Full-Time

Radiation Shielding Engineer

Antares Nuclear

Antares Nuclear

51-200 employees

Develops autonomous microreactors for remote power

Compensation Overview

$120k - $240k/yr

No H1B Sponsorship

Los Angeles, CA, USA + 1 more

More locations: Idaho Falls, ID, USA

In Person

US Citizenship Required

Category
Mechanical Engineering (1)
Requirements
  • Bachelor’s degree in nuclear or mechanical engineering, physics, material science, or related field
  • 3+ experience with radiation shielding analysis and design
  • Proficiency in modern radiation shielding analysis tools, such as MCNP/ADVANTG, SCALE/MAVRIC, or similar Monte Carlo variance reduction tools
  • Ability to navigate regulatory requirements, shielding design features, analysis tools and manufacturing methods
  • Ability to work long hours and weekends as necessary to support critical milestones
  • Ability to travel to regulatory locations as needed
Responsibilities
  • Ownership of radiation shielding design and analysis
  • Development of trade studies of materials choices
  • Development of neutronics simulations to characterize radiation sources during operation and in post-operation configurations
  • Optimization of radiation shielding for deployment and post-operation transportation
  • Engagement in regulatory requirement compliance strategies and application to licensing pathways
  • Ensuring utilized tools and analyses are established and maintained in comliance with Antares quality assurance program
Desired Qualifications
  • Strong interpersonal and collaborative skills, enthusiasm for problem solving, and desire to modernize nuclear design and operation
  • Master's degree or PhD in nuclear engineering
  • Demonstrated track record of high impact in the achievement of team goals
  • Strong project management skills and effective communication of technical concepts across multi-disciplinary teams
  • Broad knowledge of nuclear interactions with material selections, especially for radiation shielding applications
  • Working knowledge of a programming language, preferably Python

Preparing company description.

Company Size

51-200

Company Stage

Debt Financing

Total Funding

$126M

Headquarters

Los Angeles, California

Founded

2023

Simplify Jobs

Simplify's Take

What believers are saying

  • NRC pre-application activities began May 2025, accelerating licensing for 2027 prototype.
  • $96M Series B from Shine Capital funds factory build-out and HALEU procurement in 2025.
  • DOE approval enables Mark-0 demonstration at Idaho National Lab before July 4, 2026.

What critics are saying

  • Mark-0 fails criticality before July 4, 2026, breaching DOE Pilot Program and triggering scrutiny.
  • HALEU shortages halt 2027 Mark-1 testing, letting X-energy seize defense contracts.
  • NRC rejects autonomous controls during certification, invalidating core design by 2028.

What makes Antares Nuclear unique

  • Antares R1 microreactor uses sodium heat pipes for passive heat removal without moving parts.
  • R1 employs HALEU TRISO fuel with graphite moderator for enhanced safety in austere environments.
  • Advanced tungsten and boron carbide shielding minimizes exclusion zones for rapid military deployment.

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Benefits

Health Insurance

Dental Insurance

Vision Insurance

401(k) Retirement Plan

Flexible Work Hours

Remote Work Options

Paid Vacation

Paid Sick Leave

Paid Holidays

Hybrid Work Options

Wellness Program

Mental Health Support

Gym Membership

Phone/Internet Stipend

Home Office Stipend

Professional Development Budget

Conference Attendance Budget

Stock Options

Company Equity

Relocation Assistance

Parental Leave

Family Planning Benefits

Fertility Treatment Support

Adoption Assistance

Childcare Support

Elder Care Support

Pet Insurance

Bereavement Leave

Tuition Reimbursement

Professional Certification Support

Mentorship Program

Training Programs

Tuition Reimbursement

Growth & Insights and Company News

Headcount

6 month growth

1%

1 year growth

-1%

2 year growth

0%
Bloomberg L.P.
Apr 8th, 2026
Nuclear startup Antares wins key approval to complete demonstration reactor under US programme

Antares Nuclear Inc., a California-based startup developing small reactors, has become the first company to receive approval from federal regulators to complete its demonstration system under a US programme designed to accelerate new fission technologies. The approval from the Department of Energy marks a significant milestone for the nuclear startup as it works to advance small modular reactor technology.

Business Wire
Dec 3rd, 2025
Antares Raises $96 Million in Series B Funding to Accelerate Nuclear Microreactor Development

Antares, an advanced nuclear energy startup, today announced the close of its $96 million Series B funding round. The round was led by Shine Capital, with pa...

Startup Ecosystem Canada
Dec 3rd, 2025
Antares Raises $96M for Microreactor Development for Diverse Energy Applications

Antares raises $96M for microreactor development for diverse Energy applications. News summary. Antares, a nuclear startup, has successfully raised $96 million in a Series B funding round to advance its small modular reactor design, known as the R1 microreactor. This funding includes $71 million in equity and $25 million in debt, with participation from Shine Capital, Alt Capital, Caffeinated, FiftyThree Stations, and Industrious. The R1 microreactor is designed for commercial, defense, and space-based applications, producing between 100 kilowatts and 1 megawatt of electricity using TRISO fuel. The startup's progress follows a renewed interest in nuclear power, evidenced by significant investments in similar companies like X-energy, Deep Fission, Aalo Atomics, and TerraPower. Antares aims to demonstrate its reactor for the Department of Energy next year, with plans to activate its full-power reactor by 2027. Story coverage.

FinSMEs
Dec 2nd, 2025
Antares Raises $96M in Series B Funding

Antares raises $96M in Series B funding. Antares, a Torrence, CA-based nuclear energy startup, raised $96M in Series B funding. The round was led by Shine Capital, with participation from Alt Capital, Caffeinated, FiftyThree Stations, Industrious, and other investors, bringing its total amount to date to over $130M in funding. It consisted of $71M in new equity capital and $25M in debt for equipment, factory build-out, and uranium procurement. Led by CEO Jordan Bramble, Antares is building compact nuclear microreactors to deliver energy where it's needed most: * remote military bases, * austere industrial sites, * and, one day, deep space and underwater missions. With operations in Torrance, California; Idaho Falls, Idaho; and Aiken, South Carolina, and a team of 60, Antares is working to demonstrate a low-power test reactor before July 4, 2026, and to test its electricity-producing demonstration unit in 2027. Production units will be deployed as early as 2028.

Business Wire
Dec 2nd, 2025
Antares raises $96M Series B to accelerate nuclear microreactor development

Antares, an advanced nuclear energy startup, has closed a $96 million Series B funding round led by Shine Capital. The round includes $71 million in new equity and $25 million in debt for equipment, factory build-out and uranium procurement. Participants include Alt Capital, Caffeinated, FiftyThree Stations, Industrious and other investors. The Washington-based company is developing nuclear microreactors. CEO Jordan Bramble said the capital will accelerate the company's mission to deliver its technology, though specific deployment timelines were not disclosed.