that HAs important to safety are determined using both deterministic and probabilistic means from the safety analysis and PRA, as well as that HRA is conducted by the risk and reliability team and is an integral part of the development of a complete PRA. Section D.1.1, Purpose, of the TR states that the HFE V&V process includes the sampling of tasks that are of greatest risk-significance, with those tasks then being verified and validated. The NRC staff has determined that TerraPowers plan for TA, as considered within the context of the broader HFEPP, includes analysis of the feasibility and reliability of important HAs and, therefore, concludes that criterion 5.4(9) is met.

4.5 Overall Conclusion for the Task Analysis Element The NRC staff concludes that TerraPowers plan for TA, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff when a future TA RSR is provided.

5.0 STAFFING AND QUALIFICATIONS The NRC staffs objective in the review of this element is to verify that the applicant will systematically analyze the number and necessary qualifications of personnel in concert with task requirements and regulatory requirements. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 6.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in sections 5.1 through 5.6. It should be noted that, per NUREG-0711, an associated RSR is expected for this element, however, RSRs are not included as part of this HFEPP and will need to be submitted and reviewed as part of an OLA.

5.1 Staffing and Qualifications Guidance Conformance (Criterion 6.4(1))

NUREG-0711, criterion 6.4(1), states that the applicant should address the applicable staffing and qualifications guidance in NUREG-0800, section 13.1. However, the information to be reviewed under NUREG-0800, sections 13.1.1, Management and Technical Support Organization, [20] and 13.1.2 - 13.1.3, Operating Organization, [21] is not expected to be completely available until an OLA is submitted6. Thus, no review equivalent to that of NUREG-0800, chapter 13.1, was conducted during this evaluation of the HFEPP under NUREG-0711, section 6, Staffing and Qualifications. This represents an incomplete aspect of the NUREG-0711 review methodology that is addressed in the Limitations and Conditions section of this evaluation.

5.2 Staffing and Qualifications Regulatory Compliance (Criterion 6.4(2))

Criterion 6.4(2) states that the applicant should address the applicable staffing and qualifications requirements of 10 CFR 50.54, Conditions of licenses. Section 6.5 of the TR states that RSRs will be developed addressing at least the minimum information stipulated in NUREG-0711 and that TerraPower will provide the RSRs for NRC staff review. The NRC staff notes that, per NUREG-0711, an associated RSR is expected for the staffing and qualifications element.

6 NUREG-0800, sections 13.1.1 and 13.1.2 - 13.1.3, are referenced by the guidance and related criteria of DANU-ISG-2022-05.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION During the audit, TerraPower clarified that the requirements of 50.54(k) through (m) will be addressed by the OLA and, furthermore, that TerraPower will seek an exemption via the OLA for the omission of the STA role. Based on the above, the NRC staff has determined that evaluation of how TerraPower will address the applicable staffing and qualifications requirements of 10 CFR 50.54 can reasonably be deferred until the review of the OLA and in conjunction with the related RSR, when it becomes available. Furthermore, the treatment of the STA role by users of this TR is addressed in the Limitations and Conditions section of this evaluation.

5.3 Inputs from TA to Staffing and Qualifications Analyses (Criterion 6.4(3))

Criterion 6.4(3) states that the applicant should use the results of the TA as input to the staffing and qualifications analyses. It also states that personnel tasks should be assigned to staffing positions to ensure that jobs are defined considering task characteristics, team processes, and the persons ability to maintain situational awareness. Section C.3, Staffing Analysis Overview, of the TR describes that the major steps of staffing analysis include the TA process, during which both the definition of task steps and personnel assignments occur. The TA is stated as forming the basis for the qualifications associated with each personnel role. An expert panel reviews TA data (which includes timeline analysis for the most resource-intensive credible events) to evaluate the adequacy of staffing as it relates to responding to events. Testing is then used to evaluate workload and factors such as situational awareness, with the results being used to inform changes in staffing and/or job design. The NRC staff has determined that TerraPowers plan for analyzing staffing and qualifications considers inputs from the TA and, therefore, concludes that criterion 6.4(3) is met.

5.4 Staffing for the Full Range of Plant Conditions and Tasks (Criterion 6.4(4))

Criterion 6.4(4) states that the applicants staffing analysis should determine the number and qualifications of operations personnel for the full range of plant conditions and tasks (including operational tasks conducted under normal, abnormal, and emergency conditions; plant maintenance; plant surveillance; and testing) and should address how plant personnel working outside of the control room interface with the operators in the control room.

Section 5.4 of the TR discusses that the staffing analysis determines the minimum required staff complement. The analysis is described as beginning with staffing and shift-work assumptions from the COO as a baseline. Section 5.4 of the TR states that [t]he assumed staffing is used to analyze the most resource-intensive credible events postulated for all operating states, including normal operations, design basis events, and emergencies, and the assumptions are either validated or corrected. The NRC staff notes that, while not specifically addressed under the staffing and qualification element of the HFEPP, appendix D of the TR incorporates communications and coordination between field operators and the control room into validation testing processes. The NRC staff has determined that TerraPowers plan for analyzing staffing and qualifications addresses staffing across the full range of plant conditions and tasks and, therefore, concludes that criterion 6.4(4) is met.

5.5 Iteration (Criterion 6.4(5))

Criterion 6.4(5) states that the applicants staffing analysis should be iterative; that is, the initial staffing goals should be modified as information from the HFE analyses of other elements becomes available. Section 5.4 of the TR describes that the staffing analysis begins with

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION staffing assumptions from the COO and that this baseline staffing is either validated, or corrected, as it is subsequently used to analyze the most resource-intensive events across various operating states. Staffing levels are updated as warranted based upon the completion of further staffing analysis activities, including workload analysis and evaluations (using means such as mock-ups, modeling, or simulation) with ISV providing the final validation for staffing.

The NRC staff has determined that TerraPowers plan for analyzing staffing and qualifications provides for an iterative process and, therefore, concludes that criterion 6.4(5) is met.

5.6 Staffing-related Issues (Criterion 6.4(6))

Criterion 6.4(6) states that the applicant should address the basis for staffing and qualifications levels and lists topics to be considered. The topics are associated with the following HFE elements: OER, FRA/FA, TA, treatment of important human actions (TIHA), procedure development, and training program development. Section C.4 of the TR discusses that the staffing analysis uses, in part, inputs from the OER, AOF, and TA. ((

)) Section C.3 of the TR describes that the staffing analysis includes consideration of the most resource-intensive credible events to evaluate the adequacy of staffing.

Section 5.8 of the TR describes that the procedures developed by the associated element of the HFEPP are used for ISV. In a similar manner, section 5.9 of the TR states that the participants used for ISV will be trained using the training program developed under that element of the HFEPP to validate the integrated design. Section 5.4 discusses that staffing levels are updated as warranted based upon the completion of staffing analysis activities, with ISV serving as the final validation stage for staffing. The NRC staff notes that, while the HFEPP does not explicitly discuss each of the specific considerations listed under criterion 6.4(6), the processes and methodologies that the HFEPP describes as iteratively informing staffing, and qualifications should reasonably achieve the underlying objective of the criterion. Based on the above, the NRC staff has determined that TerraPowers plan for analyzing staffing and qualifications addresses staffing-related issues and, therefore, concludes that criterion 6.4(6) is met.

5.7 Overall Conclusion for the Staffing and Qualifications Element The NRC staff concludes that, subject to the limitations and conditions contained in this evaluation, TerraPowers plan for staffing and qualifications, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff when a future staffing and qualifications RSR has been provided.

6.0 TREATMENT OF IMPORTANT HUMAN ACTIONS The TIHA program element identifies the HAs that are most important to safety and considers those HAs in the HFE design of the plant. The design should minimize the likelihood of personnel error and help ensure that personnel can detect and recover from any errors that occur. The NRC staffs objective in the review of this element is to verify the adequacy of the TIHA program. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 7.4, Review Criteria, and the results of the NRC staffs evaluation are

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION discussed below in sections 6.1 through 6.2. The NRC staff notes that, per NUREG-0711, an associated RSR is expected for this element, however, RSRs are not included as part of this HFEPP and will need to be submitted and reviewed as part of an OLA.

6.1 Identification of Important Human Actions (Criteria 7.4(1) - (2))

Criterion 7.4(1) states that the applicant should identify risk-important HAs from the PRA and HRA. Criterion 7.4(2) states that the applicant should identify deterministically important HAs from those actions credited in accident and transient analyses, as well as those identified during any I&C-related diversity and defense-in-depth (D3) coping analyses.

Section 3 of the TR states that ((

)) Additionally, as discussed under section 3.1 of this evaluation, the AOF is described in the HFEPP as allocating functions to humans, including allocations in which a human agent provides backup to a machine agent. The allocations made during the AOF process, in turn, inform the TA. The NRC staff notes that, while D3 is not specifically addressed in the HFEPP, the identification of where human backup roles exist, as well as their relative safety significance, is consistent with the expected role of an HFE program within the broader D3 analysis and appropriate for the earlier stages (e.g., pre-OLA) of the design process. The NRC staff has determined that TerraPowers plan for the treatment of important HAs addresses the identification of important HAs and, therefore, concludes that criteria 7.4(1) -

(2) are met.

6.2 Treatment of Important Human Actions in the Human Factors Engineering Process (Criterion 7.4(3))

Criterion 7.4.3(3) states that the applicant should specify how important HAs are addressed by the HFE program in FA, TA, HSI design, procedural development, and training program development to minimize the likelihood of human error and facilitate error detection and recovery capability.

As discussed within section 4.4 of this evaluation, the HFEPP describes the AOF process as considering feasibility and reliability when making initial allocation of functions to human agents, with the output of the AOF process serving as the input into the TA. As discussed in section 6.1 of this evaluation, ((

)).

Furthermore, section 5.9 of the TR discusses that tasks which support plant functions are identified as part of TA and then selected for training according to a SAT-based training approach. Under this approach, tasks are described as being selected for training based upon a difficulty, importance, and frequency ranking process that is described as being the training equivalent to the graded approach that is taken to HAs under section 3 of the TR. ((

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION

)) Based on the above, the NRC staff has determined that TerraPowers plan for the treatment of important HAs addresses important HAs in the HFE process and, therefore, concludes that criterion 7.4.3(3) is met.

6.3 Overall Conclusion for the TIHA Element The NRC staff concludes that TerraPowers plan for TIHA, as described in the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff when a future TIHA RSR has been provided.

7.0 HUMAN-SYSTEM INTERFACE DESIGN The HSI design element represents the translation of function and task requirements into HSI design specifications. The objective of this review is to evaluate how HSI designs are identified and refined. The review verifies that the applicant has a process to translate functional and task requirements to the detailed design of alarms, displays, controls, and other aspects of the HSI through the systematic application of HFE principles and criteria. The NRC staffs objective in the review of this element is to verify the adequacy of the HSI design approach. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 8.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in sections 7.1 through 7.6. It should be noted that, per NUREG-0711, an associated RSR is expected for this element, however, RSRs are not included as part of this HFEPP and will need to be submitted and reviewed as part of an OLA.

7.1 Human-System Interface Design Inputs (Criteria 8.4.1(1) - (4))

NUREG-0711, criterion 8.4.1(1), lists analyses and inputs that the applicant should use early in the design process to identify requirements for HSI design, including operational experience, FRA/FA, TA, and staffing and qualifications analysis. Criteria 8.4.1(2) - (4) state that the applicant should identify constraints on HSI design from system requirements, regulatory requirements, and other sources, such as customer requirements, as inputs to the HSI design.

The NRC staff considered whether analyses conducted in earlier states of the HFEPP are utilized to identify HSI requirements. Section B.2.2.5.5 of the TR describes ((

)) Section B.2.2, Task Analysis Process, of the TR describes that the output of the AOF process serves as the starting input for the TA. Section B.3, Human-System Interface Design Methodology, of the TR states the output of the TA informs the design of the HSIs.

Appendix B discusses points in the HSI design process during which staffing-related inputs are considered.

The NRC staff also considered whether constraints on HSI design were identified. Section B.2.1, Task Analysis Inputs, of the TR describes inputs from the TA process that inform HSI development. ((

)) Section B.3.1.2, Human-System Interface Design Requirements Input, of the TR further describes that a main input to the HSI design includes, in part, HFE regulations and standards. The NRC staff has determined that TerraPowers plan for HSI design addresses the use of early results in the design process to identify requirements for

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION HSI design, as well as design constraints, and, therefore, concludes that criterion 8.4.1(1) is met.

7.2 Concept of Use and HSI Design Overview (Criteria 8.4.2(1) - (2))

7.2.1 Concept of Use (Criterion 8.4.2(1))

Criterion 8.4.2(1) states that the applicant should develop a concept of use stating the roles and responsibilities of operations personnel based upon anticipated staffing levels. Section 5.7.2, Human Factors Engineering Concept of Operation, of the TR states that the HFE COO document serves the role of a concept of use. The HFE COO document is described as providing information on how users interact with HSIs and with each other to operate the plant.

The HFE COO is also described as providing assumptions regarding user roles and minimum staffing. The NRC staff has determined that TerraPowers plan for HSI design addresses the development of an appropriate concept of use and, therefore, concludes that criterion 8.4.2(1) is met.

7.2.1 HSI Design Overview (Criterion 8.4.2(2))

Criterion 8.4.2(2) states that the applicant should provide an overview of the HSI, covering the technical bases and demonstrating that they constitute a state-of-the-art HSI design which supports personnel performance. Section 5.7.4 of the TR describes that the HSI design process includes the development and application of HFE design requirements (i.e., the HFE DRD) that include, in part, requirements for information displays, user interfaces, controls, alarms, safety parameter monitoring, computer-based procedures, workstations, and labeling. The HFE DRD and HFE design documents are described as being developed to comply with codes, standards, and HFE best practices (e.g., NUREG-0700). The results of HSI evaluations are described as being fed back into the HSI design using an HFE issue tracking process. The NRC staff has determined that TerraPowers plan for HSI design addresses the incorporation of appropriate technical bases to inform a state-of-the-art HSI design and, therefore, concludes that criterion 8.4.2(2) is met.

7.3 Human Factors Engineering Design Guidance for Human-System Interfaces (Criteria 8.4.3(1) - (5))

NUREG-0711, section 8.4.3, HFE Design Guidance for HSIs, includes five criteria that the NRC staff used to address design-specific HFE design guidance that an applicant should develop and use for HSI features, layout, and environment. NUREG-0711 refers to this type of design guidance as a style guide. For HSI design, the style guide should do the following:

Address the scope of HSIs and their form, function, operation, and environmental conditions that are relevant to human performance (Criterion 8.4.3(1)).

Contain guidance derived from generic HFE guidance and HSI design-related analyses and reflect the applicants decisions in addressing specific goals of the HSI design (Criterion 8.4.3(2)).

Contain precisely expressed individual guidelines and observable HSI characteristics and details for design personnel to use for the purpose of design consistency and verifiability (Criterion 8.4.3(3)).

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Contain procedures, supplemented with graphical examples, figures, and tables to facilitate comprehension, for determining where and how HFE guidance will be used in the overall design process (Criterion 8.4.3(4)).

Be readily accessible and usable by designers, with references to source documents included, and be updated as the design matures (Criterion 8.4.3(5)).

Section 5.7.4 of the TR states that the scope of a Style Guide is covered within the HFE DRD and the HSI Style Specification. The HFE DRD and HFE design documents are described as being developed to comply with codes, standards, and HFE best practices (e.g., NUREG-0700).

Section 5.7.4 of the TR states that the HFE design requirements are contained within a hierarchal document structure, with the HFE DRD serving to contain the higher-level set of HFE design requirements for the project. The HSI style specification is described, in turn, as containing the implementation-level design requirements for both hardware-based panels and software-based displays, with bases for requirements being traceable back to the HFE DRD.

Additionally, section 5.7.4 of the TR states that the HFE DRD and style specification requirements will be provided to suppliers for the NI HSIs though the procurement process, which supports consistency across the HSIs in the MCR, RSC, and LCSs. The NRC staff has determined that, while an HFE style guide is not yet available to be reviewed by the NRC staff in conjunction with the HFEPP, TerraPowers plan for HSI design addresses the development of an HFE style guide and the evaluation of the completed style guide can reasonably be deferred until the review of an OLA in conjunction with the HSI Design RSR.

7.4 HSI Detailed Design and Integration (Criteria 8.4.4.1 - 8.4.4.6) 7.4.1 General HSI Design and Integration (Criteria 8.4.4.1(1) - (8))

7.4.1.1 HSI Design Supports IHAs (Criterion 8.4.4.1(1))

Criterion 8.4.4.1(1) states that for important HAs, the applicants design should minimize the probability that errors will occur and maximize the probability that any error made will be detected.

The NRC staff considered whether state-of-art HFE principles are applied in the HSI design process for important HAs to minimize human errors. Section 5.6 of the TR states that ((

)) Section B.3.2, Human-System Interface Design Process, describes that, ((

))

The NRC staff notes that these activities help to minimize human errors and facilitate the ability of human errors to subsequently be detected and corrected. The NRC staff has determined that TerraPowers plan for HSI design addresses minimization of human errors and, therefore, concludes that criterion 8.4.4.1(1) is met.

7.4.1.2 HSI Layout is Based on Job Analysis (Criterion 8.4.4.1(2))

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Criterion 8.4.4.1(2) states the applicant should base the layout of HSIs within consoles, panels, and workstations on (1) analyses of personnel roles (job analysis) and (2) systematic strategies for organization, such as arrangement by importance, and frequency and sequence of use.

