Nuclear Shielding and Criticality Engineer

System One; Bellevue (WA); Remote; USD 90,000 - 130,000; Full time

Job summary

A leading company in the nuclear sector is seeking a Nuclear Shielding and Criticality Engineer for a contract position. The role involves conducting advanced radiation transport and criticality safety analysis. Candidates should possess a degree in Nuclear Engineering and extensive experience with MCNP and relevant QA standards. This remote position offers an opportunity to work on high-impact projects in a dynamic environment.

Qualifications

• Expert MCNP user with 5-20 years of experience.
• Proficiency in MCNP variance reduction techniques.
• Experience with NQA-1 QA frameworks.

Responsibilities

• Perform radiation transport analysis for advanced nuclear systems.
• Calculate dose rates, activation rates, and neutron fluence.
• Collaborate with multidisciplinary teams on technical needs.

Skills

Radiation Shielding Analysis

Communication

Documentation

Python

Education

B.S. in Nuclear Engineering

M.S. in Nuclear Engineering

Ph.D. in Nuclear Engineering

Tools

MCNP

ADVANTG

CAD tools

Attila/Attila4MC

Job description

Job Title: Nuclear Shielding and Criticality Engineer (Remote)

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