Data Report on gamma Radiolysis Tests on PBB1 and PBB3 Brines: Salt Repository Project

摘要

The tests described in this data report are described in the FY 1986 Technical Program Plan (TPP), WBS Element 0302 - Brine Radiolysis, for the Waste Package Program at Pacific Northwest Laboratory (PNL), conducted for the Salt Repository Project through the Office of Civilian Radioactive Waste Management (OCRWM), Department of Energy. Two types of tests were outlined in the FY 1986 TPP, one in which PBB1 and PBB3 brines were to be irradiated in closed systems while the buildup of gas pressure was monitored, and the second in which the Eh of PBB1 and PBB3 brines was to be monitored continuously during irradiation. The first type of test was intended to simulate repository conditions by including coupons of mild steel to represent container material. Blank tests, which involved either no radiation or no steel coupons, were added to both of the test matrices to aid in understanding the radiolysis results. Hindsight shows that the tests that included steel coupons provided corrosion-relevant data but generated little useful radiolysis information. The second type of test was intended to use platinum electrodes to measure the effect of radiolysis on the redox potential of the brines. Eh measurements were to be made during irradiation because it was thought that the redox potential might change rapidly after the irradiation was terminated. If that were true, then Eh measurements made only after irradiation would be misleading. However, platinum electrodes were found to be ill-suited for measuring the redox potential of PBB1 and PBB3 brines; therefore, a different method is needed. Some exploratory testing is being conducted, and results obtained to date are reported here along with the more extensive gas pressure and corrosion results. This data report will be followed at a later date by a summary or topical report, which will include analysis of the data. The data in this data report are preliminary; they have been neither analyzed nor evaluated. (ERA citation 12:024628)