Section B.2.2.5.3, Job Design, Preliminary Workload Analysis, and Workplace Design and Layout Organization, of the TR describes ((

)) Table B.2-4, Job Design, Preliminary Workload Analysis, and Workplace Design and Layout Organization Definition, of the TR provides ((

)) Table B.3-2, User Interface Specification and Data Connection Table Creation Process, of the TR describes ((

)) The NRC staff has determined that TerraPowers plan for HSI layout design is based on job analysis and systematic strategies for organization and, therefore, concludes that criterion 8.4.4.1(2) is met.

7.4.1.3 HSI Design Supports Inspection, Maintenance, and Testing activities (Criterion 8.4.4.1(3))

Criterion 8.4.4.1(3) states that the applicant should design the HSIs to support inspection, maintenance, test, and repair of (1) plant equipment and (2) the HSIs.

The introduction section of the TR states that one of the HFE design goals is to ensure that working areas and their environments are designed for the human to perform, in part, maintenance, inspection, surveillance, and test activities. Section B.3 of the TR discusses the HSI design methodology and states that the user task types considered, include maintenance, test, surveillance, and inspection activities. Section B.3.2 of the TR describes ((

))

Section B.6.1.4, Workstation and Panel Configurations, of the TR presents ((

)) The NRC staff has determined that TerraPowers plan for HSI design addresses the support of inspection, maintenance, test, and repair activities and, therefore, concludes that criterion 8.4.4.1(3) is met.

7.4.1.4 HSI Design Supports Task Performance Under Conditions of Minimal, Typical, and Maximum Staffing (Criterion 8.4.4.1(4))

Criterion 8.4.4.1(4) states that the applicants design should support personnel task performance under conditions of minimum-, typical-, and high-level or maximum staffing.

Section 5.7.2 of the TR describes development of the HFE COO document which, in part, includes job design aspects such as the definition of user roles and minimum staffing.

Section 5.10 of the TR describes HFE ISV that evaluates the performance of the integrated HSI design with respect to other HFE elements such as plant personnel roles, staffing and qualifications, and task assignments. ISV evaluates the performance of the integrated HSI design in terms of, in part, personnel tasks, crew coordination, situation awareness, and workload. Section B.4 of the TR describes ((

)) Additionally, section C.5.3, Staffing Analysis in the Human Factors Engineering Verification and Validation Process, of the TR discusses validation of nominal shift

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION levels, minimal shift levels, and shift turnover. The NRC staff notes that the overall HSI design testing and evaluation, ISV, and iterative HFE design processes together are consistent with the development of an HSI design that will support personnel task performance under various staffing conditions. The NRC staff has determined that TerraPowers plan for HSI tests and evaluation, as well as ISV, address HSI support for staffing conditions and, therefore, concludes that criterion 8.4.4.1(4) is met.

7.4.1.5 HSI Design Process Accounts for Fatigue (Criterion 8.4.4.1(5))

Criterion 8.4.4.1(5) states that the applicants design process should account for using the HSIs over the duration of a shift where decrements in human performance due to fatigue may be a concern.

Section 5.10 of the TR describes that HF ISV tests participants performing a set of simulated challenging scenarios and demonstrates that the integrated HSI supports safe operation of the plant, including acceptable shift staffing and workload. Section B.2 of the TR describes ((

)) Appendix C of the TR describes that both workload and situational awareness are considerations that serve as inputs within the staffing analyses. Section D.4 of the TR discusses ((

)) Additionally, section D.4.3, Representative Population Sampling, describes that the sampling of conditions during ISV should include, in part, circadian factors (i.e., with a subset of scenarios run during night-shift). These design considerations serve, in aggregate, to address fatigue among shift personnel. The NRC staff has determined that TerraPowers plan for HSI design, staffing, and ISV account for personnel fatigue and, therefore, concludes that criterion 8.4.4.1(5) is met.

7.4.1.6 HSI Characteristics Support Human Performance Under a Full Range of Environmental Conditions (Criterion 8.4.4.1(6))

Criterion 8.4.4.1(6) states that the characteristics of the applicants HSIs should support human performance under the full range of environmental conditions, ranging from normal to credible extreme conditions, such as loss of lighting and of ventilation. The NRC staff evaluated how the range of environmental conditions are considered in the HSI design process. Section B.2 of the TR describes the TA process that provides input for HSI design, with Section B.2.2.5.3 discussing ((

))

In addition, section D.4.3 of the TR describes that ISV sampling considerations should include environmental factors such as poor lighting and high noise. Section D.5.5.2, Human Factors Engineering Design Verification Evaluation Methods, of the TR specifically discusses the HFE evaluation of environmental aspects (e.g., lighting, noise, temperature, ventilation). This section notes that some of these aspects may be verified using a full-scope simulator, but others must

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION instead be verified under the design implementation element after the plant has been constructed. The NRC staff has determined that TerraPowers plans for TA, HSI design, and V&V, in aggregate, address HSI support for human performance under the range of environmental conditions and, therefore, conclude that criterion 8.4.4.1(6) is met.

7.4.1.7 The Applicant has a Change Process for HSIs in the Operating Plant (Criterion 8.4.4.1(7))

Criterion 8.4.4.1(7) states that the applicant should identify how, in an operating plant, the HSIs are modified and updated, temporary HSI changes are made, and personnel-defined HSIs are created. During the audit, TerraPower clarified that, once the plant is turned over to the licensee, any modification or updates to the HSIs will be in accordance with the administrative procedures described in the PSAR. The NRC staff has determined that review of TerraPowers process for how HSI design modifications and changes will be addressed during the operating phase can reasonably be deferred until review of the OLA.

7.4.2 Main Control Room (Criteria 8.4.4.2(1) - (15))

The NRC staff reviewed the HFEPP to determine how the HFEPP addresses the criteria outlined in NUREG-0711, section 8.4.4.2, Main Control Room, which includes the requirements in 10 CFR 50.34(f)(2) related to lessons learned from the accident at the TMI reactors. The NRC staff did not evaluate criterion 8.4.4.2(4) (applicable to pressurized-water reactors only) nor did the NRC staff evaluate criteria 8.4.4.2(8) - (9), (applicable to boiling-water reactors only) because Natrium is a non-light water reactor design.

7.4.2.1 Post-TMI HSI Inventory Requirements (Criteria 8.4.4.2(1-3), (5-7), and (10-11))

Criterion 8.4.4.2(1) addresses 10 CFR 50.34(f)(2)(iv) that discusses the safety parameter display system (SPDS). Criterion 8.4.4.2(1) states that the applicant should describe the safety parameter display system, addressing the identification of critical safety functions, identification of the parameters personnel will use to monitor each critical safety function, and evaluation of SPDS HSIs.

Criterion 8.4.4.2(2) addresses 10 CFR 50.34(f)(2)(v) that discusses the bypassed and inoperable status indication Criterion 8.4.4.2(2) states that the applicant should describe how the HSI assures the automatic indication of the bypassed and inoperable status of a safety function, and the systems actuated or controlled by the safety function.

Criterion 8.4.4.2(3) addresses 10 CFR 50.34(f)(2)(xi) that discusses relief and safety valve indication. Criterion 8.4.4.2(3) states that the applicant should describe how the HSI indicates the position of the relief and safety valves (open or closed) in the control room.

Criterion 8.4.4.2(5) addresses 10 CFR 50.34(f)(2)(xvii) that discusses containment monitoring. Criterion 8.4.4.2(5) states that the applicant should describe how the control rooms HSIs (alarms and displays) inform personnel about, in part, containment radiation intensity and noble gas effluents for potential, accident release points.

Criterion 8.4.4.2(6) addresses 10 CFR 50.34(f)(2)(xviii) that discusses core cooling.

Criterion 8.4.4.2(6) states that the applicant should describe how the HSI provides unambiguous indication of inadequate core cooling.

Criterion 8.4.4.2(7) addresses 10 CFR 50.34(f)(2)(xix) that discusses post-accident monitoring. Criterion 8.4.4.2(7) states that the applicant should describe how the HSI

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION assures monitoring of plant and environmental conditions following an accident including core damage.

Criterion 8.4.4.2(10) addresses 10 CFR 50.34(f)(2)(xxvi) that discusses leakage control.

Criterion 8.4.4.2(10) states that the applicant should describe how the HSI provides for leakage control and detection in the design of systems outside containment that contain (or might contain) accident-source-term radioactive materials after an accident.

Criterion 8.4.4.2(11) addresses 10 CFR 50.34(f)(2)(xxvii) that discusses radiation monitoring. Criterion 8.4.4.2(11) states that the applicant should describe how the HSI provides appropriate monitoring of in-plant radiation and airborne radioactivity under a broad range of routine and accident conditions.

These HSI elements are linked to regulatory requirements associated with the lessons learned from the accident at TMI and, as technologically relevant, are expected to be considered within the HSI inventory as part of the HFE design process. Thus, the NRC staff evaluated whether the HFEPP establishes how these items will be addressed within the HSI design and validation processes.

Section 5.7 of the TR describes a systematic process of HSI design, including TA, defining HSI concepts, defining key parameters to be displayed or controlled, and performing test and evaluation. It is stated that the HFE DRD includes requirements, in part, for information displays, as well as for the safety function and parameter monitoring system. Section B.2 describes TA processes that provide the input for HSI design. Table B.2-5, Human-System Interface Key Parameters Definition, describes ((

))

Additionally, section 5.7.5, Detailed Human-System Interface Design, of the TR states that HSI design specifications will be provided to the vendor in the form of a user interface specification.

Finally, it is also stated in this section that the final MCR design will provide indications that meet the technologically relevant aspects of 10 CFR 50.34 paragraphs (f)(2)(iv), (v), (xi),

(xvii), (xviii), (xix), (xxvi), and (xxvii).

The NRC staff has determined that TerraPowers plan for HSI design will address the incorporation of technologically relevant, post-TMI HSI inventory requirements and, therefore, concludes that criteria 8.4.4.2(1-3), (5-7), and (10-11) are met.

7.4.2.9 Manual Initiation of Protective Actions (Criterion 8.4.4.2(12)) and Diversity and Defense-In-Depth (Criterion 8.4.4.2(13))

Criterion 8.4.4.2(12) states that the applicant should describe how the HSI supports the manual initiation of protective actions at the system level for safety systems otherwise initiated automatically. Criterion 8.4.4.2(13) states that the applicant should describe how the HSI provides displays and controls in the control room for manual, system-level actuation of critical safety functions, and for monitoring those parameters that support them. These displays and controls should be independent of, and different from, the normal I&C.

Section 5.2 of the TR describes that a defense-in-depth methodology is included within the FRA process which establishes functions with sufficient independence (including any needed control and instrumentation diversity) to assure adequate safety should failures or degradations occur.

Additionally, section 5.2 of the TR states that certain defense line functions are specified as

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION manual HAs, with the appropriateness of those manual HAs being confirmed by means of the AOF process. Section D.6.7, Human Factors Engineering Validation Performance Measures, of the TR describes performance measures that are used during HFE ISV. ((

)) Section D.6.7.1, Plant -

Core Thermal-Hydraulic Condition, of the TR discusses ((

)) During the audit, TerraPower clarified how defense-in-depth functions are classified, as well as that no safety-related manual actions are expected.

Based on the above, the NRC staff has determined that TerraPowers plan for HSI design addresses the manual initiation of protective actions for safety systems, as well as providing diverse and independent displays and controls for manual actuation and monitoring of critical safety functions. Therefore, the NRC staff concludes that criteria 8.4.4.2(12) - (13) are met.

7.4.2.10 Important Human Actions (Criterion 8.4.4.2(14))

Criterion 8.4.4.2(14) states that the applicant should describe how the HSI provides the controls, displays, and alarms that ensure the reliable performance of identified important HAs. The NRC staff evaluated whether the HFEPP describes a process identifying important HAs, translating the associated requirements to HSI design, and testing and evaluating the design.

Section 5.7 of the TR describes a systematic process of HSI design, including TA, defining HSI concepts, defining key parameters to be displayed or controlled, designing HSI, and performing test and evaluation. Section 6 of this evaluation previously addressed the TIHA HFE element.

As noted in section 6 of this evaluation, ((

)) Section 5.7.7, Graded Application of Human Factors During Human-System Interface Design, of the TR describes ((

)) Additionally, Section B.3.2 of the TR describes ((

))

The NRC staff has determined that TerraPowers plan for HSI design addresses HSI support for important HAs and that the associated results of this plans implementation can be reviewed by the NRC staff when an associated HSI design RSR is provided. Accordingly, the NRC staff concludes that the HFEPP meets Criterion 8.4.4.2(14).

7.4.2.11 Computer-based Procedures Platform (Criterion 8.4.4.2(15))

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Criterion 8.4.4.2(15) states that the applicants computer-based procedures should be consistent with the design review guidance in NUREG-0700, section 8, Computer-Based Procedure System, and in section 1 of DI&C-ISG-5.7 Section 5.7.2 of the TR states that the HFE COO document contains the concept for computer-based procedures and includes references to standards such as IEEE 1786-2022, IEEE Guide for Human Factors Applications of Computerized Operating Procedure Systems (COPS) at Nuclear Power Generating Stations and Other Nuclear Facilities [22]. The NRC staff notes that the IEEE 1786-2022 standard addresses HFE considerations associated with computer-based procedures in a manner that would be expected to contribute to an adequate finalized design. Furthermore, section D.4 of the TR describes the methodology for sampling operational conditions during HFE V&V activities, with Section D.4.2, Minimum Sample Conditions, describing ((

))

The NRC staff has determined that TerraPowers plan for computer-based procedures addresses appropriate design review guidance and, therefore, concludes that criterion 8.4.4.2(15) is met.

7.4.3 Technical Support Center (Criteria 8.4.4.3(1) - (7)) and Emergency Operations Facility (Criteria 8.4.4.4(1) - (10))

NUREG-0696, Functional Criteria for Emergency Response Facilities, [23] states that HFE should be incorporated in the design of the on-site TSC and EOF, with consideration of both operating and maintenance personnel. Although the specific emergency facilities associated with Natrium will be established in the emergency plan in conjunction with an OLA, the NRC staff notes that the criteria of NUREG-0711, section 8.4.4.3, Technical Support Center, and section 8.4.4.4, Emergency Operations Facility, describe principles that are broadly relevant to the HFE review of emergency facilities in general. Specifically, this includes the general HFE scope covered by criteria 8.4.4.3(1) through 8.4.4.3(7) and criteria 8.4.4.4(1) through 8.4.4.4(10).

Section 1.2 of the TR describes the scope of the Natrium HFE program and states, in part, that the HFEPP applies to NI-related HSIs in the emergency support facilities. Based upon this scope of HFE program applicability, the NRC staff notes that the HSI design processes described in section 5.7 and appendix B of the TR would be applicable to emergency facilities.

Section 5.7 of the TR describes a systematic process of HSI design, including TA, defining HSI concepts, defining key parameters to be displayed or controlled, designing HSI, and performing test and evaluation. Section B.2 of the TR describes the TA methodology process which provides inputs for HSI design. Section B.2.1.2 of the TR describes ((

))

Additionally, section B.3 of the TR establishes that a primary goal for HSI design is to facilitate efficient and reliable user performance during both emergency and accident plant conditions.

The NRC staff notes that these programmatic attributes generally support the HSI design within emergency facilities.

The NRC staff has determined that, while the HFEPP establishes that TerraPower intends to apply HFE with the context of the Natrium emergency facilities, the specific details regarding both the nature of those emergency facilities and how HFE will be applied to them is not 7 This ISG guidance was incorporated into NUREG-0800, chapter 18, revision 3 (ML16125A114).

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION expected to be available until an OLA has been submitted with an associated emergency plan.

This represents an incomplete aspect of the NUREG-0711 review methodology that is addressed in the Limitations and Conditions section of this evaluation.

7.4.4 Remote Shutdown Facility (Criteria 8.4.4.5(1) - (2))

7.4.4.1 Description of Remote Shutdown Capability (Criterion 8.4.4.5(1))

Criterion 8.4.4.5(1) states that the applicant should describe how the HSI provides a design capability for remote shutdown of the reactor outside the MCR. Section 1.2 of the TR describes the scope of the program and states, in part, that the HFEPP applies to NI-related HSIs in the RSC. Based upon this scope of HFE program applicability, the NRC staff notes that the HSI design processes described in section 5.7 and appendix B of the TR would be applicable to the RSC. This entails a systematic process of HSI design, including TA, defining HSI concepts, defining key parameters to be displayed or controlled, and performing test and evaluation.

Additionally, section D.1.2, Scope, of the TR states that the HFE V&V process applies to the HSIs at the RSC. The NRC staff has determined that TerraPowers plan for HSI design addresses the capability for remote shutdown of the reactor outside the MCR and, therefore, concludes that criterion 8.4.4.5(1) is met.

7.4.4.2 Consistency of Remote Shutdown HSIs (Criterion 8.4.4.5(2))

Criterion 8.4.4.5(2) states that the applicant should describe how the HSIs at the remote shutdown facility are consistent with those in the MCR. Section 5.7.4 of the TR states that the HFE DRD and style specification requirements are provided to suppliers for the NI HSIs though the procurement process, which supports consistency across the HSIs in the MCR, RSC, and LCSs. Section 5.7.4 of the TR also states that the V&V process serves as a method to confirm the implementation of HFE requirements by suppliers. The NRC staff has determined that TerraPowers plan for HSI design addresses consistency between the HSIs located in both the MCR and RSC and, therefore, concludes that criterion 8.4.4.5(2) is met.

7.4.5 Local Control Station Design (Criteria 8.4.4.6(1) - (2))

7.4.5.1 Basis for Determining Local Control HSIs (Criterion 8.4.4.6(1))

Criterion 8.4.4.6(1) states that the applicant should describe the basis for deciding which HSIs will be included in the MCR design, and which will be provided locally.

