Radioactivity and Purity Control of APPR Primary Water

Abstract

Primary system purification for pressurized water reactors is needed to satisfy both conventional and nuclear requirements, including the need to minimize deposition on primary system components. The potential buildup of radioactivity on primary system piping and components could seriously complicate maintenance. This radioactivity buildup results from deposition and/or atom exchange. The principal nuclide which contributes to the maintenance problem is the 5.3-yr half-life cobalt-60 which results from the presence of cobalt impurities in austenitic stainless steel. A generalized curve for this buildup is given. A discussion of the effectiveness of the purification system in reducing this buildup is given. Possible ineffectiveness of purification in reducing this buildup may result because of poor location of the purification piping. The program of investigating activity buildup at the Army Package Power Reactor is discussed. Preliminary results on water samples obtained during operation of this reactor are given. Results of primary system purification, including demineralizer decontamination factors, are also presented.