Low-Activity Waste Glass Studies: FY2000 Summary Report

McGrail, B. Peter ; Icenhower, Jonathan P. ; Martin, Paul F. ; Rector, David R. ; Schaef, Herbert T. ; Rodriguez, Elsa A. ; Steele, Jackie L.

Pacific Northwest National Laboratory (U.S.)

关键词: Low-Level Radioactive Wastes;    Waste Forms;    Low Activity Waste;    36 Materials Science;    Dissolution;   

DOI  :  10.2172/15020983
RP-ID  :  PNNL-13381
RP-ID  :  AC05-76RL01830
RP-ID  :  15020983

美国|英语

来源: UNT Digital Library

【 摘 要 】

Over 200 single-pass flow-through experiments were completed with LAWABP1 glass, the reference glass for the 2001 Immobilized Low-Activity Waste Performance Assessment. These data provided the kinetic rate law parameters and Na ion-exchange rate needed to conduct long-term performance analyses using the reactive chemical transport code STORM. Pressurized unsaturated flow (PUF) experiments with five prototypic LAW glasses were also performed. The PUF test provides a means to dramatically accelerate the weathering process in a simulated vadose zone environment. The performance of these five next generation LAW glasses in the PUF test (and other accelerated tests) improved dramatically from earlier glass compositions that were being developed by BNFL, Inc. No autocatalytic corrosion rate accelerations were observed in tests that were conducted for over 1 year. SPFT and PUF experiments were run with a commercial humic acid solution, 25 to 50 times more concentrated than expected in Hanford vadose zone pore water. No difference in glass dissolution rate versus the rate measured in deionized water could be detected within experimental error. Initial development and testing of a parallelized lattice-Boltzmann method for solving reactive chemical transport problems in complex geometries was completed. This method is being examined as a means to dramatically decrease the computional time required to solve complex multidimensional reactive transport problems needed to predict long-term radionuclide release rates from LAW glasses. The results showed linear speedup behavior with number of processors for a simple test problem. Additional development and testing of the model on more realistic and complex ILAW disposal problems is planned for FY01.