Table B.2-4 of the TR presents ((

))

Section D.6.3.1.3, Testbed Verification, describes that risk-significant local field interfaces (including associated HSIs) are verified in accordance with the TSV and HFE design verification processes, which incorporate the validation of risk-significant local control operations. The NRC staff has determined that TerraPowers plan for HSI design addresses processes for determining where HSIs will be located and, therefore, concludes that criterion 8.4.4.6(1) is met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 7.4.5.2 Incorporation of HFE into local control station HSIs (Criterion 8.4.4.6(2))

Criterion 8.4.4.6(2) states that the applicant should describe how HFE was incorporated into the HSIs for LCSs to ensure they are consistent with those in the MCR, and that personnel easily understand and use the HSIs.

Section 1.2 of the TR describes the scope of the program and states, in part, that the HFEPP applies to NI-related HSIs for local controls. Based upon this scope of HFE program applicability, the NRC staff notes that the HSI design processes described in section 5.7 and appendix B of the TR would be applicable to such local controls. Section 5.7 of the TR describes a systematic process of HSI design, including TA, defining HSI concepts, defining key parameters to be displayed or controlled, and performing test and evaluation. Section 5.7.4 of the TR states that the HFE DRD and style specification requirements are provided to suppliers for the NI HSIs, which supports consistency across the HSIs in the MCR, RSC, and LCSs.

Furthermore, section D.1.2 states that the HFE V&V process applies to the HSIs associated with NI local controls. The NRC staff has determined that TerraPowers plan for HSI design addresses the application of HFE to the HSIs of LCSs, as well as their consistency with those in the MCR, and, therefore, concludes that criterion 8.4.4.6(2) is met.

7.5 Degraded Instrumentation and Controls and Human-System Interface Conditions (Criteria 8.4.5(1) - (4))

Criteria 8.4.5(1) - (4) consider whether the applicants HSI design approach adequately accounts for the identification of automation failures and degraded condition effects by operators, the timely detection of degraded I&C and HSI conditions by operators, the back-up systems needed to support personnel tasks under degraded I&C and HSI conditions, and the identification of required compensatory actions. Section 5.2 of the TR describes that a defense-in-depth methodology is included within the FRA process which establishes functions with sufficient independence (including any needed control and instrumentation diversity) to assure adequate safety should failures or degradations occur. Additionally, section 5.2 of the TR states that certain defense line functions are specified as manual HAs, with the appropriateness of those manual HAs being confirmed by means of the AOF process. Section 5.10 of the TR describes the overall HFE V&V process, which includes ISV that evaluates the performance of the integrated HSI design. Appendix D of the TR provides a detailed discussion of this V&V methodology, which incorporates considerations related to degraded I&C and HSIs.

Section D.4.2 of the TR describes ((

)) Additionally, section D.6.4.3, Selecting and Documenting Events, of the TR discusses that the selection of events for ISV scenarios should include the degradation or failure of instruments, controls, and components.

Section D.6.7 of the TR describes ((

)) Section D.6.7.1 of the TR discusses ((

)) Additionally, section D.9.1 of the TR, which describes ((

))

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION During the audit, TerraPower confirmed that defense-in-depth functions involving non-safety-related with special treatment and no special treatment manual actions will be performed using diverse, independent HSI, as described in the PSAR (TerraPower indicated that no safety-related manual actions are expected at present).

The NRC staff has determined that TerraPowers plan for HSI design addresses the identification of automation failure and degraded condition effects, the timely detection of degraded I&C and HSI conditions, the needed backup systems to support personnel tasks under degraded I&C and HSI conditions, and identification of required compensatory actions.

Therefore, the NRC staff concludes that criteria 8.4.5(1) - (4) are met.

7.6 HSI Tests and Evaluations (Criteria 8.4.6.1 - 8.4.6.2) 7.6.1 Trade-off Evaluations (Criteria 8.4.6.1(1) - (2))

7.6.1.1 Consideration of Human Performance (Criterion 8.4.6.1(1))

Criterion 8.4.6.1(1) states that in comparing design approaches, the applicant should consider those aspects of human performance important to performing tasks. This criterion describes certain factors that should be considered when selecting one design approach over another (e.g., personnel task requirements, HSI-system performance requirements, and human-performance capabilities and limitations). Section B.4.3.2, Human Interface System Evaluation and User-Based Testing, of the TR discusses that the methods used during HSI evaluation methods include, in part, trade-off evaluations. Trade-off evaluations are described as being used for assessing design alternatives against one another or, alternatively, against an existing baseline. Section B.4.3.2.2 of the TR describes ((

)) The NRC staff has determined that TerraPowers plan for HSI design addresses appropriate factors to be considered during trade-off evaluations and, therefore, concludes that criterion 8.4.6.1(1) is met.

7.6.1.2 Relative Benefits of Design Alternatives (Criterion 8.4.6.1(2))

Criterion 8.4.6.1(2) states that the applicant should explicitly state the relative benefits of design alternatives and the basis for the design approach selected.

The NRC staff considered how the relative benefits of design alternatives are evaluated under the trade-off evaluation approach described in the HFEPP. Section B.4.3.2.2 of the TR describes that selected key criteria and the design alternatives are evaluated in a Pugh Matrix trade-off tool. Within the tool, importance ratings are assigned to criteria and evaluations against options (including a benchmark option) are made, with a numerical score being tabulated for alternatives. The scoring resulting from this process is used to make HSI design alternative trade-off decisions. The NRC staff has determined that TerraPowers plan for HSI design includes a structured and reasonable methodology for the selection of design alternatives and, therefore, concludes that criterion 8.4.6.1(2) is met.

7.6.2 Performance-based Tests (Criteria 8.4.6.2(1) - (3))

7.6.2.1 Objectives of Tests (Criterion 8.4.6.2(1))

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Criterion 8.4.6.2(1) states that the applicant should identify the specific objectives of the tests.

The NRC staff considered whether the specific objectives of performance-based tests are identified under the approach described in the HFEPP. Section B.4.3.2.3, Performance-Based User Testing, of the TR establishes that the process of performance-based user testing begins with the preparation of a test plan that includes the purpose of the tests, as well as other aspects, such as the HSI design features to be tested and acceptance criteria to be used. The NRC staff has determined that TerraPowers plan for HSI design addresses establishing specific objectives for performance-based tests and, therefore, concludes that criterion 8.4.6.2(1) is met.

7.6.2.2 General Approach to Testing (Criterion 8.4.6.2(2))

Criterion 8.4.6.2(2) states that the applicant should base the general approach to testing on the tests objective(s).

This criterion describes certain aspects of tests that should be specified, including participants, testbed, HSI design features, tasks or scenarios used, performance measures, test procedures and data analyses. The NRC staff reviewed section B.4.3.2.3 of the TR, which describes test plan preparation, and notes that the described test plan elements are consistent with those of the criterion. Additionally, section B.4.3.2.3 provides further information regarding how to achieve each element such as, for example, selecting a testbed with consideration of the design features to be tested and by ensuring the population pool is sufficiently diverse and representative of the user population. The NRC staff has determined that TerraPowers plan for HSI design addresses the use of test objectives as a basis for performance-based testing and, therefore, concludes that criterion 8.4.6.2(2) is met.

7.6.2.3 Conclusions from the Tests (Criterion 8.4.6.2(3))

Criterion 8.4.6.2(3) states that the conclusions from the tests and their impact on design decisions should be described. The NRC staff considered how the processes described by the HFEPP serve to capture conclusions from performance-based testing, as well as the influence of those conclusions on design decisions.

Section B.4.3.3.4, Analysis of Results, Documentation, and Treatment of Human Factor Engineering Issues, of the TR describes the process of documenting and using the findings from performance-based user testing. Specifically, it states that an HFE test and evaluation team analyzes the testing data. Additionally, it states that this team identifies issues and enters those issues into HFEITS, in addition to also preparing a test report. The test report is described as including summarized data, findings, and recommendations for resolutions. The NRC staff has determined that TerraPowers plan for HSI design addresses the capture of conclusions from performance-based tests, as well as the impact of those conclusions on design decisions and, therefore, concludes that criterion 8.4.6.2(3) is met.

7.7 Overall Conclusion for the HSI Design Element The NRC staff concludes that, subject to the limitations and conditions contained in this evaluation, TerraPowers plan for HSI design, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff when a future HSI design RSR has been provided.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 8.0 PROCEDURE DEVELOPMENT Procedures support and guide how plant personnel interact with the plant and respond to plant-related events. The NRC staffs objective in the review of this element is to confirm that the applicant's procedure development program incorporates HFE principles and design requirements to facilitate the development of procedures that will be technically accurate, comprehensive, explicit, easy to utilize, and validated. Furthermore, an additional staff objective in the review of this element is to evaluate conformance with the requirements of 10 CFR 50.34(f)(2)(ii). The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 9.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in sections 8.1 through 8.9. Per NUREG-0711, there is no associated RSR expected for this element.

NUREG-0711, section 9, Procedure Development, references the acceptance criteria in chapter 13, Conduct of Operations, of NUREG-0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR [light water reactor] Edition [24]. Thus, a complete review of this element necessarily entails implementing the reviews of NUREG-0800, sections 13.5.1.1, Administrative Procedures - General, [25] and 13.5.2.1, Operating and Emergency Operating Procedures, [26]. While NUREG-0800 is generally applicable only to LWRs, DANU-ISG-2022-05 provides specific guidance for non-light water reactors regarding the use of NUREG-0800, sections 13.5.1.1 and 13.5.2.1. However, the complete materials to be reviewed under NUREG-0800, sections 13.5.1.1 and 13.5.2.1, are not expected to be available until an OLA is submitted. Therefore, while the NRC staff evaluated the HFEPP using NUREG-0711, section 9, to the extent practical, the completion of the related NUREG-0800, sections 13.5.1.1 and 13.5.2.1, reviews remain an incomplete aspect of the NUREG-0711 review methodology that is addressed in the Limitations and Conditions section of this evaluation.

8.1 Procedure Program Scope (Criterion 9.4(1))

Criterion 9.4(1) states that the scope of the applicants procedure development program should include the generic technical guidelines (GTG) for emergency operating procedures (EOPs),

plant and system operations (including startup, power, and shutdown operations), test and maintenance, surveillance testing, abnormal and emergency operations, and alarm response.

Section 5.8 of the TR states that the PDP addresses procedures for plant and system operations across startup, normal, and shutdown conditions, as well as for maintenance, inspection, and testing. Additionally, it is stated that the PDP includes symptom-based EOPs, event-based abnormal operating procedures (AOPs), and alarm response procedures. During the audit, TerraPower clarified that the process of obtaining vendor support for the development of the EOPs is ongoing and that technical guidelines will be produced for those EOPs. However, TerraPower indicated that a decision has not yet been made regarding whether site-specific or GTGs will be developed for the EOPs, and that this decision is not expected to be made until approximately one year from the present time. The NRC staff has determined that TerraPowers plan for procedure development includes appropriate categories of procedures and that further evaluation of this area (including that related to GTGs, as relevant) can be completed in conjunction with a future OLA review.

8.2 Basis for Developing Procedures (Criterion 9.4(2))

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Criterion 9.4(2) states that the applicant should identify the basis for developing procedures, which should include plant design bases, system-based technical requirements and specifications, results of TAs, important HAs, initiating events to be considered in the EOPs (including those in the design bases), the GTG for EOPs, and appropriate HFE of procedures.

Section 5.8 of the TR discusses that the application of HFE principles is an objective of procedure development. The PDP is described, in part, as specifying inputs for procedure development. As discussed earlier in this evaluation, section 3.1 of the TR describes ((

))

During the audit, TerraPower clarified that the process of obtaining vendor support for the development of the EOPs is ongoing and that technical guidelines will be produced for the EOPs. However, TerraPower indicated that a decision has not yet been made regarding whether site-specific or GTGs will be developed for the EOPs, and that this decision is not expected to be made until approximately one year from the present time. The NRC staff has determined that TerraPowers plan for procedure development identifies the basis for developing procedures and that further evaluation of this area (including that related to GTGs, as relevant) can be completed in conjunction with a future OLA review.

8.3 Writers Guide (Criterion 9.4(3))

Criterion 9.4(3) states that the applicant should develop a writers guide to establish the process for developing technical procedures that are complete, accurate, consistent, and easy to understand and follow. Section 5.8 of the TR states that a procedure writers guide will be developed that addresses each type of procedure. The writers guide is described as establishing criteria such that the procedures developed with it will be consistent in both style and content, with consideration of industry good practices. The NRC staff has determined that TerraPowers plan for developing a procedure writers guide is consistent with supporting the development of adequate procedures and, therefore, concludes that criterion 9.4(3) is met.

8.4 Procedure Elements (Criterion 9.4(4))

Criterion 9.4(4) states that the applicants procedures should contain elements that include title and identifying information, statement of applicability and purpose, prerequisites, precautions, important HAs, limitations and actions, acceptance criteria, check off lists, and reference material, as applicable.

Section 5.8 of the TR describes that the procedure writers guide establishes criteria such that procedures developed with it will be consistent in organization and style. It is stated that the writers guide provides instructions for procedure content, format, the way procedure steps should be written, and terminology used. During the audit, a copy of the TerraPower procedure ADI-RMD-102, Procedure Writers Manual, revision 1, was made available to the NRC staff.

The NRC staff notes that the guide addressed, in part, the following: title and identifying information; applicability and purpose; procedural structure; writing style and wording conventions; prerequisites, limitations, cautions, and warnings; level of use determination (i.e.,

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION information, reference, or continuous use); operator actions (including those which are immediate in nature); acceptance criteria; data collection, signoffs (including independent verifications), and place keeping; reference material; and review guidelines. The NRC staff has determined that TerraPowers procedure writers guide addresses appropriate procedure elements, is expected to yield procedures which contain those elements, and that further evaluation of this area can be completed in conjunction with a future OLA review.

8.5 Symptom-based GTGs and EOPs (Criterion 9.4(5))

Criterion 9.4(5) states that the applicant should develop symptom-based GTG and EOPs with clearly specified entry conditions. Section 5.8 of the TR states that the PDP includes symptom-based EOPs. During the audit, TerraPower clarified that the process of obtaining vendor support for the development of the EOPs is ongoing and that technical guidelines will be produced for the EOPs. However, TerraPower stated that a decision has not yet been made regarding whether site-specific or GTGs will be developed for the EOPs, and that this decision is not expected to be made until approximately one year from the present time. The NRC staff has determined that TerraPowers plan for procedure development includes symptom-based EOPs and that further evaluation of this area (including that related to GTGs, as relevant) can be completed in conjunction with a future OLA review.

8.6 Procedure Verification and Validation (Criterion 9.4(6))

Criterion 9.4(6) states that the applicant should verify that procedures are correct and that they should conduct V&V of procedures.

As discussed earlier in this evaluation, section 3.1 of the TR describes ((

)) The NRC staff has determined that TerraPowers plan for the validation and verification of procedures addresses the need to ensure that procedures are correct and that the planned grading of these validation activities appropriately considers both safety and risk insights. Therefore, the NRC staff concludes that criterion 9.4(6) is met.

8.7 Computer-based Procedures (Criterion 9.4(7))

Criterion 9.4(7) states that the applicants computer-based procedures should be consistent with the design review guidance in NUREG-0700, section 8, Computer-based Procedure System, and in section 1 of DI&C-ISG-58. Section 5.7.2 of the TR states that the HFE COO document contains the concept for computer-based procedures and includes references to standards such as IEEE 1786-2022. The NRC staff notes that the IEEE 1786-2022 standard addresses HFE considerations associated with computer-based procedures in a manner that would be expected to contribute to an adequate finalized design. The NRC staff has determined that TerraPowers 8 This ISG guidance was incorporated into NUREG-0800, chapter 18, revision 3.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION plan for the development of computer-based procedures includes the application of reasonable HFE standards and, therefore, concludes that criterion 9.4(7) is met.

8.8 Procedure Control (Criterion 9.4(8))

Criterion 9.4(8) states that the applicant should have a plan for maintaining procedures and controlling updates. During the audit, TerraPower confirmed that they will conform to the requirements in NQA-1-2015, Quality Assurance Requirements for Nuclear Facility Applications, [27] and ANSI/ANS-3.2-2012, Managerial, Administrative, and Quality Assurance Controls for the Operational Phase of Nuclear Power Plants, [28] (with the exception that the 2015 version of NQA-1 will be used instead of the 2008 version referenced in ANSI/ANS-3.2-2012) for procedure maintenance and development. TerraPower also clarified that the commitment for TerraPower to conform to the requirements of NQA-1-2015 is contained in section 5 of TR TP-QA-PD-0001, revision 14-A.

TP-QA-PD-0001, revision 14-A, section 5, Instructions, Procedures, and Drawings, states, in part, that quality assurance personnel shall review and approve procedures for performance of safety related work to ensure that quality requirements for the work are appropriately described. Section 6, Document Control, of TP-QA-PD-0001, revision 14-A, discusses document controls, as well as the controls associated with changes to documents. The described measures include, in part, the identifying documents that are subject to controls, establishing an electronic document management system to maintain current revisions, and identifying individuals responsible for the preparation, review, and approval of controlled documents. Additionally, it states that revisions to documents shall be reviewed and approved according to supporting procedures, with changes being reviewed and approved by the same organization(s) that performed the original approval (except when another organization has been formally designated to do so). Both section 5 and section 6 include commitments to NQA-1-2015.

Based on the above, the NRC staff has determined that TerraPowers plan for procedure development addresses maintaining procedures and controlling updates and, therefore, concludes that criterion 9.4(8) is met.

