Senior Thermohydraulic Analyst
What we do at Blykalla
At Blykalla, we're transforming the future of nuclear power by developing innovative Small Modular Reactors (SMRs). Our mission is to create a new generation of nuclear energy systems that are safer, more efficient, and environmentally friendly. As Sweden's only developer of SMRs, we're at the forefront of a groundbreaking industry.
The role
You will be the senior in-house thermohydraulic analyst for Blykalla's fluid systems, executing the one-dimensional and system-level calculations that underpin the design of the primary loop, the safety-classified systems, and the balance of plant. This means building and running the system codes that the system engineers scope, from steady-state performance and pressure drop budgets, through transient and accident analyses, to natural circulation and passive safety demonstrations.
The role is analytical, hands-on, and cross-cutting. You will not own individual systems, but you will support every system engineer in the team with the calculations they need, and you will be one of the senior technical voices Blykalla relies on when the numbers get hard.
What you'll get to do
Perform system-level thermohydraulic analyses of the SEALER primary loop under normal operation.
Build and maintain one-dimensional thermohydraulic models of the full plant and of individual loops, using nuclear system codes such as CATHARE, APROS, RELAP5, TRACE, MELCOR, or equivalent.
Verify the plant thermohydraulic models against experimental data from the Oskarshamn test facility and from the open literature, and document assumptions and limitations.
Coach junior engineers and system engineers on thermohydraulic fundamentals, best practices, and code use.
Support the qualification of the codes used in-house against international benchmarks and validation datasets.
Who you'll get to work with
The Senior Thermohydraulic Analyst sits in the Fluid Systems Engineering Team within Blykalla, and reports to the Manager of Fluid Systems Engineering.
You will collaborate daily with the fluid system engineers, and interface closely with the Nuclear and Safety, Test and Validation, as well as with academic and industrial partners on code validation and experimental campaigns. We are a diverse team that is passionate about our work and Blykalla.
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 for you to succeed in this role, these are:
More than 8 years of professional experience as a thermohydraulic analyst in the nuclear industry or in a closely related field with equivalent analytical depth.
Degree in nuclear, mechanical, energy, or chemical engineering.
Deep hands-on experience with at least two nuclear system-level thermohydraulic codes (CATHARE, APROS, RELAP5, TRACE, MELCOR, or equivalent), with a track record of building and running plant-scale 1D models from scratch.
Strong fundamentals in single-phase and two-phase thermohydraulics, natural circulation, heat transfer correlations, and reactor safety analysis.
Comfort designing nodalisation strategies, selecting constitutive models, and defending modelling choices in technical and regulatory settings.
Fluent scripting for pre- and post-processing, parametric studies, and uncertainty propagation.
Comfort writing technical reports that stand up to independent review and to regulatory scrutiny.
Fluent in English, spoken and written.
Fluency in Swedish is a plus.
Meritorious skills
Prior experience on Generation IV reactor programmes (LFR, SFR, MSR), especially heavy liquid metal systems.
Prior experience supporting a nuclear licensing submittal (SSM, NRC, or equivalent) with thermohydraulic analyses.
Code development, code coupling, or code verification and validation experience.
Experience with test facility data analysis, benchmark exercises, or international validation projects.
Familiarity with uncertainty quantification methods (BEPU, CSAU, or equivalent).
Basic familiarity with CFD tools (STAR-CCM+, ANSYS Fluent, OpenFOAM, or equivalent), sufficient to interpret results produced by others and to identify where 3D analysis complements the 1D work.
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?
Take the chance to be at the forefront of revolutionizing nuclear power. Join our team as Senior Thermohydraulic Analyst 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!
We do not accept applications via email.
We are not open to external help from recruitment agencies.
- Team
- Engineering
- Location
- Stockholm
About Blykalla
Blykalla is a global leader in advanced lead-cooled nuclear technology. Its small modular reactor, the SEALER, delivers 55 MWe per unit and is designed to provide clean baseload power when and where it's needed, from heavy industry to AI infrastructure.
Lead has been used as a reactor coolant since the 1960s, but corrosion has historically hindered commercial viability. Blykalla's founders solved that problem with a self-healing steel - the result of more than 25 years of research. Now the company is taking lead-cooled nuclear technology to market, developing factory-built reactors designed for serial production and true co-location with the industries they serve.
Blykalla is growing fast, with offices in Stockholm, New York, and Austin, and multiple reactor parks under development.