b'A P P E N D I X BReactorLast Day of Name Acronym S t a r t u p Operation7.Boiling Water Reactor Experiment No. 2 BORAX-II 10-19-54 March 1955BORAX-II continued the testing program for boiling water reactors, this time at a power level capacity of 6 megawatts. Tests used fuels with varying enrichments of uranium-235. 8. Boiling Water Reactor Experiment No. 3 BORAX-III 6-9-55 1956The operating capacity of BORAX-III was 15 megawatts. The reactor was connected to a 2000-kilowatt turbine/generator set so that engineers could generate electricity, the ultimate objective of the reactor test program. On the night of July 17, 1955, the reactor produced sufficient power to light the city of Arco (500 kilowatts), the BORAX test facility (500 kilowatts), and part of the Central Facilities Area at the NRTS (1000 kilowatts).9.Boiling Water Reactor Experiment No. 4 BORAX-IV 12-3-56 June 1958BORAX-IV, with a power level of 20 megawatts, tested fuel elements made from mixed oxides (ceramics) of uranium and thorium. These materials had a high capacity to operate in the extreme heat of a reactor before they failed.The ceramic core demonstrated that a reactor loaded with this fuel could operate safely and feasibly. The fuel could operate in higher temperatures, was less reactive with the water coolant in case the cladding ruptured, was cheaper to manufacture, and burned a larger percentage of the fuel before loosing its reactivity. The reactorproduced measurable quantities of the artificial thorium-derived fuel, uranium-233. One series of BORAX-IVtests involved operating the reactor with experimentally defective fuel elements in the core.10. Boiling Water Reactor Experiment No. 5 BORAX-V 2-9-62 Se p emb e r tBORAX-V could operate at a power level of 40 megawatts. This flexible reactor advanced the boiling water19 64reactor concept by testing the safety and economic feasibility of an integral, nuclear superheat system. On October 10, 1963, it produced superheated (dry) steam entirely by nuclear means for the first time. The reactordemonstrated that improved efficiency from manufactured steam is obtainable by incorporating as a design feature a number of superheated fuel assemblies in the reactor core lattice.11. Cavity Reactor Critical Experiment CRCE 5-17-67 Early 1970sLocated at TAN, CRCE was an outgrowth of a program begun by NASAin the 1960s to investigate thepropulsion of space rockets by nuclear power, offering the possibility of much greater thrust per pound of propellant than chemical rockets. The concept for the cavity reactor core was that the uranium would be in avapor, or gaseous, state. Hydrogen propellant flowing around it would theoretically attain much higher temperaturesup to 10,000 Fthan in conventional solid core rockets. The experiments at TAN used simulatedhydrogen propellant and produced data on the reactor physics feasibility of a gaseous core being able to go critical.The core was uranium hexafluoride (UF 6 ); the experiments were all done at the relatively low temperature of about 200 F. In the proposed ultimate application, the ball of uranium gas would be held in place by the hydrogen flowing around it, something like a ping-pong ball suspended in a stream of air. Uranium core temperatures as high as 100,000 F were considered possible.12. Coupled Fast Reactivity Measurement Facility CFRMF 1968 1991When the ARMF-II reactor was modified in 1968, it was given a new name, the CFRMF.A section of the core was modified to produce a region of high-energy neutron flux useful in comparing calculated and observed results. This tool provided physics information about the behavior of fast (ie, unmoderated) neutrons. Physicists studied differential cross sections and tested calculational methods. The CFRMF contributed to the development of fast neutron reactors.13. Critical Experiment Tank CET 1958 1961The CET reactor produced a source of neutrons used to calibrate various types of neutron sensors and chambers.Part of the Aircraft Nuclear Propulsion program and located at Test Area North (TAN), the CETwas a low-powerreactor (one of three in the A NPprogram) originally designed to mock-up the HTRE-I and HTRE-II reactors. Later, fuel test bundles intended for testing in HTRE-II were first evaluated for reactivity characteristics in the CET.261'