Thermal-Hydraulic Safety Analysis Engineer I-III — V&V

X-energy; Gaithersburg (MD); Hybrid; USD 120,000 - 180,000; Full time

Job summary

X-energy is seeking an engineer to support the Risk Informed Safety Analysis team in Gaithersburg, MD. You will perform thermo-hydraulic safety analyses for Xe-100 design, assess AOOs, DBEs, DBAs, and BDBEs, and help ensure core cooling and defense-in-depth through code-based assessments.

The role collaborates with neutronics, structures, materials, and reactor systems to establish safety requirements, supports V&V activities, and prepares regulatory submittals in a QA-compliant environment.

Qualifications

• Bachelor's degree in engineering (nuclear, chemical, mechanical, etc.) from an accredited institution.
• A master's degree in engineering or related field may be in lieu of two years of experience.
• A Ph.D. in engineering or related field may be in lieu of three years of experience.
• Level I: typically 0–2 years of experience.
• Level II: typically 3 years of experience.
• Level III: typically 5 years of experience.
• Coursework in thermo-hydraulics, heat transfer, fluid mechanics or reactor systems analysis preferred.
• Familiarity with thermal-hydraulic system codes (RELAP, TRACE, GOTHIC, Flownex) preferred.

Responsibilities

• Perform thermo-hydraulic safety analysis for designated systems and accident scenarios using approved system analysis codes and methodologies, in accordance with NRC guidance (RG 1.203) and X-energy procedures.
• Conduct transient and accident analyses evaluating core cooling, coolant flow behavior, heat transfer mechanisms, and temperatures throughout the reactor system and key components for AOOs, DBEs, DBAs, and BDBEs.
• Support SSC safety classifications through thermo-hydraulic analysis and provide evidence of component performance during accidents and transients.
• Contribute to PIRTs that identify and rank thermo-hydraulic phenomena relevant to reactor safety.
• Support scaling analyses to demonstrate applicability of data and methods to Xe-100 design and document code applicability bases.
• Assist in establishing thermo-hydraulic safety limits, margins, and acceptance criteria for regulatory compliance.

Skills

Nuclear engineering

Thermo-hydraulics

Heat transfer

Fluid mechanics

Reactor systems analysis

V&V

CGD

NQA-1

Education

Bachelor's degree in engineering (nuclear, chemical, mechanical, etc.)

Master's degree in engineering or related field

Ph.D. in engineering or related field

Tools

RELAP

TRACE

GOTHIC

Flownex

Job description

X-energy is seeking an engineer to support the Risk Informed Safety Analysis team in Gaithersburg, MD. You will perform thermo-hydraulic safety analyses for Xe-100 design, assess AOOs, DBEs, DBAs, and BDBEs, and help ensure core cooling and defense-in-depth through code-based assessments.

The role collaborates with neutronics, structures, materials, and reactor systems to establish safety requirements, supports V&V activities, and prepares regulatory submittals in a QA-compliant environment.