Nuclear Shielding and Criticality Engineer-Remote opportunity

Company: System One
Location: Bellevue
Posted on: May 14, 2025

Job Description:

Job Title: Nuclear Shielding and Criticality Engineer (Remote)

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Location: Remote (U.S.-based)
Employment Type: Contract
Company: System One

System One is actively seeking a highly skilled and motivated Nuclear Shielding and Criticality Engineer for a remote contract position supporting advanced nuclear technology projects. This is an excellent opportunity for experienced engineers who thrive in autonomous, high-impact technical environments.

About the Role:

As a Nuclear Shielding and Criticality Engineer, you will be responsible for radiation transport and criticality safety analysis using MCNP 6.2. The scope includes shielding calculations, energy deposition, neutron fluence, activation studies, and development of upper subcritical limits. You will support safety, licensing, and design efforts in accordance with high-quality nuclear standards, including NQA-1.

Responsibilities:

Perform shielding and radiation transport analysis for advanced nuclear systems.


Calculate dose rates, activation rates, neutron fluence, and energy deposition.


Conduct material activation analyses to develop radiation sources.


Perform nuclear criticality safety evaluations and define Upper Subcritical Limits (USLs).


Maintain clear, traceable, and auditable documentation aligned with QA requirements.


Collaborate remotely with multidisciplinary teams and contribute to evolving technical needs.



Required Qualifications:

B.S. in Nuclear Engineering with 5-20 years of experience, or


M.S. with 3-15 years, or Ph.D. with 2-10 years of experience.


Expert-level MCNP user with demonstrated radiation shielding analysis experience.


Proficient with MCNP variance reduction techniques (mesh tallies, weight windows, surface sources).


Strong communication and documentation skills.


Experience working within NQA-1 or equivalent QA frameworks.



Preferred Qualifications:

Familiarity with ADVANTG for weight window generation.


Experience with criticality safety methods and regulations.


Exposure to fast reactor physics and design is a plus.


Familiarity with Attila/Attila4MC, CAD tools (e.g., SolidWorks, SpaceClaim/ANSYS, Cubit).


Programming experience in Python or other scientific languages.


Ability to quickly learn and apply nuclear design concepts in support of project goals.





Ref: #161-Managed Staffing Charlotte
Remote working/work at home options are available for this role.

Keywords: System One, Seattle , Nuclear Shielding and Criticality Engineer-Remote opportunity, Engineering , Bellevue, Washington