Reactor loose-part activity

Measured Loose-Part drag coefficients were used to calculate reactor loose-part activity as a function of mass and reactor coolant flow conditions for prototype loose-part shapes. The maximum loose-part mass that could be levitated in vertical flow and the maximum loose-part mass that could impact a recirculating steam generator tube sheet were calculated as a function of flow velocity for Pressurized Water Reactor (PWR) cold and operating primary coolant water properties. The energy of steam generator tube sheet impacts was calculated as a function of mass at cold and operating conditions for a 1130 MW Pressurized Water Reactor. Substantial decreases in active loose-part mass and impact energy occurred between cold and hot flow conditions due to the decrease in water density and viscosity. Loose-parts with higher surface area to mass ratios had higher maximum levitation masses and impact energy. These calculations provide insight into the range of active loose-part mass and impact energy as a function of flow conditions. The associated range in detected signal amplitude can assist in the screening and evaluation of unknown loose-part signals. The loose-part activity modeling methods can be used to extend the results to other reactor coolant system flow conditions and geometries.