Flux test

The United States continued fast-breeder reactor research and development with the building of the fast flux test faciHty (FFTF) at Hanford and the SEFOR reactor in Arkansas (59). The next plaimed step was to build a prototype power reactor, the Clinch River fast-breeder plant (CRFBP), which was to be located near Oak Ridge, Teimessee. 

Heat Flux Tests Removable tube test heat exchangers find an ideal use in the field for monitoring heat flux (corrosion) conditions, NACE TM0286-94 (similar to laboratory test. Fig. 28-4, page 28-12). 

R.D. Watson, et al, High Heat Flux Testing of CITFirst Wall Tiles, 1988. 

The CREDO data base contains data from The Fast Flux Test Facility in Richland, Washington, The Experimental Breeder Reactor - II in Idaho Falls, Idaho, The test loops of the Energy Technology Engineering Center (ETEC) in Canoga Park, California, The JOYO Liquid Metal Fast Breeder Reactor at the 0-Arai Engineering Center (OEC) in Japan, and the test loops of OEC. 

The difficulties the Department of Energy is having in deciding what to do with its Fast Flux Test Facility provides another example of problems the industry faces. 

In a uniform heat flux test section, the CHF cannot vary by one variable without affecting another accompanying variable. Figure 5.40 is reproduced from an article by Aladyev et al. (1961). This figure actually indicates the combined effects of pressure and inlet subcooling at a constant exit quality. The CHF occurs at the exit, and the exit enthalpy is kept at saturation. Because the critical flux varies with pressure, the inlet temperature must also vary. Hence the high CHF at low pressure is achieved by means of a low inlet temperature and the favorable physical properties of water and steam under low pressures also help the heat transfer at the corebubble layer interface. 

You must determine the maximum feed rate that a thickener can handle to concentrate a waste suspension from 5% solids by volume to 40% solids by volume. The thickener has a diameter of 40 ft. A batch flux test in the laboratory for the settled height versus time was analyzed to give the data below for the solids flux versus solids volume fraction. Determine ... 

Fast flux test facility (FFTF), 17 587 Fast Fourier transform (fft) algorithm, 23 137. See also Fourier entries Fast gas chromatography, 6 434-437 Fastin, 3 91, 93t... 

Figure 19 shows the stoichiometric coefficient y versus time. The y-coefficient is the molar ratio between the amount of hydrogen in the conversion gas and the amount of carbon in the conversion gas. In this particular selection of y-graphs the dynamic ranges for the different wood fuels during a batch are fuel wood 3 0, wood pellets 2.6 0, and wood chips 2.4 0. These dynamic ranges are quite representative of the whole range of volume fluxes tested. 

Membranes for pressure and flux testing were mounted, using a brazing process developed at ANL, within four inch long, 0.75 in. O.D., heavy-wall, Iconel 600 tubing which had been machined to form a small seat to accommodate the membrane. Typically, the membrane diameter was 0.69 in. (17.5 mm.). Unmounted membranes of the same composition, as well as membranes of varying Ni content, were also available for characterization studies. Because the pressure tested membranes had to be pre-mounted, the before-and-after characterization studies refer to membranes of the same composition and fabrication, but not the same physical membranes. 

Hydrogen flux testing of the ANL-1 cermet membranes was conducted on the HMT unit. Data from these runs is plotted in Figure 2. 

Table 1. Relative elemental composition at the surface of the fresh membrane and after H2 flux testing...

XPS analysis was also performed on the membrane following the flux test. At room temperature, only Ba was detected on the surface of the tested membrane. Ni, Ce, and Y could not be detected (see Table 1). When the sample was heated to 650°C under vacuum, it was possible to detect a small quantity ofNi and Y, but no Ce. Ba had the highest concentration at the surface both at room temperature and 650°C. The relative concentration of Ni at the surface was significantly lower on the tested membrane than on the fresh membrane. The small amount of Ni observed at 650°C on the tested membrane did not appear to be in the metallic state. The XPS results indicated that there was a permanent loss of Ni from the surface region over the course of flux testing. 

Membrane surface characterization and analysis indicated that significant elemental and oxidative changes occurred on the membrane surface upon heating, and again after flux testing. In particular, XPS indicated that metallic Ni migrated or otherwise appeared at... 

At present, americium is separated and purified in Kg/yr quantities at the new plutonium facility at Los Alamos (Figure 1). The feed for the americium production comes from a line which produces high purity ceramic grade Pu02 for the Fast Flux Test Facility (FFTF) at Richland, Washington. The feed for this FFTF PuO is aged plutonium metal which contains sizable amounts of 24 Am... 

Water Flux The permeability of a UF membrane is determined by pore size, pore density, and the thickness of the membrane active layer. Water flux is measured in the absence of solute, generally on a newly made or freshly cleaned sample. The test is simple, and involves passing water through the membrane generally in dead-end flow under carefully controlled conditions. In a water flux test, the membrane behaves as a porous medium with the flow described by Darcy s law. Adjustments for viscosity and pressure are made to correct tne results to standard conditions, typically the viscosity of water at 25°C and the pressure to 50 psi (343 kPa). The water flux will be many multiples ofthe process flux when the membrane is being used for a separation. Virgin membrane has a standard water flux of over 1 mm/sec. By the time the membrane is incorporated into a device and used in an application, that flux drops to perhaps 100 pm/s. Process fluxes are much lower. 

Carpi A. and Lindberg S. E. (1998) Application of a Teflon dynamic flux chamber for quantifying soil mercury flux test and results over background soil. Atmos. Environ. 32(5), 873-882. 

Fast breeder reactor fuel rods consist of stainless-steel-clad mixed oxide (U,Pu)02 fuel however, more stable alloys for cladding and in-core structural materials, with resistance to swelling and embrittlement under fast neutron irradiation, and more efficient fuels (carbide see 17.3.12.1.2) or nitride (see 17.3.12.3)] are needed h The mechanical, metallurgical, and chemical processes in fuel element irradiation are depicted in Figure 1. Figure 2 shows the PFR (U.K.) fast breeder fuel element, and Figures 3 and 4 illustrate the Fast Flux Test Facility (FFTF) fuel system. 

---