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Job Description
This role is responsible for supporting the Risk Informed Safety Analysis team that performs nuclear safety analysis for X-energy technology (e.g., Xe-100) licensing and design, with particular emphasis on thermo-hydraulic analysis. The position provides technical leadership in conducting comprehensive safety evaluations including system and component thermo-hydraulic transient and accident analysis, analysis to support safety function identification and Structures, Systems, and Components (SSC) safety classification, and deterministic safety assessments to inform PRA. The Safety Analysis Engineer performs and oversees thermo-hydraulic safety analysis work supporting regulatory submittances, ensures proper application of NRC regulatory guidance (including RG 1.203 and design-specific interim staff guidance), and collaborates with engineering disciplines to establish design requirements derived from safety analysis. The position also supports verification and validation (V&V) activities to ensure thermo-hydraulic analysis codes are appropriately qualified for their safety analysis applications. Key responsibilities include developing Phenomena Identification and Ranking Tables (PIRTs) for thermo-hydraulic phenomena, performing scaling analyses, conducting accident scenario evaluations using system codes, establishing thermal-hydraulic safety limits and safety margins, and supporting the safety case for TRISO fuel and high-temperature gas-cooled reactor technology.
Job Profile Tasks/Responsibilities
Perform comprehensive thermo-hydraulic safety analysis for assigned systems and accident scenarios using approved system analysis codes and methodologies in accordance with NRC regulatory guidance (RG 1.203) and X-energy procedures.
Conduct transient and accident analysis evaluating core heat removal, coolant flow behavior, heat transfer mechanisms, and temperature distributions throughout the reactor system and key components for anticipated operational occurrences (AOOs), design basis events (DBEs), design basis accidents (DBAs), and beyond design basis events (BDBEs) to demonstrate adequate core cooling, heat removal capability, and defense-in-depth.
Support the development and maintenance of SSC safety classifications through thermo-hydraulic analysis, providing analytical results that demonstrate component performance and safety function capability during accident scenarios and operational transients.
Develop and maintain Phenomena Identification and Ranking Tables (PIRTs) to identify and rank thermo-hydraulic phenomena important to reactor safety for various accident scenarios and operational transients.
Conduct scaling analyses to demonstrate applicability of experimental thermo-hydraulic data and analytical methods to the Xe-100 design, documenting the technical basis for code applicability.
Establish thermo-hydraulic safety limits, safety margins, and acceptance criteria for safety analyses based on regulatory requirements, fuel temperature limits, material temperature limits, and fission product barriers.
Support probabilistic risk assessment (PRA) activities by providing deterministic thermo-hydraulic analysis results, identifying initiating events, and supporting the integration of deterministic and risk-informed approaches.
Develop technical documentation for regulatory submittals including topical reports, safety analysis reports, code applicability reports for thermo-hydraulic codes, and responses to NRC requests for additional information (RAIs).
Ensure thermo-hydraulic safety analysis work products comply with NQA-1 quality assurance requirements and X-energy procedures for safety-related calculations and analyses, and perform work in accordance with X-energy Quality Assurance procedures and maintain documentation to NQA-1 standards.
Provide technical input to design teams based on thermo-hydraulic safety analysis results, including identification of cooling requirements, flow path design constraints, heat removal capabilities, and operational limitations.
Review and approve thermo-hydraulic safety analysis work products from other analysts, subcontractors, and partners to ensure technical adequacy, regulatory compliance, and consistency with the overall safety case, and support the review and acceptance of thermo-hydraulic analysis software used for safety analysis applications, including oversight of software validation activities to ensure codes are qualified for their intended safety analysis applications.
Lead small teams of safety analysts in executing complex thermo-hydraulic safety evaluations and developing integrated safety analysis documentation.
Provide technical guidance and mentorship to junior safety analysts on thermo-hydraulic analysis methodologies, system code application, regulatory requirements, and industry best practices, serve as a technical resource for thermo-hydraulic analysis software applications, providing guidance on appropriate
selection and use of system codes, nodalization approaches, and modeling techniques for specific safety analysis problems, and share knowledge related to industry best practices, regulatory precedents, and thermo-hydraulic safety analysis standards with others across the team.
Collaborate with other engineering disciplines (neutronics, structural, materials, reactor systems) to ensure thermo-hydraulic safety analysis assumptions are consistent with design basis and that safety-derived requirements are properly implemented, and interface with regulatory agencies, industry partners, and external stakeholders to support the technical basis for X-energy's thermo-hydraulic safety analysis approach and licensing strategy.
Assess quality of information given and ask pertinent questions to stakeholders to ensure thermo-hydraulic safety analysis is based on sound technical foundations.
Provide the Xe-100 Team leads with frequent updates on progress and promptly communicate adverse findings or technical concerns related to thermo-hydraulic safety limits and safety margins.
Maintain professional demeanor and behavior at all times in all forms of communication.
Execute thermo-hydraulic safety analysis assignments with clear objectives while exercising independent judgment on technical approaches and methods.
Perform other duties as assigned by manager.
Job Minimum Qualifications
- Bachelor’s degree in engineering (nuclear, chemical, mechanical, etc.) or related degree from an accredited institution.
- Typically, ten years of experience in an engineering role.
- A master’s degree in engineering or related field (may include a combination of experience obtained through an academic institution, e.g., design projects, research, or design teams, as well as professional experience) may be in lieu of two years of experience.
- A Ph.D. in engineering or related field (may include a combination of experience obtained through an academic institution, e.g., design projects, research, or design teams, as well as professional experience) may be in lieu of three years of experience.
- Previous experience at X-energy exceeding performance standards may be in lieu of years of experience.
- Requires specialized knowledge within the function of safety analysis.
- Requires previous experience with performing V&V or CGD activities.
Location: 530 Gaither Road, Rockville, MD
Work Site Expectations: Remote eligible
Hours: 8:00am-5:00pm, Mon-Fri
Compensation
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:
$112,200- $187,000Position Job Classification
Full time - ExemptBenefits
X Energy, LLC offers a robust benefits package that includes a 401K plan with an employer match, Medical/Dental /Vision Insurance, Life and Disability Insurance, Paid Time Off, and a Tuition Reimbursement/Professional Development policy that supports the continuing education of our employees.
An Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, or protected veteran status and will not be discriminated against on the basis of disability.
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Top Skills
What We Do
X-energy is delivering the next generation of carbon-free energy by reinventing nuclear power. We believe in leaving a cleaner planet for our children and grandchildren, while continuing to provide sufficient and affordable power to sustain growing populations around the world. That is why we have reinvented nuclear power, with a unique combination of proven technologies and new innovations, to meet our current and future needs. X-energy manufactures fuel that seals uranium particles in a protective coating, which makes meltdown impossible and retains the waste inside forever. We also design plants that unlock the fuel’s potential in a process that’s as clean as wind or solar. When combined, the result is reliable carbon-free baseload power, produced more safely and affordable than ever before and available anywhere, at any time.








