Investigation of physical and chemical properties for upgraded SAP (SiO2Al2O3P2O5) waste form to immobilize radioactive waste salt

Electrochemical Salt Wasteform Development: A Review of Salt Treatment and Immobilization Options

“…These products were then mixed with glass powders at a mass ratio of 75% gel product to 25% borosilicate glass binder, and these mixtures were heat treated at 1100 °C for 4 h. The resulting wasteforms were comprised of Li-Al-Si-O, AlPO 4 , Li 3 PO 4 , and amorphous phases and showed very low releases during chemical durability testing with the ASTM C1285 method . As described in more detail in later work, phase separation was readily apparent in the wasteform where Li/P-rich droplets were seen in the glassy aluminoborosilicate network (see Figure ). The chloride content in the products was low (Figure f), and below detection limits in certain samples, demonstrating the effectiveness of this processing method to dehalogenate the starting salts.…”

“…Additional discussion will be provided to describe where research gaps exist that could be used to (1) further improve the waste loading within an existing wasteform option or (2) remove salt constituents that do not require immobilization (e.g., only immobilizing fission products). The primary wasteforms that will be compared within the context of this paper include glass-bonded sodalite (GBS) ceramic wasteforms (CWF), lead tellurite (Pb-Te-O) glasses, , lanthanide (alumino)­borosilicate (LABS) glasses, − and iron phosphate (Fe-P-O) glasses. ,, Others that will not be discussed in as much detail include dehalogenation processes for salt waste streams including one utilizing an ultrastable H-Y zeolite (USHYZ) where the dehalogenated product is immobilized by a cold-press-and-sinter process or in a low-melting glass, − a silica aluminophosphate (SAP; or upgraded SAP, U-SAP) process, − and a zinc-in-titania (Zn-Ti-O or ZIT) process. , …”

Review of Hazards Associated with Molten Salt Reactor Fuel Processing Operations

“…This process has been demonstrated at the bench scale for chloride salts, and it is anticipated that it could work for fluoride salts based on thermodynamic stabilities. 86 Rare-earth phosphates form a stable mineral, monazite or xenotine. Trapping of salt cations in zeolites is also being explored.…”

Natural Clay Minerals as a Starting Material for Matrices for the Immobilization of Radioactive Waste from Pyrochemical Processing of SNF

“…This method involves a technologically complex and long-term process of zeolite occlusion to uniformly distribute alkali Chloride salts are difficult to immobilize in both glass matrices and cements, and in most types of ceramics. Studies of new glass compositions and glass-based composite materials show that the reliable fixation of significant amounts of alkali metals' chlorides requires preliminary treatment and their transformation to the form of oxides or phosphates, i.e., an additional technological operation is required [3][4][5][6].…”