Core Designer

Blykalla
Blykalla

Design

Stockholm, Sweden

Posted on Sep 21, 2026
What we do at Blykalla

Blykalla is a global leader in advanced nuclear technology, commercialising the next generation of clean, reliable energy through its lead-cooled reactor, the SEALER. By combining decades of specialised research with world-class partners, Blykalla is building the backbone of the global AI and industrial economy. For more information, visit https://www.blykalla.com.


What you’ll get to do

We're seeking an senior core designer or core design methods developer to join our Nuclear Engineering & Safety team in Stockholm. In this role, you will design and analyze fast reactor core configurations, optimize fuel loading patterns, develop associated methods and contribute to safe, efficient, and economical operation of our nuclear reactors throughout their fuel cycles.

  • Design and optimize reactor core variants for our cutting-edge lead-cooled fast reactor designs

  • Perform neutronic and burn-up analysis using both industry-standard and new codes

  • Develop and validate core design models and methodologies

  • Prepare technical documentation, design reports, and licensing submittals for regulatory review

  • Stay current with advances in core design, computational methods, and regulatory requirements

Who’ll you’ll get to work with

The senior core designer sits in the Nuclear engineering & safety team within Blykalla, and reports to the head of Nuclear engineering & safety. We are a diverse team that is passionate about our work and our company.

Who you are

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

  • Master's degree in nuclear engineering, physics, or a related field

  • At least 5 years of industry experience in reactor core design, reactor physics, neutronics, fuel management, or associated methods development including verification & validation of computational tools

  • Proficiency with Monte Carlo neutron transport codes and experience setting up and running full-core or assembly-level models

  • Familiarity with the full core design workflow including cross-section generation, uncertainty propagation, depletion analysis and burnup-dependent reactivity feedback characterization

  • Strong understanding of reactor physics, thermal hydraulics, and fuel performance

  • Familiarity with relevant regulatory frameworks

  • Excellent analytical, problem-solving, and technical writing skills

  • Fluency in English, spoken and written

Meritorious skills:

  • Programming skills, e.g. in Python, Fortran, or MATLAB

  • Fluency in Swedish, spoken and written

If you are not sure that you are 100% qualified, but are up to the challenge, we encourage you to apply.

Location

This position is for our office in Stockholm.

So, what do you think?

Joining our team means being part of a supportive and innovative environment where your ideas are valued and your expertise is recognized. You will have the opportunity to work with industry leaders and contribute to the safe and sustainable use of nuclear power.

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.

Salary Range: SEK 57 000 – 76 000/ month, depending on experience and qualifications.

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.