A FEASIBILITY STUDY OF FAST U$sup 233$-Th BREEDER REACTORS

Technical Report · Mon Oct 10 00:00:00 EDT 1960

OSTI ID:4827931

A feasibillty study of fast U/sup 233/-Th breeder reactors was performed. The feasibility of attainment of breeding ratios greater than one was clearly demonstrated for a family of reactors fueled by U-Th metal alloy rod-type fuel elements, cooled by sodium, and structurally built of siainless steel. Initial breeding ratios of 1.43 to 1.53 were established for infinite-blanket reactors over a wide range of core sizes and compositions. In a specific reference design with a finite blanket, the net breeding ratio was estimated at 1.33. The effects on breeding ratio of long term operation in an equilibrium fuel cycle were found to be negligible. Allowance for uncertainties in cross section data, particularly for U/sup 233/, was found in the most pessimistic case to reduce the breeding ratio from 1.33 to 1.15. The reference design, optimized to achieve a minimum doubling time, would require 25 yr of full-power operation to double the total system inventory of U/sup 233/; the initial core inventory would be doubled in about 5 yr. This 760 MW/sub th/ reactor, which would operate at an average specific power of 1.4 MW/kg U/sup 233/, is governed by present-technology materials design limits. Addition of up to 20% beryllium as a moderating fuel diluent was found to cause a slight reduction in breeding ratio and increase in critical mass, but could provide design flexr-bility in achieving higher power densities and lower doubling times. Operational and safety aspects of the U/sup 233/-Th fast breeder were examined. The principal difference from other fast reactors arises as a consequence of protactinium233 (Pa/sup 233/). The 27-day half life of Pa/sup 233/, the precursor of bred U/sup 233/, delays the availability of reactivity from new U/sup 233/ and pts an unusual requirement on the control system at shutdown. Also examined were the fuel handling problem due to U/sup 233/ buildup, and the Doppler temperature coefficient. Principal areas of further investigation that are discussed relate to improvement of doubling time and reduction of nuclear data uncertainties. (auth)

• Research Organization: Nuclear Development Corp. of America, White Plains, N.Y.
• DOE Contract Number: ATN30-1)-2303(VIII)
• NSA Number: NSA-16-021723
• OSTI ID: 4827931
• Report Number(s): NDA-2134-3
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-62
• Country of Publication: United States
• Language: English

Related Subjects

REACTOR TECHNOLOGY
BERYLLIUM MODERATOR
BLANKETS
BREEDING
BURNUP
CONFIGURATION
CONTROL SYSTEMS
CRITICALITY
CROSS SECTIONS
DOPPLER EFFECT
DOUBLING TIME
FAST NEUTRONS
FUEL CYCLE
FUEL ELEMENTS
FUELS
LIFETIME
LIQUID METAL COOLANT
MASS
MODERATORS
OPERATION
PLANNING
POWER
PRODUCTION
PROTACTINIUM 233
REACTIVITY
REACTOR CORE
REACTOR SAFETY
REACTORS
REMOTE HANDLING
REPROCESSING
RODS
SHUTDOWN
SODIUM
SPECTRAL SHIFT
STAINLESS STEELS
THORIUM
THORIUM ALLOYS
URANIUM 232
URANIUM 233
URANIUM ALLOYS
VARIATIONS