HC-KA, Hot Cell Laboratory (ActUsLab)

The Hot Cell Laboratory (HC-KA) is one of Europe's leading research infrastructures for the safe handling and examination of highly radioactive materials. Comprising 24 shielded hot cells, it provides open access to state-of-the-art experimental capabilities for European and international users in the fields of spent fuel characterisation, nuclear safety and radioactive waste management. The facility is designed for the safe receipt, handling and examination of highly radioactive materials, including full-length light-water reactor fuel rods. It also includes dedicated decontamination cells and supporting infrastructure for remote handling operations, enabling the safe transfer, preparation and return of radioactive materials. Many of the hot cells are equipped with alpha-tight stainless-steel containment, allowing work to be carried out under controlled gas atmospheres whenever required.

The laboratory provides comprehensive capabilities for the Post-Irradiation Examination (PIE) of nuclear fuels, combining non-destructive and destructive examination techniques. Non-destructive examinations include visual inspection, profilometry and gamma scanning, while fission gas release and distribution can be assessed by micro X-ray fluorescence (µ-XRF). Destructive examinations include metallographic preparation, optical microscopy, electron probe microanalysis (EPMA) and scanning electron microscopy (SEM) to investigate the microstructure, composition and degradation mechanisms of irradiated fuels and cladding materials. The hydrogen content of irradiated cladding can also be determined. The laboratory is equipped with two Raman spectrometers installed directly inside the hot cells, enabling the identification and characterisation of surface phases on highly radioactive materials without removing samples from the shielded environment.

Mechanical testing capabilities support investigations of irradiated fuel rod sections and cladding materials under conditions relevant to fuel handling, interim storage and transport. These include ring compression testing and other specialised methods for assessing the mechanical behaviour and integrity of irradiated fuel components.

A suite of chemical hot cells enables investigations related to the back end of the nuclear fuel cycle, with particular emphasis on the long-term aqueous stability of spent nuclear fuel under oxidising and reducing conditions representative of geological disposal. The facility also supports studies on the aqueous stability of severe accident materials (corium) in fresh, borated and seawater, as well as separate-effect experiments using tailor-made materials containing alpha emitters and simulated fission products. Together, these capabilities enable integrated studies spanning the entire back end of the nuclear fuel cycle, from spent fuel characterisation and degradation processes to radioactive waste management and geological disposal.

A dedicated analytical section complements the hot-cell infrastructure through high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for the analysis of leachates and dissolved irradiated fuel samples, including burn-up determination. Advanced methods are available for the determination of trace-level β-emitting radionuclides, including so-called difficult-to-measure nuclides, using automated flow-injection ICP-MS systems. These capabilities are complemented by innovative laser spectroscopy techniques for radionuclides such as ¹⁴C and ³⁶Cl, together with dedicated radiometric measurement systems.

The Hot Cell Laboratory also serves as a central hub for the preparation of irradiated materials for advanced characterisation using techniques such as focused ion beam (FIB) microscopy, transmission electron microscopy (TEM), electron probe microanalysis (EPMA), Knudsen effusion mass spectrometry and thermal diffusivity measurements. As a continuously evolving research infrastructure, the laboratory supports both the Joint Research Centre's research programmes and open access for European and international users, providing state-of-the-art experimental capabilities for spent fuel characterisation, nuclear safety, severe accident research and radioactive waste management.

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Priority topics of Hot Cell Laboratory

1. Applied research on materials and methods related to the spent fuel nuclear safety
2. Spent fuel long term mechanistic release process of interest for geological disposal
3. R&I activities for the characterisation of radioactive waste including new waste forms
4. R&D on the stability and safe conditioning of damaged fuel ("corium")

Definition and conditions of access

Access to the research infrastructure is granted on the basis of Access Units. For HC-KA, the Access Unit ('AU') corresponds to an 'Operating day' made available for the experimental activities. Projects involving long-term stays (3-9 months) of students are encouraged.

Physical access to the laboratories is restricted to opening hours but, in certain cases, automatic measurements can be performed when the laboratories are closed. Users can utilise the JRC equipment with the help of JRC staff. Employment of Users own equipment is not recommended in laboratories inside the controlled area, because of the strict radiation protection rules in force at JRC Karlsruhe. If the use of own equipment is necessary, this has to be indicated and duly justified in the proposal and should be coordinated already well in advance before the scheduled laboratory time. Users of the HC-KA laboratory can only participate in experiments conducted by in-house staff scientists or technicians.

Users will be requested to complete and submit safety and security-related documents to receive access to the laboratories. Approval of access is subject to the rules of the European Commission, the Joint Research Centre and the German authorities. Submission of documents should therefore start in due time to allow completion of the approval procedure well before the start of the experiment.

• Estimated total number of Operating days allocated to the call: 30 AU*
• Average number of Operating days per Project: 15 AU  **
• Estimated maximum duration of the User Access Project: 24 months
• Estimated additional costs excluding consumables and other expenses:
  • Research infrastructure operated by JRC staff: 0€ / AU
  • Research infrastructure operated by users: Not possible

* A total of 180 Operating days will be allocated to the PAMEC, HC-KA and FMR laboratories.

