OpenPrep: Sensor Event-driven Open Column Chromatographic Sample Preparation System.

We propose a sensor event-driven, open-column chromatographic sample preparation system─OpenPrep. This system replaces the problematic flow selector valve with a noncontact built-in sensor, eliminating carryover and clogging issues, which are commonly encountered in pump-driven chromatographic systems. The innovative valveless column-flow design, combined with a compact gantry dispenser and motion stage-based fraction collector, reduces the sample flow path to a disposable component with a postcolumn dead volume of only 0.

Fabrication of nanofibrous PbO electrode embedded with Pt for decomposition of organic chelating agents.

A new fabrication method of nanofibrous metal oxide electrode comprising Pt nanofiber (Pt-NF) covered with PbO on a Ti substrate was proposed. Pt-NF was obtained by performing sputtering deposition of Pt on the surface of electrospun poly(vinyl alcohol) (PVA) nanofiber on a Ti substrate, in which PVA was then removed by calcination (Ti/Pt-NF). Subsequently, by introducing PbO to the Ti/Pt-NF using the electrodeposition method, a nanofibrous Ti/Pt-NF/PbO electrode was finally obtained.

Evaluation of physicochemical characteristics and centerline temperatures of Sr ceramic waste form.

When disposing of spent fuel, nuclides such as Cs-137 and Sr-90, which generate short-term decay heat, must be removed from the spent nuclear fuel for efficient storage facility utilization. The Korea Atomic Energy Research Institute (KAERI) has been developing a nuclide management process that can enhance disposal efficiency by sorting and collecting primary nuclides and a technology for separating Sr nuclides from the spent nuclear fuels using precipitation and distillation. In this study, we prepared Sr ceramic waste form, SrTiO, using the solid-state reaction method to immobilize the Sr nuclides, and its physicochemical properties were evaluated.

A new route to the stable capture and final immobilization of radioactive cesium.

Radioactive Cs released from damaged fuel materials in the event of nuclear accidents must be controlled to prevent the spreading of hazardous Cs into the environment. This study describes a simple and novel process to safely manage Cs gas by capturing it within ceramic filters and converting it into monolithic waste forms. The results of Cs trapping tests showed that CsAlSiO was a reaction product of gas-solid reactions between Cs gas and our ceramic filters.

Characteristics of wasteform composing of phosphate and silicate to immobilize radioactive waste salts.

In the radioactive waste management, metal chloride wastes from a pyrochemical process is one of problematic wastes not directly applicable to a conventional solidification process. Different from a use of minerals or a specific phosphate glass for immobilizing radioactive waste salts, our research group applied an inorganic composite, SAP (SiO(2)-Al(2)O(3)-P(2)O(5)), to stabilize them by dechlorination. From this method, a unique wasteform composing of phosphate and silicate could be fabricated.

Stabilization/solidification of radioactive salt waste by using xSiO2-yAl2O3-zP2O5 (SAP) material at molten salt state.

The molten salt waste from the pyroprocess is one of the problematic wastes to directly apply a conventional process such as vitrification or ceramization. This study suggested a novel method using a reactive material for metal chlorides at a molten temperature of salt waste, and then converting them into manageable product at a high temperature. The inorganic composite, SAP (SiO2-Al2O3-P2O5), synthesized by a conventional sol-gel process has three or four distinctive domains that are bonded sequentially, Si-O-Si-O-A-O-P-O-P.

Characteristics of solidified products containing radioactive molten salt waste.

The molten salt waste from a pyroprocess to recover uranium and transuranic elements is one of the problematic radioactive wastes to be solidified into a durable wasteform for its final disposal. By using a novel method, named as the GRSS (gel-route stabilization/solidification) method, a molten salt waste was treated to produce a unique wasteform. A borosilicate glass as a chemical binder dissolves the silicate compounds in the gel products to produce one amorphous phase while most of the phosphates are encapsulated by the vitrified phase.

Stabilization/Solidification of radioactive molten salt waste via gel-route pretreatment.

The volatilization of radionuclides during the stabilization/solidification of radioactive wastes at high temperatures is one of the major problems to be considered in choosing suitable wasteforms, process, material systems, etc. This paper reports a novel method to convert volatile wastes into nonvolatile compounds via a sol-gel process, which is different from the conventional method using metal-alkoxides and organic solvents. The material system was designed with sodium silicate (Si) as a gelling agent, phosphoric acid (P) as a catalyst/stabilizer, aluminum nitrate (Al) as a property promoter, and H20 as a solvent.