What we do at Blykalla

Blykalla is a Swedish deep-tech company at the forefront of the nuclear industry, pioneering the development of small modular reactors that provide clean, safe, and reliable energy. Thanks to lead-cooling, we achieve high safety in a very compact format, allowing for a simple and cost-effective design that can be mass-produced. Our unique reactor design will provide safe and green baseload energy that perfectly complements solar and wind power.

What you’ll get to do

Are you a technically sharp, self-driven engineer or scientist who understands how nuclear fuel really behaves - and how to prove it with credible models? Join Blykalla and lead the fuel development and qualification effort that underpins the use of a novel nuclear fuel in an advanced reactor. This role puts you at the center of predicting, validating, and defending fuel behaviour for the western world’s first lead-cooled SMR. You’ll own the delivery of the fuel qualification programme, and strongly influence the development of models and codes that allow for producing regulator-ready evidence to understand our fuel performance.

Build & evolve fuel performance models

● Take ownership of the development, extension, and adaption of fuel performance models for a lead-cooled fast-spectrum operation, with a focus on physical mechanisms rather than black-box use.

● Lead the benchmarking of models against multiple fuel types (including nitride, oxide and metallic fuels) and fuel performance codes, to support comparison, validation, and fallback options.

● Understand and improve model behaviour by analysing why models work, where they break down, and what must be changed for lead-cooled fast spectrum operation.

● Work closely with experimental and design teams to specify experimental testing (in- and out-of-pile) and examinations that generate data relevant for model validation or development.

Shape data, experiments, and model credibility

● Define what experimental and operational data are needed to support, challenge, and improve fuel performance models

● Work closely with experimental and design teams to specify irradiation tests and pre- and post-irradiation examinations that generate data relevant for model validation or development

● Integrate data from experiments, literature, and historical programmes to calibrate models, assess validity ranges, and reduce key uncertainties

● Contribute to cross-disciplinary activities between reactor physics, thermal hydraulics, materials, backend, safety and licensing to ensure design coherence, manufacturability, and regulatory compliance.

Align modelling with fuel qualification, licensing and industrialisation

● In collaboration with the Head of Fuel and wider fuel team, drive forward the company's advanced fuel qualification and update our plans for how the company will meet them.

● Define, maintain and own the modelling basis used in fuel qualification, including scope, gaps, assumptions, acceptance criteria, and regulatory expectations

● Coordinate with international labs and irradiation facilities to secure the knowledge and services (irradiation, PIE) needed to reach qualification and licensing goals.

● Ensure Blykalla is pro-active in interfacing with regulatory bodies and relevant programs that support advanced fuel qualification/performance modelling (including, but not limited to: SSM, DOE/NRC and IAEA).

● Contribute to the establishment of modelling workflows, documentation, and quality practices that ensure traceability, reproducibility, and regulatory readiness

Fuel Design & Development

● With the Head of Fuel and Head of Nuclear Safety, coordinate cross-disciplinary integration of the fuel design between nuclear design, thermal-hydraulics, materials group, fuel experimental and modelling teams to ensure design coherence, consistent modelling assumptions, manufacturability, and regulatory compliance."

Technical leadership

● With the Head of Fuel, support the transfer of knowledge and development of the next generation of “subject matter experts” across both fuel performance authorities or cross-disciplinary technical leadership.

● Provide technical mentorship to early career individuals, disseminating your experience and knowledge.

Who you are

You will be part of a highly skilled team with a can-do attitude. We value personnel chemistry and strive to create a workplace where you enjoy coming to. There are however a few things that we think will help in order for you to succeed in this role, these are:

Experience & Qualifications

● At least 15-years post-degree experience in nuclear fuel modelling, development and/or qualification.

● Modelling and simulation experience covering code/model modification, development or critical assessment rather than “black-box” use

● Degree, ideally PhD in nuclear engineering, physics, chemistry or a closely related field

● Experience defining and integrating experimental data from irradiation tests, post-irradiation examinations, literature, or historical programmes to support and improve modelling and accelerate fuel qualification

● Ability to define what data and experiments are needed to support model credibility and uncertainty reduction, and to work effectively with experimental and qualification teams

● Demonstrated ability to understand fuel behaviour at the mechanism level and to diagnose why models work, where they fail, and how they must be improved

● Hands-on experience with fuel performance codes such as TRANSURANUS, FRAPCON/FRAPTRAN, BISON, or similar tools, including extending, adapting, or validating models

● Understanding of how modelling contributes to fuel qualification, safety arguments, and regulatory submissions

● Ability to communicate and defend modelling assumptions, limitations, and results in technical discussions with regulators, authorities, and partners

● Fluency in English; Swedish is an advantage

● Willingness to travel within Europe, North America and occasionally beyond

● Eligibility to work with nuclear materials in Sweden

Who you’ll get to work with

The Fuel Performance Lead sits in the Fuel management team Team within Blykalla, and reports to the Head of Fuel. We are a diverse team that is passionate about our work and Blykalla. 

Location 

This position is for our office in Stockholm.

So, what do you think?

Don't miss the chance to be at the forefront of revolutionizing nuclear power. Join our team as Fuel Performance Lead and help shape the energy landscape of tomorrow. Apply today with your resume and a cover letter highlighting your relevant experience and achievements.

We are proud to foster an inclusive workplace free from discrimination. We strongly believe that diversity of experience, perspectives, and background will lead to a better environment for our employees and a better product. This is something we value deeply, and we encourage everyone to be a part of changing the way the world thinks about power supply!

Reference & Background Checks

As part of our recruitment process, we conduct background checks on all candidates. We may also conduct reference checks to gain a well-rounded understanding of your professional experience, performance, and ways of working. This includes both references provided by you and, where relevant, conversations with other professional contacts who have worked closely with you. We strive to be transparent about our reference-checking process and handle all personal data in accordance with applicable data protection regulations. Any additional references will be sought with professional judgment and only when considered relevant to the role.

We offer competitive compensation aligned with our internal salary framework and growth potential in the role.

We do not accept applications via email. 

We are not open to external help from recruitment agencies. 

Note on AI Use: Blykalla may use AI technology to assist with certain administrative aspects of the hiring process, such as note-taking, interview documentation, and reporting. However, every resume and application is reviewed directly by our recruiting team. AI tools are used solely for operational support and do not influence candidate evaluation or hiring decisions.