Overview
The Horonobe International Project (HIP)
The Horonobe International Project (HIP) is an international project, as part of the Horonobe Underground Research Laboratory (URL) Project, with the main theme of 'Challenges for Developing Advanced Technologies and Human Resources Towards Long-Term Implementation of Geological Disposal'. The HIP was set up as an NEA* joint project in February 2023 and successfully undertaken in Phase 1 (February 2023 to March 2025). This has now been taken forward into Phase 2 (April 2025 to March 2029) with the participation of nine organisations from Bulgaria, Germany, Korea, Romania and United Kingdom as well as Japan.

The main objectives of the HIP are to:
- Develop and demonstrate advanced technologies to be used in repository design, operation and closure, and a realistic safety assessment in deep geological disposal; and
- Encourage and train the next generation of engineers and researchers by sharing and transferring a vast amount of knowledge and experience developed to date in relevant organisations worldwide.
In the HIP, our priority should be given to promoting multilateral collaboration on the following three tasks as these are of great interest to many organisations worldwide as recognised during the International Roundtable discussions on the final disposal of high-level radioactive waste and spent nuclear fuel in 2019 and 2020**:
- Task A : Solute transport experiment with model testing;
- Task B : Systematic integration of repository technology options; and
- Task C : Full-scale EBS dismantling experiment.
*NEA: OECD Nuclear Energy Agency (https://www.oecd-nea.org/)
**A summary report is available on the NEA website:
https://www.oecd-nea.org/jcms/pl_39718/international-roundtable-on-the-final-disposal-of-high-level-radioactive-waste-and-spent-fuel-summary-report

Background
In the International Roundtable discussions, it was very much agreed that enhancing international cooperation would be of great importance to maintain and strengthen technological capabilities for the final disposal. Looking towards the long-term effective implementation of a geological disposal project from an international perspective, the technical understanding for the project should be further strengthened by, for example, transforming research and development (R&D) results into practical and reliable technologies and managing temporal uncertainties associated with long-term predictive modelling. To this end, international cooperation utilising URLs made internationally available should be facilitated as sharing financial and human resources as well as transferring R&D knowledge and experience to the next generation of engineers and researchers would be of much value and benefit.
News
- 18 March 2025
- A decision was made to take the HIP forward into Phase 2 (April 2025 to March 2029) with the written approval of the following participating organisations:
- BGE: the Bundesgesellschaft für Endlagerung mbH, Germany;
BGS: the British Geological Survey, UK;
CRIEPI: the Central Research Institute of Electric Power Industry, Japan;
KAERI: the Korea Atomic Energy Research Institute, Korea;
NUMO: the Nuclear Waste Management Organization of Japan, Japan;
RATEN: the Regia Autonomă Tehnologii pentru Energia Nuclear, Romania;
RWMC: the Radioactive Waste Management Funding and Research Center, Japan;
SERAW: the State Enterprise Radioactive Waste, Bulgaria; and
JAEA.
- 6 March 2025
- The fifth Management Board meeting was held online and approved the results of Phase 1 (February 2023 to March 2025), which were obtained as originally planned.
- 3-4 February 2025
- An on-site Task A meeting was held between the Central Research Institute of Electric Power Industry (CRIEPI, Japan), the Nuclear Waste Management Organization of Japan (NUMO, Japan) and JAEA at the Horonobe URL.
- 26 November 2024
- A suite of Task A in situ tracer experiments commenced at the 250 m Niche off the West Shaft No.1 with the first injection of a fluorescent tracer cocktail in the imposed dipole flow-field.
- 13-15 November 2024
- Two talks were given by JAEA on the simulation studies of excavation damaged zone (EDZ) evolution in Task B and Task C and a poster presentation was also made by the Korea Atomic Energy Research Institute (KAERI, Korea) on the modelling of EDZ propagation in Task B at the Fourth International Conference on Coupled Processes in Fractured Geological Media: Observation, Modeling, and Application (CouFrac2024), Kyoto, Japan.