** In addition, a total of 100 Access Units (Operating days) can be granted for each User Project that consider Users visiting the JRC for long-term stays.

Support of Users for travel and subsistence

The JRC may provide a financial or in-kind contribution to support Users from User Institutions located in EU Member States or countries associated to the Euratom Research Programme (only Ukraine) to cover their costs of travel and subsistence (T&S) related to the User Stay Days. This is subject to the availability of funds, personnel and other resources.

A User Stay Day is a day of physical presence of a User at the concerned Research Infrastructure for Access related to the User Project. A User Stay Day counts as a registered entry to the JRC site where the Research Infrastructure is located.

• Estimated total number of User Stay Days for short- term stays eligible for T&S allocated to the call: 10
• Estimated total number for long- term stays (months) eligible for T&S allocated to the call: 6

A short-term stay corresponds to a stay of up to 20 User Stay Days.

A long-term stays corresponds to a stay exceeding 20 User Stay Days, up to a maximum of 200 User Stay Days.

For more information on the support offered to users please consult the Rules on the contribution to travel and subsistence expenses of external users.

Long-term stays are primarily meant for undergraduate and graduate students and have a duration of at least one month. They are typically three to nine months for Karlsruhe, and one to six months for Petten and Geel.

The Lead User is invited to fill in the User travel and subsistence form and and send it to JRC-ACTUSLAB-KARLSRUHEec [dot] europa [dot] eu (JRC-ACTUSLAB-KARLSRUHE[at]ec[dot]europa[dot]eu) by the closing date of the call. For more information the Lead User may contact the JRC Research Infrastructure at JRC-ACTUSLAB-KARLSRUHEec [dot] europa [dot] eu (JRC-ACTUSLAB-KARLSRUHE[at]ec[dot]europa[dot]eu).  

Allocation of intellectual property rights

• The JRC and the entitled party (person or organisation that has been granted access) become co-owners in equal shares of all raw data, treated data and documentation data developed with respect to the access (i.e. Option 1).

Eligibility criteria

• The Lead User Institution and User Institutions (see definitions in the Framework) must be from an EU Member State, or country associated to the Euratom research programme (at the time of the publication of the call this only includes Ukraine and Switzerland*).
• The scope of the work for nuclear Research Infrastructures must be in line with the activities defined in Annex I of Council Regulation (Euratom) 2021/765.
• The Lead User Institution must be from a university, research or public institution, or from a Small-Medium-Enterprise (SME).
• User Institutions belonging to international organisations provided that the JRC has concluded a Collaboration instrument that ensures reciprocity for Access of Users from the JRC and User Institutions to their respective Research Infrastructures. The JRC Director General may exceptionally authorise the participation of User Institutions belonging to international organisations in the absence of a Collaboration instrument.
• User Institutions established in an EU Member State or in a country associated to the Euratom programme must not be directly or indirectly controlled by non-associated third countries, or by legal entities of non-associated third countries. The JRC Director General may exceptionally authorise the participation of User Institutions controlled directly or indirectly by non-associated third countries, or by legal entities of non-associated third countries.
• Individual Users must be nationals of an EU Member State or a country associated to the Euratom programme. The JRC Director General may exceptionally authorise the participation of Users that are not nationals of EU Member States, or of a country associated to the Euratom programmes, for overriding justified reasons.
• Ethical considerations in accordance with EU Law, in particular Art. 19 of Regulation (EU) 2021/695, and applicable laws and regulations in the EU Member States.
• The proposal submission form is complete and complies with the instructions.

* Swiss institutions can apply as from now. However, the actual participation in the activities will be subject to the conclusion of the agreement between the EU/Euratom and Switzerland on Union Programmes, currently in the process of formal adoption.

Selection criteria

Proposals will be evaluated in accordance with the following selection criteria:

• Scientific implementation (50 points)
• Collaboration, training and access of new User Institutions (20 points)
• Strategic relevance (30 points)

How to apply

The proposal must be prepared using the Relevance-driven Proposal Submission Form.

During preparation of the proposal, applicants are encouraged to:

• Read the "Framework for Access to the physical Research Infrastructures of the JRC" and its annexes.
• Contact the research infrastructure at JRC-ACTUSLAB-KARLSRUHEec [dot] europa [dot] eu (JRC-ACTUSLAB-KARLSRUHE[at]ec[dot]europa[dot]eu) to specify the level of experience of the User(s) to perform related tests and to assess feasibility aspects related to the capacity of the research infrastructure concerning:
  • Material
  • Test parameters,
  • Specimen geometry.

Proposal should be submitted to JRC-RI-OPEN-ACCESSec [dot] europa [dot] eu (JRC-RI-OPEN-ACCESS[at]ec[dot]europa[dot]eu) by the closing date of the call. The deadline is 5 October 2026.

The User Selection Committee will only evaluate proposals that are complete and comply with the instructions in the proposal submission form.