Ex-vessel delayed neutron detection systems for the ASTRID Sodium-cooled Fast Reactor

Romain Coulon (1) , Emmanuel Rohée (2) , Jonathan Dumazert (1) , Sara Garti (1) , Philippe Filliatre (3) , Christian Jammes (3)

1 LCAE - Laboratoire Capteurs et Architectures Electroniques
2 ANDRA - Agence Nationale pour la Gestion des Déchets Radioactifs
3 DER - Département Etude des Réacteurs

Monitoring fuel integrity during sodium-cooled fast reactor operation becomes a crucial issue when sodium uranoplutonate formed consecutively to a clad aperture will foster cooling defaults. Delayed neutron detection (DND) systems are the key tools allowing to prevent and to mitigate such an accident by monitoring the concentration of delayed neutron precursors contained into the coolant. DND systems operate in hard gamma-rays fluxes and low-neutron activity levels. They have to be carefully optimized in order to detect, as early as possible, potentially harmful failures. A discussion is conducted on privileged ways to design DND systems, and some conclusions are stated.

Keywords: sodium-cooled fast reactor; fuel integrity; safety systems; nuclear fuels; neutron detectors; Fission reactor instrumentation; Delayed neutron detection (DND); gamma-rays; neutrons; instrumentation; nuclear instrumentation; detector

Domains: Physics [physics]; Physics [physics]; Instrumentation and Detectors [physics.ins-det]; Physics [physics]; Nuclear Experiment [nucl-ex]

Romain Coulon, Emmanuel Rohée, Jonathan Dumazert, Sara Garti, Philippe Filliatre, et al.. Ex-vessel delayed neutron detection systems for the ASTRID Sodium-cooled Fast Reactor. IEEE Transactions on Nuclear Science, 2018, 65 (9), pp.2502-2509. ⟨10.1109/TNS.2018.2832987⟩. ⟨cea-01915954⟩