Powder technological vitrification of medium and high level waste by in-can hot pressing [report]

G. Ondracek, E.H. Toscano
Powder technology is used to immobilize medium Ievel nuclear waste (MLW) in sintered glass. By in-can bot pressing (temperature 923 K; pressure 0.4 MPa; heating rate = 100 Kjh; cooling rate 5 K/h) glass products containing simulated MLW (20 wt%) have been produced in stackable steel cans ( "; 300 mm diameter). High densities ( = 93% TD), bulk integrities and homogeneities for the waste element distributions are realized. The advantages of powder technology as, for example: (i) no segregation
more » ... ) no segregation due to solid state vitrification, (ii) low evaporation Iosses and no compatibility problems due to low densification temperatures (sinter temperature = 0.6 softening temperature of glass), (iii) production in easily arrangable and interchangeable stacking units at modest pressures adequate especially for the use in bot cells under remote handling conditions, all Iogether hold for the process which therefore is appropriated for high Ievel waste (HL W), medium Ievel waste and HLWjMLW common vitrification as weil. ABSTRACT The paper presents a method for the immobilization of different waste streams based in the uniaxial in-can hat pressing of a glass frit tagether with the waste oxides. The process reported herein offers engineering simplicity in combination with many technological advantages such as significant decrease in temperature, use of small pressure, improved homogeneity of the products., production in easily arrangeable and interchangeable units. Furthermore, the proposed method has also proved to be suitable for treating intermediatelevel waste streams containing Zry-4 cladding fragments.
doi:10.5445/ir/270020457 fatcat:7zlelbpshna4lkjkzi2zt65tfq