Thermal Analysis Engineer

X-energy LLC conducts a thorough recruiting process and will never issue offers without interview to discuss qualifications and responsibilities. All applications will be submitted via our company career page,  We will never ask you to provide payment information as part of the recruiting process. If anyone claiming to represent X-energy directs you in a manner otherwise, please contact us at

X-energy is seeking Thermal Analysis Engineers responsible for the engineering design and development of mechanical systems, structures, and components. This includes concept development, evaluation of concepts, analysis of systems, structures, and components for their ability to perform their intended function, and ensuring they meet all technical specifications and requirements. The role will ensure the development of the systems and components through production including any necessary prototyping, testing, and commissioning.

• Develop mechanical/physical concepts, design and support development of processes to create or identify structures, systems, and components (SSCs) for use in nuclear products or facilities with a focus on nuclear safety.
• Identify, collect, and document applicable requirements, interfaces, design basis and criteria by coordinating with key stakeholders/systems engineers and support identifying applicable industry codes and standards and the direction of project leads and systems engineers.
• Planning and performing the analysis required to assess aspects of the SSCs to ensure they can perform their intended functions and meet technical specifications and design requirements.
• Perform computations utilizing hand calculations and analytical tools for structural, thermal, hydraulic, and other scoping calculations as required at the direction of project leads and systems engineers to ensure SSCs can meet technical requirements.
• Support the development of reactor and plant control philosophy and implement in plant models, simulations, and digital twins.
• Support the sizing and analysis of components including heat exchangers, pumps, circulators, and turbo machinery.
• Perform system-level thermodynamic analyses and process design using system-level simulation codes to support design iterations of X-energy developed reactors and supporting subsystems.
• Support the assessment of SSCs for manufacturability as well as assembly and integration considerations at the direction of project leads.
• Write and develop design documentation including design basis documents, technical reports, calculations, and drawings in accordance with applicable procedures.
• Develop Verification and Validation (V&V) plans for analytical tools and support qualification of toolset.
• Perform work in accordance with X-energy quality procedures for design and configuration management to ensure project quality requirements are met.
• Provide independent reviews and acceptance reviews of engineering deliverables and data.
• Maintain professional demeanor and behavior at all times in all forms of communication.
• Perform other duties as assigned by manager.

• Bachelor’s degree in mechanical engineering, or related engineering discipline (e.g., nuclear aerospace, chemical, etc.) from an accredited institution required.
• Level I:
  Typically, zero years of experience in an engineering role required.
• Level II:
  Typically, two years of experience in an engineering role required.
• Level III:
  Typically, five years of experience in an engineering role required.
• Proficiency with engineering hand calculations is required.
• Use of 1D flow-solvers performing heat/energy and mass balance (e.g., RELAP, Flownex, NPSS, SINDA/FLUINT, Flomaster, or similar).

530 Gaither Road, Rockville, MD

4 days in office

Up to 10% as needed

8:00am - 5:00pm, Mon-Fri

As required by Maryland and other applicable state law, X Energy, LLC (X-energy) lists the expected compensation range for a publicly advertised job opportunity based upon the job requirements (e.g. education/training, experience, skill sets, etc.). Individual candidates who meet the job requirements for the posted position will be offered a salary within this range based on their respective levels of education/training, experience, and other qualifications unique to them.

Salary ranges may vary based on the specific office location and region referenced in the posting to take into consideration differences in cost of living and may not be reflective of all regions. Please note that compensation ranges listed for US job postings reflect base salary only and do not include benefits or other incentives.

A reasonable estimate for this position at the level of experience required is:

Level I: $70,050 - $116,750
Level II: $79,500 - $132,500
Level III: $97,875 - $163,125

Full time - Exempt

X Energy, LLC offers a robust benefits package that includes a 401K plan with an employer match, Medical/Dental /Vision Insurance,…