Senior/Staff Nuclear Safety Analysis Engineer

About the company

Antares is a nuclear power startup developing small modular reactors (SMRs) using TRISO fuel for deployment at U.S. military bases.

About this role

About Us At Antares, our long-term mission is to make clean energy abundant from Earth to the Asteroid Belt. We’re fueled by the belief that advanced nuclear energy can strengthen our military, solve the climate crisis, elevate global living standards, and expand humanity's presence in outer space. To achieve our mission, we’re building mass-producible, inherently safe, deployable microreactors that can be used terrestrially, underwater, and in space. The Antares team hails from SpaceX, the White House, the Pentagon, the Department of Energy, MIT, Rigetti Computing, General Atomics, Relativity Space, Ursa Major, and National Laboratories like Idaho, Oak Ridge, Los Alamos, and Savannah River. Antares has raised over $600M in venture capital from top-tier investors and has hundreds of million-dollars on contract with the military services, NASA, and the Department of Energy. About the Role   Antares Industries is seeking a Senior or Staff Nuclear Safety Analysis Engineer to take ownership of the safety analysis product delivered in support of the final design of the Mark 1 reactor. This individual will lead intact-event (non-breach) safety analysis, drive source term calculations rooted in TRISO fuel behavior and qualification, and translate reactor physics and neutronics uncertainty into radiological dose results. The role requires the judgment to scope phenomenological work appropriately—rigorous enough to defensibly bound figures of merit, without being exhaustive—and the independence to coordinate across every design discipline, the licensing team, and the testing and materials organizations. This is a technical ownership role: the successful candidate will be accountable for the quality, defensibility, and timeliness of safety analysis deliverables that directly support licensing of Mark 1 and inform the technical basis for follow-on designs.   Roles and Responsibilities   - Take end-to-end technical ownership of the safety analysis deliverables supporting final design of the Mark 1 reactor scope, technical approach, schedule, and quality. - Perform and oversee deterministic safety analysis of intact (non-breach) events. Apply Phenomena Identification and Ranking Table (PIRT) methods and other systematic scoping approaches to focus analysis on dominant phenomena, ensuring figures of merit are adequately and defensibly bounded without exhaustive, low-value modeling. - Develop source term calculations that account for TRISO fuel behavior and qualification, including mechanistic failure of fuel layers (e.g., buffer/IPyC/SiC/OPyC) under irradiation and elevated temperature, fission product release and transport, radionuclide grouping, and identification of dominant dose drivers. - Understand and quantify how neutronics model uncertainties (power distribution, burnup/depletion, isotopics, cross-section data) propagate through fuel performance and source term models into final dose calculations. - Work independently across all design disciplines (core, fuel, mechanical, materials, I&C, plant systems) to define analysis inputs and design-basis requirements, and interface directly with the licensing team to shape license application content, respond to regulator requests for additional information (RAIs), and support licensing evidence documentation development. - Identify where test and qualification data (fuel performance, materials, thermal-hydraulic phenomena) is sparse, uncertain, or absent, and partner with the testing and materials teams to define a credible success path for closing those gaps for Mark 1 and beyond. - Drive cross-team efforts to verify and validate (V&V) the codes, methods, and tools used in safety analysis, ensuring they are qualified under the applicable nuclear quality program for use in licensing-basis calculations. - Author and review quality-affecting technical documentation — calculation packages, methodology reports, safety analysis reports, and topical report content — to a standard suitable for regulatory submittal. - Provide technical mentorship to less experienced engineers on safety analysis phenomenology, tools, and methods, and help build organizational depth in these areas.   Basic Qualifications   - B.S. in Nuclear, Mechanical, or a related field (M.S. or Ph.D. preferred) - 4+ years of relevant reactor safety analysis experience, or an equivalent combination of education and experience. - Demonstrated hands-on experience with at least one system-level thermal-hydraulic / systems analysis code (e.g., RELAP5-3D, TRACE, SAM, GOTHIC, SAS4A/SASSYS-1, MELCOR, or equivalent), with a track record of learning new phenomenology, tools, and methods quickly. - Working knowledge of TRISO (or other advanced) fuel performance and qualification, including mechanistic failure modes of fuel coating layers under irradiation and thermal loading. - Experience developing source terms and radiological dose consequence calculations (e.g., mechanistic or alternative source term methods, radionuclide release and transport, dose driver identification). - Demonstrated ability in reactor physics / neutronics fundamentals and how model and nuclear data uncertainties propagate into downstream safety and dose calculations. - Familiarity with PIRT development or comparable phenomena-scoping methods to right-size analysis scope against schedule and risk. - Demonstrated technical writing skills, with experience producing quality-affecting calculations, methodology reports, or content supporting regulatory submittals. - Demonstrated ability to work independently, manage competing priorities, and drive alignment and delivery across multidisciplinary engineering teams without close supervision.   Preferred Skills & Experience   - Probabilistic risk assessment (PRA) and its integration with deterministic analysis to define and categorize licensing basis events (LBEs), consistent with risk-informed, performance-based methodologies (e.g.,