A STUDY OF URANIUM CARBIDE AND CLADDING MATERIALS FOR HIGH-TEMPERATURE SODIUM-COOLED REACTORS

Technical Report · Fri Mar 15 00:00:00 EST 1963

OSTI ID:4752823

Hahn, R D

Irradiation experiments were conducted to determine the irradiation performance characteristics of uranium monocarbide, exposed to high-temperature ( approximates 2000 deg F), high heat flux ( approximates -10/sup 6/ Btu/hr-ft/sup 2/), high-burnup ( approximates 25,000 Mwd/ MTU) operation. Hyperstoichiometric uranium carbide fuels have sustained maximum conditions of burnup and average central temperature of 24,000 and 10,000 Mwd/ MTU at 1550 and 2150 deg F, respectively. Hypostoichiometric uranium carbide fuels were exposed to conditions of 1800 deg F average central temperature for a burnup of approximates 7000 Mwd/ MTU. Fission gas release, in general, was low. Values for fuel dimensional increases were scattered, due to thermal or mechanical effects over the fuel column lengths, and could not be correlated with burnup or average fuel central temperatures. The fuel density decrease profile of the fuel length was similar to the burnup profile. Hyperstoichiometric UC/Na (or NaK) Type 304 stainless steel systems show excessive cladding carburization at fuel surface temperatures as low as 1000 deg F for an acceptable reactor residence time. Hypostoichiometric UC/Na Type 304 stainless steel systems are compatible at 1200 and 1600 deg F under isothermal conditions for at least 6400 and 3000 hr, respectively. For the latter system, it appears feasible to operate fuel elements at central temperatures of approximates -2000 deg F to burnups in excess of 25,000 Mwd/MTU. Niobium and zirconium alloys have shown promise as cladding materials for the utilization of hyperstoichiometric uranium monocarbide. Out-of-pile tests have shown that zirconium and niobium alloys are compatible with hyperstoichiometric UC to 1600 deg F. Zirconium alloys are strength limited above 1150 deg F. Niobium, while satisfactory from a strength standpoint at 1600 deg F, may be limited by nuclear considerations. (auth)

• Research Organization: Atomics International. Div. of North American Aviation, Inc., Canoga Park, Calif.
• DOE Contract Number: AT(11-1)-GEN-8
• NSA Number: NSA-17-016650
• OSTI ID: 4752823
• Report Number(s): NAA-SR-7696
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-63
• Country of Publication: United States
• Language: English

Related Subjects

METALS, CERAMICS, AND OTHER MATERIALS
BURNUP
CARBIDES
DENSITY
DIFFUSION
EXPANSION
FISSION PRODUCTS
FUEL CANS
GASES
HEAT TRANSFER
HIGH TEMPERATURE
IRRADIATION
LIQUID METAL COOLANT
NIOBIUM ALLOYS
PERFORMANCE
SODIUM
STAINLESS STEEL- 304
STAINLESS STEELS
TEMPERATURE
TENSILE PROPERTIES
URANIUM CARBIDES
ZIRCONIUM ALLOYS