At the latest International Conference on Nuclear Engineering ICONE 30, held in Kyoto from 21 to 26 May 2023, Hugo Laffoley won the "Best papers Award" for the presentation of his work on the experimental synthesis of Caesium-containing microparticles simulating those found near FukushimaDaiichi (photo below).

Hugo, a doctoral student at Ecole doctorale 3M, is working on his thesis on severe accident experimentation at CEA Cadarache, under joint supervision with Subatec


Ten years after the nuclear accident in Fukushima, studies to understand the causes and consequences of the nuclear disaster continue. After the accident, the three reactor cores melted, producing several hundred tonnes of corium and fuel debris, continuously generating heat through the radioactive decay of the fission products present in the corium.
Coordinated by Subatech, a collaboration with JAIEA, Kyshu University and Tokyo University of Technology in Japan and the French Atomic Energy Commission (CEA) has been initiated to summarise the research of the ten years after the accident.
These studies are crucial for any planning of reactor decommissioning.
The temporal evolution of water chemistry and radionuclide inventories leached from the debris by the cooling water was studied. A comparison between the concentration ratios of actinides and fission products measured in water and the results of leaching studies of spent nuclear fuel or debris simulated in the laboratory was carried out.
As with the leaching of spent fuel in the laboratory, the fractions of the 134,137Cs inventories that are analysed in the cooling water are orders of magnitude larger than those of the actinides. After more than 10 years of contact between fuel debris and water, the release rates of 137Cs remain higher than those of actinides even though the release rate of 137Cs from the debris has decreased by a factor of about 100 during this period. Actinide fixation in the debris is strong. The high stability of actinide fixation in debris makes the option of direct disposal of fuel debris as waste in appropriate containers after the decommissioning of reactors in the future viable.

Access to the article "Ten years after the NPP accident at Fukushima : review on fuel debris behavior in contact with water, Journal of Nuclear Science and Technology",
Authors : Bernd Grambow, Ayako Nitta, Atsuhiro Shibata, Yoshikazu Koma, Satoshi Utsunomiya, Ryu Takami, Kazuki Fueda, Toshihiko Ohnuki, Christophe Jegou, Hugo Laffolley& Christophe Journeau (2021)
Status of reactor corres, Fukushima at 2018: a) unit 1; b) unit 2, c) unit 3. In blue: as the cooling water flowed, the cores largely melted and much of it fell onto the concrete at the bottom, references:  Mizokami S, Rempe JL. The Events at Fukushima Daiichi. Reference Module in Earth Systems and Environmental Sciences . Elsevier; 2020.


The radiolysis of carbonates (CO32-), studied in the Radiochemistry team of the SUBATECH laboratory and using the irradiation beam of the Arronax cyclotron in collaboration with the ISTerre laboratory, has proved to be the explanation for the origin of life on Earth? Indeed, the radiolysis of carbonate ions produced the organic matter necessary for the development of life on Earth, thus allowing the transition from an inorganic world to an organic world.
This work, the result of a collaboration with Laurent Truche, a geochemist at the Institute of Earth Sciences at the University of Grenoble Alpes, led at Subatech by Johan Vandenborre, a CNRS research fellow, is published in the journal Earth and Planetary Science Letters.
On the same subject, an article was published in Quanta Magazine for which Johan Vandenborre, Laurent Truche and Bénédicte Menez, geobioligist at the Institut de physique du globe de Paris, were interviewed.
Read article --- >
Quanta Magazine Podcast ---->

image origine de la vie        Radiolysis Team at ARRONAX CyclotronRadiolyse Subatech from left to right: Johan Vandenborre (researcher - manager team),
Guillaume Blain (engineer), Vincent Fiegel (postdoc),
Emeline Craff (PhD student), Simon Guillonneau (trainee Master 2)

Photos Guerard Montavon Galland

Ilustration formules

Astatine is the rarest chemical element on Earth, and its 211 isotope is very promising for applications in targeted radiotherapy of cancers. Progress in this approach depends on a better understanding of the chemistry of astatine. Researchers from the CRCINA, Subatech and CEISAM laboratories have published a 15-year review of their work in the prestigious Accounts of Chemical Research journal. The most fundamental studies has made it possible to establish the nature of the astatine stable forms in water (Pourbaix diagram) and to reveal astatine ability to form so-called halogen bond interactions, i.e. specific and very directional attractive interactions. Thanks to a collaboration established with the European Organization for Nuclear Research (CERN - Switzerland), the electron affinity of astatine was successfully determined, which is essential to better understand its chemical behavior. The production of astatine-211 by the ARRONAX cyclotron has also enabled the development of new radiochemical synthesis methods and a real leap forward in its use in cancer therapy. The region Pays de la Loire has been supporting this work since 2005; it has also benefited from funding from the Programme d'Investissements d'Avenir (IRON and ArronaxPlus projects) and from the SIRIC ILIAD, and today Nantes is become the main world player in astatine research. This recognition is distinguished at the European level by the creation of an international clinical network (NOAR COST action) which aims to demonstrate that astatine-211 can become the European standard for the treatment of some cancerous pathologies

Guérard, F., Maingueneau, C., Liu, L., Eychenne, R., Gestin, J.-F., Montavon, G. & Galland, N. Advances in the Chemistry of Astatine and Implications for the Development of Radiopharmaceuticals. Acc. Chem. Res. 54, 3264–3275 (2021)


Pollusols indexWith the creation of the OSUNA (Observatoire des Sciences de l'Univers de Nantes Atlantique) in 2008, the radiochemistry team of the Subatech laboratory positioned itself on environmental issues related to "nuclear" activities in the Loire catchment area (release of tritium from nuclear power plants, management of former uranium mines). The projects are now well structured at regional (POLLUSOLS programme), national (creation of the ZATU in 2015, collaboration with EDF, CEA-DAM....) and European (Radonorm) levels. At the regional level, the POLLUSOLS programme (2015-2021) funded by the Pays de la Loire region is coming to an end. It is in this context that several events are taking place:


POLLUSOLS project in the media


Subatech scientific staff involved in the POLLUSOLS project


Gilles Montavon
Gilles Montavon
Research Director CNRS



Catherine Landesman
Catherine Landesman
Research engineer CNRS



Karine David IMG 2635
Karine David
Engineer CNRS


Olivier Peron v2
Olivier Péron
Lecturer at the University of Nantes


Read more :