Endothermic process: application to immobilization of Hanford in-tank solidified waste

Technical Report · Sun Jul 01 04:00:00 EDT 1973

DOI:https://doi.org/10.2172/4424528· OSTI ID:4424528

Kupfer, M. J.; Schulz, W. W.

Conversion of high-level solid radioactive waste to a nonleachable silicate glass is accomplished in the Endothermic process by simple melting of a mixture of the waste with crushed basalt. Dense (2.5 g cm/sup -3/) green-black glasses are obtained by melting mixtures containing 30 to 40 wt% Hanford In-Tank Solidified (ITS) waste, 50 to 70 wt% basalt, and 0 to 10 wt% B/sub 2/O/sub 3/. Addition of B/sub 2/O/sub 3/ to the process charge is desirable to lower its melting range from about 1100--1150 deg C to 1000--1050 deg C. Leach rates of these glasses (calculated from the sum of the concentrations of Fe, Na, Ca, Si, Mg, Al, Sr, and Cs in the leach liquor) in water at 25 deg C range from 10/sup -7/ to 10/sup -5/ g/cm/sup 2/ day. The lea ch rate, based on /sup 137/Cs, of a typical Endothermic process glass made from actual ITS waste, is 3.0 x 10/sup -8/ g/cm/sup 2/ day. This leach rate corresponds to removal of 2.1 x 10/sup -14/ g / sup 137/Cs per day from a square centimeter of glass containing 57 mu Ci /sup 137/Cs per gram. Judging from initial tests, the Endothermic process is a very promising scheme to increase immobilization of the ITS waste. (auth)

• Research Organization: Atlantic Richfield Hanford Co., Richland, Wash. (USA)
• NSA Number: NSA-29-002567
• OSTI ID: 4424528
• Report Number(s): ARH--2800
• Country of Publication: United States
• Language: English

Related Subjects

*RADIOACTIVE WASTE PROCESSING-- SOLID WASTES
BASALT
CESIUM 137
LEACHING
N40430* --Chemistry--Radiochemistry & Nuclear Chemistry-- Radioactive Waste Treatment
SILICATES