Nuclear Engineer I/II
- Salary
- $120K - $175K
- Level
- Junior
- Work type
- On-site · Los Angeles
Not stated in the posting: visa.
Open. First seen 2 October 2026.
About the role
About Us
Antares's standard text
At Antares, our long-term mission is to make clean energy abundant from Earth to the Asteroid Belt. We’re fueled by the belief that advanced nuclear energy can strengthen our military, solve the climate crisis, elevate global living standards, and expand humanity's presence in outer space. To achieve our mission, we’re building mass-producible, inherently safe, deployable microreactors that can be used terrestrially, underwater, and in space.
The Antares team hails from SpaceX, the White House, the Pentagon, the Department of Energy, MIT, Rigetti Computing, General Atomics, Relativity Space, Ursa Major, and National Laboratories like Idaho, Oak Ridge, Los Alamos, and Savannah River. Antares has raised over $600M in venture capital from top-tier investors and has hundreds of million-dollars on contract with the military services, NASA, and the Department of Energy.
About the Role
As a member of the nuclear engineering team, you will become the responsible engineer for a key component of the Antares reactor design such as reactivity controls and instrumentation, radiation shielding, fuels, materials, thermal hydraulics, safety, or licensing. The ideal candidate has a mix of industry and academic experience, and has worked in a team-oriented environment to mature nuclear concepts. While you may have a specialty, you’re not afraid to operate as a generalist in a growing organization.
Roles and Responsibilities:
- Assist with neutronics modeling and simulations using MCNP, Serpent, or SCALE
- Support Multiphysics analyses (thermal-hydraulics, heat transfer, structural mechanics)
- Participate in experimental validation of simulation results
- Collaborate with senior engineers on iterative design tasks
- Contribute to documentation and regulatory reporting
- Participate in hardware demonstrations and prototype testing
Basic Qualifications:
- Bachelor's degree in Nuclear Engineering or related technical field
- Familiarity with neutron transport software (MCNP, Serpent, SCALE)
Preferred Skills & Experience:
- Familiarity with Python or similar programming language
- Coursework or internships involving Multiphysics modeling
- Interest or experience in microreactors, heat pipe cooled reactors, or other advanced reactors
- Exposure to fast-paced project environments
- Proven ability to quickly learn new technical concepts
- Strong communication skills
Pay Ranges
Nuclear Engineer I: 120k-135k
Nuclear Engineer II: 135k-165k
Your actual level and base salary will be determined on a case-by-case basis and may vary based on the following considerations: job-related knowledge and skills, education, and experience.
Culture
Antares's standard text
At Antares, we like to specifically tie each role to our founding document’s set of values–here are the top five cultural values we think you should believe at your core to be successful:
- Think in Systems - Energy and Defense are complex ecosystems with numerous stakeholders with competing priorities, conflicting policies, perverse incentives, and emergent and path-dependent properties. First principles thinking alone is insufficient. Think probabilistically and then take action. “If you want to be certain, then you are apt to be obsolete.” Over-optimizing the components often degrades the system
- Obsess over the End User - The customer and end user are often not the same. We will never build globally competitive commercial products if we lose sight of our end users and their entire interaction with the product life cycle
- Be Unconstrained by Convention - Our only limits are the laws of physics. Many, even experts, will say what we are working on is impossible. They said the same about SpaceX reusing rockets. Generationally impactful companies, by definition, must accomplish the seemingly impossible. If it were easy, it would have already been done. Never shy away from a solution because it has never been tried before, and never choose to do something because that's “how it's always been done”
- Go Where the Work Is - Never miss a chance to meet a customer, user, or stakeholder face to face, even if that means hopping on a plane. If you can’t make it, find a teammate who can channel your intentions and go in your place. Deep work can be done from anywhere, but we believe teams are built in person, and aim to maximize our time together
- Operate in the Grey - Embrace nuance in pursuit of truth. Question every fundamental assumption
Antares's standard text
Equal Opportunity
Antares is an Equal Opportunity Employer. Employment decisions are based solely on merit, competence, and qualifications, 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.
ITAR Requirements
To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.
What this role asks for
Standard for software engineering roles
Python
Common in software engineering postings at any company.
81% of this description is written for the role. The rest is Antares's standard text, folded away below.
Read against Antares's other open postings on this site.
The team: Nuclear
This role is one of 4 open in Nuclear.
WHAT THE TEAM WORKS WITH, ACROSS ITS POSTINGS
Python (3 of 4)
OTHER ROLES ON THIS TEAM
- Senior/Staff Nuclear Safety Analysis Engineer posted Aug 21
- Senior Nuclear Engineer posted Aug 5
- Senior Radiation Shielding Engineer posted Jan 5
From the team and dates on Antares's own job board.
Similar jobs
- Senior Software Engineer, Hardware Test Platform at Antares
Also at this company - Thermo-Mechanical Engineer II at Antares
Also at this company - Senior Thermo-Mechanical Engineer at Antares
Also at this company - Technical Recruiter at Antares
Also at this company - Build Quality Engineer II-Senior at Antares
Also at this company - Senior Test Engineer - Space at Antares
Also at this company
Is this your posting and you want it taken down? Email info@careerholo.com.