The Impact of Proposed delta Gp Limits on Glass Formulation Efforts: Part 1:. Model-Based Assessments

PEELER, DAVID

Savannah River Site (S.C.)

关键词: Pct;    Sludges;    Global Positioning System;    Wastes Durability;    Forecasting;   

DOI  :  10.2172/835620
RP-ID  :  WSRC-TR-2004-00203
RP-ID  :  AC09-96SR18500
RP-ID  :  835620

美国|英语

来源: UNT Digital Library

【 摘 要 】

The Savannah River National Laboratory (SRNL) has initiated studies to assess alternative durability options that may provide access to compositional regions of interest in support of the accelerated cleanup mission at the Defense Waste Processing Facility (DWPF). One of the options being pursued is the redefinition of the durability model acceptability limits. Some of the conservative steps used in establishing the current limits without comprising the high confidence required for meeting the specification on the wasteform quality were identified and eliminated. The results led to a set of three new Property Acceptability Region (PAR) values for the preliminary glass dissolution estimator or free energy of hydration durability model which have the potential to allow access to compositional regions of interest to improve melt rate or waste throughput. Although these limits are available for implementation, there is currently no driving force to do so (i.e., the current Frit 418 - Sludge Batch 3 (SB3) system is liquidus temperature (TL) limited). In this report, glass formulations were identified with the intent of generating incentive for applying the new durability limits for SB3. More specifically, higher alkali frit compositions were identified or developed to transition into and through the region of .Gp acceptability as defined by the current and proposed durability limits. All other property prediction criteria were satisfied. An eight glass test matrix has been identified to meet these objectives. These glasses will be fabricated in the laboratory and their durability measured and compared to model predictions (and to the assessments by the index system). Although incentive for implementation of the proposed durability limits could be demonstrated through the measured durability response for these higher alkali systems, assessments of melt rate should also be performed to establish a clear motive or driver to implement a frit change. More specifically, a ''significant'' increase in melt rate may be required to provide the incentive for DWPF to implement the change rather than a ''paper study'' and/or durability assessment.