Senior Mechanical Design Engineer — ASME Section III

Aalo Atomics is pioneering a new era in clean energy with factory-fabricated microreactors designed to deliver affordable, scalable, and reliable nuclear power. Our mission is to make nuclear energy globally accessible, starting with the Aalo-1, a 10 MWe reactor leveraging cutting‑edge safety, modularity, and efficiency. Based in Austin, TX, we’re rapidly growing as we work to deploy the world’s first fleet of advanced microreactors.

Join us and help revolutionize energy for a sustainable future.

Aalo Atomics is seeking a Senior Mechanical Design Engineer with expert knowledge of ASME BPVC Section III to lead design of reactor vessel and pressure‑boundary systems for our sodium‑cooled, graphite‑moderated reactor.

This hands‑on role is for an independent engineer who can contribute immediately in a fast‑paced startup environment. You will develop code‑compliant designs, supporting analyses, and technical documentation while partnering with manufacturing, materials, quality, and licensing teams.

In addition to reactor pressure vessel design, you will play a central role in Aalo’s ASME certification efforts—supporting demonstration projects for our N, G, and GC stamps and establishing the Section III design and compliance framework that underpins our path to fabrication.

• 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 Over pressure 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 (nuclear vessels), G‑stamp (nuclear supports), and GC‑stamp (nuclear containment vessels).
• Develop the technical deliverables, procedures, and documentation required for stamp certification, including Quality Assurance program support, Design Reports, and coordination with the Authorized Nuclear Inspector (ANI).
• 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 (manufacturing, materials, quality, licensing) 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.

• 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…