Head of Power Conversion

AdAstra Talent Advisors; Los Angeles (CA); On-site; USD 180,000 - 300,000; Full time

Benefits offered by this job

Competitive pay

Equity

Benefits

Relocation support

Job summary

AdAstra Talent Advisors is representing a stealth-mode nuclear fission startup seeking a mechanical engineering leader. You will own a complex electromechanical system, guide a multidisciplinary team, and drive the project from a ~500kW prototype to full‑scale deployment.

You’ll interact with vendors, production, and leadership to ensure scalable, safe, and reliable operation. The role is on-site in the Los Angeles area with relocation support for non-local candidates and a strong emphasis on

Qualifications

• Demonstrated experience leading engineers in a fast‑paced hardware environment.
• Experience designing, analyzing, or building complex mechanical or electromechanical hardware.
• Bachelor's degree in mechanical engineering or related technical discipline.

Responsibilities

• Lead a multidisciplinary team of mechanical, electrical, and controls engineers reporting to the CEO/Chief Engineer.
• Own the prototype through full-scale nuclear deployment.
• Drive design choices, write requirements, and run first‑principles system models.
• Collaborate with vendors and production to ensure scalability.
• Recruit and build the team.

Skills

Leadership

Hardware design

Mentoring engineers

Education

Bachelor's degree in mechanical engineering

Job description

Our client is a stealth-mode nuclear fission startup founded by accomplished SpaceX alumni, and they're not trying to invent new reactor physics. Fission already works, that part's been solved for decades. What's actually broken is how slowly and expensively the industry builds it.

So this team is doing what their founders know how to do best: taking a proven, physics-de-risked reactor design and building it the way you'd build a rocket, fast, iteratively, and at real volume, instead of the usual one‑off, decade‑long megaproject.

They're not asking "can nuclear work." They're asking "why does it take ten years and a small city of engineers to build one," and then setting out to prove it doesn't have to.

This is a direct hire, permanent placement position for a client of AdAstra Talent Advisors.

Responsibilities

This is a leadership hire first. We’re looking for a mechanical engineering leader who has owned a complex electromechanical or fluid system end to end in a fast‑paced, high‑ownership hardware environment, and has genuinely led other engineers in doing it. You’ll take a subscale prototype through to full‑scale nuclear deployment, recruiting and running your own multidisciplinary team while reporting directly to the CEO/Chief Engineer.

We want great engineers with high drive and strong first‑principles thinking. You do not need a nuclear or power‑conversion background to be a great fit here. The physics and domain specifics (turbines, feedwater trains, condensate polishing) are learnable on the job; what isn’t learnable in a few months is the judgment that comes from having owned real hardware in a high‑ownership environment, made the hard calls under ambiguity, and led a team through it. If that’s you, the rest is trainable.

The team moves fast and needs a leader in this seat who holds a high bar, and genuinely wants to see abundant clean energy become a reality.

What You’ll Own

This role owns everything that happens after the reactor makes heat: turning that heat into usable electricity, safely and continuously. A true founding hire for an entire function.

In plain terms: a hot, high‑pressure stream comes off the reactor and drives a large turbine, spinning a shaft that turns a generator into electricity. From there, the fluid gets condensed, filtered, and polished back to purity in a train of tanks before it’s reheated and sent back to the reactor to do it again. Separately, the system rejects waste heat by routing cooling water through shipping‑container‑sized heat rejection equipment. Own that whole loop, turbine and generator, the high‑power electrical systems that interface with the load, the feedwater and condensate train, control electronics, and heat rejection, and you own the thing that actually turns this technology into a power plant.

You’ll stand this system up twice:

• First, a one‑off, roughly 500kW non‑nuclear prototype, built lean and fast (expect real use of off‑the‑shelf components where they get you there faster) to prove the approach out.
• Then at full scale, designed from day one to be manufactured and deployed at a high rate.

Along the way you’ll drive the conceptual design and architecture trades, write the requirements where none exist yet, run first‑principles system models, work directly with vendors on procurement, and partner with the production team to make sure what you design is scalable.

You’ll report directly to the CEO / Chief Engineer and recruit/build the multi‑disciplinary team of mechanical, electrical, and controls engineers who deliver this with you.

Requirements

Our client cares about hiring the right person versus a specific level, therefore leveling, title, and compensation are all flexible for the right person.

• Demonstrated experience leading engineers, ideally in a fast‑paced, high‑ownership hardware environment
• Relevant engineering experience designing, analyzing, or building complex mechanical or electromechanical hardware
• A Bachelor's degree in mechanical engineering or a related technical discipline

No direct nuclear, power generation, or power‑conversion experience required. If you’re close but not a perfect match on paper, apply anyway. The trajectory matters more than the checklist.

Preferred Experience

• Background in a fast‑paced, high‑ownership hardware environment (aerospace, space, or similar) strongly preferred
• Experience with fluid systems, thermal/thermodynamic systems, or rotating equipment is a plus, but not required
• A creative, multi‑disciplinary problem solver who can pull mechanical, electrical, and controls thinking together
• Comfortable in a fast‑paced, autonomous, demanding environment
• Strong documentation, communication, and organizational instincts, even when moving quickly
• A track record of rapid growth: successive roles of increasing responsibility, ramping up fast, and doing something meaningfully hard early in your career

The above qualifications are desired, not required. We encourage you to apply if you are a strong candidate with only some of the desired skills and experience listed.

Logistical Requirements

• On‑site in the Los Angeles Area; relocation support for non‑local candidates
• Periodic travel to suppliers and reactor construction sites

What Success Looks Like

In the near term, the subscale prototype system is designed, built, and running, proving out your team's approach to clients and investors. From there, the full nuclear‑scale system is designed for manufacturability, scalability, and deployability. Throughout this role, this position will flex between player and coach.

Competitive base salary, meaningful equity, and comprehensive benefits. The right candidate will get excited about the mission and ground‑floor upside at an early‑stage company.

To conform to U.S. Government space technology export regulations, applicant must be a U.S. citizen, lawful permanent resident of the U.S., protected individual as defined by ITAR (22 CFR §120.15), or eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.

Base salary is just one part of our client’s total rewards package. You may also be eligible for 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.

You will also receive access to comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, paid vacation, parental leave, and various other perks. Employees accrue paid sick leave pursuant to Company policy which satisfies or exceeds the accrual, carryover, and use requirements of the law.

Compensation is determined by role, level, location, and alignment with market data. Individual level and base pay is determined on a case‑by‑case basis and may vary based on job‑related skills, education, experience, technical capabilities and internal equity. (For CA companies with over 10 employees, we recommend adding a very wide salary band to adhere to state pay transparency law) In addition to base salary, you may also be eligible for long‑term incentives, in the form of stock options, and access to medical, vision & dental coverage as well as access to a 401(k) retirement plan.

Our client is an equal opportunity employer. They evaluate qualified applicants without regard to race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.

About AdAstra

AdAstra Talent Advisors is a headhunting and talent advising firm focused on the Climate, Space, and Defense sectors of Hard Tech. We specialize in pairing highly technical and executive talent with some of the world’s leading Hard Tech startups.

At AdAstra, we catalyze the innovations that future generations depend on by placing the right people in the right seats. Our dedicated work enables inconceivable technology from Earth, to the stars. And it’s all because of trailblazing talent like you - those driven to do what’s never been done before.

We care about long term relationships with both candidates and companies. Even if the role we initially discuss isn’t a perfect fit, it’s likely we’ll have something relevant to share with you in the future.

Join us on our journey by following along via LinkedIn!