OPERATION OF THE AIRCRAFT REACTOR EXPERIMENT

Technical Report · Thu Sep 01 04:00:00 EDT 1955

DOI:https://doi.org/10.2172/4237975· OSTI ID:4237975

Cottrell, W B; Hungerford, H E; Leslie, J K; Meem, J L

The Aircrift Reactor Experiment (ARE) was oporated successfully and without untoward difficulty in November 1954. The reactor became critical with a mass of 32.8 lb of U/sup 235/, which gave a concentration of 23.9 lb of U/sup 235/ per cubic foot of fluoride fuel. For operation at power, the U/sup 235/ content of the fuel mixture was increased to 26.0 lb/ft/sup 3/, and thus the final composition of the fuel mixture was 53.09 mole% NaF, 40.73 mole% ZrF/sub 4/, and 6.18 mole% UF/sub 4/. The maximum power level for sustained operation was 2.5 Mw, with a temperature gradient of 355 deg F; the maximum fuel temperature at this level was 1580 deg F. Temperatures as high as 1620 deg F were recorded during transients. From the time the reactor first went critical until the final shutdown, 221 hr had elapsed, and for the final 74 hr the power was in the megawatt range (0.1 to 2.5 Mw). The total integrated power was about 96 Mw-hr. While at power the reactor exhibited excellent stability and it was easily controlled because of its high negative temperature coefficient of reactivity, which made the reactor a slave to the load placed upon it. The fuel temperature coefficient was -9.8 x 10/sup -5/ ( DELTA k/k)/ deg F, and the over-all coefficient for the reactor was -6.1 x 10/sup -5/. Practically all the gaseous fission products and probably some of the other volatile fission products were removed from the circulating fuel. In a 25-hr run at 2.12 Mw the upper limit of the reactor poisoning due to xenon was 0.01% DELTA k/k. No more than 5% of the xenon stayed in the molten fluoride fuel. The total time of operation at high temperature (l000 to 1600 deg F) for the sodium circuit was 635 hr, and, for the fluoride fuel system, 462 hr. During most of the operating period the sodium was circulated at 150 gpm nnd the fuel at 46 gpm. The fabricability and compatibility of the materials system, i.e., fluoride fuel, stadium coolant, and lnconel structure, were demonstrated, at least for the operating times, temperatures, and flux levels present. All components and, with few exceptions, all instrumentation performed according to design specifications. The performance of the pumps was particularly gratifying, and the low incidence of instrumentation failure was remarkable in view of the quantity and complexity of the instruments used. (auth)

• Research Organization: Oak Ridge National Lab., Tenn.
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-13-015780
• OSTI ID: 4237975
• Report Number(s): ORNL-1845(Del.)
• Country of Publication: United States
• Language: English

Related Subjects

AIRCRAFT-- ALUMINUM ALLOYS-- ARE-- CHROMIUM ALLOYS-- FABRICATION-- FLUORIDES-- FUELS-- FUSED SALT FUEL-- INCONEL ALLOYS-- LIQUID METAL COOLANT-- MEASURED VALUES-- NEUTRON FLUX-- NICKEL ALLOYS-- NIOBIUM ALLOYS-- OPERATION-- PERFORMANCE-- PLANNING-- POWER PLANTS-- REACTORS-- SODIUM-- TITANIUM ALLOYS
AIRCRAFT-- ARE-- CONCENTRATION-- CRITICALITY-- FLUORIDES-- FUELS-- HIGH TEMPERATURE-- MASS-- MEASURED VALUES-- MIXING-- OPERATION-- POWER-- POWER PLANTS-- REACTORS-- SODIUM FLUORIDES-- TRANSIENTS-- URANIUM FLUORIDES-- URANIUM 235-- VOLUME-- ZIRCONIUM FLUORIDES
AIRCRAFT-- ARE-- CONTROL-- MEASURED VALUES-- OPERATION-- POWER-- POWER PLANTS-- REACTIVI
REACTORS