8.9 Access to Procedures (Criterion 9.4(9))

Criterion 9.4(9) states that the applicant should evaluate the physical means by which personnel access and use procedures, especially during operational events. Section 5.8 of the TR states the MCR HSIs will be designed to support use of computer-based procedures. Additionally, it states that both the MCR and RSC will contain storage space for hardcopy sets of operating procedures. The NRC staff has determined that TerraPowers plan for procedure development addresses the physical availability of procedures, including during those operational events that could MCR access (i.e., by also providing for the availability of procedures at the RSC) and, therefore, concludes that criterion 9.4(9) is met.

8.10 Overall Conclusion for the Procedure Development Element The NRC staff concludes that, subject to the limitations and conditions contained in this evaluation, TerraPowers plan for procedure development, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff in conjunction with a future OLA.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 9.0 TRAINING PROGRAM DEVELOPMENT Training programs are important in ensuring that plant personnel can safely and reliably operate nuclear power plants by providing personnel with the knowledge, skills, and abilities needed to perform their roles and responsibilities. The NRC staffs objective in the review of this element is to verify that the applicant will employ a SAT for developing personnel training, an approach that is required by 10 CFR 50.120(b)(2) and contains the five elements listed in 10 CFR 55.4. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 10.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in sections 9.1 through 9.7. Per NUREG-0711, there is no associated RSR expected for this element.

NUREG-0711, section 10, Training Program Development, references the acceptance criteria of NUREG-0800, chapter 13. Thus, a complete review of this element would entail a review of a comparable scope to that of NUREG-0800, section 13.2.1, Reactor Operator Requalification Program; Reactor Operator Training, [29] and section 13.2.2, Non-Licensed Plant Staff Training, [30]. While NUREG-0800 generally applies only LWRs, DANU-ISG-2022-05 provides review guidance of a similar scope to these sections for non-light water reactors. Specifically, DANU-ISG-2022-05, section 11.1.3.2, Licensed Operator Initial and Continuing (Requalification) Training, addresses licensed operator initial and continuing training, sections 11.1.3.1, Training for Plant Staff, and 11.1.3.4, Non-licensed Personnel Training, address plant staff training, and section 11.2, Staff Review Guidance - Acceptance Criteria, contains related acceptance criteria for these topics.

However, the complete materials to be reviewed within these areas are not expected to be available until an OLA is submitted. Therefore, while the NRC staff evaluated the HFEPP using NUREG-0711, section 10, to the extent practical, the completion of the full review scope remains an incomplete aspect of the NUREG-0711 review methodology that is addressed in the Limitations and Conditions section of this evaluation.

9.1 General Approach (Criteria 10.4.1(1)-(3))

9.1.1 Systematic Approach to Training (Criterion 10.4.1(1))

Criterion 10.4.1(1) states that the applicant should develop a systematic approach to the training of plant personnel as defined in 10 CFR 55.4, Definitions, and as required by 10 CFR 50.120, Training and qualification of nuclear power plant personnel. Section 5.9 of the TR states that a TPDP will be established to specify a systematic approach to training (SAT). The TPDP is further described as incorporating the stages of a SAT, including analysis, design, development, implementation, and evaluation. The NRC staff notes that these stages correspond to the SAT elements defined under 10 CFR 55.4. The NRC staff has determined that TerraPowers plan for training program development incorporates a SAT and, therefore, concludes that criterion 10.4.1(1) is met.

9.1.2 Training Program Scope (Criterion 10.4.1(2))

Criterion 10.4.1(2) states that the overall scope of the applicants training program should include categories of personnel to be trained, specific plant conditions, specific operational activities, and use of the HSIs. Section 5.9 of the TR describes the TPDP as specifying that a

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION SAT-based training approach be applied to the positions included in the minimum staff complement described in section 5.4 of the TR. Section 5.4 of the TR, in turn, states that a staffing analysis process will be used to systematically determine the minimum staff complement. Section 5.9 of the TR further describes, in part, that the SAT-based training program determines the training needed for the specified job positions based on assigned tasks, analyzes those tasks to determine the required abilities, uses those required abilities to support training design, and provides assurance that plant personnel have the abilities needed to perform their roles and responsibilities.

The NRC staff notes that this methodology is adaptable in nature and generally bounds specific plant conditions, operational activities, and use of facility HSIs. During the audit, TerraPower clarified that compliance with 10 CFR 50.120 will be addressed via the PSAR. The NRC staff has determined that TerraPowers training program will have an adequate scope and that review of the categories of personnel covered by the training program can be deferred until review of the OLA.

9.1.3 Job Qualifications (Criterion 10.4.1(3))

Criterion 10.4.1(3) states that the applicants training program should provide reasonable assurance that personnel have qualifications commensurate with the performance requirements of their jobs. Section 5.9 of the TR describes, in part, that the SAT-based training program determines the training needed for specific job positions based on assigned tasks, analyzes those tasks to determine the required abilities, uses those required abilities to support training design, and provides assurance that plant personnel have the abilities needed to perform their roles and responsibilities. Furthermore, it states that the TPDP addresses the requirements and guidance provided in RG 1.8, which endorses ANSI/ANS-3.1-2014. The NRC staff has determined that TerraPowers training program addresses personnel qualifications using methods (i.e., SAT-based training and RG 1.8) that the NRC staff have previously determined to be acceptable and, therefore, concludes that criterion 10.4.1(3) is met.

9.2 Organization of Training (Criteria 10.4.2(1)-(3))

9.2.1 Roles in Training Development (Criterion 10.4.2(1))

Criterion 10.4.2(1) states that the applicant should define the roles of all organizations for developing the training requirements, training information sources, and materials for training, and thereafter, implementing the training program. Section 4.1 of the TR describes the roles and responsibilities within the HFE organization, including that of the HF operations/maintenance team role in training program development and coordination of training issues. During the audit, TerraPower clarified that they intend to obtain accreditation of their training program through the Institute of Nuclear Power Operations (INPO). Additionally, TerraPower indicated that they plan to achieve training program accreditation within 18 months of initial fuel load. The NRC staff notes that accreditation via INPOs National Academy for Nuclear Training (NANT) represents an acceptable method of meeting certain requirements associated with SAT-based training programs.9 Additionally, the NRC staffs review of an OLA using DANU-ISG-2022-05 would entail verification that SAT-based training programs were established and, as relevant, whether 9 The Memorandum of Agreement Between the Institute of Nuclear Power Operations and the U.S.

Nuclear Regulatory Commission, dated December 1, 2022 (ML23026A093), discusses that the NRC recognizes NANT accreditation as being an acceptable means of meeting the requirements of 10 CFR 50.120 and 10 CFR Part 55 as they relate to the use of SAT-based training programs.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION NANT accreditation was obtained. The NRC staff has determined that review of TerraPowers definition of training-related roles can be deferred until review of the OLA.

9.2.2 Training Organization Qualifications (Criterion 10.4.2(2))

Criterion 10.4.2(2) states that the applicant should define the qualifications of organizations and personnel involved in developing and conducting training. Section 5.9 of the TR states that the TPDP addresses the guidance provided in RG 1.8. The NRC staff notes that this standard describes an approach to the qualifications of training management, supervision, and instructors which the NRC staff have previously determined to be acceptable. The NRC staff has determined that TerraPowers plan for personnel qualifications addresses the qualifications of the training organization and, therefore, concludes that criterion 10.4.2(2) is met.

9.2.3 Facilities and Resources (Criterion 10.4.2(3))

Criterion 10.4.2(3) states that the applicant should define the facilities and resources needed to satisfy the requirements of the training program (e.g., plant-referenced, full-scope simulators).

During the audit, TerraPower confirmed that they plan to establish a full-scope, plant-referenced simulator, in addition to obtaining accreditation of their training program through INPO within 18 months of initial fuel load. The NRC staff has determined that review of TerraPowers training-related facilities and resources, including a plant-referenced simulator or Commission-approved simulator, can be deferred until the review of the OLA.

9.3 Learning Objectives (Criteria 10.4.3(1)-(2))

9.3.1 Basis for Learning Objectives (Criterion 10.4.3(1))

Criterion 10.4.3(1) states that the applicant should derive learning objectives from the analysis describing the desired performance after training. This analysis should include, but not be limited to, the training needs identified in the licensing basis, OER, FRA/FA, TA, TIHA, HSI design, plant procedures, and V&V. Section 5.9 of the TR states that the TPDP specifies the use of a SAT and that learning objectives will develop under the design element of a SAT-based process. The NRC staff notes that a SAT is required by 10 CFR 50.120(b)(2) and represents an acceptable methodology for the development of learning objectives. The NRC staff has determined that TerraPowers plan for training addresses the development of learning objectives and, therefore, concludes that criterion 10.4.3(1) is met.

9.3.2 Adequacy of Learning Objectives (Criterion 10.4.3(2))

Criterion 10.4.3(2) states that the applicants learning objectives for personnel training should address the knowledge and skill needs and attributes of all relevant dimensions of the trainees job, such as interactions with the plant, the HSIs, and other personnel. Section 5.9 of the TR describes that the analysis stage of the SAT process determines the training needed for job positions based on assigned tasks, with the tasks being identified through TAs. Tasks that are selected for training are analyzed to determine required skills, knowledge, and abilities. The design stage of the SAT process is then used to develop learning objectives based upon these inputs. The NRC staff notes that a SAT is required by 10 CFR 50.120(b)(2) and represents an acceptable methodology for the development of learning objectives. The NRC staff has determined that TerraPowers plan for the development of learning objectives addresses relevant task needs and, therefore, concludes that criterion 10.4.3(2) is met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 9.4 Design of the Training Program (Criteria 10.4.4(1)-(2))

9.4.1 Training on Learning Objectives (Criterion 10.4.4(1))

Criterion 10.4.4(1) states that the applicant should define how learning objectives will be conveyed to the trainee. Section 5.9 of the TR describes that learning objectives are developed during the design stage of the SAT process and that a plan for training (to include methods and settings) is established. In the development stage of the SAT, lesson plans, training materials, and assessment tests are established with instructors delivering the training to trainees during the subsequent implementation stage of SAT. The NRC staff notes that a SAT is required by 10 CFR 50.120(b)(2) and represents an acceptable approach for training development. The NRC staff has determined that TerraPowers plan for training addresses how learning objectives will be conveyed to trainees and, therefore, concludes that criterion 10.4.4(1) is met.

9.4.2 Simulator Training (Criterion 10.4.4(2))

Criterion 10.4.4(2) states that the applicants training of reactor operators using nuclear power plant simulation facilities should conform to RG 1.149, Nuclear Power Plant Simulation Facilities for Use in Operator Training, License Examinations, and Applicant Experience Requirements, [31], which endorses ANSI/ANS-3.5-2009, Nuclear Power Plant Simulators for use in Operator Training and Examination, [32] as well as that the applicant should provide the details of the program for simulator training, including length of time (weeks) and a description of the simulation facility as required by 10 CFR 55.45(b) and 10 CFR 55.46, Simulation facilities. During the audit, TerraPower clarified their intention for the simulator facility to model the initial MCR design and, later, the as-built MCR. TerraPower also stated that they intend for the training simulator to comply with the requirements of 10 CFR 55.46 as they relate to plant-referenced simulators and continued assurance of simulator fidelity. The NRC staff notes that establishment of a plant-referenced simulator is not expected to occur prior to completion of the HFE design of the MCR and, since the simulator will be used to support operator licensing, further details regarding the training simulator are not required at this time. The NRC staff has determined that review of TerraPowers program for simulator-based training, including any commitments associated with either a plant-referenced or Commission-approved simulator, can be deferred until review of the OLA.

9.5 Content of the Training Program (Criteria 10.4.5(1)-(4))

9.5.1 Job Task Training (Criterion 10.4.5(1))

Criterion 10.4.5(1) states that the applicants training of factual knowledge should be taught using actual tasks so that personnel learn to apply it in the work environment. Section 5.9 of the TR describes that the analysis stage of the SAT process determines the training needed for job positions based on assigned tasks, with tasks being identified through a TA. The design stage of the SAT process is used to develop learning objectives based upon these inputs, with a plan for training (to include methods and settings) being established. In the development stage of SAT, lesson plans, training materials, and assessment tests are established, with instructors subsequently delivering the training to trainees during the implementation stage. The NRC staff has determined that TerraPowers plan for training uses actual job tasks as a basis and, therefore, concludes that criterion 10.4.5(1) is met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 9.5.2 Training Environment (Criterion 10.4.5(2))

Criterion 10.4.5(2) states that the applicants training of skills should be structured so that the environment is consistent with the level of skill being taught. Section 5.9 of the TR describes that tasks that are selected for training are analyzed to determine required skills, knowledge, and abilities. The design stage of the SAT process is then used to develop learning objectives based upon these inputs and a plan for training that includes settings is established. The NRC staff has determined that TerraPowers plan for training addresses the selection of environments and, therefore, concludes that criterion 10.4.5(2) is met.

9.5.3 Decision-making (Criterion 10.4.5(3))

Criterion 10.4.5(3) states that the applicants training should address rules for decision-making for plant systems, HSIs, and procedures. More specifically, this criterion considers whether applicant training includes rules for accessing and interpreting information, as well as for interpreting the symptoms of failures of systems, HSIs, and procedures. The NRC staff notes that this type of information is typically found within conduct of operations procedural guidance which would be anticipated to be available in conjunction with an OLA. The NRC staff has determined that review of this criterion can reasonably be deferred until the review of an OLA.

9.5.4 Degraded Conditions Training (Criterion 10.4.5(4))

Criterion 10.4.5(4) states that the applicants training for performance under degraded conditions should support personnel performance.

Section 5.2 of the TR describes that a defense-in-depth methodology is included within the FRA process which establishes functions with sufficient independence (including any needed control and instrumentation diversity) to assure adequate safety should failures or degradations occur.

Additionally, section 5.2 of the TR states that certain defense line functions are specified as manual HAs, with the appropriateness of those manual HAs being confirmed by means of the AOF process. Section 5.6 of the TR states that the TA identifies task requirements to accomplish those functions that are allocated to humans (including any partial allocations made to humans). Section 5.9 of the TR describes that the analysis stage of the SAT process determines the training needed for job positions based on assigned tasks, with tasks being identified through TA. Tasks that are selected for training are analyzed to determine required skills, knowledge, and abilities. In the implementation stage of SAT, instructors deliver the training to trainees and the trainees are tested to determine if they have mastered objectives.

The NRC staff has determined that TerraPowers plan for implementation of a SAT-based training approach should reasonably address the performance of identified tasks that may occur under degraded conditions and, therefore, concludes that criterion 10.4.5(4) is met.

9.6 Evaluation and Modification of Training (Criteria 10.4.6(1)-(3))

9.6.1 Evaluation of Training Effectiveness (Criterion 10.4.6(1))

Criterion 10.4.6(1) states that the applicant should define the methods and criteria of evaluation and assessment. Section 5.9 of the TR describes the implementation and evaluation stages of the SAT process. As part of the implementation stage, trainees are described as being tested to determine if they have mastered objectives, with the results of the testing being examined during the evaluation stage. The evaluation stage is, in turn, described as utilizing the review of

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION training results, training feedback, and continual monitoring of work performance to examine training effectiveness. The NRC staff has determined that TerraPowers plan for training addresses the evaluation of training effectiveness and, therefore, concludes that criterion 10.4.6(1) is met.

9.6.2 Accuracy and Completeness of Training Material (Criterion 10.4.6(2))

Criterion 10.4.6(2) states that the applicant should define the methods for verifying the accuracy and completeness of the training course materials. Section 5.9 of the TR describes that lesson plans and instructional materials are created in the development stage of the SAT process, with the training package subsequently being reviewed, piloted on trainees, and revised if necessary.

The NRC staff has determined that TerraPowers plan for training addresses the accuracy and completeness of training materials and, therefore, concludes that criterion 10.4.6(2) is met.

9.6.3 Updates and Modification to Training (Criterion 10.4.6(3))

Criterion 10.4.6(3) states that the applicant should establish procedures for refining and updating the content and conduct of training, including procedures for tracking modifications in the training courses.

Section 5.9 of the TR describes that the analysis stage of the SAT process determines the training needed for job positions, with the design stage then being used to develop a plan for training. The subsequent development stage of SAT establishes lesson plans, training materials, and assessment tests. The NRC staff notes that the SAT methodology represents an acceptable training approach, and that the SAT process is, by design, responsive to changes in training needs that may occur over time. During the audit, TerraPower confirmed their intention to obtain accreditation of their training program through INPO; the NRC staff notes that accreditation via INPOs NANT represents an acceptable method of meeting certain requirements associated with SAT-based training programs. The NRC staff has determined that TerraPowers plan for training addresses the development of training materials in a manner that should reasonably enable training updates and modifications by means of a SAT-based process and, therefore, concludes that criterion 10.4.6(3) is met.

9.7 Periodic Retraining (Criteria 10.4.7(1)-(2))

9.7.1 Provisions for Retraining (Criterion 10.4.7(1))

Criterion 10.4.7(1) states that the applicants program should contain provisions to periodically retrain personnel. Section 5.9 of the TR states that the analysis stage of the SAT-based training process determines the training needed for specific job positions based upon assigned tasks, with factors including the difficulty, importance, and frequency of those tasks being used to inform decisions regarding periodic retraining. However, the NRC staff notes that complete information regarding the retraining of personnel, as required by the associated requirements of 10 CFR Part 50 and 10 CFR Part 55, is expected to be developed in conjunction with an OLA10.

The NRC staff has determined that TerraPowers plan for training considers personnel retraining needs, and that further staff review can be deferred until an OLA.

