Nuclear Core Physics Engineer — Onsite (El Segundo) + Equity

Radiant; El Segundo (CA); On-site; USD 107,000 - 146,000; Full time

Benefits offered by this job

Stock options

Medical plan

One Medical

Vision coverage

Dental coverage

Life insurance

Paid parental leave

Daily catered lunch

Flexible PTO

Team events

HQ near Pacific Ocean

Job summary

Radiant in El Segundo, CA is seeking a Nuclear Engineer, Core Physics to design and execute the 2026 demonstration reactor testing program. You will develop procedures, conduct neutronic and transient analyses, and collaborate with fellow nuclear and systems engineers to meet safety and test objectives.

The role requires hands-on reactor operations experience, strong knowledge of radiation transport, and the ability to document procedures and train operators for the control room interface.

Qualifications

• Bachelor’s degree in nuclear engineering or equivalent from an accredited institution.
• 2+ years of experience with reactor operations.
• Experience with radiation transport methods and codes such as MCNP/OpenMC/Serpent.
• Knowledge of thermal hydraulic fundamentals.

Responsibilities

• Collect testing requirements, objectives, and success criteria from nuclear engineers.
• Develop procedures that satisfy test requirements within the operational bounds of Kaleidos.
• Perform various reactor physics calculations (neutronic and transient analyses) to verify proposed testing sequence addresses all requirements.
• Document testing procedures and support operator training and control room GUI development.

Skills

Reactor operations

Thermal hydraulics

Radiation transport methods

Education

Bachelor's degree in nuclear engineering

Tools

MCNP/OpenMC/Serpent

Job description

Radiant in El Segundo, CA is seeking a Nuclear Engineer, Core Physics to design and execute the 2026 demonstration reactor testing program. You will develop procedures, conduct neutronic and transient analyses, and collaborate with fellow nuclear and systems engineers to meet safety and test objectives.

The role requires hands-on reactor operations experience, strong knowledge of radiation transport, and the ability to document procedures and train operators for the control room interface.