We proposed a thermoacoustic cooling system as a technique using solar heat energy. My previous study confirmed that this system can drive and cool materials using solar heat energy. The amount of solar heat energy depends on the season because solar heat energy is natural energy. Therefore, examination of whether a long-term drive of this system is possible irrespective of the season is necessary for practical use of thermoacoustic cooling systems using solar heat energy. This report descries a driving experiment of the system operating between April and December. Results demonstrate the possibility of long-term driving of the thermoacoustic cooling system using solar heat energy by shortening the time until reaching this system's oscillation temperature.

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Radioactive Corrosion Product (CP) is a main cause of personal radiation exposure during maintenance with no breached fuel in fast breeder reactor (FBR) plants. The most important CP is ⁵⁴Mn and ⁶⁰Co. In order to establish techniques of radiation dose estimation for radiation workers in radiation-controlled areas of the FBR, the PSYCHE (Program SYstem for Corrosion Hazard Evaluation) code was developed. We add the Particle Model to the conventional PSYCHE analytical model. In this paper, we performed calculation of CP transfer in JOYO using an improved calculation code in which the Particle Model was added to the PSYCHE. The C/E (calculated / experimentally observed) value for CP deposition was improved through use of this improved PSYCHE incorporating the Particle Model. Moreover, among the percentage of total radioactive deposition accounted for by CP in particle form, ⁵⁴Mn was estimated to constitute approximately 20 % and ⁶⁰Co approximately 40 % in the cold-leg region. These calculation results are consistent with the measured results for the actual cold-leg piping in the JOYO.

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Flow accelerated corrosion (FAC) rate downstream from an orifice was measured in a high-temperature water test loop to evaluate the effects of flow field on FAC. Orifice flow was also measured using laser Doppler velocimetry (LDV) and simulated by steady RANS simulation and large eddy simulation (LES). The LDV measurements indicated the flow structure did not depend on the flow velocity in the range of Re = 2.3×10⁴ to 1.2×10⁵. Flow fields predicted by RANS and LES agreed well with LDV data. Measured FAC rate was higher downstream than upstream from the orifice and the maximum appeared at 2D (D: pipe diameter) downstream. The shape of the profile of the root mean square (RMS) wall shear stress predicted by LES had relatively good agreement with the shape of the profile of FAC rate. This result indicates that the effects of flow field on FAC can be evaluated using the calculated wall shear stress.

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