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Senior Mechanical Design Engineer — ASME Section III

Aalo· Engineering
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Hybrid (Austin, TX / Idaho Falls, ID)$0Full-timePosted 4d ago

About the role

Senior Mechanical Design Engineer with expert knowledge of ASME BPVC Section III to lead design of reactor vessel and pressure-boundary systems for a sodium-cooled, graphite-moderated reactor, and to support ASME certification efforts (N, G, GC stamps) in a fast-paced startup.

Responsibilities

  • Lead mechanical design and ASME BPVC Section III compliance for reactor vessels, pressure-boundary components, supports, and penetrations.
  • Perform and own Section III code calculations for pressure, thermal, fatigue, buckling, seismic, and other design-basis and service-level loads.
  • Classify components and systems per NCA/NB/NC/ND requirements, establishing the design classification framework for reactor pressure-boundary and safety-related equipment.
  • Apply Section III rules (Subsections NB, NC, ND, NF, and NE as applicable) to pressure vessels, piping, supports, and containment structures, ensuring correct load combinations, stress limits, and service-level criteria.
  • Develop Design Specifications, Design Reports, and Overpressure Protection Reports in accordance with Section III requirements.
  • Evaluate elevated-temperature design considerations including creep, creep-fatigue, and thermal ratcheting where applicable.
  • Support demonstration projects for ASME N-stamp, G-stamp, and GC-stamp and establish the design/QA framework for certification.
  • Develop technical deliverables, procedures, and documentation required for stamp certification, including Quality Assurance program support, Design Reports, and ANI coordination.
  • Work with quality and manufacturing teams to establish compliant fabrication, examination, and testing processes that satisfy stamp requirements.
  • Own designs from concept through release, fabrication support, testing, and verification.
  • Create CAD models, drawings, specifications, and calculation packages.
  • Partner with cross-functional teams to resolve design, fabrication, and compliance challenges.
  • Lead design reviews and communicate technical assumptions, risks, and trade-offs.
  • Support prototype builds, supplier engagement, fabrication issues, and testing.

Qualifications

  • Bachelor’s degree in Mechanical Engineering or a related discipline.
  • 7+ years of relevant mechanical design experience with pressure vessels, pressure-retaining equipment, or nuclear mechanical systems.
  • Expert knowledge of ASME BPVC Section III and its application to pressure-boundary design, including familiarity with Subsections NCA, NB, NC, ND, and NF.
  • Demonstrated experience with Section III design classification (safety class, seismic category, quality group) and the application of code rules to establish design requirements.
  • Experience performing or reviewing Section III code calculations, including stress analysis, fatigue evaluation, and load-combination assessments.
  • Experience designing vessels, shells, heads, nozzles, penetrations, flanges, or similar structures.
  • Strong understanding of pressure-vessel mechanics, fatigue, buckling, thermal stress, and load combinations.
  • Ability to independently drive ambiguous technical work to documented engineering decisions.
  • Proficiency with 3D CAD and FEA or structural-analysis tools.
  • Ability to work on-site in Austin, TX or Idaho Falls, ID.

Skills

Required:ASME BPVC Section IIISection III calculations3D CADFEA / Structural analysis
Nice to have:Design for ASME stampsNuclear component design

Benefits

  • Competitive salary based on technical level
  • Health, Dental, Vision Insurance
  • Paid Time Off
  • Corporate Gym Membership
Last updated Oct 22, 2026. Interested? Apply on the company site.

About Aalo

Welcome to the dawn of a Second Atomic Age

Creating abundant and dependable clean energy to power humanity for generations.

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