Senior Mechanical Engineer, Structures

AdAstra; United States; On-site; USD 120,000 - 190,000; Full time

Benefits offered by this job

Stock options

Discretionary bonuses

Employee Stock Purchase Plan

Medical, vision, and dental coverage

401(k) retirement plan

Paid vacation

Paid parental leave

Job summary

AdAstra is seeking a Sr. Structures Engineer to design and build reactor hardware for a 25 MWe nuclear pilot. You will own complex structural components and lead efforts to meet regulatory, cost, mass, and manufacturability goals.

Requirements include a Bachelor's in mechanical engineering and 5+ years designing mechanical hardware; leadership experience; hands-on with high‑pressure vessels, welding, ASME BPVC, and safety-critical systems.

Qualifications

• Bachelor's degree in mechanical engineering or related technical discipline.
• 5 years of engineering experience designing, analyzing, and building mechanical hardware.
• Experience acting as a technical lead—scoping work and guiding engineers.

Responsibilities

• Design, build and test pressure vessels, containment structures, seismic isolation, and secondary structures.
• Carry out trade studies for optimal structural materials balancing cost, mass and manufacturability.
• Validate designs with rigorous testing and document results for reports.
• Collaborate with manufacturers to optimize lead times and manufacturability.
• Mentor junior structures engineers and set high technical standards.

Skills

Mechanical design

Structural analysis

Team leadership

First principles reasoning

High-pressure systems

Education

Bachelor's degree in Mechanical Engineering

Tools

ASME BPVC

Finite element analysis (FEM)

Job description

About the Company

Humanity faces two critical challenges: securing reliable energy for everyone and aggressively lowering our environmental impact. Our client believes nuclear fission is the key to solving both at once. Today they are actively developing the technology to rapidly scale the deployment of nuclear fission.

The Opportunity

As a structures engineer, you'll be responsible for designing and building reactor hardware such as the pressure vessel, containment, and structural elements for a 25 MWe reactor. These designs must withstand the extreme temperature and pressure environments of the reactor while meeting regulatory requirements and being optimized for cost, mass, and manufacturability. Sr. Structures Engineers will own the most complex structural hardware while setting the technical bar for the structures engineering team. Successful candidates will have previously demonstrated extreme ownership in delivering mechanical systems in fast-paced, high-reliability environments.

Responsibilities

• Design, build and test pressure vessels, containment structures, seismic isolation, and secondary structures for the pilot nuclear reactor
• Carry out trade studies for optimal structural materials, balancing cost, mass, strength, corrosion resistance, and manufacturability
• Validate reliability of designs with rigorous testing: thermal cycling, pressure cycling, shock, vibration, radiation embrittlement, and corrosion. Design experiments to ground analysis, develop fixturing, and create technical reports based on results
• Work with manufacturers to understand process limitations and adapt designs for lead times and manufacturability
• Collaborate with peers from different systems to develop designs that balance cost, efficiency, and deployment logistics
• Support the assembly of your hardware in the factory, witness your designs being brought to life daily, and watch them power an abundant, clean future
• Provide training and mentorship to junior structures engineers, setting the standard for technical rigor across the team

Basic Qualifications

• Bachelor's degree in mechanical engineering or a related technical discipline
• 5 years of engineering experience designing, analyzing, and building mechanical hardware

Preferred Skills and Experience

• Strong interpersonal and collaborative skills, enthusiasm for problem solving, and desire to enable abundant clean energy
• 5 years of experience designing and analyzing mechanical systems via professional work experience, project/research-based student experience, or a combination of both
• Experience acting as a technical lead --- scoping work, reviewing designs and processes, and guiding other engineers to successful outcomes
• Ability to perform trade studies and make clear recommendations using first principles and engineering fundamentals even with partial information
• Experience working at a nimble engineering organization or in a highly technical position that required a scrappy, entrepreneurial manner to accomplish tasks with tight time or budget constraints
• Hands on experience designing, testing, and operating high-pressure systems and pressure vessels
• Experience with forging for large, high-pressure vessels
• Experience with welding processes, inspection, and qualification
• Experience designing to the ASME Boiler and Pressure Vessel Code
• Hands-on experience with fluid, gas, or thermal systems

Additional Requirements

• The position will be based in the Los Angeles Metro The position will be full-time in the office.
• Ability to work extended hours and weekends as necessary
• Ability to travel to reactor construction sites in other states as necessary

Compensation and Benefits

• Competitive Base Compensation - DOE
• Long-term incentives, in the form of company stock or stock options, as well as potential discretionary bonuses and the ability to purchase additional stock at a discount through an Employee Stock Purchase Plan
• Access to comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, paid vacation, paid parental leave, and various other perks.