SNAP-8 Corrosion Program

Abstract : A corrosion-study program was initiated in June 1963 at the Oak Ridge National Laboratory in support of the SNAP-8 electrical generating system. The primary objectives of the program are (1) to evaluate the compatibility of the proposed structural materials with the proposed reactor coolant,Nak containing hydrogen, and (2) to provide information on the behavior, control, and disposition of the hydrogen present in the SNAP-8 primary coolant, particularly with respect to the diffusion of hydrogen from the SNAP-8 primary circuit through Croloy 9M boiler tubes into the power conversion circuit. The program initially provided for 12 loop experiments, with time and space available in the schedule for a thirteenth loop. The 12 initial experiments included the operation of eight loops to obtain information for a factorial replicate study of three variables at two levels each, two loops for a time-series study at SNAP-8 conditions, and two (or three) additional loops for investigating means of limiting hydrogen egress through the Croloy 9M cooler section of the loop. In addition, the program included a study of hydrogen permeability for three SNAP-8 container materials with and without Nak present and an investigation of the relationships between hydrogen solubility and partial pressure in NaK as a function of temperature.