Abstract: A process and a system for detecting defective nuclear fuel assemblies in situ. The system includes two basic subsystems. The first subsystem is a sample collection system consisting of a hood placed over the fuel. A technique whereby a vacuum is drawn across a submerged nozzle of a degas tank is used to draw up the sample of fluid out of a fuel assembly. The second subsystem determines the amount of Kr-85 radioisotope contained in the fluid sample. This information is used to determine whether the fuel assembly contains a defective, i.e., leaking, fuel rod. The measurement values for Kr-85 in the fluid sample extracted from the fuel assembly are compared to the measurement values for Kr-85 in fluid samples taken from the reactor pool prior to fuel assembly testing and fluid samples taken from non-leaking control cells, the latter values representing the background to which the subject fuel assembly is compared.

Abstract: A process and system for the rapid concentration, separation and measurement of Kr-85 and Xe-133. By measuring the amount of Kr-85 radioisotope which is present, false positive signals for the vacuum sipping process can be eliminated. The fission gases are trapped by passing the recirculating gas stream through an adsorbing media. During this process, a known mixture of nonradioactive krypton and xenon is added to the gas stream which enters a thermal conductivity (TC) detector to calibrate the latter. The trapped gases are desorbed and injected into the inlet of a separating column. The column discharges into the TC detector. The TC detector discharge is diverted for counting to an evacuated beta detector chamber during the time that krypton is sensed by the TC detector. Any minute amount of Kr-85 is captured in the chamber, free of Xe-133. The detector discharge is diverted for counting to another evacuated beta detector chamber during the time that xenon is sensed by the TC detector.

Abstract: An analytical testing means for determining the ion contents of nuclear reactor coolant water comprising ion chromatograph means and a conductivity detector. Reagent containing ion exchange resin is recycled, concentrated and the ion exchange resin regenerated to provide a more economic procedure.

Abstract: Water testing means for monitoring circulating water coolant in service within a water cooled nuclear reactor system is disclosed. The invention is an improvement in such water testing means and comprises a preconditioning of selected sample specimens of water with a pH adjustment for inhibiting unbalancing an equilibrium in solution of water coolant with ion solutes.

Abstract: Water testing apparatus for monitoring circulating water coolant in service within a water cooled nuclear reactor system is disclosed. The invention is an improvement in such water testing apparatus and comprises filtering and a preconditioning of selected sample specimens of the coolant water with a pH adjustment for inhibiting unbalancing an equilibrium in solution of water coolant with ion solutes.

Abstract: A mixture of two sets of similarly sized particles having different terminal velocities in a separation liquid is separated. This is done by removing either the smaller particle portion of the set having the greater terminal velocity, or the larger particle portion of the set having the lesser terminal velocity, or both, for example, by sieving. The resulting mixture is introduced into a tube in which the separation liquid is flowing upwardly. This eliminates intermixing of the fines of one set with the larger particles of the other set. The flow of liquid in the tube can be arranged to provide laminar flow separated by two regions of turbulent flow to improve separation of particles. Anion and cation exchange resin particles can be separated in this manner, regenerated and returned to service.