Irradiation conditions Program

ASTM E185-82 also provides the option of including correlation monitor material in the capsules. Correlation monitor material provides an independent check on the irradiation conditions because other specimens of the same correlation monitor material have been irradiated in other reactors and its response to irradiation (embrittlement characteristics) is well documented. An example of a common correlation monitor is Heavy Section Steel Technology (HSST) Plate 02 (an SA533 Grade B, Class 1 material). Correlation monitor material is also included in the surveillance program to provide a means of validating neutron fluence estimates for the surveillance capsules. The data obtained from correlation monitors should... 

The irradiation surveillance program for System 80+ will be conducted to assess the neutrc n-induced changes in the RTj,j.,j, (reference temperature) and the mechanical properties of rne reactor vessel materials. Changes in the impact and mechanical properties of the material will be evaluated by the comparison of pre- and post-irradiation test results. The capsules containing the surveillance test specimens used for monitoring the neutron-induced property changes of the reactor vessel materials will be irradiated under conditions which represent, as closely as practical, the irradiation conditions of the reactor vessel. 

The characterization of the steel and weel materials was established through industrial and governmental studies which examined the material properties in both the unirradiated and the irradiated condition. Inservice inspection and material surveillance programs are also conducted during the service life of the vessel, further ensuring adequate vessel integrity and safety margin. 

On the other hand, samples can be irradiated at constant microwave power over a certain fixed period, for example at 100 W for 10 min. As there is no control over the resulting temperature or pressure, care has to be taken not to exceed the operational limits of the system and this type of program should only be used for well-known reactions with non-critical limits, or under open-vessel (reflux) conditions. Since in this method only the applied energy and not the resulting temperature is controlled, the quality of reaction control is often superior employing a temperature-controlled program. 

It is concluded that under the exptl conditions of this study in which the irradiated sample was continually exposed to water and other products of radio lytic decompn, no lattice energy was stored. The mechanism by which the initially induced lattice enemy storage was lost is believed to be, not thermal annealing, but rather recrystallization due to contact with water formed by partial sample decompn In the extensive study on the NERVA program, Avrami and Voreck (Ref 192) reported on... 

Crown-6 (0.5 mmol, 10%) was added to the aromatic substrate (5 mmol) and potassium alkoxide (7.5 mmol). The mixture was introduced into a Pyrex vessel adapted to the microwave equipment (Synthewave 402 monomode reactor from Prolabo) fitted with a mechanical stirrer. S402 software permitted programming in time and monitoring of the temperature by modulation of the power from 15 to 300 W. Irradiation was carried out according to the conditions indicated in the Tables. At the end of the reaction, the organic products were extracted into diethyl ether, and filtration through Celite 545 was carried out. The products were identified (GC-MS, NMR) by comparison with authentic samples and analyzed by GC (internal standard = a-naphthol). 

Proton induced X-rays emission (PIXE) Samples were pelletized inserted in a boric acid cap. Samples were irradiated with a 2.0 MeV proton beam for filtered spectra and with a 1.2 MeV for filterless conditions. Spectra were obtained with a 200 eV Si(Li) X-ray detector and analysed with AXIL computer code. Concentrations were then calculated with the DATTPIXE program. Quality control was made by analysing in similar conditions to lichen samples the IAEA 336 lichen material and the CTA-OTL-1 tobacco leaves. Contents for the following elements were determined silicon, phosphorous, sulphur, chlorine, potassium, calcium, titanium, vanadium, chromium, manganese, iron, nickel, copper, zinc, gallium, arsenic, bromine, rubidium, strontium, zirconium, barium, and lead (the elements which are determined by both techniques are shown in bold type). 

Fig. 4.31. Block diagram of a dye laser using an irradiation source and UV/Vi spectrometer for time-resolved examination of photo-degradations of the dye solution at laser conditions. Two synchronised microprocessors are used for control. The assembler program amounts to...

Studies of the homomolecular and heterolytic exchange processes are generally in the form of the measurement of rates under isothermal conditions. However, studies have also been made of temperature programmed isotopic exchange, in which the oxide is subjected to a temperature ramp under the reaction atmosphere, and the partial pressures of various isotopic oxygen species is determined as a function of temperature (e.g., Refs. 20-21). The photoactivation of oxygen exchange has also been reported in a number of studies which have been performed under UV irradiation (e.g.. Refs. 18, 22, 23). 

The initial step in the program is the development of a characterization project to assess the effect of a number of primary variables on the performance of laminates under irradiation and at 4 K. Typical variables are reinforcement type, resin system, and cure cycle. The materials will represent a cross section of the existing commercial laminate production. Several laminates will be specially fabricated to provide increased radiation resistance. They will utilize commercial, boron-free glass for reinforcement and epoxy systems cured with aromatic amines. All test laminates will be made by a commercial producer under conditions dupli-... 

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