Cable-driven parallel robots are mechanisms that control the position and attitude of an object using multiple cables. Typical cable-driven parallel robots have been studied for use on land, but not ...for use in water. This is because the position and attitude control of object and motion analysis become difficult underwater due to the large deformation of cables caused by fluid forces. In this paper, we propose an underwater cable-driven parallel robot consisting of multiple on-water robots and derive a dynamics model that considers the cable dynamics underwater. Then, we proposed a position and attitude control system for the suspended object based on the inverse kinematics problem for the suspended object and studied its effectiveness by simulation by using the planar two degrees-of-freedom underwater cable-driven parallel robot.
Thermodynamic calculation of volatile radionuclides such as Cs, I and Te in a cladding failure accident of a sodium-cooled fast reactor has been conducted for the evaluation of an in-vessel source ...term. Important chemical reactions and chemical forms such as Cs, Cs2, Te, CsI, Cs2I2, Cs2Te, CsNa, NaI, Na2I2, Cs2Te, Na2Te, AgTe and Cs2MoO4 were suggested by the results of interaction among fuel, fission products, a cladding tube and Na coolant at high reduction rates inside the fast reactor vessel. As the cladding failure accident proceeds, it was confirmed that 15% and 60% of Cs was in gas phase at 1,155 K and 5.7 MPa and at 1,670 K and 10.5 MPa, respectively. 58% and 66% of Cs was in the gas phase at 1,155 K and 1,670 K at 0.1 MPa owing to cladding failure. Under Na mixing conditions, almost 100% of Cs became gas. Furthermore, we confirmed the same behavior as in light water reactors, that is, the release of Cs is suppressed at high pressures, but we observed that Cs rarely oxidizes and that the amount of Cs released increases with Na mixing in the fast reactor.
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