Test Reactor Operations Experiment

Operation of an All-Gas-Core Critical Experiment, J. F. Kmze, L. S. Masson, G. D. Pincock (GE-Idaho)r R. E. Hyland NASA-Letvis) 

Approach to criticality was made in the usual stepwise continuous fashion of incremental fuel additions. Start-up with a cold core was always quite smooth and free of reactivity fluctuations. However, the shutdown cooling process created some unusual reactivity spikes evidently caused by selective condensation pf the 1)F, on the cooled walls of the tank. Noise analyses at (derating conditions revealed a few small resonaiuses in the Bode Plot in the O.OS- to 0.10-Hz range, probably caused by gas circulation inside the tanki 

The gas-core data showed that the simulated cores constructed of foils had a critical mass bias about 15%. These foil cores were then redesigned to a second mock-up that exhibited only about a 4% bias,on critical mass. This experiment demonstrated not only how foil experiments could be appropriately planned and interpreted but also how gas mcperiments can be more easily performed. A series of all-gas experiments in spherical geometry is now being conducted with greater operating efficiency than is possible with a foil core mockiqi. 

The coaxial flow cavity reactor ctmcept has been studied under cold flow, non-nuclear conditions. The flow pattern was, seen to contain gas waves of substantial amplitude, and these have been mocked up in the critical experiment using foil fuel. Waves of large amplitude created-reactivity perturbations of as much as 3%dk. However, control systems of the drum or sleeve type were measured and found to provide as much as 10 and 20%Ak, respectively, in reactivity swing worth. This, plus the long (3 msec) prompt-neutrcm lifetinie makes the cavity reactor an easily controllable s mtern despite the potentially large worth of waves. 

Nuclear Propulsion for Space Exploration, NASA TM X-168S, National Aeronautics and Space Administration (November 1968). 

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The present status with respect to the fast breeder test reactor operating experience and prototype fast breeder reactor design are presented below. 

A recent focused effort, funded by DOE/NE, has permitted detailed analyses of several AHTR design features. However, frequent use continues to be made of design approaches, existing testing or operational experience, and anecdotal information from other reactor and nonreactor systems in order to qualitatively bound the expected performance of the AHTR in cases where detailed analyses have not been performed yet. 

Propene (CsHe) and carbon monoxide (CO) were used as model compounds to study the activity of a freshly prepared Pt catalyst. The experiments were carried out in a test reactor operating at atmospheric conditions in the absence of diffusion effects. The conversions of CO and propene (HC), rjco and t hc> were measured at the reactor outlet. Initial concentrations at the reactor inlet were known (xo,co>, 02> >, H2o)-... 

Event frequency data were developed from a detailed review of plant trip reports and shift supervisor s logbook entries. The first two years of plant experience were discarded as they appear to represent experience typical of early plant operation and tests that are not typical of operation in later years. The plant experience was used to perform a Bayesian update of EPRI NP-2230 reactor trip experience. 

A theory has been developed which translates observed coke-conversion selectivity, or dynamic activity, from widely-used MAT or fixed fluidized bed laboratory catalyst characterization tests to steady state risers. The analysis accounts for nonsteady state reactor operation and poor gas-phase hydrodynamics typical of small fluid bed reactors as well as the nonisothermal nature of the MAT test. Variations in catalyst type (e.g. REY versus USY) are accounted for by postulating different coke deactivation rates, activation energies and heats of reaction. For accurate translation, these parameters must be determined from independent experiments. 

The catalyst samples from both experiments were then analyzed by a variety of techniques described below. Portions of each catalyst sample [ 5g) were loaded into one of four laboratory micro reactors operated under identical experimental conditions. The catalysts were kept on line until the activity, as measured by the daily drainage of water and hydrocarbon products, had stabilized. The activity was determined as a function of water produced under these steady state conditions. Each of the laboratory micro reactors was tested with a known catalyst standard to establish both the data reproducibility and possible effects of the different reactors on the activity measurements. The different reactors gave results with relative differences of less than 3%. 

The Tokamak Fusion Test Reactor was the first fusion facility with extensive experience with tritium fuelling and removal. During the 3.5 years of D-T operation, 3.1 g T was supplied to the plasma by neutral beam injection and... 