9.7.2 Evaluation of Changes (Criterion 10.4.7(2))

10 DANU-ISG-2022-05 includes licensed operator initial training, licensed operator requalification training, and non-licensed personnel training within its scope.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Criterion 10.4.7(2) states that the applicant should evaluate whether any changes in retraining are warranted following plant modernization programs. Section 5.9 of the TR describes that the analysis stage of the SAT process determines the training needed for job positions based on assigned tasks, with tasks being identified through TA. The NRC staff notes that a SAT is required by 10 CFR 50.120(b)(2) and represents an acceptable training approach, and that the SAT process is, by design, responsive to changes in training needs that may occur over time.

During the audit, TerraPower confirmed their intention to obtain accreditation of their training program through INPO which, the NRC staff notes, represents an acceptable method of meeting certain requirements associated with SAT-based training programs. The NRC staff has determined that TerraPowers plan for training addresses the development of training materials in a manner that should, by means of a SAT-based process, reasonably address retraining needs associated with future plant modifications and, furthermore, that additional staff review can be deferred until the review of an OLA.

9.8 Overall Conclusion for the Training Program Development Element The NRC staff concludes that, subject to the limitations and conditions contained in this evaluation, TerraPowers plan for training program development, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff in conjunction with a future OLA.

10.0 HUMAN FACTORS VERIFICATION AND VALIDATION The Verification and Validation (V&V evaluations determine whether an HFE design conforms to design principles and enables personnel to successfully and safely perform their tasks. This HFE element is comprised of HSI TSV, HFE design verification (DV), ISV, and HEDs resolution.

The NRC staffs objective in the review of this element is to verify the adequacy of the overall V&V approach. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 11.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in sections 10.1 through 10.4. It should be noted that, per NUREG-0711, an associated RSR is expected for this element, however, RSRs are not included as part of this HFEPP and will need to be submitted and reviewed as part of an OLA.

10.1 Sampling of Operational Conditions (Criteria 11.4.1.1 - 11.4.1.4) 10.1.1 Sampling Dimensions (Criteria 11.4.1.1(1)-(3))

10.1.1.1 Plant dimensions (Criterion 11.4.1.1(1))

Criterion 11.4.1.1(1) states that the plant conditions should include the following: normal operational events; I&C and HSI failures and degraded conditions; and transients and accidents.

Section 5.10 of the TR presents an overview of the HFE V&V plan, with appendix D of the TR describing the plan in greater detail. Section 5.10 of the TR discusses that an operational condition sampling approach is used to ensure that representative range of operating conditions is included in the scenarios used for ISV. Section D.1.2 of the TR describes that the scope of the V&V process includes hardware and software-based HSIs that are used for, in part, normal, abnormal, and emergency operations. Section D.4.2 of the TR discusses the minimum sample

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION conditions which serve to ensure that an essential set of operations conditions are included within the V&V scope. ((

)) The NRC staff has determined that TerraPowers plan for V&V addresses the sampling of an adequate range of plant dimensions and, therefore, concludes that criterion 11.4.1.1(1) is met.

10.1.1.2 Types of Personnel Tasks (Criterion 11.4.1.1(2))

Criterion 11.4.1.1(2) states that the types of personnel tasks should include important HAs, important systems, and dominant accident sequences, manual initiation of protective actions, automatic system monitoring, OER-identified problematic tasks, the range of procedure guided tasks, the range of knowledge-based tasks, the range of human cognitive activities, and the range of human interactions.

Section D.4 of the TR describes the process of sampling operational conditions. Section D.4.1, Task Analysis Graded Approach Output Information, of the TR states that the sampling strategy starts from the graded approach which incorporates risk insights during the TA and HSI design processes. Section D.4.2 of the TR establishes ((

)) Section D.4.3 of the TR discusses

((

)) Additionally, section D.4.3 of the TR also describes the sampling of tasks that include a range of human cognitive abilities (e.g., monitoring, diagnosing, decision-making, manipulations, and monitoring), communications, and human interactions.

The NRC staff has determined that TerraPowers plan for V&V addresses an appropriate scope and range of types of personnel tasks and, therefore, concludes that criterion 11.4.1.1(2) is met.

10.1.1.3 Situational Factors (Criterion 11.4.1.1(3))

Criterion 11.4.1.1(3) states that the situational factors or error-forcing contexts should include high-workload situations, varying-workload situations, fatigue situations, and environmental factors. Section D.4.2 of the TR establishes ((

)) Additionally, section D.4.3 of the TR describes representative sampling conditions that include situational factors of operationally difficult tasks identified via the OER, scenarios designed to generate human errors, varying crew sizes, both high and low workloads, varying workloads, circadian factors, and environmental factors (e.g., high noise, poor lighting, etc.). The NRC staff has determined that TerraPowers plan for V&V addresses

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION appropriate situational factors and error-forcing contexts and, therefore, concludes that criterion 11.4.1.1(3) is met.

10.1.2 Identification of Scenarios (Criteria 11.4.1.2(1)-(2))

10.1.2.1 Combination of Sampled Results (Criterion 11.4.1.2(1))

Criterion 11.4.1.2(1) states that the applicant should combine the results of the sampling to identify a set of V&V scenarios to guide subsequent analyses.

Section D.4.2 of the TR establishes ((

)) Section D.4.4, Sample Selection, of the TR states that scenarios are selected from a representative population sample set which, together, will fulfill the minimum conditions. Section D.4.4 further describes ((

))

The NRC staff has determined that TerraPowers plan for V&V addresses the combining the results from sampling to identify a set of V&V scenarios and, therefore, concludes that criterion 11.4.1.2(1) is met.

10.1.2.2 Avoidance of Bias (Criterion 11.4.1.2(2))

Criterion 11.4.1.2(2) states that the applicant should not bias the scenarios by overly representing scenarios for which only positive outcomes are expected, scenarios that are relatively easy to conduct, or scenarios that are familiar and well-structured.

Section D.2.1, Human Factors Engineering Verification and Validation Team Roles, of the TR states that, to ensure V&V activities are free from bias, the HF engineers that conduct V&V activities must be different from those involved in the design process. Section D.6.4, Human Factors Engineering Validation Scenario Set Identification and Development, of the TR describes that ISV scenarios are developed using a structured process to ensure the minimization of bias. A provided example of these measures is coordination with operations training to avoid schedule overlap between given training topics and HFE ISV testing scenarios with related content. Section D.6.4.3 of the TR discusses that the sequence of events selected for scenarios incorporates realistic conditions to limit potential operator bias due to anticipated scenario progression. Additionally, section D.6.4.4, Qualitative and Quantitative Scenario Attributes, of the TR states ((

))

Section D.6.4.8, Measures Taken to Eliminate or Control Scenario Development Bias, of the TR provides a description of measures that test personnel use to avoid sample bias during scenario development. These measures include, in part, procedural controls for scenario development and validation processes, use of a representative range of conditions during

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION scenarios, evaluation of scenario attributes and their distribution, and pilot studies. Furthermore, section D.6.4.9, Scenario Set Review and Approval, discusses that scenario sets undergo a post-development review to identify biases, with the review specifically looking for 1) scenarios for which only positive outcomes are expected, 2) scenarios that are administratively easy to conduct, or 3) scenarios that are familiar and well structured.

Based on the above, the NRC staff has determined that TerraPowers plan for V&V addresses measures to avoid bias in scenarios and, therefore, concludes that criterion 11.4.1.2(2) is met.

10.1.3 Scenario Definition (Criteria 11.4.1.3(1)-(3))

10.1.3.1 Identification of Operational Conditions (Criterion 11.4.1.3(1))

Criterion 11.4.1.3(1) states that the applicant should identify operational conditions and scenarios to be used for HSI TSV, DV, and ISV. Section D.4 of the TR describes the process of sampling operational conditions for V&V activities. Section D.5.4.1, Task Support Verification Acceptance Criteria, of the TR describes that the TSV process incorporates verification criteria that are identified during TA and provides the criteria against which HSIs are verified. Section D.5.5, Human Factors Engineering Design Verification, of the TR describes that the DV process evaluates the HSI design against the HFE DRD to verify that the design complies with HFE design principles. Section D.6.4 of the TR describes that the scenarios used to exercise the selected operational conditions during ISV are governed by procedures which include requirements for the documentation of, in part, scenario objectives, initial conditions, events, and attributes. The NRC staff has determined that TerraPowers plan for V&V will identify the operational conditions and scenarios to be used during V&V activities and, therefore, concludes that criterion 11.4.1.3(1) is met.

10.1.3.2 Replication of Operator Tasks (Criterion 11.4.1.3(2))

Criterion 11.4.1.3(2) states that the applicants scenarios should realistically replicate operator tasks in the tests; then, the findings from the test can be generalized to the plants actual operations.

Section 5.10 of the TR describes ISV as an integrated and dynamic activity with simulated scenarios that represent a realistic and generalizable set of conditions. The process of sampling operational conditions for V&V activities is described in section D.4 of the TR, which incorporates an objective for HFE V&V results to be generalizable by means of ensuring that samples are broad and diverse in nature. Section D.6.4.2, Initial Conditions, of the TR describes the use of scenario initial conditions that establish realism and section D.6.4.3 of the TR emphasizes the use of realistic events in ISV scenarios as a means of avoiding scenario predictability, recognizability, and potential bias. Additionally, section D.6.4.4 of the TR establishes attributes for scenarios, which include both realistic plant response and simulator modeling as qualitative attributes. Furthermore, section D.6.5, Scenario Detailed Definition and Documentation, of the TR describes ((

)) The NRC staff has determined that TerraPowers plan for V&V addresses the realistic replication of operator tasks within scenarios and, therefore, concludes that criterion 11.4.1.3(2) is met.

10.1.3.3 Environmental Effects on Performance (Criterion 11.4.1.3(3))

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Criterion 11.4.1.3(3) states that when the applicants scenarios include work associated with operations remote from the MCR, the effects on personnel performance due to potentially harsh environments should be realistically simulated.

Section D.1.2 of the TR states that the HFE V&V process applies to both the NI RSC and local controls, including local field HSIs that support operations, protection systems, and plant safety.

Section D.6.3.1.3 discusses that ISV scenarios model local tasks that are important to risk or safety, with scenario event guides incorporating factors associated with local operations to guide the performance of simulations. Additionally, risk-significant local control operations are described as being validated using simulations and mock-ups. Section D.6.5.12 discusses

((

)) The NRC staff has determined that TerraPowers plan for V&V addresses realism in simulations to account for the effects of environmental conditions in the field and, therefore, concludes that criterion 11.4.1.3(3) is met.

10.2 Design Verification (Criteria 11.4.2.1 - 11.4.2.3) 10.2.1 HSI Inventory and Characterization (Criteria 11.4.2.1(1)-(3))

10.2.1.1 Scope (Criterion 11.4.2.1(1))

Criterion 11.4.2.1(1) states that the applicant should develop an inventory of all HSIs that personnel require to complete the tasks covered in the validation scenarios that were identified by the applicants sampling of operational conditions.

Section D.4 of the TR describes the process of sampling operational conditions for V&V activities. Section D.5, Human Factors Engineering Verification, of the TR states that HFE verification activities confirm that the design fulfills the task requirements from the TA (verified during TSV) and complies with design requirements from the HFE DRD (verified during DV).

Section D.5.1, Human Factors Engineering Verification Inputs, of the TR discusses that the inputs for HFE verification activities include an HSI inventory, along with the tasks associated with each HSI. Section D.5.5 of the TR describes that the DV process evaluates the HSI design against the HFE DRD to verify that the design complies with HFE design principles. Specifically, DV is described as focusing on, in part, static and dynamic HSI features, workstations, interface management features, and degraded HSI conditions. Section D.5.5.2 of the TR describes that the designed HSIs, as defined in the HSI inventory, are verified against the HFE DRD.

The NRC staff has determined that TerraPowers plan for V&V addresses the development of an appropriate inventory of the required HSIs and, therefore, concludes that criterion 11.4.2.1(1) is met.

10.2.1.2 HSI Characterization (Criterion 11.4.2.1(2))

Criterion 11.4.2.1(2) states that the applicants inventory should describe the characteristics of each HSI within the scope of the verification.

Section D.5.1 of the TR discusses that the inputs for HFE verification activities include an HSI inventory that contains the HSIs and a characterization that describes the HSIs. The HSI inventory is derived from the user interface specification for each plant system, while the characterization includes a unique identification code, plant system, associated tasks, and type

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION of HSI (e.g., hardware, software, alarm, computerized procedure, etc.). Section D.5.5.1, Human Factors Engineering Design Verification Acceptance Criteria, of the TR describes that the HFE DRD contains the applicable criteria for HSI design, as well as that the acceptance criteria used within DV include verification that HSI characteristics meet design requirements. Additionally, section D.5.5.2 of the TR states that designed HSIs and their characteristics (as defined in the HSI inventory and characterization) are verified against the HFE DRD. The NRC staff has determined that TerraPowers plan for V&V addresses the development of an HSI inventory and, therefore, criterion 11.4.2.1(2) is met.

10.2.1.3 Inventory Verification (Criterion 11.4.2.1(3))

Criterion 11.4.2.1(3) states that the applicant should verify the inventory description of HSIs to ensure that it accurately reflects their current state. The NRC staff considered several aspects of the HFEPP to determine whether the V&V plan has a process for verifying the accuracy of the HSI inventory. First, section D.5.1 of the TR describes that the HSI inventory is derived from each plant system user interface specification. Second, section D.1.1 of the TR discusses that the HFE V&V process incorporates an iterative cycle between V&V activities and HSI design processes. Section D.5.1 of the TR further states that HEDs identified during HFE verification activities (which are used to track issues for resolution) are entered into HFEITS. Third, section D.5.3 of the TR describes tools used for HFE verification, which include the use of high-fidelity, part-task, and full-scope simulators to verify that HSI designs correctly represent system and plant status, as well as control response.

The NRC staff notes that these processes, considered as an integrated process, would be expected to accomplish the verification of HSI inventory accuracy to the current state. The NRC staff has determined that TerraPowers plan for V&V addresses verification of HSI inventory accuracy and, therefore, concludes that criterion 11.4.2.1(3) is met.

10.2.2 HSI Task Support Verification (Criteria 11.4.2.2(1)-(4))

10.2.2.1 Task Support Verification Criteria (Criterion 11.4.2.2(1))

Criterion 11.4.2.2(1) states that the applicant should base the HSI task support criteria on the alarms, controls, displays, and task support needed by personnel to complete their tasks as identified by the applicants TA. Section D.5.1 of the TR states that the inputs for HFE verification activities include a task support inventory which is developed from the TA. This task support inventory is broadly described as containing the alarms, controls, and indications necessary for the support of tasks. Section D.5.4.1 of the TR provides the acceptance criteria that are used within the TSV process in comparing HSI elements (i.e., alarms, controls, and indications) that were identified by the TA to those included in the final design. The NRC staff has determined that TerraPowers plan for V&V addresses HSI task support criteria that are based on the TA and, therefore, concludes that criterion 11.4.2.2(1) is met.

10.2.2.2 Task Support Verification General Methodology (Criterion 11.4.2.2(2))

Criterion 11.4.2.2(2) states that the applicant should compare the HSIs and their characteristics (as defined in the HSI inventory and characterization) to the needs of personnel identified in the TA for the defined sampling of operational conditions (as noted in section 11.4.1, Sampling of Operational Conditions, of NUREG-0711). Section D.4 of the TR describes the process of sampling operational conditions for V&V activities. Section D.5.4.1 describes that the TSV

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION process incorporates verification criteria that are identified during TA and provides the criteria against which HSIs are verified. These criteria include the acceptance criteria that are used within the TSV process in comparing HSI elements (i.e., alarms, controls, and indications) that were identified by the TA to those included in the final design. The NRC staff has determined that TerraPowers plan for V&V addresses the comparison of the HSIs inventory and characteristics to the needs of personnel and, therefore, concludes that criterion 11.4.2.2(2) is met.

10.2.2.3 Task Support Verification HED Identification (Criterion 11.4.2.2(3)) and Documentation (Criterion 11.4.2.2(4))

Criterion 11.4.2.2(3) states that the applicant should identify and document an HED when an HSI needed for task performance is unavailable, HSI characteristics do not match the requirements of personnel, or when HSIs are available but are not needed for any task.

Criterion 11.4.2.2(4) states that the applicant should document HEDs to identify the HSI, the tasks affected, and the basis for the deficiency (i.e., what aspect of the HSI was identified as not meeting task requirements). Section D.5.4.3 of the TR describes that the outputs of the TSV process include HEDs that document both deficiencies and unnecessary components that were identified. Specifically, it states that HEDs are entered into the HFEITS to document unsupported (or partially supported) tasks, HSI characteristics that are inconsistent with task requirements, unnecessary HSI components, and instances of identified discrepancies or deficiencies in TA outputs. The NRC staff has determined that TerraPowers plan for V&V addresses the identification and documentation of HEDs for issues identified during TSV and, therefore, concludes that criterion 11.4.2.2(3) is met.

10.2.3 HFE Design Verification (Criteria 11.4.2.3(1)-(4))

10.2.3.1 DV Criteria (Criterion 11.4.2.3(1))

Criterion 11.4.2.3(1) states that the applicant should base the criteria used for HFE DV on HFE guidelines. Section 5.7.4 of the TR describes that the HFE DRD includes, in part, requirements for information displays, user interfaces, controls, alarms, safety parameter monitoring, computer-based procedures, workstations, and labeling. Section 5.7.4 of the TR states that the HFE DRD is being developed to comply with codes, standards, and HFE best practices (e.g.,

NUREG-0700). Section D.5.5 of the TR describes that the DV process evaluates the HSI design against the HFE DRD to verify that the design complies with HFE design principles. Section 5.5.1 of the TR states the that the HFE DRD contains the acceptance criteria used in the DV of the HSI design. The NRC staff has determined that TerraPowers plan for V&V addresses the use of HFE guidelines within DV and, therefore, concludes that criterion 11.4.2.3(1) is met.

