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Neutronics Engineer



Santa Clara, CA, USA
Posted on Tuesday, June 25, 2024
Thanks for your interest in Oklo! We are searching for a Neutronics Engineer to work with our engineering team and help us wrangle the neutrons.

Position Description

The Neutronics Engineer is responsible for responsible for performing reactor design calculations that include core design and fuel cycle analyses.

Specific responsibilities may include:

  • Perform the complete range of actions involved in core design and fuel cycle analysis using Monte Carlo and deterministic codes on Oklo reactors. These include core design, core sizing, core optimization, reactivity feedback, core lifetime, and criticality analyses, among others.
  • Perform calculations and analyses in Monte Carlo based codes such as MCNP, Serpent, and OpenMC.
  • Perform calculations and analyses with fast reactor deterministic codes such as DIF3D, PERSENT (familiarity with CASMO/SIMULATE is also beneficial).
  • Be aware of and familiar with fast reactor core design and analysis work being performed internationally, as well as related benchmark calculations and experiments being performed internationally
  • Provide technical feedback to quick-iterating design teams.
  • Document work using modern tools and techniques, and write well-written, thoughtful technical reports.


We are looking for a neutronics engineer that is:

  • Passionate about clean energy
  • Passionate about making advanced fission a reality
  • Willing and able to learn quickly
  • Knowledgeable about fast reactor design
  • Highly skilled with Monte Carlo neutronics tools such as MCNP, SERPENT, and Open-MC
  • Skilled with deterministic fast reactor tools, or wiling and eager to learn
  • Eager to work on a dynamic team, receive constructive feedback, and grow with us
  • Willing to think differently and do things in new ways
  • Comfortable in a fast-paced, highly iterative startup environment
  • Excited to think creatively, critically, and reflectively about the problems they are solving, while not leaning only on what has been done before
  • Willing to propose novel and creative solutions to technical problems
  • An excellent writer who can write in modern active voice, so make your cover letter compelling and write it well!
  • Able to communicate technical content and results verbally

Who you are:

A startup person. You aren't driven by titles or hierarchy, and prefer efficiency to excess process. You don't need or expect to have a lot of guidance but you enjoy working in a fast-paced team. If you prefer the culture and feel of a large organization, that is great, but you likely won't enjoy working with us! There is plenty of important work and plenty of good opportunities with organizations like that.

Motivated: You are self-motivated. You bring an enthusiasm to the team, and imbue a sense of passion that goes beyond clocking in and clocking out. This isn't about a fake or arbitrary "pieces of flair" mentality or lack of work-life balance! It is about being a part of the vision and feeling a part of reaching team goals.

A team-player: Oklo genuinely is a team. We aren't about taking credit for ourselves, and we aren't about pushing blame to others. We do incredible things because we work as a team.

An excellent communicator: We need a person who is not only technically competent but also a clear and upbeat communicator.

Creative: being creative means that when things fall outside clear scopes or processes or problems arise without clear solutions, you are able to identify it as well as invent ways to solve a problem or fill a need without micromanagement. The successful person in this job will not only be creative, but also enjoy being creative and solving open-ended problems which may change day-by-day.

Detail-oriented: this focus is a big part of excellence, consistency, and quality. Even excellent grammar and spelling matter for both good communication as well as the image of the company that we put forward.

Minimum Qualifications:

  • If you have experience and expertise in reactor design, apply! We also think the following are good indicators of qualifications to do this job: Bachelors, Masters, or PhD in a technical field, such as nuclear engineering, with experience in reactor design and analysis (Masters or PhD may be preferable)
  • Fluency with Python
  • Experience with modern object oriented languages, preferably C++
  • Proficiency with high performance computing systems
  • Experience with fast reactor design and analysis is highly recommended
  • Proficiency with MCNP and SERPENT is highly recommended
  • Proficiency with Argonne's ARC codes (MC2, DIF3D, etc.) is recommended

About Oklo compensation:

Salary: $102,000-$225,000

Salary may fall outside of the range provided and will be dependent on applicant experience.

Oklo offers untracked paid time off, competitive pay, equity, 401k, health insurance, FSA, flexible work hours, and other benefits.

We are looking to fill this position immediately!

About Oklo Inc.: Oklo is a California-based company developing clean energy plants to provide emission-free, reliable, and affordable energy using advanced fission. Oklo is a fast-growing startup with a history of reliable funding and milestones for more than 5 years. Oklo's first product is a microgrid scale powerhouse. The powerhouse can produce clean energy for decades without needing to refuel, and also has the capability to turn nuclear waste into clean energy.

Oklo received a Site Use Permit from the U.S Department of Energy, demonstrated fabrication of its fuel, was awarded fuel from the Idaho National Laboratory, and submitted the first accepted advanced fission license application to the regulator.

Oklo has been featured in Popular Mechanics, Wired, Architectural Digest, Hyperallergic, POWER Magazine, and has been the subject of a Harvard Business School case, and was featured in the documentary The New Fire, among many other features.