Immobilization of krypton-85 in zeolite 5A and porous glass

Technical Report · Tue Dec 01 04:00:00 EST 1981

OSTI ID:5258470

Christensen, A B; DelDebbio, J A; Knecht, D A; Tanner, J E; Cossel, S C

This report demonstrates the technical and economic feasibility for immobilizing krypton-85 by high pressure/high temperature encapsulation in zeolite 5A or thirsty Vyco porous glass. Data are presented to show how process conditions affect the encapsulation and how to compact the zeolite beads with glass frit or other additives to form a fused mass with low dispersibility potential. Krypton specific loadings of 30 and 50 m/sup 3/ STP gas per m/sup 3/ solid are readily achieved at 100 MPa in porous glass at 900/sup 0/C and zeolite 5A at 700/sup 0/C. Krypton is encapsulated by a sintering process where the porous glass and zeolite 5A voids are sealed. With zeolite 5A, the initial water concentration has a catalytic effect on the sintering, resulting in a transition from crystalline zeolite 5A to an amorphous aluminosilicate. Krypton leakage experiments are used to predict leakage rates from glass or zeolite of less than 0.03% and 0.3% for 10-y storage at 300 and 400/sup 0/C, respectively. Heating the loaded zeolite at 600 to 700/sup 0/C for 4 h removes 0.1% of the total krypton which is loosely held and reduces the subsequent leakage rates at 300 to 400/sup 0/C. Zeolite 5A is chosen as the preferred material to immobilize krypton-85. A preconceptual design and cost estimate is given for a facility to encapsulate 110% of the krypton production of a 2000 metric ton of heavy metal per year reprocessing plant, or 230 m/sup 3/ of gas containing 19 MCi of krypton-85. A hot isostatic press (HIP) with an isolated work zone of 8 or 16 L capacity is required to operate for 600 or 300 cycles per year, respectively. Existing HIP technology uses work zones from 1 to 3500 L capacity at similar production rates. A preliminary safety evaluation shows that an incredible worst case accident could be contained and the maximum off-site dose would be well below accident protective action guidance levels.

• Research Organization: Exxon Nuclear Idaho Co., Inc., Idaho Falls (USA)
• DOE Contract Number: AC07-79ID01675
• OSTI ID: 5258470
• Report Number(s): ENICO-1102; ON: DE82011257
• Country of Publication: United States
• Language: English

Related Subjects

050800 -- Nuclear Fuels-- Spent Fuels Reprocessing
052001* -- Nuclear Fuels-- Waste Processing
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ACCIDENTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COST
DESIGN BASIS ACCIDENTS
DOSES
ENCAPSULATION
EVEN-ODD NUCLEI
FEASIBILITY STUDIES
FUEL REPROCESSING PLANTS
HEATING
HOURS LIVING RADIOISOTOPES
INORGANIC ION EXCHANGERS
INTERMEDIATE MASS NUCLEI
ION EXCHANGE MATERIALS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KRYPTON 85
KRYPTON ISOTOPES
LEAKS
MATERIALS
MINERALS
NUCLEAR FACILITIES
NUCLEI
OFF-GAS SYSTEMS
POROUS MATERIALS
RADIATION DOSES
RADIOISOTOPES
REACTOR ACCIDENTS
SAFETY
VYCOR
YEARS LIVING RADIOISOTOPES
ZEOLITES