Mechanical Design Engineer – Reactor Internals (In-Vessel Shielding)

*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,* [*www.x-energy.com/careers/*](https://www.x-energy.com/careers/)*. 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* [*www.x-energy.com/contact-us*](https://www.x-energy.com/contact-us)*.* **Job Description** X-energy is seeking a Mechanical Design Engineer responsible for the engineering design, analysis, and development of the in-core shielding elements that comprise the Reactor Vessel Internals (RVI) for X-energy's advanced high-temperature gas-cooled reactor. This role supports the design lifecycle from concept development through detailed design, analysis, manufacturing support, testing, and commissioning while ensuring compliance with nuclear safety, quality, and regulatory requirements. The engineer will work closely with cross-functional engineering teams to develop shielding component designs that satisfy structural, thermal, manufacturing, and integration requirements within the reactor vessel. Success in this role requires strong mechanical and nuclear design fundamentals, an understanding of complex assemblies, and the ability to balance performance, manufacturability, and nuclear safety requirements throughout the product development lifecycle. **Responsibilities** - 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. - Integrate design activities across engineering team members, partners, and suppliers and perform supporting scoping and sizing calculations to downselect design features to meet design requirements using guidance from consensus codes and standards. - Create and maintain CAD-generated engineering models of reactor SSCs. - Develop innovative mechanical solutions to refine and deploy concepts, technologies, and designs associated with X-energy developed reactors, including pressure vessels and piping, reactor internals, nuclear fuel, and high temperature materials such as graphite. - 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. **Minimum Qualifications** - Typically, five years of experience in an engineering role required. - Bachelor’s degree in mechanical e…