Abstract: An improved boiling water nuclear reactor and method for preventing intergranular stress crack corrosion in the recirculation line of the reactor system where recirculation line coolant water containing dissolved oxygen is diverted from the recirculation loop, hydrogen gas is introduced into the recirculation loop coolant water and the hydrogen-containing recirculation loop coolant water is contacted with a catalyst to enhance reaction of the hydrogen gas with the dissolved oxygen. The deoxygenated recirculation loop coolant water is then returned to the reactor vessel for passage through the core thereof. The hydrogen gas may be added in a stoichiometric amount to remove the dissolved oxygen or in a slight excess so as to suppress radiolysis in the reactor core.

Abstract: Water for use in steam generation systems, which is contained in a storage tank, is deoxygenated for use in the system by adding hydrogen to a stream of the water and intimately mixing the same, pressurizing the stream to a pressure of 60-150 psig, and contacting the pressurized stream with a catalyst bed of palladium or platinum dispersed on a solid carrier. The hydrogen reacts with the dissolved oxygen in the presence of the catalyst at ambient temperatures, to produce a deoxygenated stream of water containing less than 10 ppb of oxygen. The deoxygenated water can be returned to the storage tank or supplied directly to the steam generation system.

Abstract: A process for removing dissolved oxygen from an aqueous medium, using hydrazine to react with the oxygen, where the aqueous medium is contacted with a catalyst bed of palladium or platinum metal dispersed on a solid carrier, at ambient temperatures. The catalyst bed effects reaction of the hydrazine with the dissolved oxygen to provide residual oxygen contents of below 10 ppb. Preferably, the hydrazine is intimately mixed with the aqueous medium prior to contact with the catalyst bed. The process is especially useful in removing dissolved oxygen from recirculating aqueous medium of a steam generation system, where the hydrazine-containing aqueous medium is contact with the catalyst bed after passage through the condenser pump but prior to the feedwater heaters.