Nuclear Mechanical Engineer

Date: Apr 3, 2024

Location: Oak Ridge, TN, US, 37830

Company: Oak Ridge National Laboratory

Requisition Id 12813 


We are seeking a Nuclear Mechanical Engineer to join the Systems Engineering (SE) Group within the Research Reactors Division (RRD) at Oak Ridge National Lab (ORNL)! Our group is responsible for the High Flux Isotope Reactor (HFIR) configuration management program. The SE Group also provides technical support to operations and maintenance and performs systems analysis. In this role, you will perform design engineering and support manufacturing and fabrication of reactor core components, fuel elements, control rods and plates, etc. You will also handle maintaining overall cognizance of assigned HFIR structures, systems, and components (SSCs) and provide systems engineering support for operations and maintenance. 


Major Duties/Responsibilities:   


  • Prepares engineering designs for new installations and for replacement and upgrade of HFIR structures, systems, and components (SSCs).  
  • Performs calculations and analyses to support design basis and requirements. 
  • Applies relevant codes and standards, such as ASTM, ASME, AWS, GD&T, QS9000, ISO14001, etc.  
  • Supports development of reactor core components replacement plan. 
  • Prepares design specifications to define and determine acceptance criteria for component upgrades. 
  • Prepares material specifications and provides technical support in procurement of materials. 
  • Project leads fabrication, machining, and assembly of reactor core components, experiments, special tooling, etc. in accordance with HFIR specifications. 
  • Implements modifications in accordance with RRD configuration control processes. 
  • Prepares and maintains as-built documentation for assigned HFIR SSCs, including engineering drawings, specifications, system descriptions, relevant databases, and labeling. 
  • Provides project management for installation of mechanical design changes. 



  • Fixes and analyzes system and component failures and develops corrective actions. 
  • Provides written work package instructions to perform and document work. 
  • Provides field technical support to craft supervisors and craft. 
  • Provides input to preventive and predictive maintenance work instructions. 


  • Performs operability assessments to determine equipment impact on HFIR operation. 


  • Analyzes and trends results of preventive and predictive maintenance data. 
  • Analyzes equipment performance history. 
  • Performs overall systems health evaluation in accordance with HFIR Reliability Program, which involves the following: 
  • System Health Indicators 
  • Identification of new and status of existing equipment vulnerabilities 
  • HFIR 3-Year Planning Activities 
  • Identification of Spare Parts deficiencies 
  • Walk-Downs to Assess System Configuration and Material Condition 
  • Assessment of open Modifications, Deviations, and Corrective Work Packages 
  • Deliver ORNL’s mission by aligning behaviors, priorities, and interactions with our core values of Impact, Integrity, Teamwork, Safety, and Service. Promote diversity, equity, inclusion, and accessibility by fostering a respectful workplace – in how we treat one another, work together, and measure success. 


Basic Qualifications: 

  • A BS in mechanical engineering related field and at least 15 years of proven experience. 
  • Experience in project management, leading maintenance tasks, procedure development, procurement of materials and equipment analysis. 


Preferred Qualifications: 

  • Experience and thorough understanding of ASME vessel and piping codes. 
  • Ability to diagnose mechanical equipment problems and develop formal work package instructions for performance and documentation of repairs. 
  •  A strong understanding of reading and interpreting mechanical design drawings as well as understanding of GD&T principles from ASME Y14.5. 
  •  Familiarity with mechanical design and maintenance activities in a nuclear reactor operating environment.   
  • Experience in operation and troubleshooting HVAC systems, and familiarity with the code on Nuclear and Gas Treatment ASME AG-1. 
  • Experience with cryogenics and working with cryogenic equipment. 
  • Strong thermodynamics background and experience. 
  • Familiarity with the regulatory programs which define the HFIR work environment, including DOE Orders pertaining to conduct of operation and maintenance, OSHA requirements.   


Special Requirements:  

Work involves various physical requirements and working conditions. As such, a pre-hire physical will be required after offer. 


L Clearance:

This position requires the ability to obtain and maintain a clearance from the Department of Energy. As such, this position is a Workplace Substance Abuse (WSAP) testing designated position. WSAP positions require passing a pre-placement drug test and participation in an ongoing random drug testing program. 


Visa sponsorship is not available for this position.  


Benefits at ORNL:   

We offer competitive pay and benefits programs to attract and retain hardworking people! The laboratory offers many employee benefits, including medical and retirement plans and flexible work hours, to help you and your family live happy and healthy. Employee amenities such as on-site fitness, banking, and cafeteria facilities are also provided for convenience. 


Other benefits include the following: Prescription Drug Plan, Dental Plan, Vision Plan, 401(k) Retirement Plan, Contributory Pension Plan, Life Insurance, Disability Benefits, Generous Vacation and Holidays, Parental Leave, Legal Insurance with Identity Theft Protection, Employee Assistance Plan, Flexible Spending Accounts, Health Savings Accounts, Wellness Programs, Educational Assistance, and Employee Discounts. Relocation Assistance is available for this position. 


If you have difficulty using the online application system or need an accommodation to apply due to a disability, please email: or call 1.866.963.9545. 







This position will remain open for a minimum of 5 days after which it will close when a qualified candidate is identified and/or hired.

We accept Word (.doc, .docx), Adobe (unsecured .pdf), Rich Text Format (.rtf), and HTML (.htm, .html) up to 5MB in size. Resumes from third party vendors will not be accepted; these resumes will be deleted and the candidates submitted will not be considered for employment.

If you have trouble applying for a position, please email

ORNL is an equal opportunity employer. All qualified applicants, including individuals with disabilities and protected veterans, are encouraged to apply.  UT-Battelle is an E-Verify employer.

Nearest Major Market: Knoxville