Staff Control Systems Engineer, Safety & Interlock Systems

About Thea Energy: Thea Energy is leveraging recent breakthroughs in stellarator physics and engineering to create a faster and simpler approach to commercializing fusion energy. The company is reinventing the stellarator using computer-controlled arrays of planar coils thereby replacing the intricate, complex modular magnets required in all other stellarator architectures. Thea Energy is on a mission to create a limitless source of zero emission energy for a sustainable future.

Position Overview: You will develop PLC-based and hardwired control systems for personnel access, equipment permissives, interlocks, and protective shutdown functions. Your work will span requirements, electrical and software design, hardware integration, testing, commissioning, and operational support. You will collaborate with controls engineers, subsystem owners, physics, operations, and safety specialists to implement and verify the required protective functions.

As Eos advances through design and into construction, you will contribute reusable PLC software, electrical designs, interface specifications, and test methods that support consistent implementation across plant systems. This is a hands-on engineering role requiring strong controls development and troubleshooting skills, practical experience with safety-rated hardware, and sound judgment in applying functional safety requirements.

Key Responsibility Areas:

• Develop control architectures for safety and interlock systems, including personnel access, emergency shutdown, and interfaces with subsystem controls and machine protection. Work with system owners to define signal interfaces and the required independence between safety functions, normal plant control, and equipment protection.
• Translate approved safety and operational requirements into control specifications, functional descriptions, cause-and-effect matrices, I/O lists, and interface control documents. Maintain traceability between requirements, hardware and software implementation, and test results.
• Participate in hazard and design reviews with system owners and safety specialists. Provide controls expertise to identify failure modes, evaluate proposed protective actions, and translate risk assessment findings into implementable control functions.
• Work with safety specialists to establish the integrity and performance requirements applicable to each control function. Implement and document safe states, response times, diagnostics, fault handling, reset conditions, and provisions for proof testing in the hardware and software design.
• Select and integrate safety PLCs, safety-rated I/O, hardwired circuits, and communications appropriate to the specified functions. Evaluate fault behavior, common-cause vulnerabilities, maintainability, and availability when developing control architectures.
• Design personnel access and exclusion systems, including controlled zones, search-and-secure sequences, trapped-key interlocks, door monitoring, emergency stops, warning systems, and prevention of unexpected restart.
• Implement interlock and shutdown controls for systems involving high voltage, high current and stored energy, superconducting magnets, RF and neutral beam heating, radiation-generating equipment, cryogenics, oxygen deficiency monitoring, and hazardous gases, working with the responsible technical and safety specialists.
• Define coordinated trip, inhibit, isolation, and shutdown sequences across plant systems. Ensure that protective actions account for stored energy and preserve cooling, ventilation, monitoring, or other services required to reach and maintain a safe state.
• Coordinate interfaces with magnet quench protection, power supply protection, radiation monitoring, gas detection, and facility emergency systems. Define ownership, signal integrity, response timing, and fault behavior at each interface.
• Specify behavior across operating modes and transitions, including preparation, energization, plasma operation, shutdown, maintenance, and fault recovery. Establish controlled provisions for commissioning overrides, bypasses, and inhibited functions.
• Produce and review electrical schematics, safety loop diagrams, panel designs, I/O schedules, cable and grounding requirements, equipment specifications, and installation work packages using EPLAN or comparable tools.
• Develop, document, and test safety PLC application software and configuration using approved platform tools and IEC 61131-3 languages. Establish reusable function blocks, coding practices, version control, and controlled release processes.
• Specify and integrate safety-rated sensors, switches, relays, final elements, power supplies, and communications. Evaluate the complete sensor-to-final-element chain, including component suitability and failure modes.
• Integrate status, alarms, first-out trip information, and diagnostics with the supervisory control system while preserving the integrity and independence of the safety functions. Design operator interactions that support clear decisions and safe recovery.
• Develop and execute hardware and software verification plans, factory and site acceptance tests, integration tests, and commissioning procedures. Provide test results and configuration records to support independent validation and safety reviews as required.
• Define technical work packages and acceptance criteria; review supplier designs and test evidence; and coordinate implementation with vendors, integrators, and internal system owners.

Required Qualifications:

• Bachelor's degree in electrical engineering, controls engineering, automation, or a related technical discipline, or equivalent relevant professional experience.
• Typically 8 or more years of relevant controls or electrical engineering experience, including hands-on design, programming, integration, and commissioning of PLC-based control systems with safety or interlock functions.
• Demonstrated experience delivering controls for personnel access, interlocks, or protective shutdown systems in fusion facilities, particle accelerators, synchrotrons, spallation sources, or comparable large scientific facilities.
• Practical understanding of functional safety requirements and experience applying IEC 61508, IEC 61511, IEC 62061, or ISO 13849, as relevant, to control hardware, application software, and verification activities.
• Hands-on experience programming, integrating, and validating safety PLCs, safety-rated I/O, interlock circuits, and field devices. Experience with Rockwell Automation GuardLogix, Siemens SIMATIC F systems, or comparable platforms.
• Ability to translate functional and safety requirements into electrical designs, PLC logic, and measurable acceptance criteria, with documented traceability and configuration control.
• Experience designing personnel access controls, emergency shutdown functions, and safe interfaces to hazardous equipment or processes.
• Strong electrical design and troubleshooting skills, including schematic development, control panel integration, instrumentation, and testing of complete safety loops.
• Experience with system integration, commissioning, functional testing, and maintenance or proof testing of safety systems in an operating facility.
• Ability to resolve control system interface issues across disciplines, explain design tradeoffs clearly, and produce electrical, software, and test documentation suitable for engineering reviews.

Preferred Qualifications:

• Direct experience with fusion plant safety controls, superconducting magnets, high-energy power systems, RF heating, neutral beam systems, or radiation-generating equipment.
• Experience integrating radiation protection, oxygen deficiency monitoring, gas detection, laser safety, or cryogenic safety systems into a facility safety architecture.
• Experience supporting reliability or safety integrity assessments through hardware failure analysis, diagnostic implementation, response-time evaluation, and proof-test design.
• Familiarity with applicable US electrical and machinery safety practices and standards, such as NFPA 70, NFPA 70E, and NFPA 79, and experience working with safety and compliance specialists to define the project requirements.
• Experience with EPLAN or comparable electrical design software, PLC development environments, requirements and configuration management tools, and interfaces to SCADA or scientific control environments such as EPICS.
• Functional safety training or certification, such as CFSE, CFSP, or a recognized functional safety engineer qualification, particularly where applied to PLC-based control system implementation.

Company Benefits:

• Salary Range: $180,000 - $230,000 per year
• Comprehensive health benefits (e.g. medical/dental/vision)
• Employee equity stock options
• 20 days PTO

Requirements:

• Ability to occasionally lift up to 50 lbs.
• Ability to perform activities such as typing, standing, or sitting for extended periods of time.
• Willingness to occasionally travel or work required nights/weekends/on-call.
• Ability to work in a facility that contains industrial hazards including heat, cold, noise, fumes, strong magnets, high voltage, high current, pressure systems, and cryogenics.

It’s not necessary to meet all of the skillsets outlined above. Please feel free to send us a note and tell us why you would still be a great fit for this role or Thea Energy.

Diversity and Inclusion: Thea Energy is an equal opportunity employer committed to creating a company of diverse backgrounds. By creating a diverse environment, we will bring new ideas and approaches to solving some of the world’s hardest (and most important) problems. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, gender, sexual orientation, gender identity or expression, national origin, family or marital status, age, disability, veteran’s status, or other characteristic protected by applicable laws and regulations.