Reactor Atmosphere Instrumentation

Reactor atmosphere Instrumentation should be Improved In four areas 1) Moisture Monitoring 2) gas an dysls 3) makeup equipment and If) remote and automatic control of the 113 Buildings. 

Reactor atmosphere Instrumentation consists of flov rate temperatuzei moisture content gas pressure and make-up flov rate equipment, m the old reactors this equipment is located In the 105 control rooms and the II3 Building. At the K Reactors the equipment Is mostly In the control room. 

Ihe present Instrumentation concept Is adequate c Reactor Atmosphere Instrumentation... 

Ttxere are four general areas of improvement for reactor atmosphere Instrumentation ... 

All instrumentation and controls for the reactor atmosphere should be designed to provide for the possibility of future remote operation of the 11 Building. 

Apparatus for carrying out hydrogenation at several atmospheres can be constructed readily (1,78,93), but there seems little point in this exercise since good commercial equipment is available. The most commonly used commercial low-pressure equipment is the Parr hydrogenator (manufactured by Parr Instrument Co., Moline, Illinois). This equipment (Fig. 1) has withstood the test of time it was first described in 1922 and offered commercially in 1926. It comes in two sizes one for 500-ml reactor bottles and one for 1000-and 2000-ml reactor bottles. Specially made smaller bottles, down to 50 ml, can be used also but require special holders to compensate for differences in bottle heights. Shaker bottles should not be more than half full to ensure good mixing, a consideration in selection of bottle size. 

Catalytic tests were performed in an isothermal flow quartz reactor apparatus under atmospheric pressure, provided with on-line gas chromatographic (GC) analysis of the reagent and products by two GC instrument equipped with flame ionization and thermoconducibility detectors. The activity data reported refers to the behavior after at least two hours of time on stream, but generally the catalytic behavior was found to be rather constant in a time scale of around 20 hours. 

An early intercomparison of LPA and CTM measurements of HO within a chemical reactor has been reported (120, 121). The measurements were made by directing the beam transverse to the detection axis within the reactor at atmospheric pressure N2 was replaced by He to improve fluorescence efficiency. A folded-path LPA measurement within a calibration chamber would have obvious advantages in an instrumental intercomparison and seems within the realm of possibility. 

Regime "D" Finally, after plasma treatment, free radical sites at or near the polymer surface can remain active for extensive periods of time (11). When the treated sample is subsequently exposed to ambient atmosphere, these radicals can chemically react with atmospheric constituents such as oxygen or water vapor. This certainly can occur during the time interval while the sample is transferred through atmosphere from the plasma reactor to the ESCALAB surface instrument. 

Most studies about the microwave-assisted extraction of PAHs from solid samples have been conducted using closed-vessel systems [12,214,226,236,239-246] and only a few with open-vessel focused microwave devices [57,247-252]. Because open-vessel systems operate at atmospheric pressure, the extraction vessel can be used as a reactor in order to perform on-line purification pretreatments of the total extracts (reagents can be readily added to the medium) [53] or directly introduce the extract into the determination instrument, as in the focused microwave-assisted extractor with on-line fluorescent monitoring of Fig. 5.10, which provides a matrix-independent approach to the extraction of PAHs [61]. 

Temperature programmed reduction (TPR) of the calcined samples were performed in a RIG-100 In Situ Research Instruments catalyst characterization apparatus. The TPR experiments were performed in a quartz gas flow reactor, from room temperature to 1000°C, with a heating rate of 7.5 °C.min under a stream of 5% v/v H2 in argon (total flow rate 25 ml.min ) at atmospheric pressure. 

In instrument neutron activation analysis (INAA) a small fraction of the stable atomic nuclei present in the sample are made radioactive by irradiation with neutrons or other particles. By measuring the resulting radioactivity, the original elements present can be determined. Reactor or thermal neutrons are usually used. The method does not work well for certain key elements of environmental interest including silicon, sulfur, and lead. Table 6.2 shows INAA detection limits for various elements and typical concentrations of these elemenis in urban air. In atmospheric samples, the fiiiiii of detectability for a particular clement depends on the quantities of the other elements in the filter matrix. The table is based on a total air sample of 17 actually used in the measurements. The tabulated results show that all elements listed could be detected in this air volume with the exception... 

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