Multibarrier waste forms. Part I. Development

Technical Report · Fri Sep 01 04:00:00 EDT 1978

DOI:https://doi.org/10.2172/6525018· OSTI ID:6525018

Rusin, J M; Lokken, R O; Lukacs, J M; Sump, K R; Browning, M F; McCarthy, G J

The multibarrier concept produces a composite waste form with enhanced inertness through improvements in thermal stability, mechanical strength, and leachability by the use of coatings and metal matrices. This report describes research and development activities resulting in the demonstration of the multibarrier concept for nonradioactive simulated waste compositions. The multibarrier concept is to utilize up to three barriers to isolate radionuclides from the environment: a solid waste inner core, an impervious coating, and a metal matrix. Two inner core materials, sintered supercalcine and glass marbles, have been demonstrated. The coating barrier provides enhanced leach, impact, and oxidation resistance as well as thermal protection during encapsulation in the metal matrix. Py/Al/sub 2/O/sub 3/ coatings deposited by chemical vapor deposition (CVD) and glass coatings have been applied to supercalcine cores to improve inertness. The purpose of the metal matrix is to improve impact resistance, protect the inner core rom any adverse environments, provide radiation shielding, and increase thermal conductivity, yielding lower internal temperatures. The development of gravity sintering and vacuum casting techniques for matrix encapsulation are discussed. Four multibarrier products were demonstrated: (1) Glass marbles encapsulated in vacuum-cast Pb-10Sn; (2) uncoated, sintered supercalcine pellets encapsulated in vacuum-cast Al-12Si; (3) glass-coated, sintered supercalcine pellets encapsulated in vacuum-cast Al-12Si; and (4) PyC/Al/sub 2/O/sub 3/-coated supercalcine encapsulated in gravity-sintered Cu. 23 figs., 20 tables.

• Research Organization: Battelle Pacific Northwest Labs., Richland, WA (USA)
• DOE Contract Number: EY-76-C-06-1830
• OSTI ID: 6525018
• Report Number(s): PNL-2668-1
• Country of Publication: United States
• Language: English

Related Subjects

052001* -- Nuclear Fuels-- Waste Processing
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON
CHALCOGENIDES
COATINGS
DIFFUSION BARRIERS
ELEMENTS
GLASS
MATRIX MATERIALS
METALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PYROLYTIC CARBON
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
REACTOR MATERIALS
REFRACTORIES
WASTES