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Reactor Neutronics Specialist

X Energy LLC
Greenbelt, Maryland, 20770, United States
November 08, 2016

X Energy LLC is searching for an experienced Reactor Neutronics Specialist to work in our Greenbelt, Maryland office.


1. Develop and implement Verification, Validation and Uncertainty Quantification (VVUQ) plan for codes and models for pebble bed HTR reactor design and analysis.

2. Provide inputs to Mechanistic Source Term (MST), Probabilistic Risk Assessment (PRA), and System Engineering personnel on nucleonic aspects, including nuclear materials properties, requirements, nuclear boundary conditions, and processes.

3. Perform pebble bed HTR core neutronics design, reactivity, feedback, and safety analyses.

4. Perform criticality and shielding design and considerations for fresh and spent fuel


• PhD in Nuclear Engineering from a US accredited university

• Demonstrated expertise with Unix operating systems

• At least 5 years of experience with High Performance Computing (HPC) clusters

• Expertise with C++ and Fortran90 programming languages

• Scripting experience (Perl or Python)

• Pebble bed HTR experience highly recommended

• Able to perform physics code development and perform multi-scale, multi-physics modeling of the physics characteristics of HTRs

• Knowledge of MCNP, RELAP, (deterministic and stochastic) neutron transport and fuel performance is highly recommended

• Knowledge of Predictive Capability Maturity Model (PCMM) and VVUQ is highly recommended.

• Willingness to gain thorough understanding of the VSOP and TINTE/MGT system of codes.

• Able to effectively communicate results and analytical findings verbally and in writing.