10.2.3.2 DV General Methodology (Criterion 11.4.2.3(2))

Criterion 11.4.2.3(2) states that the applicants HFE DV methodology should include procedures for comparing the characteristics of the HSIs with HFE guidelines, procedures for determining whether the HSI is "acceptable" or "discrepant," for each guideline and procedures for evaluating whether an HED is a potential indicator of additional issues. Section D.5.5.2 of the TR discusses DV evaluation methods. The general approach is described as consisting of verifying designed HSIs and their characteristics against the HFE DRD, with individual HSI features being compared to the associated design requirements of the HFE DRD. For each HSI element that is evaluated, documentation includes the HFE DRD requirements that were

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION applied, as well as whether the HSI element passed or failed each requirement. Where HEDs are identified, the HFE verifier describes the non-compliance to capture the specific deficiency or issue. Section 5.5.3 of the TR further states that HEDs involving standardized features are assessed to determine whether discrepancies across similar HSIs may exist. The NRC staff has determined that TerraPowers plan for V&V addresses evaluation of HSIs against HFE guidelines and, therefore, concludes that criterion 11.4.2.3(2) is met.

10.2.3.3 DV HED identification (Criterion 11.4.2.3(3)) and Documentation (Criterion 11.4.2.3(4))

Criterion 11.4.2.3(3) states that the applicant should identify an HED when a characteristic of the HSI is "discrepant" from a guideline. Criterion 11.4.2.3(4) states that the applicant should document HEDs in terms of the HSI involved and how its characteristics depart from a particular guideline. Section 8.1 of the TR describes that HEDs are placed into HFEITS when a deviation from a human factors DRD requirement is discovered during DV. Section D.5.5.2 of the TR discusses the DV of designed HSIs and their characteristics against the HFE DRD. For each HSI element that is evaluated during DV, documentation includes the HFE DRD requirements that were applied, as well as whether the HSI element passed or failed each requirement.

Where HEDs are identified, the HFE verifier describes the non-compliance to capture the specific deficiency or issue. The NRC staff has determined that TerraPowers plan for V&V addresses the identification of HEDs related to HSI discrepancies and the appropriate documentation of HEDs identified during DV and, therefore, concludes that criterion 11.4.2.3(3) is met.

10.3 Integrated System Validation (Criteria 11.4.3.1 - 11.4.3.8) 10.3.1 Validation Team (Criterion 11.4.3.1(1))

Criterion 11.4.3.1(1) states that the applicant should describe how the team performing the validation has independence from the personnel responsible for the actual design. Section D.2.1 of the TR states that the HF engineers performing HFE V&V activities must be different engineers from the ones involved in the design process to ensure HFE V&V activities are conducted independently and free from bias. The NRC staff has determined that TerraPowers plan for V&V addresses the independence of personnel who conduct V&V activities and, therefore, concludes that criterion 11.4.3.1(1) is met.

10.3.2 Test Objectives (Criterion 11.4.3.2(1))

Criterion 11.4.3.2(1) states that the applicant should develop detailed test objectives to provide evidence that the integrated system adequately supports plant personnel in safely operating the plant. Section D.6.4 of the TR states that procedures related to the performance of ISV will include guidance for the development of scenario objectives. Section D.6.4.1 of the TR describes that these predetermined objectives will be used in evaluating the ability of operators to effectively use the HSI in responding to events during scenarios. Specifically, observations during scenarios will be used to assess, in part, the ability of operators to conduct integrated plant operations, utilize the integrated HSI, diagnose abnormal plant conditions, use appropriate procedures, and communicate effectively. Additionally, there will also be objectives related to the specific operational conditions and events contained within the scenarios. The NRC staff has determined that TerraPowers plan for V&V addresses the development of ISV test objectives and, therefore, concludes that criterion 11.4.3.2(1) is met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 10.3.3 Validation Testbeds (Criteria 11.4.3.3(1)-(9))

10.3.3.1 Interface Completeness and Fidelity (Criteria 11.4.3.3(1) - (7))

Criteria 11.4.3.3(1) - (7) state that the applicants testbed should represent the integrated system, in addition to also having interface physical fidelity, interface functional fidelity, environmental fidelity, data completeness fidelity, data content fidelity, and data dynamics fidelity. NUREG-0711, section 11.4.3.3, Validation Testbeds, provides guidance that one approach that can be used to acceptably meet these criteria is to use a testbed that complies with ANSI/ANS-3.5-2009. Section 5.10 of the TR discusses that the assessment of testbed fidelity is informed by standards, such as IEEE 2411-2021, IEEE Guide for Human Factors Engineering for the Validation of System Designs and Integrated Systems Operations at Nuclear Facilities [33]. Section D.6.3.1.2, Validation Testbed Requirements, of the TR (which also references IEEE 2411-2021) presents simulator fidelity requirements that must be met for the scope of the validation conducted. The NRC staff reviewed these simulator fidelity requirements and note that they are generally consistent with those described in Criteria 11.4.3.3(1) - (7) of NUREG-0711. The NRC staff also notes that IEEE 2411-2021 references ANSI/ANS-3.5-2009 for informing the preparation of a simulator test bed for use in validations.

The NRC staff further notes that, since establishment of a simulator that complies with ANSI/ANS-3.5-2009 would generally not be expected prior to the completion of the MCR design, the degree to which these standards are applied within the HFEPP is reasonable. As discussed previously, during the audit, TerraPower indicated that they will review their system design and ability to conform to RG 1.149, revision 4 (which endorses ANSI/ANS-3.5-2009).

TerraPower stated that they plan to engage with the NRC staff on potential exceptions to this RG (or on the possible use of newer standards) at an appropriate point in the design.

Based on the above, the NRC staff has determined that TerraPowers plan for V&V reasonably addresses interface completeness and fidelity and, therefore, concludes that criteria 11.4.3.3(1)-(7) are met.

10.3.3.8 Verification of Human Performance Requirements (Criterion 11.4.3.3(8))

Criterion 11.4.3.3(8) states that for important HAs at complex HSIs remote from the MCR (e. g.,

a remote shutdown facility), where timely, precise actions are essential, the use of a simulator or mockup should be considered to verify that the requirements for human performance can be met. Section D.1.2 of the TR describes that the HFE V&V process includes both the NI RSC and local controls within its scope. Furthermore, section D.6.3.1.3 of the TR states that risk-significant local control operations are validated using simulations and mock-ups. The NRC staff has determined that TerraPowers plan for V&V addresses the consideration of mock-ups in the verification of important, remote HAs and, therefore, concludes that criterion 11.4.3.3(8) is met.

10.3.3.9 Conformance of Testbed to Required Characteristics (Criterion 11.4.3.3(9))

Criterion 11.4.3.3(9) states that the applicant should verify the conformance of the testbed to the testbed-required characteristics before validation tests are conducted. Section D.6.3.1.3 of the TR discusses that testbeds are verified at each phase of validation testing to ensure that fidelity requirements are met. Specifically, this is accomplished by confirming that the software and computers used for development of the simulator match what is to be installed the plant, with

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION testbed verification occurring during pilot tests before validation. HSI changes are incorporated during system development such that the HSI design will be stabilized by the time the full-scope simulator is developed; this is used to ensure that the testbed will be consistent with the current design. The NRC staff has determined that TerraPowers plan for V&V addresses verification of the conformance of the testbed to required characteristics prior to validation tests and, therefore, concludes that criterion 11.4.3.3(9) is met.

10.3.4 Plant Personnel (Criteria 11.4.3.4(1)-(4))

10.3.4.1 Selection of Appropriate Personnel (Criterion 11.4.3.4(1))

Criterion 11.4.3.4(1) states that participants in the applicants validation tests should be representative of plant personnel who will interact with the HSI. Section D.6.6, Human Factors Engineering Validation Participant Selection, of the TR describes that the participants for early validation activities may be selected from among training staff, formerly licensed operators, procedure writers, and engineers (e.g., startup I&C, PRA, or HFE). During later ISV activities, the participants can subsequently include individuals enrolled in the initial licensed operator training. The NRC staff notes that this participant selection pool and approach is reasonable since operators who are licensed for the Natrium facility will not yet be available during the timeframe in which validation activities will primarily occur. The NRC staff has determined that TerraPowers plan for V&V addresses the selection of appropriate validation participants and, therefore, concludes that criterion 11.4.3.4(1) is met.

10.3.4.2 Representative Sampling of Participants (Criterion 11.4.3.4(2))

Criterion 11.4.3.4(2) states that to properly account for human variability, the applicant should use a sample of participants that reflects the characteristics of the population from which it is drawn. Section D.6.6 of the TR discusses that variables which contribute to variations in task performance are accounted for during the sampling of validation participants. Section D.6.6 of the TR further states that the population characteristics considered include operator licenses, qualifications, shift staffing, skills, experience, and minimum operations staffing. Additionally, it states that a minimum of three crews will be tested during full-scope simulator HSI testing. The NRC staff has determined that TerraPowers plan for V&V addresses validation participant sampling that reflects population characteristics and, therefore, concludes that criterion 11.4.3.4(2) is met.

10.3.4.3 Consideration of Staffing Levels (Criterion 11.4.3.4(3))

Criterion 11.4.3.4(3) states that in selecting personnel for participating in the tests, the applicant should consider the minimum shift staffing levels, nominal levels, and maximum levels, including shift supervisors, ROs, shift technical advisors, etc. Section D.6.6 of the TR describes that the participants for early validation activities may include formerly licensed operators and that later ISV activities can subsequently include individuals enrolled in the initial licensed operator training. It also states that that the population characteristics considered for validation include operator licenses, qualifications, shift staffing, and minimum operations staffing. Additionally, it states that a minimum of three crews will be tested during full-scope simulator HSI testing, with at least two SROs and two ROs in each crew.

As previously noted in this evaluation, section 5.4 of the TR describes a staffing analysis process that systematically determines the minimum staff complement. Appendix C of the TR

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION describes the HFE staffing analysis plan. Section C.5.3 of the TR discusses the validation of nominal shift levels, minimal shift levels, and shift turnover. ((

)) During the audit, TerraPower clarified that TerraPower will seek an exemption via the OLA for the omission of the STA role. The NRC staff has determined that TerraPowers plan for V&V addresses variations in staffing levels and that the review of the justification for omission of the STA role can be deferred until the review of the OLA.

10.3.4.4 Avoidance of Bias (Criterion 11.4.3.4(4))

Criterion 11.4.3.4(4) states that the applicant should prevent bias in the sample of participants by avoiding the use of participants who are members of the design organization, who participated in prior evaluations, or who were selected for some specific characteristic. Section D.6.6.2, Prevention of Participant Sampling Bias, of the TR states that participants are selected from a representative population using a randomized sampling methodology. Section D.6.6.2 of the TR describes that sampling bias is avoided in participant selection by excluding design organization personnel, individuals who participated in prior design evaluations, or participants selected for some specific characteristic. The NRC staff has determined that TerraPowers plan for V&V addresses the avoidance of bias in participant sampling and, therefore, concludes that criterion 11.4.3.4(4) is met.

10.3.5 Performance Measurement (Criteria 11.4.3.5.1 - 11.4.3.5.2) 10.3.5.1 Types of Performance Measures (Criteria 11.4.3.5.1(1)-(6))

10.3.5.1.1 Identification of Performance Measures (Criterion 11.4.3.5.1(1))

Criterion 11.4.3.5.1(1) states that the applicant should identify the specific plant performance measures applicable to each ISV scenario.

Section D.6.7 of the TR describes the performance measures used in ISV. ((

)) Two types of performance measures are stated to be used within ISV. ((

)) The second type are supplemental measures which provide validation information and support design refinement and enhancement. These supplemental measures include crew communication, crew coordination, situation awareness, physical workload, cognitive workload, ergonomics and physiological factors. The NRC staff has determined that TerraPowers plan for V&V addresses ISV scenario performance measures and, therefore, concludes that criterion 11.4.3.5.1(1) is met.

10.3.5.1.2 Identification of Primary Task Measures (Criterion 11.4.3.5.1(2))

Criterion 11.4.3.5.1(2) states that the applicant should identify the primary task measures applicable to each ISV scenario.

Section D.6.7 of the TR describes the performance measures used in ISV. Two types of performance measures are stated to be used within ISV, specifically decisive measures and

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION supplemental measures. ((

))

Specifically, section D.6.7.1 of the TR states ((

)) Section D.6.7.2, Plant-Safety Analysis and Probabilistic Risk Assessment, of the TR states ((

)) Lastly, section D.6.7.3, Personnel Tasks, of the TR states ((

))

The NRC staff has determined that TerraPowers plan for V&V addresses the identification of primary task measures for ISV scenarios and, therefore, concludes that criterion 11.4.3.5.1(2) is met.

10.3.5.1.3 Identification of Secondary Task Measures (Criterion 11.4.3.5.1(3))

Criterion 11.4.3.5.1(3) states that the applicant should identify the secondary task measures applicable to each scenario. Section D.6.7 of the TR describes the performance measures used in ISV, which include supplemental measures. Supplemental measures are described as providing validation information and support design refinement and enhancement. These supplemental measures include crew communication, crew coordination, situation awareness, physical workload, cognitive workload, ergonomics and physiological factors.

Section D.6.7.4, Crew Communication and Coordination, of the TR states ((

)) Section D.6.7.5, Situation Awareness, of the TR states ((

. )) Section D.6.7.6, Workload, of the TR states

((

)) Lastly, section D.6.7.7, Ergonomic and Physiological Factors, of the TR states that control room ergonomics are evaluated against anthropometric guidelines during HSI development and HFE DV, with significant ergonomic issues also being entered as HEDs in the HFEITS. The NRC staff has determined that TerraPowers plan for V&V addresses the identification of secondary task measures for ISV scenarios and, therefore, concludes that criterion 11.4.3.5.1(3) is met.

10.3.5.1.4 Situational Awareness Measures (Criterion 11.4.3.5.1(4))

Criterion 11.4.3.5.1(4) states that the applicant should identify the measures of situation awareness applicable to each scenario. Section D.6.7.5 of the TR discusses how situational awareness is assessed during V&V activities. It is described that operators perceptions about situations, as they compare to reality, are tested in conjunction with scenarios as a means of assessing situation awareness. During early validation testing, section D.6.7.5 of the TR states

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION that the situation awareness global assessment technique (SAGAT) is applied, in which simulations are periodically frozen, system displays are blanked out, and operators are questioned regarding their situational understanding.

Section D.6.7.5 of the TR further states that the SAGAT is only used during early validation testing and is also used along with the situation awareness rating technique (SART). SART is not used in isolation and assessment of situation awareness is augmented with behavior observations and performance measures. Furthermore, additional supplemental information is obtained using participant eye-movement tracking. Section D.6.7.5 of the TR states that the basis for this methodology is that the use of mixed performance measures during early validation testing helps to establish concurrent validity of the SART and the supplemental performance measures as a means of assessing situation awareness relative to the SAGAT while assessment using mixed methods together enables the data analyst to more closely approximate the actual level of participant awareness and make an assessment regarding overall adequacy.

However, during subsequent ISV scenarios, section D.6.7.5 of the TR states that the simulation is not frozen and questions to measure situation awareness are instead administered following the completion of a scenario. The questions used are described as covering three different levels of situation awareness, specifically perception of data, comprehension of meaning, and projection of the future. D.6.7.5 of the TR further discusses that the assessment of situation awareness during ISV is also supplemented through observations, recordings of participant task performance, participant debriefing, and participant self-reflection of performance outcomes.

Determinations regarding the acceptability of performance is determined by assessing the level of situation awareness in terms of both perception of data, comprehension of meaning, and projection of the future, with HEDs being entered into the HFEITS as warranted.

Based on the above, the NRC staff has determined that TerraPowers plan for V&V identifies the measures of situation awareness that will be applied during scenarios and, therefore, concludes that criterion 11.4.3.5.1(4) is met.

10.3.5.1.5 Workload Measures (Criterion 11.4.3.5.1(5))

Criterion 11.4.3.5.1(5) states that the applicant should identify the workload measures obtained for each scenario.

Section D.6.7.6 of the TR describes the methods that are used to assess both physical and cognitive workload during V&V. Test personnel use video recordings and observations to evaluate the effects of physical workload on performance, as well as to identify conditions involving forceful exertions, awkward postures, repetitiveness, vibration, or pressure points.

Physical workload measures that exceed criteria (which are stated to be derived from both State of Washington Department of Labor and Industries and National Institute for Occupational Safety and Health guidelines) are documented as HEDs in the HFEITS. Section D.6.7.6 of the TR further discusses that workload is assessed as part of a cumulative evaluation process that occurs across the design lifecycle (versus only being assessed during the ISV). This is described as including assessment of workload by subject matter experts during both the AOF and TA, using platforms and mock-ups during HSI testing, using layout evaluation and procedure step-though during task support validation, and, lastly, through the confirmatory workload assessment of the ISV.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Section D.6.7.6 of the TR states that cognitive workload is measured during ISV by the NASA-TLX. The tasks and event sequences that make up these ISV scenarios include workload conditions with high error potential, operator burdens, or time pressures. The NASA-TLX approach consists of a subjective measurement of workload that uses post-scenario participant questionaries to assess six dimensions of mental workload-related factors (i.e., mental demand, physical demand, temporal demand, performance, effort, and frustration). Weighting factors are the applied to develop an overall measure of cognitive workload. ((

))

Section D.6.7.6.2, Cognitive Workload, of the TR describes that cognitive workload is assessed in an integrated manner to offset the subjective nature of self-report data and allow HFE analysts to triangulate cognitive workload using a combination of mixed methods, providing a more comprehensive assessment of cognitive workload. These methods are described as including assessing cognitive workload in relation to situation awareness, supplementing the assessment of cognitive workload through observations of performance (e.g., reaction times, number of errors, and task completion times), and using eye-movement tracking to provide insights into cognitive load.

