Organic cooled first wall and shield design for the ARIES-III D 3He reactor

An efficient organic cooled low activation ferritic steel first wall and shield were designed for the D-³He power reactor ARIES-III. The design allows removal of the large surface heat load without exceeding temperature and stress design limits. The structure is expected to last for the whole reactor life. The major concerns regarding using the organic coolant in fusion reactors were greatly alleviated. Organic coolant at a pressure of 2.6 MPa and inlet and outlet temperatures of 350 and 425°C are used. The low activation modified HT-9 alloy is used as structural and shielding material, allowing the radwaste to qualify as Class A waste. The total inboard first wall and shield thickness required for protecting the toroidal field coils is 65 cm. The first wall is coated by a 1.5-mm layer of beryllium, which is separated from the steel wall by a 100 μm layer of tungsten. The first wall is subjected to a high surface heat flux with a peak of 1.86 MW/m². The steel front layer of the first wall is 1 mm thick, resulting in a maximum temperature of 531°C and acceptable thermal stresses. The end-of-life peak damage is only 63 dpa, implying that no change-out is required