Health Physicist

Job description

## **About Fuse** We are building one of the most potentially consequential companies of the century. Our mission is to accelerate the world's transition to fusion energy while safeguarding humankind. This is not a normal company. This is not a normal job. We are committed for the long term to win. ## **About the Role** You are the lead Health Physicist on site, responsible for the technical radiation-protection program: source terms, shielding, instrumentation, dosimetry, surveys, and the operational decisions that flow from them. This is a hands-on lead role. ## **Core Responsibilities** - Independently verify shielding designs developed by physics and engineering — geometry, source definition, tally choice, variance reduction, and uncertainty. Catch the errors before the concrete is poured. - Run MCNP, PHITS, or GEANT4 transport calculations for the fusion generators, target chambers, beamlines, diagnostic ports, and shielded penetrations. - Build and maintain validated source-term models: D-T neutron yield and spectrum, capture and inelastic gammas, bremsstrahlung, and characteristic line emission. - Perform activation analysis on hardware in the neutron field and produce contact dose-rate vs. cool-down curves that operations can plan around. - Dosimetry & Instrumentation - Specify the radiological instrument fleet from first principles. Match detector physics to field characteristics: pulsed vs. continuous response, neutron energy range, photon discrimination, deadtime behavior, and true dose-equivalent response across the spectrum we produce. - Select personal dosimetry technology appropriate for mixed neutron/photon fields and tritium-intake monitoring. - Be responsible for the calibration program for high-end instruments to a standard that survives regulator review. - Operational Release & Clearance - Be the technical authority on whether hardware and areas are safe to touch or enter. Survey activated and potentially contaminated hardware, evaluate against release criteria, and document the basis. - Develop and be responsible for activation-based clearance procedures: wait times, dominant nuclides over time, allowable contact handling, and packaging for off-site transfers. - Conduct radiological surveys before, during, and after non-routine operations. - Author radiological work permits with credible dose estimates derived from your own field characterization. - Partnership with the Team - Sit in design reviews with physicists and engineers from the start, not at the end. - Partner with the RSO: you produce the technical basis; they translate it into licensed scope, procedures, and regulatory submissions. - Train operators, engineers, and physicists on what their dosimeters and area monitors are actually telling them, including their limitations. ## **Minimum Qualifications** - Master's degree in Health Physics, Nuclear Engineering, Radiological Sciences, Physics, or a related field. - Certification by the American Board of Health Physics (CHP). Fuse will support maintenance of certification status. - 5+ years of operational health physics experience in environments with non-trivial neutron and photon fields, with at least 2 years in a tritium-handling environment. - Demonstrated production-grade proficiency with at least one major transport code: MCNP, MCNPX, PHITS, GEANT4, or FLUKA. - Working knowledge of 10 CFR 835 or 10 CFR 20, DOE-STD-1098, DOE-HDBK-1129, and 20.3 NMAC. - Hands-on experience with tritium bioassay programs, internal-dose assessment, and ICRP biokinetic models for HTO. - Experience leading activation analysis and authoring defensible "safe to handle" decisions on activated hardware. ## **Preferred Qualifications** - Experience with pulsed radiation sources such as DPF, Z-pinch, ICF drivers, or pulsed accelerators and the dosimetry challenges they create. - Prior role specifying or commissioning a radiation-instrument fleet for a new facility. - Track record partnering with R&D physicists and engineers as a working collaborator, not a downstream reviewer. - Prior responsibility for DoD/DOE environmental monitoring programs and safety protocols. - Experience integrating radiation controls with non-radiological hazards including HV, vacuum, cryogenics, and lasers, and with broader EHS systems. - Familiarity with PDM/PLM and document-control practices, including change control for procedures and drawings. ## **What We Value** - Give a shit. Build things you're proud of. - Take responsibility. If something is broken and you can fix it, fix it. See things through. - Move fast. Make decisions, learn quickly, and keep moving forward. - Think bigger. Simplify relentlessly. Don't default to the safe answer. - Disagree and commit. The best idea wins. Once a decision is made, we move. - Desire to win. This is hard. Expect intensity. We are here to win. - Plan B is to make Plan A work. ## **Additional Requirements** - This is not a remote position and will require relocation if not already local to the applicable Fuse facility. - Security Clearance - This role may require the ability to obtain and maintain a U.S. government security clearance. ## **Benefits** - Medical, dental, and vision coverage. - Relocation assistance for roles that require it. - Flexible time off. Take what you need, no accrual tracking. - 2 weeks of paid time off built into the end of each year, subject to team and business needs. - Supportive leave of absence policies. - Paid leave for new parents. ## **ITAR Requirements** To conform to U.S. Government technology export regulations, including the International Traffic in Arms Regulations (ITAR), you must be a U.S. citizen, lawful permanent resident of the U.S., protected individual as defined by 8 U.S.C. 1324b(a)(3), or eligible to obtain the required authorizations from the U.S. Department of State. ## **Equal Opportunity** Fuse is an Equal Opportunity Employer; employment with Fuse is governed on the basis of merit, competence, and qualifications and will not be influenced by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, ancestry, immigration status, sexual orientation, gender identity, marital status, mental or physical disability, or any other legally protected status.