![]() Type 304 and type 316 steel samples neutron irradiated at 561K up to 9.2x10 25 n/m 2 were obtained and minute compositional profiles across grain boundaries were examined using an analytical scanning transmission electron microscope equipped with a field emission electron gun. The radiation induced segregation of solutes to the grain boundary in austenitic stainless steels were studied. It is demonstrated that grain boundary silicon segregation under irradiation may lead to grain boundaryγ'-Ni3 Si precipitation over a certain temperature range.Ĭhanges in grain boundary composition induced by neutron irradiation of austenitic stainless steelsĪsano, K. Predictions ofγ'-Ni3Si precipitation at grain boundaries ave made for a dilute Ni-Si alloy subjected to irradiation. For this reason, we have theoretically treated grain boundary precipitation under irradiation in dilute binary alloys. Until now the kinetic models for irradiation-induced grain boundary precipitation have been sparse. Irradiation-induced grain boundary segregation of solute atoms frequently bring about grain boundary precipitation of a second phase because of its making the solubility limit of the solute surpassed at grain boundaries. Institute of Scientific and Technical Information of China (English) GRAIN-BOUNDARY PRECIPITATION UNDER IRRADIATION IN DILUTE BINARY ALLOYS The results may have a practical importance since gibberellic acid has just been introduced into the brewery industry. Amylolytic activity decreased immediately after irradiation but in samples treated with growth regulators it was higher than in those without regulators. A ''regenerating'' effect of growth substances, mainly gibberellic acid and betain hydrochloride in 10 -4 M solutions, was observed. By treating the irradiated barley with solutions of growth regulators it was possible to diminish the loss of enzyme activity. Following growth-regulators were used: gibberellic acid (Polish preparation ''Gibrescol''), kinetin (6-furfurylo-aminopurin), CCC (2-chloroethyl trimethyl ammonium chloride), and betaine hydrochloride. ![]() The experiments have been carried out on brewery barley var. The effect of some growth regulators on irradiated grain has been investigated. The effect of some growth regulators on enzyme systems in irradiated barley grain using disinfestation dosesĭisinfestation doses of 20 to 100 krad may cause changes in the biological systems of barley grain and, therefore, may influence undesirably the technological quality of malted grain. ![]() However, any inhibition is equivalent to that expected for a systematic 5 percent underpredicition in reactor power. Grain sizes calculated using the laboratory equation in a fuel performance code tend to be greater than those measured in irradiated natural fuel, suggesting irradiation-induced inhibition of grain growth. Apparent activation energy for grain growth, Q, depends on fuel type and varies from 150+-10 kJ/mol for early AU powder to 360+-10 kJ/mol for pellets from ADU fabricated in the MOFFL. All data fit a ( grain size)sup(2.5) versus annealing time relationship. Samples were step-annealed in vacuo at 1870-2070 K for up to 32.5 h. Fuel examined includes natural UO 2 commercially fabricated from ADU powder for CANDU reactors natural UO 2 commercially fabricated from AU powder natural UO 2 from ADU and AU powder, fabricated in the MOFFL and commercially fabricated UO 2 enriched 1.7, 4.5, and 9.6 wt. Grain growth studies have been carried out on UO 2 to provide data for the fuel modelling program and to evaluate fuel fabricated in commissioning the Mixed Oxide Fuel Fabrication Laboratory at Chalk River Nuclear Laboratories. International Nuclear Information System (INIS)
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