Delayed neutron measurements with a natural uranium fission product source in Fast Breeder Test Reactor

• Delayed neutron measurements performed with a Fission Product Source (FPS) FBTR.
• FPS provided by natural U–Ni pins with perforated clad.
• Measurements have helped in quantification of sensitivity of DND system in FBTR.

An assessment of the sensitivity and localization capabilities of clad failure detection by Delayed Neutron Detection (DND) system in Fast Breeder Test Reactor at Kalpakkam has been done, by a series of delayed neutron measurements. Experimental simulation of failed fuel pin is done by considering a natural uranium fission product source in the form of special subassembly containing natural uranium pins, each having a large exposed area in the form of small holes. The measurements and analysis of delayed neutron signals with special subassembly in several selected locations are presented.