In vessel detection of delayed neutron emitters from clad failure in sodium cooled nuclear reactors: An estimation of the signal

Ex-Vessel Delayed Neutron Detection Systems for the ASTRID Sodium-Cooled Fast Reactor

“…They allow detecting and locating with a short response time, about 20 s, fuel failures [16]. It can also be noted that high temperature fission chambers are investigated for the ASTRID reactor to be installed in vessel [17]. This approach has the advantage to reduce to response time with a very short sodium transit time from fuel to detector (≈ 6 s), to be intrinsically blind to gamma rays thanks to the very high Q-value of the fission reaction, and to suppress photoneutron problem.…”

Design of a delayed neutron detection system for the ASTRID Sodium-cooled fast reactor

“…The objective of DND systems in the safety policy of the reactor is to detect the release of fission products emitting delayed neutrons (FPDN) as bromine 87 or iodine 137. In-vessel fission chambers have been studied to efficiently detect the loss of FPDN but exvessel DND system is still a favorite, as immune to any interference from core-neutrons [1]. In this ex-vessel configuration, remaining interferences can arise from:…”