First Measurement of Neutrino Emissions from Spent Nuclear Fuel by the Double Chooz Experiment
Double Chooz Collaboration, T. Abrahão, H. Almazan, J. C. dos Anjos, S. Appel, J. C. Barriere, I. Bekman, T. J. C. Bezerra, L. Bezrukov, E. Blucher, C. Bourgeois, C. Buck, J. Busenitz, A. Cabrera, M. Cerrada, E. Chauveau, P. Chimenti, O. Corpace, J. V. Dawson, J. F. Du, Z. Djurcic, A. Etenko, H. Furuta, I. Gil-Botella, A. Givaudan, H. Gomez, M. C. Goodman, T. Hara, J. Haser, D. Hellwig, A. Hourlier, M. Ishitsuka, J. Jochum, C. Jollet, K. Kale, M. Kaneda, M. Karakac, T. Kawasaki, E. Kemp, D. Kryn, M. Kuze, T. Lachenmaier, C. E. Lane, T. Lasserre, D. Lhuillier, H. P. Lima Jr, M. Lindner, J. M. LoSecco, B. Lubsandorzhiev, J. Maeda, C. Mariani, J. Maricic, J. Martino, T. Matsubara, G. Mention, A. Meregaglia, T. Miletic, R. Milincic, A. Minotti, X. Mougeot, D. Navas-Nicolás, Y. Nikitenko, P. Novella, L. Oberauer, M. Obolensky, A. Onillon, A. Oralbaev, C. Palomares, I. M. Pepe, L. Perisse, G. Pronost, J. Reichenbacher, S. Schönert, S. Schoppmann, L. Scola, R. Sharankova, V. Sibille, V. Sinev, M. Skorokhvatov, P. Soldin, A. Stahl, I. Stancu, M. R. Stock, L. F. F. Stokes, F. Suekane, S. Sukhotin, T. Sumiyoshi, C. Veyssiere, B. Viaud, M. Vivier, S. Wagner, C. Wiebusch, G. Yang, F. Yermia
Published: 2025/10/6
Abstract
Neutrino emission from nuclear reactors provides real-time insights into reactor power and fuel evolution, with potential applications in monitoring and nuclear safeguards. Following reactor shutdown, a low-intensity flux of ``residual neutrinos'' persists due to the decay of long-lived fission isotopes in the partially burnt fuel remaining within the reactor cores and in spent nuclear fuel stored in nearby cooling pools. The Double Chooz experiment at the Chooz B nuclear power plant in France achieved the first quantitative measurement of this residual flux based on 17.2 days of reactor-off data. In the energy range where the residual signal is most pronounced, the neutrino detector located 400$\,$m from the cores recorded $106 \pm 18$ neutrino candidate events (5.9$\sigma$ significance). This measurement is in excellent agreement with the predicted value of $88 \pm 7$ events derived from detailed reactor simulations modeling the decay activities of fission products and incorporating the best-available models of neutrino spectra.