Open AccessHERMETIC SEALING PROBLEMS IN A SMALL BOILING WATER REACTOR
Author(s) -
G.O. Haroldsen
Publication year - 1964
Language(s) - English
Resource type - Reports
DOI - 10.2172/4004649
Subject(s) - radiolysis , pellets , boiling , decomposition , coolant , boiling water reactor , corrosion , hydrogen , oxide , catalysis , chemistry , chemical engineering , nuclear engineering , waste management , materials science , metallurgy , composite material , engineering , mechanical engineering , aqueous solution , organic chemistry
The results of an extensive survey of the literature and of the subsequent analysis permit the prediction of the rate of radiolytic decomposition of the water coolant. Due to the difficulty in assessing the rate of the back reactions, fundamental data from water radiation chemistry could not be applied in a straightforward manner. It proved more expedient to employ the actually observed decomposition rate data from other boiling water reactors and to extrapolate to the operating conditions of SNAP 4. By this approach, the water decomposition rate was estimated to be 5 lbs/day. To assure adequate capacity under all conditions, the catalyst bed was sized to handle twice this rate. Based on the design method of Garber and Peebles, a catalyst bed 3 inches in diameter by 12 inches long, consisting of platinum-coated alumina pellets, appears ample. Operation of the recombiner in a closed recirculatory system was analyzed. It appears that an excess of hydrogen will result as oxygen is preferentially consumed in the initial corrosion process (metal oxidation). Once a stable oxide film is established on the stainless steel surfaces and the excess hydrogen is drawn from the system, the recombiner can thereafter handle the radiolytic gases satisfactorily. (auth