Based on the above, the NRC staff has determined that TerraPowers plan for V&V identifies the workload measures that will be utilized during scenarios and, therefore, concludes that criterion 11.4.3.5.1(5) is met.

10.3.5.1.6 Anthropometric and Physiological Measures (Criterion 11.4.3.5.1(6))

Criterion 11.4.3.5.1(6) states that the applicant should identify the anthropometric and physiological measures obtained for each scenario.

Section D.6.7.7 of the TR states that MCR ergonomics are evaluated against the anthropometric data of the HSI style guide during HFE DV, with both system-specific and integrated validation testing being utilized to confirm the adequacy of the HSI ergonomic design during simulation. A set of physical measurement (e.g., stature, seat height, eye height, span, hand length, etc.) are taken for the ISV testing participants, which are used in conjunction with observations and self-reporting to identify ergonomic issues. Evaluation of anthropometric and ergonomic data is described as occurring using ergonomic guidelines, expert judgement, and the HFE DRD. Ergonomic design issues related to MCR layout and HSIs that result in procedures not being correctly accomplished within time constraints result in ISV failures.

Additionally, any identified risks to operator safety result in HEDs being entered into the HFEITS. The NRC staff has determined that TerraPowers plan for V&V addresses the identification of the anthropometric and physiological measures to be obtained during ISV and, therefore, concludes that criterion 11.4.3.5.1(6) is met.

10.3.5.2 Performance Measure Information and Validation Criteria (Criteria 11.4.3.5.2(1)-(5))

Criteria 11.4.3.5.2(1) - (5) state that the applicant should describe (1) the methods by which performance measures are obtained, (2) when each measure is obtained (recorded), (3) the characteristics of the performance measures, (4) the specific criterion for each measure used to judge the acceptability of performance and describe its basis, and (5) whether each measure is a pass/fail one or a diagnostic one.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Section D.6.7 of the TR describes the HFE validation performance measures that are used to assess the adequacy of the integrated system, which include the following: core thermal-hydraulic condition, safety analysis and probabilistic risk assessment, personnel tasks, crew communication and coordination, situation awareness, workload, and ergonomic and physiological factors. The methods by which the performance measures are obtained vary according to the measure involved and include, in part, observations, simulator data, tests, and questionnaires. The description provided for these measures includes when they are obtained, such as before, during, or after ISV scenarios. Additionally, relevant characteristics of these performance measures (e.g., construct validity, sensitivity, and objectivity) are addressed by the descriptions provided within this section of the HFEPP. For performance measures, the specific criteria used to assess acceptability, as well their underlying bases (e.g., performance requirements or expert judgement), are generally addressed. Lastly, two distinct types of performance measures are stated as being used within ISV, specifically decisive measures (i.e.,

pass/fail measures) and supplemental measures (i.e., those providing validation information and supporting design refinement and enhancement). The NRC staff has determined that TerraPowers plan for V&V addresses appropriate performance measure information and, therefore, concludes that criteria 11.4.3.5.2(1) - (5) are met.

10.3.6 Test Design (Criteria 11.4.3.6.1 - 11.4.3.6.5) 10.3.6.1 Scenario Sequencing (Criteria 11.4.3.6.1(1)-(2))

10.3.6.1.1 Balance of Scenario Range (Criterion 11.4.3.6.1(1))

Criterion 11.4.3.6.1(1) states that the applicant should balance scenarios across crews to provide each crew with a similar, representative range of scenarios. Section D.6.8, Test Design, of the TR states that the ISV test design process addresses the avoidance of bias in scenario assignments and test personnel qualifications. Section D.6.8.1, Scenario Assignment, of the TR discusses ((

)) The NRC staff has determined that TerraPowers plan for V&V addresses the balancing of scenarios across crews and, therefore, concludes that criterion 11.4.3.6.1(1) is met.

10.3.6.1.2 Balance of Scenario Order (Criteria 11.4.3.6.1(2))

Criterion 11.4.3.6.1(2) states that the applicant should balance the order of presentation of scenarios to crews to provide reasonable assurance that the scenarios are not always presented in the same sequence. Section D.6.8.2, Scenario Sequencing, of the TR discusses

((

)) The NRC staff has determined that TerraPowers plan for V&V addresses the balanced ordering of scenario presentation and, therefore, concludes that criterion 11.4.3.6.1(2) is met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 10.3.6.2 Test Procedures (Criteria 11.4.3.6.2(1)-(2))

10.3.6.2.1 Use of Procedures (Criterion 11.4.3.6.2(1))

Criterion 11.4.3.6.2(1) states that the applicant should use detailed, unambiguous procedures to govern the conduct of the tests. These procedures should include identifying which scenarios that crews receive, the order that scenarios should be presented in, directions for the personnel conducting tests, guidance for addressing testing difficulties, data collection instructions, and documentation procedures. Section D.6.8 of the TR describes, ((

)) The NRC staff notes that the processes described by the HFEPP for these areas should reasonably lead to adequate procedures when they are fully developed prior to ISV implementation. The NRC staff has determined that TerraPowers plan for V&V addresses processes and procedures to govern the conduct of the tests and, therefore, concludes that criterion 11.4.3.6.2(1) is met.

10.3.6.2.2 Avoidance of Bias (Criterion 11.4.3.6.2(2))

Criterion 11.4.3.6.2(2) states that the applicants test procedures should minimize the opportunity for bias in the test personnels expectations and in the participants responses.

Section D.6.8.2 of the TR states ((

)) Section D.6.8.3, Test Steps, of the TR describes

((

)) Additionally, section D.6.10.3, Controlling for Bias, of the TR discusses ((

)) The NRC staff has determined that TerraPowers plan for V&V addresses measures to minimize the opportunity for bias and, therefore, concludes that criterion 11.4.3.6.2(2) is met.

10.3.6.3 Test Personnel Training (Criterion 11.4.3.6.3(1))

Criterion 11.4.3.6.3(1) states that the applicant should train test personnel (those who conduct or administer the validation tests) on the use and importance of test procedures, bias and errors that test personnel may introduce into the data through failures to either follow test procedures accurately or interact with participants properly, and the importance of accurately documenting problems arising during testing (even if they were due to an oversight or error by those conducting the test). Section D.6.8.9 of the TR states that prior to the beginning of ISV, test personnel will complete training that is comparable to that of simulator instructors/evaluators.

The scope of this training is described as including, in part, the usage and importance of test procedures, the potential errors and biases that can be introduced by not properly interacting

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION with test participants or adhering to procedures, and the importance of documenting testing problems irrespective of whether test personnel themselves caused them. The NRC staff has determined that TerraPowers plan for V&V appropriately addresses the training of test personnel and, therefore, concludes that criterion 11.4.3.6.3(1) is met.

10.3.6.4 Participant Training (Criteria 11.4.3.6.4(1)-(2))

10.3.6.4.1 Training of Participants (Criterion 11.4.3.6.4(1))

Criterion 11.4.3.6.4(1) states that the applicants training of participants should be very similar to the training plant personnel receive.

Section D.6.8.10, Test Participants Training and Requisites, of the TR states that comprehensive knowledge of the systems included in the ISV testing is attained by means of a combination of classroom and simulator training. ISV test participants that were previously licensed at a nuclear power plants will complete Natrium-specific systems training, procedure training and simulator training. Additionally, training on generic fundamentals is provided for test participants who lack previous nuclear power plant OE. This training program is described as culminating with both a comprehensive examination and systems job performance measures using the simulator. Test participants are administered a comprehensive operating test using a full-scope simulator prior to participating in full-scope simulator V&V testing. The NRC staff notes that the scope, format, content, and assessment methods described for the training of ISV participants generally parallel those that would be expected for licensed operators. The NRC staff has determined that TerraPowers plan for V&V addresses the training of ISV participants to a similar degree as that which would be expected for plant personnel and, therefore, concludes that criterion 11.4.3.6.4(1) is met.

10.3.6.4.2 Representative participant performance (Criterion 11.4.3.6.4(2))

Criterion 11.4.3.6.4(2) states that to assure that the participants performance is representative of plant personnel, the applicants training of participants should result in near asymptotic performance (i.e., stable, not significantly changing from trial to trial) and should be tested for such before conducting the validation. Section D.6.8.10 of the TR states that ISV test participants will have been trained sufficiently for them to demonstrate acceptably stable performance across trials. Additionally, it further states that ISV test participants are administered a comprehensive operating test using a full-scope simulator prior to participating in full-scope simulator V&V testing. The NRC staff has determined that TerraPowers plan for V&V addresses the establishment of stable test participant performance and, therefore, concludes that criterion 11.4.3.6.4(2) is met.

10.3.6.5 Pilot Testing (Criteria 11.4.3.6.5(1)-(2))

10.3.6.5.1 Conduct of Pilot Study (Criterion 11.4.3.6.5(1))

Criterion 11.4.3.6.5(1) states that the applicant should conduct a pilot study before the validation tests begin to offer an opportunity for the applicant to assess the adequacy of the test design, performance measures, and data collection methods. Section D.6.9, Pilot Testing, of the TR states that a pilot study is to be conducted before V&V occurs in the simulator, including the running of the future ISV scenarios in advance of the actual ISV testing. Section D.6.9 of the TR states that the pilot study tests the processes used to evaluate design adequacy, determines

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION appropriate data collection techniques, and verifies completeness and fidelity of the testbed.

((

)) The NRC staff has determined that TerraPowers plan for V&V addresses the conduct of a pilot study in advance of validation and, therefore, concludes that criterion 11.4.3.6.5(1) is met.

10.3.6.5.2 Selection of Pilot Participants (Criterion 11.4.3.6.5(2))

Criterion 11.4.3.6.5(2) states that the applicant should not use participants in the pilot testing who will then be participants in the validation tests. Section D.6.9 of the TR states that personnel who fill the roles of crew members during pilot testing will not be later utilized as test participants during the ISV. Participants in the pilot testing are instead described as subsequently filling roles as test personnel during ISV (which is distinct from serving as participants) due to their familiarity with the tests that will be performed. The NRC staff has determined that TerraPowers plan for V&V addresses the selection of appropriate participants for pilot testing and, therefore, concludes that criterion 11.4.3.6.5(2) is met.

10.3.7 Data Analysis and HED Identification (Criteria 11.4.3.7(1)-(7))

10.3.7.1 Use of Quantitative and Qualitative Methods (Criterion 11.4.3.7(1)) and Method of Data Analysis (Criterion 11.4.3.7(2))

Criterion 11.4.3.7(1) states that the applicant should use a combination of quantitative and qualitative methods to analyze data. Criterion 11.4.3.7(2) states that the applicant should discuss the method by which data is analyzed across trials, and include the criteria used to determine successful performance for a given scenario.

Section D.6.10, Data Analysis, of the TR describes that data analysis is structured around a four-tier hierarchical set of performance measures, with the analyses depending on the type of associated data. ((

)) Furthermore, section D.6.10 of the TR states that test participant observations are collected to facilitate qualitative assessments factors such as lighting and noise levels.

The NRC staff notes that the combination of data analyses presented in section D.6.10 encompasses both quantitative analysis (e.g., assessment of whether core thermal limits were met or whether tasks were completed within required times) as well as qualitative analysis (e.g.,

communications and noise-related issues). The NRC staff has determined TerraPowers plan for V&V addresses the use of an appropriate combination of methods to analyze data, as well as how data is analyzed to determine successful scenario performance and, therefore, concludes that criteria 11.4.3.7(1) - (2) are met.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 10.3.7.2 Degree of Convergence Between Measures (Criterion 11.4.3.7(3))

Criterion 11.4.3.7(3) states that the applicant should evaluate the degree of convergence between related measures (i.e., consistency between measures expected to assess the same aspect of performance). Section D.6.10.2, Establishing Convergent Validity, of the TR discusses that convergent validity is determined during data analysis by comparing data across performance measures that are intended to measure similar performance aspects. ((

)) Section D.6.10.2 of the TR also states that HEDs will be entered into the HFEITS to document any instances where performance measures that intended to measure the same thing lack correlation. The NRC staff has determined that TerraPowers plan for V&V addresses convergence between related measures and, therefore, concludes that criterion 11.4.3.7(3) is met.

10.3.7.3 Interpretation of Test Results (Criterion 11.4.3.7(4))

Criterion 11.4.3.7(4) states that when interpreting test results, the applicant should allow a margin of error to reflect the fact that actual performance may be slightly more variable than observed validation-test performance. Section D.6.10 of the TR describes that test personnel will consider that actual performance can be more variable than observed validation test performance and will account for this when drawing inferences and making generalizations between observed test performance and estimated real-world performance. The NRC staff has determined that TerraPowers plan for V&V addresses the potential for actual performance to be more variable than test performance and, therefore, concludes that criterion 11.4.3.7(4) is met.

10.3.7.4 Correctness of Data Analysis (Criterion 11.4.3.7(5))

Criterion 11.4.3.7(5) states that the applicant should verify the correctness of the analyses of the data and also that this verification should be done by individuals or groups other than those who performed the original analysis. Section D.6.10.1, Data Verification, of the TR states that Data analysis and the conclusions drawn are independently verified. The NRC staff has determined that TerraPowers plan for V&V addresses the independent verification of analyses and, therefore, concludes that criterion 11.4.3.7(5) is met.

10.3.7.5 Identification of HEDs (Criterion 11.4.3.7(6))

Criterion 11.4.3.7(6) states that the applicant should identify HEDs when the observed performance does not meet the performance criteria. Multiple subsections within section D.6 of the TR discuss the documentation of HEDs during ISV, with deficiencies and discrepancies that are identified during V&V activities being entered into the HFEITS as HEDs. Examples of the various instances in which the HFEPP addresses the identification of HEDs during ISV include, in part, the following:

occurrences of significant sampling bias; tasks resulting in failures of a crew to meet acceptance criteria; performance concerns identified in supplemental measurement areas; physical workload occurrences that exceed criteria; instances where two performance measures that are intended to measure the same thing lack correlation; determinations that an ISV test must be completed using the plant instead;

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION

((

))

HSI ergonomics that represent a risk to operator safety or well-being; or performance on a performance measure which only passes the related acceptance criteria by a small margin.

The NRC staff has determined that TerraPowers plan for V&V addresses the identification of HEDs during ISV and, therefore, concludes that criterion 11.4.3.7(6) is met.

10.3.7.6 Resolution of HEDs (Criterion 11.4.3.7(7))

Criterion 11.4.3.7(7) states that the applicant should resolve HEDs identified bypass/fail measures before the design is accepted. Section D.6.7 of the TR discusses the performance measures used in ISV, which include decisive measures. ((

)) Section D.6.10 of the TR states that, [F]or performance measures used as pass/fail indicators, failed indicators are resolved before the design is validated. The NRC staff has determined that TerraPowers plan for V&V addresses the resolution of those HEDs identified bypass/fail measures prior to design acceptance and, therefore, concludes that criterion 11.4.3.7(7) is met.

10.3.8 Validation Conclusions (Criteria 11.4.3.8(1)-(2))

10.3.8.1 Documentation of Bases for Acceptability (Criterion 11.4.3.8(1))

Criterion 11.4.3.8(1) states that the applicant should document the statistical and logical bases for determining that performance of the integrated system is, and will be, acceptable. Section D.6.11 of the TR states that the bases for acceptable performance and conclusions developed from validation will be documented. Section D.8 discusses that the results from ISV are documented afterwards in a results report. The NRC staff has determined that TerraPowers plan for V&V addresses documentation of the bases for ISV acceptability and, therefore, concludes that criterion 11.4.3.8(1) is met.

10.3.8.2 Documentation of Limitations (Criterion 11.4.3.8(2))

Criterion 11.4.3.8(2) states that the applicant should document the limitations in the validation tests, their possible effects on the conclusions of the validation, and their impact on implementing the design. Section D.6.11, Human Factors Validation Outputs, of the TR states that validation testing limitations, as well as how these limitations might affect validation conclusions or design implementation, will be documented. Several examples of these potential issues are discussed, including testing aspects that were not well controlled, differences between testing and actual operating situations, and differences between the design that was validated and the actual as-built design. The NRC staff has determined that TerraPowers plan for V&V addresses the potential effects of validation testing limitations and, therefore, concludes that criterion 11.4.3.8(2) is met.

10.4 Human Engineering Discrepancy Resolution (Criteria 11.4.4(1)-(5))

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Criteria 11.4.4(1) - (5) state that the applicant should (1) include an adequate scope within the HED analyses (i.e., personnel tasks and functions, plant systems, cumulative effects of HEDs, and HEDs as indications of broader issues), (2) conduct an evaluation to identify which HEDs to correct, (3) identify design solutions to correct HEDs, (4) evaluate design solutions to demonstrate the resolution of that HED and ensure that new HEDs are not introduced, and (5) document each HED (including the basis for not correcting an HED, related personnel tasks and functions, related plant systems, cumulative effects of HEDs, and HEDs as indications of broader issues).

Section 5.10 of the TR states that V&V plan includes the identification, documentation, prioritization, analysis, and resolution of HEDs. Section 8 of the TR describes the overall processes associated with the identification and resolution of HEDs. HEDs are documented and tracked for dispositioning in the HFEITS. Section 5.6 of the TR states ((

)) Section 8.1 of the TR also describes that HEDs are documented, in part, when deviations from HF DRD requirements are identified or when an HSI does not meet information and control requirements that were established by the TA.

