{"id":1271866,"url":"https://alion.io/job/terrapower-senior-engineer-safety-methods","title":"Senior Engineer, Safety Methods","company":{"id":10977,"name":"TerraPower","domain":"terrapower.com","url":"https://alion.io/company/terrapower","size_band":"501-1000","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Greenhouse","truth_index":{"grade":"A","score":95,"open_postings":20,"ghost_share":0,"stale_share":0,"repost_share":0,"time_to_fill_p50_days":71,"computed_at":"2026-09-28T05:45:00Z"}},"role":"Industrial Engineering","role_family":"Industrial Engineering","seniority":"senior","employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Bellevue, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":131828,"max":171206,"currency":"USD","period":"year","gross":null,"usd_annual":171206},"salary_estimate":null,"experience_years_min":3,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"MATLAB","optional":false},{"name":"Python","optional":false},{"name":"SAS","optional":false}],"status":"live","first_seen_at":"2026-05-21T20:53:12Z","employer_posted_date":"2026-09-25","last_verified_at":"2026-09-29T01:16:42Z","board_verified":true,"closed_at":null,"days_open":130,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":130},"description":"TerraPower is a nuclear technology company based in Bellevue, Washington. At its core, the company is working to raise living standards globally through a more affordable, secure, and environmentally friendly form of nuclear energy along with innovations in medical isotopes to improve human health. In 2006, TerraPower originated with Bill Gates and a group of like-minded visionaries who evaluated the fundamental challenges to raising living standards around the world. They recognized energy access was crucial to the health and economic well-being of communities and decided that the private sector needed to take action and create energy sources that would advance global energy deployment. TerraPower’s mission is to be a world leader in new nuclear technologies, while developing innovators and future leaders in the nuclear field. As a result, the company’s activities in the fields of nuclear energy and related sciences are yielding significant innovations in the safety and economics of nuclear power, hybrid energy and medical applications - all for significant human health benefits.”\nTerraPower is seeking to hire highly motivated and forward-thinking professionals who are interested in focusing on advanced nuclear reactor research and development and influencing change within the nuclear power landscape and bringing forward the critical production of medical isotopes. TerraPower is an Equal Opportunity Employer. We do not discriminate in hiring on the basis of sex, gender identity, sexual orientation, race, color, religious creed, national origin, physical or mental disability, protected Veteran status, or any other characteristic protected by federal, state, or local law. \nSenior Engineer, Safety Methods\nThe Senior Engineer, Safety Methods is part of a growing team supporting the design and licensing of the Natrium Demonstration reactor and is primarily responsible for developing methods to perform Licensing Basis Events (LBE) analyses.\nThe Senior Engineer may also contribute subject matter expertise to other projects under development by the TerraPower Sodium Fast Reactor (SFR) Program. Other engineering activities include, but are not limited to, closure model formulation, system transient codes development and maintenance, performing reactor transient analyses, code benchmark with Integral Effect Tests (IETs) or Separate Effect Tests (SETs), scaling analysis, software commercial-grade dedication, contributing to code assessment and adequacy evaluation, as well as performing verification and validation activities.\nUnder TerraPower SFR Program, the Senior Engineer receives administrative, technical, and project supervision from the Manger of Plant Thermal Hydraulics Methods.\nResponsibilities\nDevelop system-level thermal hydraulic analysis methods, including modeling strategies, numerical approaches, and closure models.\nPerform steady-state and transient system-level analyses to characterize model behavior, assess method performance, and define method fidelity requirements.\nSupport method qualification, including numerical verification, applicability envelopes, and performance characterization.\nFormulate and integrate closure models and empirical correlations (e.g., heat transfer, pressure drop, mixing, component-level physics) into existing analysis frameworks.\nIdentify modeling gaps and support method enhancement using and sensitivity studies.\nDevelop automated workflows and tools for model setup, execution, post processing, and repeatable method application.\nDocument modeling methodologies, assumptions, method applicability, and numerical performance for design processes and licensing support activities.\nWork across disciplines to ensure thermal hydraulic methods integrate effectively with plant design, safety analysis, and coupled simulation workflows.\nApply and improve TerraPower’s SQA and NQA 1 modeling practices, ensuring traceability, configuration control, and reproducibility of methods.\nKey Qualifications and Skills\nDegree in Mechanical, Nuclear, Chemical Engineering, or similar fields, with 3+ years of experience in system-level thermal hydraulic modeling and method development for nuclear or complex energy systems.