Waste Engineer

Thorizon is a European developer of next-generation small modular reactors (SMRs) based on molten salt technology. The company builds compact, modular nuclear reactors designed to deliver reliable baseload power and high-temperature industrial heat for sectors such as manufacturing, data centers, and energy-intensive industry. Spun off from NRG, the Netherlands' national nuclear research institute, Thorizon is commercializing molten salt reactor technology that was developed over decades of quiet research. The company aims to begin reactor construction in the early 2030s, with designs optimized for series production and flexible deployment close to end users. Thorizon's mission centers on providing clean, affordable, and safe nuclear energy without compromise. A defining feature of its technology is the use of existing nuclear waste as fuel, dramatically improving fuel efficiency and reducing the long-term waste burden of nuclear power. The company's patented cartridge system divides the reactor core into smaller, factory-produced modules, enabling off-site manufacturing, faster construction timelines, and true modular scalability. Operating at low pressure, the reactors offer an intrinsically safer profile compared to conventional nuclear designs. Thorizon has secured investment and signed a memorandum of understanding with partners including EPZ and NRG PALLAS, as well as provincial authorities, to build Europe's first commercial molten salt reactor in the Netherlands. The company has also received recognition for innovation, winning the ASML Emerging Innovator Award. By working with partners across engineering, fuel production, operations, and financing, Thorizon is positioned to scale its reactor technology to meet the growing demand for clean, dispatchable energy.

Your mission

Help shape the waste management strategy for a new generation of nuclear technology.
At Thorizon, we are developing molten salt reactor technology, and radioactive waste management needs to be considered from the very beginning of the design.
We are looking for a Waste Engineer to take a leading technical role in developing a credible, licensable and economically viable waste management strategy for our projects, with Pioneer as the immediate priority.

As Waste Engineer, you will be Thorizon’s reference expert for radioactive waste management. You will ensure that waste requirements, acceptance criteria and potential treatment and disposal routes are integrated into our engineering and licensing work from the earliest stages.
This is not simply a role applying established solutions. Some waste streams associated with molten salt reactor technology require new approaches and dedicated development programmes. You will therefore combine hands-on technical assessment with the development of solutions for questions where an established industrial route does not yet exist.

In this role you will:

• Develop waste management strategies and plans for Pioneer and Thorizon’s future projects.
• Define waste streams, inventories, classification proposals and characterisation needs.
• Translate waste acceptance criteria and waste-minimisation objectives into design and operational requirements.
• Develop treatment, conditioning, storage, transport and disposal approaches.
• Address specific technical challenges associated with chloride-bearing and alpha-contaminated waste.
• Contribute waste expertise to nuclear safety and licensing documentation.
• Define and support research programmes for waste-management questions where solutions still need to be developed.
• Build the technical interfaces with organisations including COVRA, NRG PALLAS, regulators, research organisations, treatment providers and transport organisations.
• Manage technical studies and external suppliers where required.

You will work across Safety & Licensing, Chemistry, Reactor Architecture, Fuel Cycle and reactor physics, Mechanical Engineering, Operations & Maintenance, Validation and Project Management.

About you:

We are looking for someone with strong expertise in several of the following areas:

• Radioactive waste management and characterisation.
• Waste acceptance criteria and disposal constraints.
• Radiochemistry and/or the nuclear fuel cycle.
• Radioactive waste treatment and conditioning technologies.
• Nuclear safety and licensing.
• Storage, transport and disposal of radioactive waste.
• Systems engineering.
• Decommissioning.

You combine technical depth with strong analytical judgement and clear communication. You are comfortable working across multiple engineering disciplines, making progress when information is incomplete, and engaging effectively with regulators and external technical organisations.
Ideally, you have:

• An MSc or PhD in nuclear engineering, radiochemistry, chemical engineering, physics or a related discipline.
• At least five years of relevant experience in radioactive waste, nuclear fuel cycle, radiochemistry, decommissioning or nuclear licensing.
• Experience working with waste acceptance organisations, regulators or nuclear facility design is strongly preferred.

Waste management decisions have consequences throughout the reactor lifecycle. In this role, your work will directly influence licensing, nuclear safety, reactor design, project schedule and lifecycle costs.
Your expertise will help ensure that assumptions around waste translate into robust engineering decisions covering equipment design, maintenance, decontamination, operations and ultimately decommissioning.
You will have significant autonomy to conduct technical assessments, develop recommendations and coordinate technical work. Strategic commitments, regulatory positions, external agreements and major programme decisions remain subject to management approval.
If you want to apply deep nuclear expertise to a technology where important waste-management questions are still being solved, we’d like to hear from you.

What you can expect from us:

• The opportunity to help realize the most promising reactor technology and advance Europe's energy future
• Being part of an exceptional team that combines engineering rigor, scientific excellence, and entrepreneurial drive
• Working in multidisciplinary teams on ambitious missions, with responsibility and meaningful impact from day one
• A fast-moving deep-tech environment where initiative is valued and people are trusted to make decisions
• Complex, multidisciplinary challenges that will stretch you and accelerate your growth
• Competitive compensation and participation in our employee profit-sharing plan
• An international workplace with offices in the heart of Amsterdam and Lyon