Catalytic measurements. The catalytic tests were performed in fixed bed reactors operating at 463-498 K and total pressure of 1-20 bar. The H2/CO ratio was 2 in all experiments. Prior to the reaction, the catalysts were reduced in the flow of hydrogen at 753-773 K for 5 h. FT catalytic rates and selectivities were measured at the stationary regime after 24 h time-on-stream. FT reaction rates were normalized by the number of cobalt auims in the reactor. The reaction products were analyzed by gas chromatography. 

Wang et al. " compared the model predictions to experimental data on the desulfurization of simulated coal gas from a laboratory-scale fixed-bed reactor and from a process development reactor operated on actual coal gas. The solid reactant was formed from cylindrical pellets of zinc and titanium oxides. Data from six experiments using different temperatures, pressures, feed gas flow rates, and feed gas H2S concentrations were available. Product gas concentrations were measured as a function of time, and the axial distribution of sulfur within the reactor was determined at the conclusion of the test. 

The HTR-10 test reactor was erected in 2000. First criticality was achieved in December 2000. Full power operation was achieved in January 2003. Since then, the HTR-10 has been under operation. Valuable operational experience is under accumulation. Important safety experiments have been performed with HTR-10. Overall, the construction and operation of HTR-10 has been very successful so far. Table 2 shows the comparison of key design and operation data. 

Glucose utilization was higher than 90% for all tested WEH suspensions, whereas xylose conversion remained lower, between 72 and 80%. The lowest sugar conversions of 90 and 72%, respectively, for glucose and xylose were seen at 40% WEH. This could be attributed to a technical problem with the pH control system because the pH value was maintained around 6.S-6.7 instead of pH 7, and the reactor operated under these conditions (pH 6.5-6.7) with 40% WEH until the end of the experiment. The overall sugar conversion efficiency to ethanol for all these experiments was in a range of 68-76% (Table 1). 

Non-Steady-State Reactors for Testing Fixed-Bed Catalysts In non-steady-state reactors, reaction conditions such as temperature or reactant concentrations are changed temporarily [103-105]. Temperatnre-programmed snrface reaction (TPSR) experiments, temperatnre-programmed desorption (TPD), and temperature-programmed reduction and oxidation (TPR, TPO) [106,107] are established methods dealing with non-steady-state reactor operation. Among these methods, TPSR is a technique that can be applied directly under reaction conditions relevant for catalytic processes. 

The size or volume of chemical reactors varies widely. Reactor volumes can range from hundreds of nanoliters for combinatorial, lab-on-a-chip reactor systems, to several hundred thousand liters for certain petroleum refining operations. In the combinatorial reactors, one is interested in determining if a reaction proceeds and in minimizing the scale of the experiment so many combinations or conditions can be screened rapidly. Figure 1.6 presents a schematic view of 1 pi test reactors that are used for combinatoria screening of heterogeneous catalysts. 

In the following discussion, we will detail the results and operational experiences the enhanced SBCR system. Objectives of the ran were to 1) test the new slurry level control system 2) compare the performance of a precipitated Fe/K Fischer Tropsch Synthesis (FTS) catalyst in the enhanced SBCR and a continuous stirred tank reactor (CSTR) and 3) determine the effectiveness of the catalyst/wax filtration system. 

Considerable experience has been gained by the Russian specialists on tests and operation of sodium cooled fast reactors (over 100 reactor-years). Based on this experience, modifications were made of systems and components of the reactors in operation, as well as of the BN-800 reactor design. 

Fast Breeder Test Reactor (FBTR) is a 40 MWt/ 13.2 MWe sodium cooled, mixed carbide fuelled, loop type reactor. It has two primary and secondary sodium loops and a common steam water circuit, which supplies high pressure, high temperature superheated steam to turbine generator (TG). Heat is rejected in cooling tower (Fig 1). A 100% capacity dump condenser is provided for reactor operation even when the TG is not in service. The mmn aim of the reactor is to generate experience in the design, construction and operation of sodium cooled fast reactors and to serve as an irradiation facility for the development of fuels and structural material for fast reactors. It achieved first criticality in Oct 85 with Mark I core... 

Kapoor.R.P. et al - Safety related Operating Experience with Fast Breeder Test Reactor,... 

Kapoor.R.P. et al - Operating Experience of Fast Breeder Test Reactor and its utilization as an Experimental Facility, 5th Asian symposium on Research Reactors, May 29-31, 1996, Taejon, Korea. 

FAST BREEDER TEST REACTOR. 15 YEARS OF OPERATING EXPERIENCE... 

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