HFIR Mechanical Engineer for Systems & Plant Engineering
Date: Aug 28, 2025
Location: Oak Ridge, TN, US, 37830
Company: Oak Ridge National Laboratory
Requisition Id 15278
Overview:
We are seeking a Mechanical Engineer to provide system engineering support for Cold Source Operations. This position resides within the Research Reactors Division (RRD) at Oak Ridge National Lab (ORNL).
The Cold Source is designed to circulate supercritical hydrogen pressurized to 14 bara at an approximate temperature of 20 K at a rate of approximately one liter per second through a moderator vessel, which cools neutrons emitted from the reactor core. The cold source is an integrated system of the major sub-systems, a hydrogen circulation loop, a hydrogen loop pressurization system, a helium refrigerator, a cryogenic helium transfer system, and vacuum systems. The new cold neutron source facility has been added to HFIR since 2006 to support the increased capabilities to perform research using cold neutrons.
Major Duties/Responsibilities:
Configuration Management
- 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.
- 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 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.
Maintenance Support
- Troubleshoots 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.
Operations Support
- Performs operability assessments to determine equipment impact on HFIR operation.
Systems Analysis
- 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 equal opportunity by fostering a respectful workplace – in how we treat one another, work together, and measure success.
Basic Qualifications:
- A BS degree in mechanical engineering, nuclear engineering or related field.
- A minimum of 5 years of experience in mechanical engineering.
- Project management experience, including maintenance, procedure development, procurement, and equipment analysis.
- Proficient in 3D CAD software (SolidWorks, Siemens NX, Creo, Inventor).
- Capable of performing engineering calculations and technical analyses.
- Experienced in creating design specs, technical procurement, and material documentation.
Preferred Qualifications:
- An MS degree in mechanical engineering, nuclear engineering, or a related field.
- Experience working with research reactors or DOE national laboratory facilities.
- Skilled in engineering design and manufacturing, with expertise in welding, joining, and machine design.
- Knowledge of ASME Codes (Sections III & VIII, B31.1) and DOE Orders/Standards (e.g., DOE O 420.1C, DOE STD-1189, STD-1073-2016).
- Strong understanding of GD&T (ASME Y14.5).
- Comprehensive understanding of nuclear technology (e.g., nuclear reactor safety basis, design, and construction)
- Familiarity with nuclear reactor systems.
- Experience with NQA-1 quality assurance requirements for nuclear facilities.
- Knowledge of AWS welding codes and standards.
- Familiarity with finite element analysis (FEA) software, such as ANSYS or Abaqus, for structural and thermal analysis.
- Understanding of radiation shielding design principles and nuclear safety analysis.
Special Requirements:
- Physical 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.
Security, Credentialing, and Eligibility Requirements:
For employment at Oak Ridge National Laboratory (ORNL), a Real ID compliant form of identification will be required. Additionally, ORNL is subject to Department of Energy (DOE) access restrictions. All employees must also be able to obtain and maintain a federal Personal Identity Verification (PIV) card as mandated by Homeland Security Presidential Directive 12 (HSPD-12) and Department of Energy (DOE) Order 473.1A, which requires a favorable post-employment background investigation.
To obtain this credential, new employees must successfully complete and pass a Federal Tier 1 background check investigation. This investigation includes a declaration of illegal drug activities, including use, supply, possession, or manufacture within the last year. This includes marijuana and cannabis derivatives, which are still considered illegal under federal law, regardless of state laws.
For foreign national candidates:
If you have not resided in the U.S. for three consecutive years, you are not eligible for the PIV credential and instead will need to obtain a favorable Local Site Specific Only (LSSO) risk determination to maintain employment. Once you meet the three-year residency requirement, you will be required to obtain a PIV credential to maintain employment.
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: ORNLRecruiting@ornl.gov.
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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 ORNLRecruiting@ornl.gov.
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.
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