Chemical Engineer

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X-energy LLC is hiring a mid-level Chemical Engineer to support the design, implementation, and optimization of chemical processes and systems used in the production of materials and products. The role works cross-functionally with project leadership and other engineering disciplines to deliver on defined project objectives. The focus of this engineering role is on thermal‑hydraulic and process systems engineering for High‑Temperature Gas‑cooled Reactors (HTGRs).

Responsibilities include modeling, analysis, and integration of chemical, mechanical, and thermal systems. The position applies a chemical engineering background in nuclear applications, with particular emphasis on thermal‑fluid modeling tools (e.g., ASPEN, COMSOL), high‑temperature materials behavior, and reactor systems integration. This role supports the full lifecycle of HTGR systems and components, from design and analysis to qualification.

• Collaborate in planning, scheduling, and execution of engineering tasks across multiple phases of HTGR system development.
• Provide technical oversight and direction to internal and external design teams, ensuring adherence to project objectives and quality standards.
• Lead and participate in reviews and presentations for internal and customer design evaluations, focusing on chemical and thermal‑hydraulic system performance.
• Translate customer needs into functional requirements, contributing to the definition and validation of chemical engineering specifications and interface documents.
• Organize and coordinate efforts between chemical engineering, systems engineering, nuclear design, and external stakeholders, including suppliers and contractors.
• Maintain professional conduct in all forms of communication and project engagement.
• Develop and validate thermal‑hydraulic models for HTGR cores, secondary systems, and balance‑of‑plant using advanced simulation tools such as ASPEN, COMSOL, and other process modeling platforms.
• Conduct system‑level heat and mass balance analyses for steady‑state and transient operating conditions, including load‑following and accident scenarios.
• Integrate chemical engineering principles into HTGR plant design, covering helium Brayton and Rankine cycles, heat exchanger networks, hydrogen production, tritium control, and off‑gas systems.
• Evaluate high‑temperature material behavior—including oxidation, corrosion, and creep—for alloys, graphite, and reactor‑grade materials under HTGR‑relevant conditions.
• Support the specification, sizing, and performance evaluation of key system components such as recuperators, compressors, turbo machinery, and helium circulators.
• Execute or review CFD and FEA analyses to support component‑level assessments of flow distribution, thermal gradients, and structural integrity.
• Contribute to plant operational strategies including control schemes, startup/shutdown procedures, and accident mitigation approaches.
• Support licensing and QA efforts through preparation of technical reports, engineering calculations, and safety analyses in compliance with NRC and ASME standards.
• Lead or mentor small engineering teams in solving complex design and integration challenges within HTGR systems.
• Execute the core tasks and responsibilities listed above with minimal supervision.
• Provide ownership, responsibility, and accountability over technical scope involving the coordination of multiple individual contributors working in a specific area.
• Perform other duties as assigned by the manager.

• Bachelor’s degree in chemical engineering or related degree from an accredited institution.
• Typically, five years of experience in a chemical engineering role.
• Master’s degree in engineering or related field (may include a combination of…