\nDemonstrated experience in developing or improving analysis methods, including numerical scheme development, closure model formulation, and stability/accuracy optimization strategies.\nExperience performing system-level thermal hydraulic analyses using tools such as RELAP5 3D, GOTHIC, SAS, or equivalent, with the ability to extend or tailor modeling approaches within these frameworks.\nStrong foundation in thermal fluids and reactor system behavior, including complex thermal hydraulic phenomena relevant to advanced reactor designs.\nExperience in sensitivity analyses and model gap identification that support method development priorities.\nFamiliarity with scientific programming and workflow automation (e.g., Python, MATLAB).\nFamiliarity with NQA 1 quality assurance for modeling workflows, including documented methodologies, configuration control, and model traceability.\nStrong analytical thinking, clear technical communication, and the ability to support multiple method development efforts in parallel.\nThe successful candidate will possess a high degree of trust and integrity, communicate openly and display respect and a desire to foster teamwork\nThis position is subject to qualification requirements in accordance with ANSI/ANS 3.1. Candidates must meet the minimum education and experience criteria applicable to the role, including relevant nuclear industry experience where required. Verification of data will be part of the hiring process.\n\nJob Functions:\nJob Functions are physical actions and/or working conditions associated with the position. These functions may also constitute essential functions for the job which the employee must be able to fulfill, with or without accommodation. Information provided below is to help describe the job so that the applicant has a reasonable understanding of the job duties/expectations. An applicant's ability to perform and/or tolerate these actions and conditions will be discussed and workplace accommodations may be made on a case-by-case basis following an individualized assessment of the applicant and other considerations, including but not limited to any governing safety standards.\nMotor Abilities: Sitting for extended periods, bending/stooping, grasping/gripping, fine motor control (hands)\nPhysical exertion and/or requirements: Minimal, with ability to safely lift up to 25 pounds.\nRepetitive work: Prolonged\nSpecial Senses: Visual and audio focused work\nWork Conditions: Stairs, typing/keyboard, standard and/or sitting working environment of >8 hours/day\nTravel required 0-10%\nTerraPower’s technology is controlled for export by various agencies of the U.S. Government. TerraPower must evaluate applicants who are foreign nationals (other than asylees, refugees, or lawful permanent residents) in accordance with U.S. Government export control requirements. To facilitate TerraPower’s export control reviews, you will be asked as part of the application process to identify whether you are a U.S. Citizen or national, asylee, refugee, or lawful permanent resident of the United States. Government export authorization approval times vary. Based on the business needs for a particular position, TerraPower may not consider a foreign national from a country if it is impracticable to obtain timely Government export approval.\nJob details\nSalary Range: $131,828 - $171,206\nAny salary offered within the posted salary band is based on market data and commensurate with the selected candidate’s qualifications and experience. This range is specific to Washington State.\nJob Type: Full-time\nBenefits:\nCompetitive Compensation\nSalary, eligible to participate in discretionary short-term incentive payments\nComprehensive Medical and Wellness BenefitsMedical\nVision\nDental\nLife and Disability\nGender Affirmation Benefits\n\nParental Leave\n401k Plan\nGenerous Paid Time Off (PTO)21 days of annually accrued PTO\n\nGenerous Holiday Schedule10 paid holidays\n\nRelocation Assistance\nProfessional and Educational Support Opportunities\nTerraPower Career and Benefits information: https://www.terrapower.com/contact-us/careers/","description_format":"text","description_chars":8289,"description_truncated":false,"requirements":{"experience_years_min":3,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["401k plan","Parental leave","Relocation assistance"],"hiring_locations":[{"name":"United States","iso":"US","kind":"country"}],"hiring_excludes":[],"relocation_offered":true,"industries":["Nuclear Energy","Nuclear Engineering"],"lifecycle":[{"event":"open","at":"2026-09-26T00:32:03Z"}],"liveness":{"score":26,"band":"fade","label":"Fading","p_open":1,"p_active":0.725,"p_room":0.36,"age_days":129,"expected_fill_days":71,"reasons":["conf:2","velocity","win:tail","crowd:"],"computed_at":"2026-09-28T05:45:00Z"},"pay":{"stated_usd_annual":171206,"is_top_pay":true},"html_url":"https://alion.io/job/terrapower-senior-engineer-safety-methods","json_url":"https://alion.io/job/terrapower-senior-engineer-safety-methods.json","meta":{"generated_at":"2026-09-29T02:30:00Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","usage":{"tier":"crawler","counted_by":"address","units_charged":1,"used_today":2258,"day_limit":5000,"remaining_today":2742,"minute_limit":60,"resets_at":"2026-09-30T00:00:00Z"}}}