Abstract: In the shaft sealing device according to one embodiment, a seal ring includes a machine-interior-side seal ring member, and a machine-exterior-side seal ring member. A ring gap is left between the machine-interior-side seal ring member and the machine-exterior-side seal ring member. A seal gap is left between an inner peripheral surface of the machine-interior-side seal ring member and an outer peripheral surface of the rotary shaft and between an inner peripheral surface of the machine-exterior-side seal ring member and the outer peripheral surface of the rotary shaft. The inner peripheral surface of the machine-interior-side seal ring member is a flat surface that generally follows along the outer peripheral surface of the rotary shaft, and a groove extending along a direction of rotation of the rotary shaft is formed in the inner peripheral surface of the machine-exterior-side seal ring member.

Abstract: In the shaft sealing device according to one embodiment, a seal ring includes a machine-interior-side seal ring member, and a machine-exterior-side seal ring member. A ring gap is left between the machine-interior-side seal ring member and the machine-exterior-side seal ring member. A seal gap is left between an inner peripheral surface of the machine-interior-side seal ring member and an outer peripheral surface of the rotary shaft and between an inner peripheral surface of the machine-exterior-side seal ring member and the outer peripheral surface of the rotary shaft. The inner peripheral surface of the machine-interior-side seal ring member is a flat surface that generally follows along the outer peripheral surface of the rotary shaft, and a groove extending along a direction of rotation of the rotary shaft is formed in the inner peripheral surface of the machine-exterior-side seal ring member.

Abstract: A chemical decontamination apparatus of the present invention chemically dissolves radioactive substance-containing oxide films formed or adhering on the surface of a decontamination object by using ozone water to conduct decontamination. The chemical decontamination apparatus includes an ozone generating unit for generating ozone gas, an ozone supplying device for supplying the generated ozone gas to an ozone supplying unit in water, and a sintered metal element 37 which is disposed in the ozone supplying unit and to which ozone gas is supplied from the ozone supplying device. The ozone gas supplied to a sintered metal element interior from the ozone supplying device is allowed to flow out of the element into water so as to generate ozone water.

Abstract: A system for chemically decontaminating radioactive material.

Abstract: A chemical decontamination apparatus of the present invention chemically dissolves radioactive substance-containing oxide films formed or adhering on the surface of a decontamination object by using ozone water to conduct decontamination. The chemical decontamination apparatus includes an ozone generating unit for generating ozone gas, an ozone supplying device for supplying the generated ozone gas to an ozone supplying unit in water, and a sintered metal element 37 which is disposed in the ozone supplying unit and to which ozone gas is supplied from the ozone supplying device. The ozone gas supplied to a sintered metal element interior from the ozone supplying device is allowed to flow out of the element into water so as to generate ozone water.

Abstract: A system for chemically decontaminating radioactive material.

Abstract: A system for chemically decontaminating radioactive material.

Abstract: A system for chemically decontaminating radioactive material.

Abstract: A method for chemically decontaminating radioactive material. The method includes reducing-dissolving step for setting surface of radioactive material in contact with reducing decontamination liquid including mono-carboxylic acid and di-carboxylic acid as dissolvent; and oxidizing-dissolving step for setting the surface of the radioactive material in contact with oxidizing decontamination liquid including oxidizer. The method may include repeated pairs of steps, each pair including the reducing-dissolving step and the oxidizing-dissolving step. The mono-carboxylic acid may include formic acid, and the di-carboxylic acid includes oxalic acid. The oxidizer may be ozone, permanganic acid or permanganate.

Abstract: A method for chemically decontaminating radioactive material. The method includes reducing-dissolving step for setting surface of radioactive material in contact with reducing decontamination liquid including mono-carboxylic acid and di-carboxylic acid as dissolvent; and oxidizing-dissolving step for setting the surface of the radioactive material in contact with oxidizing decontamination liquid including oxidizer. The method may include repeated pairs of steps, each pair including the reducing-dissolving step and the oxidizing-dissolving step. The mono-carboxylic acid may include formic acid, and the di-carboxylic acid includes oxalic acid. The oxidizer may be ozone, permanganic acid or permanganate.