Corrosion and environmental-mechanical characterization of iron-base nuclear waste package structural barrier materials. Annual report, FY 1984

Autor: R.E. Westerman, J.H. Haberman, L.A. Sigalla, S.G. Pitman, B.A. Pulsipher
Rok vydání: 1986
Předmět:
DOI: 10.2172/5851243
Popis: Disposal of high-level nuclear waste in deep underground repositories may require the development of waste packages that will keep the radioisotopes contained for up to 1000 y. A number of iron-base materials are being considered for the structural barrier members of waste packages. Their uniform and nonuniform (pitting and intergranular) corrosion behavior and their resistance to stress-corrosion cracking in aqueous environments relevant to salt media are under study at Pacific Northwest Laboratory. The purpose of the work is to provide data for a materials degradation model that can ultimately be used to predict the effective lifetime of a waste package overpack in the actual repository environment. The corrosion behavior of the candidate materials was investigated in simulated intrusion brine (essentially NaCl) in flowing autoclave tests at 150/sup 0/C, and in combinations of intrusion/inclusion (high-Mg) brine environments in moist salt tests, also at 150/sup 0/C. Studies utilizing a /sup 60/Co irradiation facility were performed to determine the corrosion resistance of the candidate materials to products of brine radiolysis at dose rates of 2 x 10/sup 3/ and 1 x 10/sup 5/ rad/h and a temperature of 150/sup 0/C. These irradiation-corrosion tests were ''overtests,'' as the irradiation intensities employed were 10 tomore » 1000 times as high as those expected at the surface of a thick-walled waste package. With the exception of the high general corrosion rates found in the tests using moist salt containing high-Mg brines, the ferrous materials exhibited a degree of corrosion resistance that indicates a potentially satisfactory application to waste package structural barrier members in a salt repository environment.« less
Databáze: OpenAIRE