Studies Related to Chemical Mechanisms of Gas Formation in Hanford High-Level Nuclear Wastes

Barefield, E. Kent ; Liotta, Charles L. ; Neumann, Henry M.

Georgia Tech Research Corp. Georgia Institute of Technology (United States)

关键词: Flammability;    Hanford Reservation;    Gases;    Chemical Reaction Kinetics;    Storage Facilities;   

DOI  :  10.2172/793569
RP-ID  :  DOE/ER/14690
RP-ID  :  FG07-96ER14690
RP-ID  :  793569

美国|英语

来源: UNT Digital Library

【 摘 要 】

The objective of this work is to develop a more detailed mechanistic understanding of the thermal reactions that lead to gas production in certain high-level waste storage tanks at the Hanford, Washington site. Prediction of the combustion hazard for these wastes and engineering parameters for waste processing depend upon both a knowledge of the composition of stored wastes and the changes that they undergo as a result of thermal and radiolytic decomposition. Since 1980 when Delagard first demonstrated that gas production (H2and N2O initially, later N2 and NH3)in the affected tanks was related to oxidative degradation of metal complexants present in the waste, periodic attempts have been made to develop detailed mechanisms by which the gases were formed. These studies have resulted in the postulation of a series of reactions that account for many of the observed products, but which involve several reactions for which there is limited, or no, precedent. For example, Al(OH)4 has been postulated to function as a Lewis acid to catalyze the reaction of nitrite ion with the metal complexants, NO is proposed as an intermediate, and the ratios of gaseous products may be a result of the partitioning of NO between two or more reactions. These reactions and intermediates have been the focus of this project since its inception in 1996.