b'P ROVING THE P RINCIPLEReactorLast Day of Name Acronym S t a r t u p Operation1.Advanced Reactivity Measurement Facility No. 1 ARMF-I 10-10-60 1974The ARMF-I, a reactor located in a small pool in a building east of the MTR in the Test Reactor Area, was used to determine the nuclear characteristics of reactor fuels and other materials subject to testing in the MTR. Together with the MTR, the reactor helped improve the performance, reliability, and quality of reactor core components. Until the next generation reactor, the ARMF-II, this was considered the most sensitive device for reactivity determinations then in existence.2.Advanced Reactivity Measurement Facility No. 2 ARMF-II 12-14-62The ARMF-II was built in the opposite end of the tank occupied by ARMF-I. It had a readout system which automatically recorded measurements on IBM data cards. This refinement over the ARMF-I meant that operators could process data quickly in electronic computers. Designers of the ARMF-II benefitted from previous experience with the ARMF-I and the Reactivity Measurement Facility (described below).3. Advanced Test Reactor ATR 7-2-67ContinuingLocated at the Test Reactor Area, the ATR, which continued to operate in 2000, is a materials testing reactor. It simulates the environment within a power reactor for the purpose of studying the effect of radiation on steel, zirconium, and other materials.The ATR produces an extremely high neutron flux up to 1 x 10 25 neutrons per square centimeters per second. Target materials are exposed to the neutron flux for selected periods of time to test their durability within an environment of high temperature, high pressure, and high gamma radiation fields. Data that normally would require years to gather from ordinary reactors can be obtained in weeks or months in the ATR.The ATR can operate at a power level of 250 megawatts. Its unique four-lobed design can deliver a wide range of power levels to nine main test spaces, or loops. Each loop has its own distinct environment apart from that of the main reactor core. Therefore, nine major experiments can take place simultaneously.Additional smaller test spaces surrounding the loops allow for additional tests.In addition to materials testing, the ATR has made radioisotopes used in medicine, industry, and research.4.Advanced Test Reactor Critical Facility ATRC 5-19-64 ContinuingThe ATRC performs functions for the ATR similar to those of the ARMF reactors in relation to the MTR. It was a valuable auxiliary tool in operation long before the ATR startup. It verified for reactor designers theef fectiveness of control mechanisms and physicists predictions of power distribution in the large core of the AT R. Low-power testing in the ATRC conserved valuable time so that the large ATR could irradiate experiments at highpower levels. The ATRC is also used to verify the safety of a proposed experiment before it is placed in the AT R. 5.Argonne Fast Source Reactor AFSR 10-29-59 Late 70sThe Argonne Fast Source Reactor was a tool used to calibrate instruments and to study fast reactor physics, augmenting the Zero Power Plutonium Reactor research program. Located at Argonne-West, this low-power reactordesigned to operate at a power of only one kilowattcontributed to an improvement in the techniques and instruments used to measure experimental data.6.Boiling Water Reactor Experiment No. 1 BORAX-I 1953 July 1954BORAX-I was a pioneer reactor that tested the safety and operating parameters of reactors which used boiling water as a moderator and coolant. In this reactor type, water is allowed to boil in the core. Saturated steam drives the turbines and generates power.BORAX-I, like the later BORAX experiments, was located just north of EBR-I. It demonstrated that the boilingwater moderated reactor concept was feasible for power reactors. Its design capacity was 1.4 megawatts. Operators destroyed it in July 1954 in a deliberately planned destructive test, the purpose of which was to subject it to extreme operating conditions and learn more about the limits of its safe operation.26 0'