Junior Core Design Engineer

Overview

At PNNL, our core capabilities are divided among major departments that we refer to as Directorates within the Lab, focused on a specific area of scientific research or other function, with its own leadership team and dedicated budget.

Our Science & Technology directorates include National Security, Earth and Biological Sciences, Physical and Computational Sciences, and Energy and Environment. In addition, we have an Environmental Molecular Sciences Laboratory, a Department of Energy, Office of Science user facility housed on the PNNL campus.

The National Security Directorate (NSD) drives science-based, mission-focused solutions to take on complex,real-world threats to our nation and the world.

The Nuclear, Chemical, and Biological Technologies Division, within the National Security Directorate, works across fundamental science, research and development, and operations to counter emerging national security threats. We focus on discovering signatures and understanding threats by creating materials, methods, and technologies to detect and analyze them. Our researchers deliver the solutions necessary for addressing complex mission challenges, such as explosives detection, biological threat detection, chemical and nuclear forensics, and special nuclear materials.

The Nuclear Engineering Group at Pacific Northwest National Laboratory (PNNL) is seeking an early-career nuclear engineer to support reactor physics analyses, modeling, and simulations for commercial pressurized water reactors (PWRs).

This position supports PNNL’s Tritium Technology Program, which provides technical leadership for the U.S. national security infrastructure. The program serves as the design authority for Tritium-Producing Burnable Absorber Rods (TPBARs), specialized rods installed in commercial PWRs to produce tritium. The successful candidate will apply nuclear engineering principles to support TPBAR performance analysis, reactor modeling, and related technical activities.

Responsibilities

• Model PWR core physics and TPBAR performance using neutron transport, diffusion, depletion, and fuel-cycle methods.
• Analyze TPBAR effects on reactivity, power distribution, neutron flux, and tritium production.
• Develop, run, and evaluate simulations using established reactor physics codes.
• Automate analyses and process results with Python or similar scripting tools.
• Perform data checks, sensitivity studies, and basic uncertainty assessments to support technically defensible results.
• Document methods and findings in technical reports and presentations.
• Collaborate with experienced engineers and contribute to projects involving both near-term analyses and longer-term model development.
• Expected to work with non-sensitive, sensitive, and classified information as appropriate for individual projects and should demonstrate an ability to navigate sensitive business situations and contribute to positive outcomes. The person in this position must recognize and accept that they will be working in technical areas associated with the National Security of the United States

This position offers a hybrid work arrangement. The selected individual should expect regular on-site work to support project activities involving sensitive information and collaboration with team members.

Minimum Qualifications:

• BS/BA and 2 years of relevant experience
  -OR-
• MS/MA
  -OR-
• PhD

Preferred Qualifications:

• Foundational knowledge of reactor physics, PWR core design, fuel behavior, and nuclear fuel cycles.
• Familiarity with burnup, depletion, neutron transport, and isotope-production modeling.
• Interest in applying reactor physics methods to TPBAR design, performance, and operational analyses.
• Experience with one or more reactor physics or radiation…