Section 8.3, Human Engineering Discrepancy Cumulative Effects Analysis, of the TR discusses the analysis of the cumulative effects of HEDs, which includes grouping HEDs such that their combined effects and interactions are understood. Section D.6, Human Factors Engineering Validation, of the TR discusses ((

)) Section 8.2 of the TR describes the prioritization of HEDs according to a three-leveled approach with priority 1 representing highest priority (i.e., involving safety consequences), priority 2 representing high priority (i.e., involving plant or personnel performance effects), and Priority 3 representing low priority (i.e., enhancements). Section 8.4 of the TR describes the process for determining the adequacy of a revised design, the processes and HFE methods by which HEDs will be retested as part of their resolution, as well as the process by which HEDs may, with an acceptable basis, be justified and closed. The NRC staff has determined that TerraPowers plan for V&V addresses HED analysis, selection of HEDs to correct, development and evaluation of design solutions, and the documentation of HED evaluations. Therefore, the NRC staff concludes that criteria 11.4.4(1) - (5) are met.

10.5 Overall Conclusion for the V&V Element The NRC staff concludes that TerraPowers plan for V&V, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff when a future V&V RSR has been provided.

11.0 DESIGN IMPLEMENTATION The NRC staffs objective in the review of this element is to verify the adequacy of the applicants processes for ensuring that the as-built design will conform to the verified and validated design that resulted from the HFE design process. The NRC staff evaluated the HFEPP using the relevant review criteria in NUREG-0711, section 12.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in section 11.1. It should be noted that, per NUREG-0711, an associated RSR is expected for this element, however, RSRs are

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION not included as part of this HFEPP and will need to be submitted and reviewed as part of an OLA.

11.1 Final Verification of the HFE Design NUREG-0711 provides four criteria for the design implementation element (i.e.,

criteria 12.4.1(1-4)) which address whether (1) an applicant evaluates aspects of the design that were not addressed in V&V by an appropriate V&V method, (2) compares the final HSIs, procedures, and training with the detailed description of the design to verify that they conform to the planned design resulting from the HFE design process and V&V activities, (3) verifies that all HFE-related issues in the issue tracking system are adequately addressed, and (4) provides a description of how the HFE program addressed each important HA.

Section 5.11, Design Implementation, of the TR presents a high-level list of activities to be conducted during design implementation and states that the detailed methodology will be developed in a HF design implementation methodology plan. The NRC staff notes that the described activities include the following:

Verification of aspects of the design not previously evaluated in the V&V process. It is stated that the scope of this verification includes hardware, software, and new/modified displays that were not included in the simulator-based ISV. Additionally, it is described that physical and environmental differences between those aspects present during V&V activities and those reflected in the as-built facility (such as, for example, lighting and noise considerations) will be verified as well.

Verification that the as-built HSIs, procedures, and training are consistent with those resulting from HFE design and V&V activities. Additionally, it is stated that any deviations from the design and their HFE effects will be evaluated as part of the design implementation process.

Verification of the resolution of open items from HFEITS, as well as remaining HEDs.

((

))

Based on the above, the NRC staff has determined that TerraPowers plan for design implementation addresses 1) aspects of the as-built design that were not addressed during V&V activities, 2) verifying that HSIs, procedures, and training conform to the planned design, 3) the resolution of HFE-related issues in the issue tracking system, and 4) the HFE treatment on important HAs. Therefore, the NRC staff concludes that criteria 12.4.1(1) - (4) are met.

11.2 Overall Conclusion for the Design Implementation Element The NRC staff concludes that TerraPowers plan for design implementation, as described by the TR, is generally consistent with the relevant criteria of NUREG-0711. The associated results of this plans implementation can be reviewed by the NRC staff when a future design implementation RSR has been provided.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 12.0 HUMAN PERFORMANCE MONITORING The NRC staffs objective in the review of this element is to verify that the applicant has prepared a human performance monitoring strategy for ensuring that no significant safety degradation occurs because of any changes that are made in the plant and to verify that the conclusions that have been drawn from the human performance evaluation remain valid over the life of the plant. The NRC staff evaluated the TR using the relevant review criteria in NUREG-0711, section 13.4, Review Criteria, and the results of the NRC staffs evaluation are discussed below in section 12.1. It should be noted that, per NUREG-0711, there is no associated RSR expected for this element.

12.1 Program Scope, Development, Structure, Use of Approximations, and Corrective Actions (Criteria 13.4(1) - (5))

Criterion 13.4(1) states that the scope of the applicants performance monitoring program should provide reasonable assurance that personnel can use the design effectively, changes do not adversely affect human performance, important HAs can be accomplished within the criteria for time and performance, and that an acceptable level of performance is maintained. Criterion 13.4(2) states that the applicant should develop and document a human performance monitoring program which should be able to 1) trend human performance after the plant is operational, or after modifications were made to demonstrate that performance is consistent with that assumed in the various analyses that were conducted to justify the change and 2) begin at initial loading of the plants fuel. Criterion 13.4(3) states that the applicant should structure the program such that the level of monitoring for human actions is commensurate with their safety importance, feedback of information and corrective actions are accomplished in a timely manner, and degradations in performance can be detected and corrected before they compromise plant safety. Criterion 13.4(4) states that the applicant should use approximations of performance data when the performance of the plant or personnel under actual design basis conditions may not be readily measurable. Finally, criterion 13.4(5) states that the applicant should include, within the program, provisions for determining the specific cause of performance degradation and failures, undertaking corrective actions, and trending them.

Section 5.12, Human Performance Monitoring, of the TR states that human performance monitoring will be performed by the operating entity throughout the operational phase of the plant and that metrics of human performance will be tracked to ensure that the acceptable level of performance achieved by the integrated HFE design during HFE V&V is maintained. A human performance monitoring plan is described as detailing the process for detecting performance degradations and providing HF solutions. During the audit, TerraPower clarified that the aspects of the human performance monitoring element that are covered by this criterion are outside of the scope of the TR and that a future report will be provided in conjunction with OLA that addresses these items.

The NRC staff concludes that review of TerraPowers plan for human performance monitoring can be deferred until review of an OLA. This represents an incomplete aspect of the NUREG-0711 review methodology that is addressed in the Limitations and Conditions section of this evaluation.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION LIMITATIONS AND CONDITIONS The NRC staff identified the following limitations and conditions, applicable to any licensee or applicant referencing this TR:

1. Applicants or licensees referencing this TR must make the RSRs associated with the following HFE elements available to support staff review of an OLA:

a. Operating experience review

b. Functional requirements analysis and function allocation

c. Task analysis

d. Staffing and qualifications

e. Treatment of important human actions

f.

Human-system interface design

g. Verification and validation

h. Design implementation

2. Applicants or licensees referencing this TR must provide a schedule of HFE tasks, consistent with criteria 2.4.3(4) and 2.4.5(2) of NUREG-0711, to facilitate staff reviews of HFE submittals associated with applications for facility licensing. Additionally, the status of HFE activities will need to be provided, consistent with criterion 2.4.5(1).

3. To address the Staffing and Qualification element of NUREG-0711 section 6, operating license (OL) applicants referencing this TR must provide sufficient information to meet the relevant criteria in NUREG-0800, chapters 13.1.1 and 13.1.2 - 13.1.3, consistent with the guidance and related criteria of DANU-ISG-2022-05.

4. Applicants or licensees referencing this TR must either address STA staffing or provide an adequate justification to the NRC staff to support the omission of the STA from the staffing model, as well as any associated exemption request(s).

5. To address NUREG-0711, sections 8.4.4.3 and 8.4.4.4, OL applicants referencing this TR must provide information sufficient to demonstrate how the relevant criteria of these sections will be met by the emergency facilities that are included in the emergency plan.

6. To address the Procedure Development element of NUREG-0711, section 9, OL applicants referencing this TR must provide information sufficient to meet the relevant criteria NUREG-0800, sections 13.5.1.1, and 13.5.2.1 consistent with the guidance and related criteria of DANU-ISG-2022-05.

7. To address the Training Program Development element of NUREG-0711, section 10, OL applicants referencing this TR must provide information sufficient to meet the guidance and related criteria DANU-ISG-2022-05 for licensed operator initial training, licensed operator requalification training, and non-licensed plant staff training (including the specific categories of personnel to be trained under the SAT-based training programs).

8. Applicants or licensees referencing this TR must provide a plan for human performance monitoring that is adequate to meet the criteria of NUREG-0711, section 13.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION

9. Applicants or licensees referencing this TR outside the context of a Licensing Modernization Project (LMP) based approach must describe how the TR remains applicable outside of an LMP-based context and, as appropriate, supplement the TR as needed.

10. Applicants or licensees referencing this TR without also incorporating NATD-LIC-RPRT-0001-A, Revision 0 Regulatory Management of Natrium Nuclear Island and Energy Island Design Interfaces, (ML24011A321) must describe how this TR remains applicable in light of any differences and, as appropriate, supplement this TR as needed.

CONCLUSION The NRC staff has determined that, subject to the limitations and conditions contained in this evaluation, the HFEPP described within the TR presents an overall methodology that is generally consistent with a state-of-the-art approach to HFE, as described by NUREG-0711.

The HFEPP presents plans associated with the various elements of the Natrium HFE program.

The NRC staff concludes that these plans are adequate to address the related HFE elements and should reasonably lead to the development of a design that incorporates appropriate HFE principles. However, as the HFEPP only represents the IPs for these HFE elements, the NRC staff further has determined that a making subsequent finding on the overall HFE acceptability of a design produced via implementation of the HFEPP will require future staff review of both the information contained in the RSRs from implementation of the relevant elements of the HFEPP, as well as of the associated OLA.

ACRONYMS AOF allocation of function AOP abnormal operating procedures COO concept of operations D3 diversity and defense-in-depth DRD design requirements document DV design verification EI energy island EOF emergency operations facility EOP emergency operating procedures FRA functional requirement analysis FA function allocation GTG generic technical guidelines HA human action HEDs human engineering discrepancies HEFITS human factors engineering issue tracking system HF human factors HFE human factors engineering HFEPP human factors engineering project plan HSI human-system interface HRA human reliability analysis I&C instrumentation and control IEC International Electrotechnical Commission IHAs important human actions IP implementation plan

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION IEEE Institute of Electrical and Electronics Engineers ISV integrated system validation JPM job performance measure LCS local control station MCR main control room NASA-TLX National Aeronautics and Space Administration-Task Load Index NI nuclear island OE operating experience OER operating experience review OL operating license OLA operating license application PDP procedure development plan PRA probabilistic risk analysis RSC remote shutdown complex RSR results summary report SAGAT situational awareness global assessment technique SART situational awareness rating technique SAT systems approach to training SPDS safety parameter display system SRO senior reactor operator SSC structure, system, and components STA shift technical advisor position TA task analysis TIHA treatment of important human actions TMI Three Mile Island TR topical report TSC technical support center TPDP training program development plan TSV task support verification V&V verification and validation REFERENCES

[1]

R. Sprengel, letter to U.S. Nuclear Regulatory Commission, TerraPower Human Factors Engineering Program Plan and Methodologies Topical Report, dated April 26, 2023 (ML23116A226).

[2]

M. Sutton, email to G. Wilson, TerraPower: Human Factors Engineering Program Plan and Methodologies, Topical Report Completeness Determination, dated June 21, 2023 (ML23167A692).

[3]

U.S. Nuclear Regulatory Commission, NRC 898 - Topical Report Completeness Determination for TerraPower, LLC Topical Report 'HFE Program and Methodologies' TP-LIC-LET-0069, dated June 20, 2023 (ML23167A483).

[4]

TerraPower Human Factors Engineering Program Plan and Methodologies Topical Report, Revision 1, dated September 17, 2024 (ML24261B925).

[5]

U.S. Nuclear Regulatory Commission, Regulatory Audit Summary Report TerraPower, LLC Topical Report Natrium Human Factors Engineering Program Plan and Methodologies, dated November 15, 2024 (ML24271A169).

[6]

Institute of Electrical and Electronics Engineers, IEEE 1023-2020, IEEE Recommended Practice for the Application of Human Factors Engineering to Systems, Equipment, and Facilities of Nuclear Power Generating Stations and Other Nuclear Facilities, 2020.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION

[7]

U.S. Nuclear Regulatory Commission, NUREG-0711, Human Factors Engineering Program Review Model, revision 3, dated November 30, 2012 (ML12324A013).

[8]

U.S. Nuclear Regulatory Commission, NUREG-0700, Human-System Interface Design Review Guidelines, revision 3, dated July 31, 2020 (ML20162A214).

[9]

U.S. Nuclear Regulatory Commission, NUREG-1764, Guidance for the Review of Changes to Human Actions, revision 1, dated September 30, 2007 (ML072640413).

[10]

Electric Power Research Institute, EPRI 3002004310, Human Factors Guidance for Control Room and Digital Human-System Interface Design and Modification, 2015.

[11]

TerraPower, LLC, Kemmerer Power Station Unit 1 Preliminary Safety Analysis Report, revision 0, dated March 28, 2024 (ML24088A065)

[12]

U.S. Nuclear Regulatory Commission, DANU-ISG-2022-05, Advanced Reactor Content of Application Project chapter 11, Organization and Human-System Considerations Interim Staff Guidance, dated March 31, 2024 (ML23277A143).

[13]

U.S. Nuclear Regulatory Commission, Final Safety Evaluation of Topical Report NATD-LICRPRT-0001, Regulatory Management of Natrium Nuclear Island and Energy Island Design Interfaces, dated October 4, 2023 (ML23257A258).

[14]

U.S. Nuclear Regulatory Commission, Regulatory Guide 1.8, Qualification and Training of Personnel for Nuclear Power Plants, revision 4, June 30, 2019 (ML19101A395).

[15]

American Nuclear Society, ANSI/ANS-3.1-2014, Selection, Qualification, and Training of Personnel for Nuclear Power Plants, 2014.

[16]

NEDO-11209-A, GE Hitachi Nuclear Energy Quality Assurance Program Description, revision 17, dated December 14, 2021 (ML21348A339).

[17]

R. Sprengel, letter to U.S. Nuclear Regulatory Commission, Submittal of Approved TerraPower, LLC Quality Assurance Topical Report [TP-QA-PD-0001, TerraPower QA Program Description], dated August 1, 2023 (ML23213A199).

[18]

U.S. Nuclear Regulatory Commission, NUREG/CR-6400, Human Factors Engineering (HFE) Insights for Advanced Reactors Based Upon Operating Experience, dated January 31, 1997 (ML063480112).

[19]

US SFR Owner, LLC, Kemmerer Power Station Unit 1 Preliminary Safety Analysis Report, revision 0, dated March 28, 2024 (ML24088A065).

[20]

U.S. Nuclear Regulatory Commission, NUREG-0800, section 13.1.1, Management and Technical Support Organization, revision 6, dated August 31, 2016 (ML15005A449).

[21]

U.S. Nuclear Regulatory Commission, NUREG-0800, section 13.1.2-13.1.3, Operating Organization, revision 7, dated August 11, 2016 (ML15007A296).

[22]

Institute of Electrical and Electronics Engineers, IEEE 1786-2022, IEEE Guide for Human Factors Applications of Computerized Operating Procedure Systems (COPS) at Nuclear Power Generating Stations and Other Nuclear Facilities, 2022.

[23]

U.S. Nuclear Regulatory Commission, NUREG-0696, Functional Criteria for Emergency Response Facilities, dated February 28, 1981 (ML051390358).

[24]

U.S. Nuclear Regulatory Commission, NUREG-0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition Conduct of Operations, (chapter 13).

[25]

U.S. Nuclear Regulatory Commission, NUREG-0800, section 13.5.1.1, Administrative Procedures - General, revision 2, dated August 11, 2016 (ML15006A205).

[26]

U.S. Nuclear Regulatory Commission, NUREG-0800, section 13.5.2.1, Operating and Emergency Operating Procedures, revision 2, dated March 27, 2007 (ML070100635).

[27]

American Society of Mechanical Engineers, NQA-1-2015, Quality Assurance Requirements for Nuclear Facility Applications, 2015.

[28]

American Nuclear Society, ANSI/ANS-3.2-2012, Managerial, Administrative, and Quality Assurance Controls for the Operational Phase of Nuclear Power Plants, 2012.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION

[29]

U.S. Nuclear Regulatory Commission, NUREG-0800, section 13.2.1, Reactor Operator Requalification Program; Reactor Operator Training, revision 4, dated August 11, 2016 (ML15006A035).

[30]

U.S. Nuclear Regulatory Commission, NUREG-0800, section 13.2.2, Non-Licensed Plant Staff Training, revision 4, dated August 11, 2016 (ML15006A129).

[31]

U.S. Nuclear Regulatory Commission, Regulatory Guide 1.149, Nuclear Power Plant Simulation Facilities for Use in Operator Training, License Examinations, and Applicant Experience Requirements, revision 4, dated April 30, 2011 (ML110420119).

[32]

American Nuclear Society, ANSI/ANS-3.5-2009, Nuclear Power Plant Simulators for use in Operator Training and Examination, 2009.

[33]

Institute of Electrical and Electronics Engineers, IEEE 2411-2021, IEEE Guide for Human Factors Engineering for the Validation of System Designs and Integrated Systems Operations at Nuclear Facilities, 2021.

PRINCIPAL CONTRIBUTORS J. Seymour, NRR/DRO/IOLB J. Xing, RES/DRA/HFRB PROJECT MANAGERS R. Brusselmans, NRR/DANU/UAL1 S. Devlin-Gill, NRR/DANU/UAL1