Innovative characterisation techniques for large volumes (ICARUS)

Objectives

Further development, optimization and harmonization of innovative techniques for characterizing radiological, physical and chemical properties of LLW/ILW-mixed waste which could be critical for the safe implementation of radioactive waste management programmes, including destructive techniques (DT) on laboratory scale and its relation to non-destructive techniques (NDT) and scaling factors (SF) at the raw waste and package scale user cases. 

Major highlights (March 2025 - March 2026) 

• A first meeting was held to identify possible synergies with the International Network of Laboratories for Nuclear Waste Characterization – IAEA-LABONET.
• The young generation is being actively engaged in ICARUS. Besides some post-doc researchers, so far, 3 Ph.D. candidates and 7 M.Sc. students have actively contributed to the research activities.
• Significant progress has been achieved in T2.1: the Initial State of the Art Report (D5.1) was published. The T2.2 activities have focused on initiating comprehensive training needs assessment across WP5-WP6-WP7 for predisposal activities. Joint training on geopolymers is being organized with WP6 and WP7, incl. non‑destructive testing.
• T3 (NDT) and T4 (DT) have set up working groups (WGs) to favor knowledge/experience sharing, implement a problem-solving approach, avoid potential work duplications: 5 WGs on NDT (physical properties, chemical properties, gamma radiation, neutron radiation, data management) 3 WGs on radiochemical methods (Cl-36, Ca-41, Tc-99), 2 WGs on measurement techniques (mass spectrometry, and liquid scintillation counting).
  • Data management is now centralized and operational via templates. It consists of a unified web platform (Django) for automated in-situ data collection and processing, integrated with different data collection frameworks (e.g. Thingsboard), processing pipelines, and ML/AI for prediction.
  • In addition to WGs, where some new protocols are already quite mature, some partners are focusing their developments on C-14, Mo-93, Pd-107, and Cm-243/244. 
  • Intercomparison exercises are being organized in 2 stages: 1) Reference Samples for internal validation of developed analytical protocols (by the end of Year 3); 2) Blind (Real) Samples for broader intercomparison involving EU/SH and partners from other WPs for validation of the recommended methods (Year 4).
• T5 (SF) has produced three key technical reports: 
  • T5.1 – Theoretical analysis of Scaling Factors (SF): Two draft theoretical models for PWR and BWR NPPs have been developed and consolidated into a single document.
  • T5.2 – SF sampling design: A draft report on the statistical models has been prepared.
  • A joint document integrating theoretical and statistical analyses is under preparation.

Forward look

• The Annual Meeting for year 2 will be organized in Ljubljana on 28-29 April 2026. 
• Dissemination actions will be implemented, including presentations at RADCHEM conference.
• T2 will co-organize the joint training on geopolymers and some contributions will be made on the topic of NDT: X-ray, ultrasound, tomography.
• T3 will implement the structured topics and use cases from the initial SotA into the workplan on the NDE techniques and innovative approaches on decommissioning use cases.
  • The milestone MS71 “Selection of specific use cases to test the developed NDT and methods in relevant industrial conditions” is under preparation. 
  • Preliminary measurements with different techniques will be shared, and synergies between complementary methods will be explored to improve the characterization, both from a physical and radiological point of view, of the waste forms selected in the working groups, e.g.: big metal box, raw waste conveyer belt, box with boxes and box with drums.
• T4 will continue the technical discussions within the WGs, creating forums to discuss practical aspects, exchange ideas, and share best practices to support the development of optimized radiochemical procedures to be integrated with radiometric and non-radiometric methods.
  • The developed methods will be summarized in detailed protocols to be validated.
  • The internal validation of the protocols will be pursued through reference samples to be shared among the partners. 
  • On a later stage, reference and blind samples will be prepared and shared within intercomparison exercises to demonstrate the robustness and reliability of the developed methods.
• T5 will continue the work programme:
  • Two technical reports will be finalized on Theoretical analysis and Sampling design. 
  • A joint and coordinated analysis of both the theoretical SF document and the statistical SF document will be performed. The aim is to harmonize the theoretical and statistical approaches, ensuring consistency between the underlying physical models and their statistical implementation, and to identify areas where theoretical insight can support statistical robustness and, conversely, where statistical evidence can inform or refine theoretical assumptions. 
  • The next phase will extend the SF analysis from the model level to waste packages, including an inventory of packages in storage/disposal facilities.

Description of the WP

• To identify the best available characterization techniques for large volume raw waste in industrially relevant decommissioning situations, a comprehensive SotA is needed.

• To achieve fast and sufficiently accurate gamma activity distribution in complex large packages (1^st use case), NDTs require innovation and optimization to be proficiently implemented in industrial applications, encompassing decommissioning and ongoing operational processes. 

• To improve and simplify the inventory of physical-chemical properties and alpha emitters compared to current expensive DT and high uncertainty SF methods (2^nd use case), the optimization of NDT needs to be investigated in relevant industrial scenarios (decommissioning/operational processes). 

• To improve sensitivity, accuracy, uncertainty and cope with expensive and time-consuming conventional radiochemical analysis (3^rd use case), cutting-edge DTs need to be developed for determining critical long-lived Difficult To Measure (DTM) radionuclides (C-14, Cl-36, Ca-41, Se-79, Zr-93, Mo-93, Tc-99, Pd-107, Cs-135, Cm-243, Cm-244) in decommissioning/operational samples to develop a comprehensive inventory.

• To lower the uncertainties and improve accuracy and reliability to meet ever stringent requirements set by national regulators for raw mixed waste (4^th use case), the SF approach needs to be thoroughly investigated.

Outcomes

• 1^st use case: improved NDT methods and approaches for radiological characterization (incl. in-situ and remote characterization, gamma and neutron analyses) of complex large packages (incl. mixed wastes as heterogeneous legacy waste) to safely implement subsequent stages of waste management lifecycle strategy.

• 2^nd use case: improved NDT methods for characterisation of physical-chemical properties and chemicals inventory to optimize waste segregation, treatment and conditioning and enhance pre-disposal safety. 

• 3^rd use case: development/optimisation/innovation of fast and cheap DTs to characterise DTM radionuclides identified as critical and for which limitations/difficulties remain in the available characterisation techniques, to improve the sensitivity, accuracy, uncertainty and obtain a comprehensive radiological inventory. 

• 4^th use case: development of innovative methods for the optimization and validation of SF methodology to improve accuracy, uncertainty, and reliability of DTM radionuclides estimation in raw mixed waste.