Test & Validation Engineer

Every design choice in our SEALER reactor needs evidence that it works. As Test & Validation Engineer for SEALER-E, our research setup at the Advanced Reactor Test Site in Oskarshamn, you shape the tests that provide it: you plan the tests, write the test plans and assess the results.

Our product development follows the V-model, with a gate review at each stage. You make sure every gate rests on evidence the project can trust. You work side by side with the V&V Architect and a project team guided by a Project Manager, while our Commissioning and Test Engineers run the tests on site.

This role ensures that SEALER technologies progress from concept to deployable system in a coherent, traceable, and strategically well-aligned way.

What we do at Blykalla

Blykalla is developing the next generation of nuclear technology with our Small Modular Reactor (SMR) based on innovative fuel, materials, and reactor designs. As Sweden's only SMR developer, we are on a mission to decarbonize industries and enable safe, scalable, and sustainable energy solutions. Our technology uses uranium nitride fuel and lead coolant, creating novel challenges and opportunities for the fuel cycle and supporting systems.

What You'll Get to Do

As Test & Validation Engineer, you connect requirements, tests and evidence along the V-model. On the left side you shape the test programme and the test plans together with the system / design engineers. On the right side you assess the results and help the project close its gate reviews. Tests range from thermal-hydraulics and mechanical components to instrumentation and system integration. Your responsibilities will include:

Test Programme & Test Matrix

• Build the test programme and test matrix for SEALER-E together with the technology domain owners, based on the Design Verification Plan, the Technology Maturation Plans and the failure modes and risks from the safety assessment.
• Sort tests into development, verification, qualification and demonstration tests, and link each to a V-model stage.
• Agree on instrumentation and data needs with I&C, and plan how the test rigs contribute evidence to the project.

Test Plans & Campaigns

• Write test specifications and plans with objectives, conditions, acceptance criteria and stop points, together with the system / design engineers and safety.
• Coordinate each test campaign from the project planning side: scope, sequence and readiness for cold and hot commissioning. Hand the plan over to the Commissioning and Test Engineer who runs the campaign on site, and stay available for questions, deviations and changes.
• Review test data, deviations and uncertainty after each test, and write the test report with conclusions, follow-up actions and feedback to design.

Verification, Validation & Gate Reviews

• Review requirements early to make sure they can be verified, and choose the verification and validation method for each: inspection, analysis, test or demonstration.
• Take accountability for the verification and validation sign-off at each gate review, based on evidence that is sufficient, valid and traceable.
• Keep the evidence record up to date from requirement to test result, raise open gaps early and route them into change and corrective action.

Working with the Project

• Work with the Project Manager, who guides the project and owns the delivery gate, and keep the test matrix and V&V status visible to the whole team.
• Work with system / design engineers, suppliers, external laboratories and research partners, and use their results as evidence without co-authoring them.
• Review the test plans and acceptance criteria of another project, and have yours reviewed in return.

Where This Role Can Take You

You will help shape how SEALER tests turn into trusted evidence, from the first test rig to fleet deployment. As the V&V team grows, this role can develop into guiding the Test & Validation Engineers or into broader technical responsibility within SEALER's development.

Who You Are

You are a curious engineer who enjoys turning a technical question into a clear plan, and a plan into evidence the team can trust. You bring technical depth, a structured way of working, and the honesty to say when a requirement is not yet verified, and why.

We believe you have:

• A relevant engineering degree (mechanical, chemical, process, nuclear, aerospace, systems engineering, or similar).
• Experience in test engineering, commissioning or verification and validation of complex systems.
• Experience writing test plans with acceptance criteria, and keeping a test matrix or verification plan (for example DVP&R) traceable to requirements.
• Experience with instrumentation, data acquisition and test data evaluation (for example in Python or MATLAB), including how results scale from small rigs to larger systems.
• Understanding of systems engineering methods, including the V-model, gate reviews and stage-gate ways of working.
• Working knowledge of FMEA and failure mode identification, risk-based thinking and process understanding, to set safe test conditions.
• Familiarity with Technology Readiness Levels (TRL) and readiness assessments.
• Strong communication and collaboration skills across disciplines, including system / design engineers, site engineers and the Project Manager.
• A background in nuclear, aerospace or another regulated industry, with NQA-1 or AS9100 experience, is a plus, as is test experience with hazardous or high-temperature media such as liquid metal.

Location

The position is based in Stockholm, with travel to Oskarshamn and partners expected.

You report to the Test and Operations Manager. Full-time and permanent, with the option to start as a contractor and move into permanent employment.