Help us Build What's Next in Nuclear Energy

The Mechanical Designer will support ZettaJoule’s HTGR reactor design by developing detailed 3D CAD models, assemblies, and manufacturing drawings for high-temperature nuclear components. The role combines mechanical design, GD&T, materials, thermal considerations, configuration management, and design-for-manufacturing principles while collaborating closely with engineering, analysis, and fabrication teams. The ideal candidate has 5+ years of mechanical design experience, advanced proficiency in SolidWorks or similar 3D CAD software, experience with industrial or energy equipment, and familiarity with PDM/PLM and controlled engineering environments. Experience with nuclear, high-temperature/high-pressure systems, ASME standards, or advanced CAD workflows is highly valued.

The Mechanical Engineer – High-Temperature Stress Analysis will lead structural analysis and ASME Code qualification of metallic components for ZettaJoule’s HTGR reactor, with a focus on high-temperature behavior, creep, creep-fatigue, ratcheting, and nonlinear FEA. The role works closely with design, materials, thermal-hydraulics, systems, and licensing teams to develop and document ASME Section III, Division 5 design analyses and support Section VIII pressure equipment design. The ideal candidate has 8+ years of stress analysis experience, strong expertise in elevated-temperature design and nonlinear FEA (ANSYS/Abaqus), and demonstrated experience preparing formal analyses under a nuclear quality assurance program. Experience with advanced reactors, ASME Code committees, high-temperature alloys, or Code certification is highly valued.

The Licensing Engineer will support ZettaJoule’s advanced HTGR licensing program by developing, managing, and defending regulatory submissions to the U.S. Nuclear Regulatory Commission (NRC) throughout the reactor’s licensing lifecycle. The role works closely with engineering, systems, safety, design, and quality teams to translate complex reactor designs and analyses into clear, technically defensible licensing documentation, including Safety Analysis Reports and regulatory responses. The position is suited for engineers with 4+ years of commercial nuclear, advanced reactor, national laboratory, or regulatory experience and expertise in one or more areas such as reactor safety analysis, siting/environmental, mechanical/structural systems, fuel/materials, or instrumentation and electrical systems. Strong knowledge of NRC regulations, nuclear licensing frameworks, technical writing, and regulatory engagement is essential. Experience with HTGRs/SMRs, ASME Section III Division 5, TRISO fuel, or nuclear industry standards committees is highly valued.

ZettaJoule is seeking a Systems Engineering Lead to establish and lead systems engineering practices for its reactor/plant design program. The role focuses on requirements management, system architecture, interface management, verification & validation, and configuration/change control across the full engineering lifecycle. Key responsibilities: Build and implement systems engineering processes, procedures, and best practices. Establish and manage plant-level requirements, system boundaries, architecture, and requirements flow-down. Define and manage interfaces between engineering disciplines and systems. Oversee verification/validation, technical reviews, configuration management, and change control. Select, configure, and administer requirements management/MBSE tools such as DOORS, Innoslate, Polarion, or Cameo. Maintain the technical/design baseline and support the Project Manager with technical strategy, priorities, and resources. Help ensure the overall plant design is integrated, constructable, and maintainable. Ideal candidate: BS in Engineering (Systems Engineering preferred). 6+ years of Systems Engineering experience. Experience with a modern SE lifecycle framework. Hands-on experience with requirements management or MBSE tools. Experience implementing SE processes/toolchains for energy, nuclear, or large industrial projects. Preferred extras: SysML/MBSE, INCOSE certification, startup experience, and Japanese proficiency. Important requirement: Must be a U.S. citizen or permanent resident due to applicable export-control and nuclear technology requirements. In one line: This is a senior systems engineering/process leadership role focused on building the SE infrastructure and controlling requirements, interfaces, architecture, and technical baselines for a complex reactor/energy project.

The Lead, Records Management & Document Control (RMDC) will build and oversee ZettaJoule’s document control and records management program from the ground up, supporting nuclear licensing, engineering, quality, and commercial deployment. The role will establish company-wide procedures, select and implement an EDMS/PLM system, manage engineering and regulatory documentation, and ensure records are controlled, traceable, secure, and audit-ready. The ideal candidate will have 8+ years of nuclear document control or records management experience, strong knowledge of ASME NQA-1, 10 CFR 50 Appendix B, and NRC requirements, and experience implementing document management systems in a regulated environment.

The Nuclear Fuel Performance Engineer will develop and validate models to predict TRISO fuel behavior in ZettaJoule’s High-Temperature Gas-cooled Reactor (HTGR) under normal operating and accident conditions. Key responsibilities include using BISON to model fuel coating stresses, particle failure probabilities, and fission product release; developing Python-based simulation automation; performing uncertainty and sensitivity analyses; and validating models against experimental data. The role also supports fuel qualification, safety analysis, NRC licensing documentation, and collaboration with fuel suppliers and national laboratories. Ideal candidate: A nuclear, materials, or mechanical engineer with hands-on TRISO fuel modeling experience in BISON, strong Python automation skills, and experience in nuclear fuel performance analysis and technical documentation. A minimum of 5 years of relevant experience with a bachelor's degree, 3 years with a master's degree, or a relevant PhD is required. Key screening priorities: Direct BISON/TRISO modeling experience, fuel failure and fission product transport analysis, Python workflow automation, and nuclear quality assurance experience.

Zetta Joule is seeking an experienced Project Scheduling Lead to develop and manage integrated project schedules supporting advanced nuclear reactor design and construction activities. This role will lead scheduling processes, maintain Primavera P6 schedules, manage the baseline, monitor critical paths, assess schedule risks, and provide reporting and insights to project leadership. The ideal candidate has 6+ years of scheduling experience, strong CPM and schedule risk analysis skills, and experience managing complex energy or industrial projects. Experience with EVM, startup environments, and PMI-SP/PMP certification is a plus. U.S. citizenship or permanent residency is required.

The Workplace Community Manager & HR Coordinator at ZettaJoule is a full-time, on-site position based in Houston, Texas, reporting to the Director of Human Resources. This role combines office management, HR administration, employee onboarding, basic IT coordination, and workplace engagement to ensure smooth daily operations and a positive employee experience within a fast-growing nuclear technology startup. Key responsibilities include managing office facilities, supplies, vendors, and visitors; maintaining employee records and HR documentation; coordinating new-hire onboarding and orientation; preparing laptops and office equipment in collaboration with IT; scheduling interviews; supporting leadership with calendars and meetings; and organizing company events and employee engagement activities. The ideal candidate will have at least four years of experience in office management, HR coordination, or administrative support, along with strong organizational, communication, multitasking, and confidentiality skills. Proficiency in Microsoft Office or Google Workspace and Slack, as well as comfort with basic technology setup, is expected. Experience with HRIS or payroll platforms, startup environments, and the energy or engineering sector is an advantage. Overall, this is a hands-on People Operations role suited to a proactive, detail-oriented, and service-minded professional who can manage multiple priorities, improve administrative processes, and help build a welcoming and efficient workplace as the company grows.