Criticality Safety Engineer

Criticality Safety Engineer

Aalo Atomics is pioneering a new era in clean energy with factory-fabricated microreactors designed to deliver affordable, scalable, and reliable nuclear power. Our mission is to make nuclear energy globally accessible, starting with the Aalo-1, a 10 MWe reactor leveraging cutting-edge safety, modularity, and efficiency. Based in Austin, TX, we're rapidly growing as we work to deploy the world's first fleet of advanced microreactors. Join us and help revolutionize energy for a sustainable future.

We are seeking a Criticality Safety Engineer to perform criticality safety evaluations, develop and maintain criticality safety controls, and serve as a Criticality Safety Officer (CSO) for assigned facilities at the Aalo-X campus. Reporting to the Nuclear Safety Manager, this role is responsible for ensuring that all operations involving fissionable materials comply with DOE criticality safety requirements and applicable ANSI/ANS-8 series standards. You will perform independent criticality safety analyses, check and review the work of others, and provide technical guidance to operations, design, and facility management teams.

As a CSO for assigned Criticality Control Areas, you will also serve as the on-the-ground liaison between Criticality Safety Engineering and facility operations, performing regular walkdowns and surveillance, advising operating personnel on criticality safety limits and controls, and ensuring that new or modified equipment and activities are covered by active criticality safety evaluations. This combined engineering and facility oversight role requires deep technical expertise in nuclear criticality safety, strong analytical skills, and the ability to communicate complex safety requirements clearly to diverse technical and operational audiences.

What You'll Do

• Perform criticality safety evaluations (CSEs) independently in accordance with DOE-STD-3007, including scoping calculations for design, technical guidance, and formal safety basis analyses.
• Check and verify criticality safety evaluations for accuracy, including performing independent calculations and analyses to confirm that all evaluation requirements have been met.
• Perform criticality safety reviews and assessments of existing facilities and planned activities, including facility modifications and process changes.
• Review safety basis documents, proposed safety basis documents, and facility/process modifications for criticality safety implications.
• Oversee and support the implementation of the Aalo Atomics Criticality Safety Program requirements, limits, and controls across assigned facilities.
• Serve as the Criticality Safety Officer for assigned Criticality Control Areas, acting as the facility advocate for criticality safety and liaison between facility management and Criticality Safety Engineering.
• Perform regular facility walkdowns and surveillances to maintain familiarity with operations and verify compliance with criticality safety controls.
• Advise operating personnel and supervision on conformance to criticality safety limits and requirements, and identify when Criticality Safety Engineering consultation is needed.
• Authorize the implementation of new or modified equipment and activities within assigned Criticality Control Areas, ensuring they are covered by active CSEs and the criticality safety basis.
• Participate in the development and approval of facility-specific criticality safety controls, including attending review meetings and concurring with facility criticality controls.
• Provide guidance to operations and facility management on the identification of violations and areas of concern related to criticality safety.
• Support the development and maintenance of criticality safety documentation, including the Criticality Safety Program plan, procedures, and training materials.
• Coordinate with nuclear safety, design engineering, and operations teams to ensure criticality safety requirements are integrated into facility design and operational procedures.
• Support development of recovery plans and emergency response procedures related to criticality safety events.
• Perform or support Unreviewed Safety Question (USQ) evaluations for changes with potential criticality safety implications.

Qualifications

• Bachelor of Science degree in Nuclear Engineering, Nuclear Physics, Physics, or a closely related scientific or engineering discipline.
• 8+ years of experience in nuclear criticality safety, including the independent preparation and review of criticality safety evaluations at DOE nuclear facilities.
• Proficiency with Monte Carlo neutron transport codes (e.g., MCNP, SCALE, OpenMC, or Serpent) for criticality safety analysis.
• Strong working knowledge of DOE criticality safety requirements, including 10 CFR 830, DOE Order 420.1 Chapter III, and DOE-STD-3007.
• Thorough familiarity with the ANSI/ANS-8 series standards for nuclear criticality safety.
• Experience reviewing and assessing safety basis documents for criticality safety adequacy.
• Demonstrated ability to perform independent criticality safety assessments of facilities, processes, and proposed modifications.
• Strong technical writing and communication skills, with the ability to prepare clear and defensible criticality safety evaluations and technical reports.
• Effective interpersonal skills with the ability to communicate criticality safety requirements to operations, design, and management personnel.
• Knowledge of nuclear criticality safety training and qualification requirements per ANSI/ANS-8.26.

Preferred Qualifications

• Advanced degree (M.S. or Ph.D.) in Nuclear Engineering, Nuclear Physics, or a related discipline.
• Experience serving as a Criticality Safety Officer with facility-specific oversight responsibilities.
• Hands-on criticality safety training or practical experience with parameters affecting neutron multiplication of fissionable material systems.
• Experience with validation of neutron transport methods per ANSI/ANS-8.24, including benchmark experiment selection and bias determination.
• Familiarity with DOE-STD-3009 and the integration of criticality safety into Documented Safety Analyses.
• Experience with criticality accident alarm systems design and evaluation per ANSI/ANS-8.3.
• Knowledge of transportation criticality safety requirements, including 10 CFR 71 and 49 CFR 173.
• Experience supporting DOE readiness assessments, Operational Readiness Reviews, or similar authorization activities for criticality safety.
• Background in advanced reactor fuel handling, storage, and processing operations.
• Familiarity with Integrated Safety Management System principles as applied to criticality safety.

Work Environment

• Combination of office and field environment at the Aalo-X campus.
• Regular facility walkdowns in Criticality Control Areas with appropriate PPE and access controls.
• Occasional travel to DOE headquarters, other Aalo locations, or industry events as required.

What Success Looks Like

• Criticality safety evaluations that are technically rigorous, clearly documented, and defensible under DOE review.
• Assigned Criticality Control Areas operating in full compliance with criticality safety controls and limits.
• Early identification and resolution of criticality safety concerns in facility modifications, new activities, and design changes.
• Strong working relationships with operations, design, and facility management teams, built on clear communication and trusted technical judgment.
• A well-maintained criticality safety basis with current evaluations, controlled documentation, and effective configuration management.
• Successful support of DOE authorization milestones and readiness assessments for criticality safety.

What It Takes to Succeed at Aalo

We're building technology that will help reshape the future of energy. The pace is fast, the problems are difficult, and the expectations are high. Successful team members consistently demonstrate:

• Extreme Ownership — You take responsibility for outcomes, not just tasks. You proactively identify problems, drive solutions, and follow through.
• A Passion for Solving Hard Problems — You are energized by challenges that others avoid and enjoy finding practical solutions to complex technical issues.
• A Sense of Urgency — You move quickly, make thoughtful decisions, and maintain momentum while balancing quality and execution.
• Based in the United States
• Willing to work on-site in Idaho Falls, ID

What We Offer:

• Competitive salary based on experience
• Health, Dental, Vision Insurance
• Paid Time Off
• Corporate Gym Membership

Additional Information:

Aalo Atomics provides a collaborative and supportive work environment, opportunities for professional growth, intellectually challenging careers, and competitive compensation. Aalo Atomics is an equal opportunity employer and considers all employment decisions without regard to race, color, religion, national or ethnic origin, sex, sexual orientation, gender identity or expression