Senior Nuclear Criticality Safety Engineer

Senior Nuclear Criticality Safety Engineer

Santa Clara, CA or Remote

Oklo is seeking a Senior Nuclear Criticality Safety Engineer to perform criticality safety evaluations, develop the nuclear criticality safety basis, and architect the nuclear criticality safety program for a first‑of‑a‑kind used nuclear fuel recycling facility.

• Identify and evaluate nuclear criticality safety hazards for fuel cycle facilities.
• Perform criticality safety evaluations (CSEs) to demonstrate subcriticality under normal and credible abnormal conditions.
• Develop the criticality code validation report.
• Demonstrate compliance with the double‑contingency principle.
• Document criticality hazard analyses, CSEs, and supporting technical information.
• Evaluate and implement controlled parameters for the NCS program.
• Develop the criticality accident alarm system and inadvertent criticality emergency response plan.
• Support safety basis development and licensing efforts.
• Develop and administer the NCS program, methodologies, and management measures.

• Bachelor’s, Master’s, or PhD in nuclear engineering, chemical engineering, chemistry, or related field.
• Minimum 5+ years experience performing CSEs as part of a nuclear facility’s safety basis.

• Knowledge of used nuclear fuel recycling technologies.
• 10+ years experience performing criticality safety evaluations for an NRC licensed fuel cycle facility.
• Knowledge of nuclear science, physics of criticality, and chemistry.
• Knowledge of nuclear fuel cycle processes and accident scenarios.
• Proficiency with Attila4MC, MCNP, SCALE, and/or Serpent codes and modules.
• Familiarity with critical experiments and their purpose.
• Knowledge of criticality‑specific codes, standards, regulatory requirements, and industry practices for nuclear fuel cycle facilities.
• Familiarity with NUREG‑1513, NUREG‑1520, NUREG/CR‑6410, NUREG/CR‑6698, NUREG/CR‑7311, and NRC RG 3.71.
• Passionate about clean energy and advanced fission.
• Knowledgeable about structural design, analysis, and construction.
• Eager to work on a dynamic team, receive constructive feedback, and grow with us.
• Willing to think differently, learn quickly, and adapt to a fast‑paced startup environment.
• Excellent written communication skills.

• Competitive salary and equity.
• 401(k) plan.
• Health, dental, and vision insurance.
• Flexible paid time off.
• Remote work options.

Oklo is an equal opportunity employer. All qualified applicants will receive consideration regardless of race, color, religion, sex, gender identity, sexual orientation, national origin, disability, or veteran status.