Lead Reactor Physics & Shielding Engineer

BlueCore Energy; Long Beach (CA); On-site; USD 180,000 - 240,000; Full time

Job summary

BlueCore Energy in Long Beach, CA seeks a Lead Reactor Physics & Shielding Engineer to own neutronics doctrine, core geometry, and shielding strategy for a marine compact PWR on a barge. You will define reactivity control, dose mapping, and safety cases across fuel life cycles, working closely with cross-functional teams in a hands‑on startup environment.

You will apply advanced Monte Carlo transport, depletion codes, and shielding tools, ensuring compliance with SRP guidelines while driving

Qualifications

• MS or PhD in Nuclear Engineering, Reactor Physics, Health Physics, or radiation transport.
• Hands‑on production depth in continuous‑energy Monte‑Carlo transport and criticality codes such as CASMO/SIMULATE, SCALE, MCNP, Serpent, or OpenMC.
• Experience with variance reduction tools like MAVRIC/Monaco, MCNP, or OpenMC.
• Experience with a lattice-physics or depletion code such as CASMO, SCALE, or Serpent.
• Proficiency with a nuclide‑inventory and decay tool such as ORIGEN.
• Deep understanding of NUREG-0800 SRP sections 4.2, 4.3, 9.1.1, 11.1, and 12.2–12.5.

Responsibilities

• Provide comprehensive neutronics support, establishing core geometry, enrichment, lattice, beryllium reflector, and rotating-drum control architecture.
• Own criticality, reactivity coefficients (MTC, Doppler), kinetics, depletion, and cycle length.
• Establish and own the shutdown-margin and criticality-safety cases across the full fuel life cycle, including fresh, in-core, spent, and storage phases.
• Maintain the criticality base deck and the SCALE calculation catalog.
• Develop core and coolant source terms, and set the activation and decommissioning source term.
• Design the primary and secondary shields, mapping both occupational and crew doses for a space-constrained vessel.
• Analyze deep-penetration radiation streaming through structural penetrations utilizing variance reduction techniques.
• Supply critical neutronics inputs to Chapters 4, 5, and 15, and calculate control-room and offsite design-basis accident (DBA) doses.

Skills

Monte Carlo transport

Lattice-physics / depletion

Radiation shielding

Nuclear engineering knowledge

ORIGEN / decay tools

NUREG-0800 SRP knowledge

Education

MS or PhD in Nuclear Engineering, Reactor Physics, Health Physics, or radiation transport

Tools

CASMO/SIMULATE

SCALE

MCNP

Serpent

OpenMC

MAVRIC/Monaco

OpenMC_ENDF/B data

Job description

Our Mission Is Simple: Democratize Access To Clean Energy

Welcome to BlueCore Energy! We are on a relentless mission to democratize access to clean energy. By designing and building advanced floating Pressurized Water Reactors (PWRs) on barges right here in Long Beach, CA, we are bringing scalable, clean, and reliable power to the world. Joining our team means getting in on the ground floor of a revolution in marine small modular reactors (SMRs). If you are passionate, driven, and ready to tackle some of the most exciting challenges of our time, we want you on our team!

Our Values

• Humility — We hold strong opinions loosely, say “I don’t know,” ask for help early, and let the best idea win regardless of who it came from.

• Inclusivity — The best engineering comes from many perspectives. We build a team where everyone is heard, and we mean it.

• Pragmatism — We solve the real problem in front of us, reuse what already works, and value a tested answer over an elegant one.

About the Role

The Lead Reactor Physics & Shielding Engineer will own the neutronics doctrine and the radiological safety of our marine compact PWR. You will be responsible for defining the core geometry, reactivity control, and shutdown margins, while simultaneously owning the shielding analysis, radiological dose mapping, and source terms.

Responsibilities

• Provide comprehensive neutronics support, establishing core geometry, enrichment, lattice, beryllium reflector, and rotating-drum control architecture.

• Own criticality, reactivity coefficients (MTC, Doppler), kinetics, depletion, and cycle length.

• Establish and own the shutdown-margin and criticality-safety cases across the full fuel life cycle, including fresh, in-core, spent, and storage phases.

• Maintain the criticality base deck and the SCALE calculation catalog.

• Develop core and coolant source terms, and set the activation and decommissioning source term.

• Design the primary and secondary shields, mapping both occupational and crew doses for a space-constrained vessel.

• Analyze deep-penetration radiation streaming through structural penetrations utilizing variance reduction techniques.

• Supply critical neutronics inputs to Chapters 4, 5, and 15, and calculate control-room and offsite design-basis accident (DBA) doses.

Required Qualifications & Skills

• MS or PhD in Nuclear Engineering, Reactor Physics, Health Physics, or radiation transport.

• Hands‑on production depth in a continuous‑energy Monte‑Carlo transport and criticality code such as CASMO/SIMULATE, SCALE, MCNP, Serpent, or OpenMC.

• Demonstrated radiation‑transport shielding experience utilizing variance reduction tools like MAVRIC/Monaco, MCNP, or OpenMC.

• Experience with a lattice-physics or depletion code such as CASMO, SCALE, or Serpent.

• Proficiency with a nuclide‑inventory and decay tool such as ORIGEN or an equivalent software.

• Deep understanding of NUREG-0800 Standard Review Plan (SRP) sections 4.2, 4.3, 9.1.1, 11.1, and 12.2–12.5.

Desired Qualifications & Skills

• Experience with marine compact PWR core physics, specifically drum‑controlled or near‑boron‑free cores.

• Ability to cross‑verify codes and derive Upper Subcritical Limits (USL) via IBSBEP benchmarking per NUREG/CR-6698.

• Familiarity with RG 1.183 (Alternative Source Term) and GDC 19 to ensure control‑room Total Effective Dose Equivalent (TEDE) limits are met.

• Experience utilizing ENDF/B (VII.1 / VIII.0) data libraries in criticality and transport evaluations.

Working at BlueCore Energy

On‑Site Requirement: Our team works together at our Long Beach facility, right next to our barge.

Highly Cross‑Functional: Startups move fast! You must possess the ability to seamlessly collaborate across multiple teams to rapidly solve problems and keep production moving.

Physical & Machinery Requirements: Because we are a hands‑on startup, this role may require the ability to perform physical labor, navigate active construction/manufacturing zones, and/or operate heavy machinery and specialized manufacturing equipment as needed.