About Valar Atomics

At Valar Atomics, we're redefining what's possible in energy. Our mission is to make clean, high-temperature nuclear power scalable—unlocking abundant energy for industry, hydrogen, and next-generation manufacturing. We are a team of builders, engineers, and operators who believe nuclear energy should be fast to deploy, factory-made, and built for the real world. Our first pilot plant in Orangeville, Utah will demonstrate how advanced nuclear systems and fuel fabrication can power the future. Joining Valar Atomics means becoming part of a company where autonomy, ownership, and impact exist at every level.

The Team

The Model & Simulation Engineering Group is a dynamic analysis and engineering group that provides the analytical foundation for reactor and plant design, delivering high-fidelity computational analysis, integrated directly into the engineering design process.

The group responsibilities spans:

Neutronics and reactor design;
Thermal-hydraulics systems analysis covering steady-state and transient performance of the complete system; and
Computational fluid dynamics and finite element analysis for detailed flow, thermal, and structural integrity assessment.

ModSim works alongside the engineering and licensing organizations and develops and maintains the models that underpin design basis definition, transient and accident analysis, safety case development and regulatory submittals, applying rigorous verification, validation and uncertainty quantification throughout. The group's responsibilities extend beyond prediction: models are benchmarked against test data and against operating data from research and demonstration reactors in construction and service, closing the loop between simulation, as-built plant performance, and the continuous improvement of the company's analytical methods and business case.

The Role

The Director of ModSim leads VALAR Atomics’ modeling, simulation, and analysis organization across CFD, FEA, thermal-hydraulics, and nuclear engineering, and is accountable for ensuring that analysis supports the design process and outputs that get built.

Reporting to the CNO / VP of Engineering, the Director of ModSim owns the strategy, quality, throughput, resourcing, and budget of the group; the multiphysics integration and verification-and-validation (V&V) consistency that bind the disciplines together; and the licensing-grade defensibility of every deliverable under a nuclear quality program (i.e. NQA-1, 10 CFR 50 Appendix B, ASME V&V 10/20/30).

In a dynamic, speed-driven start-up racing to deploy reactors at scale, the ModSim Director is equal parts technical authority, org-builder, systems thinker, and dot-connector, growing the team from a small core, automating the simulation-to-design workflow, and wiring ModSim into design, manufacturing, licensing, and construction so that models become steel, on schedule and to code. This is a hands-on-enough leader who is as comfortable interrogating a Flownex transient or a neutronics depletion run as standing on a fabrication floor asking why the as-built diverges from the model.

Key Responsibilities

The Director carries seven areas of accountability, spanning technical leadership, people, integration, reporting, and relentless optimization of output rate, speed, and quality:

Technical leadership across the four core disciplines. Set the analysis strategy, methods, and standards for CFD, FEA, thermal-hydraulics, and neutronics; own multiphysics integration, cross-discipline data-exchange conventions, configuration control, and end-to-end V&V so the coupled picture is consistent and defensible.
Close the loop from model to build hardware. Ensure analysis directly supports design outputs, i.e., sized components, qualified structures, validated systems, and stays connected through procurement, fabrication, construction, and commissioning; drive validation and design-for-manufacture feedback so the digital model and the physical plant stay in alignment.
Build, grow, and develop the team. Recruit, mentor and retain Stream/Discipline Leads and their analysts; scale a small start-up core into a high-performing multidisciplinary group; engage SMEs and external partners; create the culture, career paths and technical bar for the organization.