Temperature-transient-to-burst tests were performed on irradiated Type 316 stainless steel cladding. Special attention was paid to control the atmosphere for specimen preparation and testing to avoid possible change in the chemical state of the fission products which remained inside the fueled specimens. Under the controlled atmosphere, the burst temperature of the irradiated fueled cladding was not degraded at lower stress level by the ‘fuel adjacency effect (FAE)’. The so-called fuel adjacency effect was suspected to be caused, at least in part, by an atmospheric effect during post-irradiation examination. The transient burst temperatures of Type 316 stainless steels were fairly insensitive to the material conditions in a controlled testing environment, although the onset of swelling acted to decrease the failure temperature. Results were also presented for irradiated advanced austenitic stainless steel and ferritic/martensitic steel cladding.

The demand for electric double-layer capacitors, which have high capacity and are maintenance-free, for use in a variety of devices has increased. Nevertheless, it is important to know the degradation behavior of these capacitors at high temperatures because they are expected to be used in severe environments. Therefore, degradation tests at 25 °C and 80 °C were carried out in the current study to analyze the degradation behavior. Steam-activated carbon, Ketjen black, and PTFE were used as the electrodes, conductive material, and binder, respectively, and KOH was used as the electrolyte. The impedance and capacitance were calculated from the voltage and current in the device using the alternating current (AC) impedance method. The results showed that the impedance increased and the capacitance decreased over 14 days at 80 °C, which is the inverse of what we observed at 25 °C. Rapid degradation was also confirmed from the 80 °C degradation test. The residual voltage after measuring the current and voltage was a prominent factor influencing this rapid degradation.

SUMMARY The introduction of renewable energy sources, such as photovoltaics or wind turbines, has been greatly promoted recently in order to improve the energy and environmental issues. In distribution systems with a large number of distributed generators, voltage profile management becomes one of serious problems due to the reverse power flow. Usual PCS (Power Conditioning System) reduces their active power output if they detect the voltage violation from the upper limit in order to get the voltage profile back to the proper range. However, since the magnitude of voltage fluctuation at the nodes with PCSs are different each other, there is a possibility that the amount of the curtailment are not the same among them. Hence, in this paper, we developed a new method which can solve the problem by using information exchange between PCSs using communication function of smart meters supposing the communication among them is available every 30 min. The proposed method was tested in 38‐node model system and its effectiveness was shown.

The demand for electric double-layer capacitors (EDLCs) has recently increased, especially for regenerative braking systems in electric or hybrid vehicles. However, using EDLCs under high temperature often enhances their degradation. Continuously monitoring EDLC degradation is important to prevent sudden malfunction and rapid drops in efficiency. Therefore, it is useful to diagnose the degradation at a lower frequency than that used in charge/discharge. Unused and degraded EDLCs were analyzed using the alternating current impedance method for measurements over a wide frequency range. Each result had a different spectrum up to 1 kHz. In addition, we show the basic inside condition of EDLCs with equivalent circuit analysis. This paper explores the possibility of degradation diagnosis at a high frequency and the basic physical mechanism.

The introduction of renewable energy sources, such as photovoltaics or wind turbines, has been greatly promoted recently in order to improve the energy and environmental issues. In distribution systems with a large number of distributed generators, voltage profile management becomes one of serious problems due to the reverse power flow. Usual PCS (Power Conditioning System) reduces their active power output if they detect the voltage violation from the upper limit in order to get the voltage profile back to the proper range. However, since the magnitude of voltage fluctuation at the nodes with PCSs are different each other, there is a possibility that the amount of the curtailment are not the same among them. Hence, in this paper, we developed a new method which can solve the problem by using information exchange between PCSs using communication function of smart meters supposing the communication among them is available every 30 minutes. The proposed method was tested in 38-node model system and its effectiveness was shown.