Category Archives: Comprehensive nuclear materials

Dysprosium

Natural dysprosium contains a mix of seven stable isotopes 156, 158, 160, 161, 162, 163, and 164 with natural abundances of 0.06%, 0.10%, 2.34%, 18.9%, 25.5%, 24.9%, and 28.2%, respectively. The low abundance of 156Dy and 158Dy are such that only the latter five make a significant contribution to neu­tron capture in a dysprosium poison rod. 164Dy has the highest […]

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Thermal Shock

Graphite can survive sudden thermally induced loads (thermal shock), such as those experienced when an arc is struck between the charge and the tip of a graphite electrode in an electric arc melting furnace, or on the first wall of a fusion reactor. To provide a quantitative comparison of a material’s resistance to thermal shock loading, several thermal shock figures […]

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BWR UO2 fuel assembly

Figure 530 shows some examples of BWR fuel assem­blies. BWRs have 110-140 mm square full-core height assemblies which, unlike their PWR counter­parts, are contained within thick-walled channel boxes of zirconium alloy. They contain arrays of 6 x 6 to 10 x 10 fuel elements, usually with eight elements acting as tie rods that screw into upper and lower tie plates. […]

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Global Parameters

Because of the complex characteristics of the irra­diated fuel, the thermal conductivity is often deduced from correlations using global parameters summariz­ing the state of the fuel: for instance, the burnup and the irradiation temperature. Some fuel characteristics are implicitly taken into account. For instance, the grain size is a parameter having a small impact on the conductivity of fresh fuels […]

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Irradiation effects on electrical, thermal, and mechanical properties

The measurement of other properties of irradiated ZrC is limited and often contradictory. Some evi­dence for an increase in mechanical strength with irradiation is available. Andrievskii eta/.164 irradiated sintered ZrC098 at 423 and 1373 Kwith a fast neutron fluence of 1.5 x 1020 cm—2, and found more substantial strengthening at low-temperature irradiation than at high temperature (bend strength increased by […]

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Corrosion and Oxidation Behavior

With regard to general corrosion and oxidation, stainless steels with 16-18% Cr passivate and have good resistance to aqueous corrosion and various types of other acidic or corrosive environments at room temperature and up to about 200-300 °C.2 Additions of molybdenum give type 316 better resis­tance to pitting and acidic attack. Effects of stress can aggravate corrosion resistance, and types […]

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