Shields

About: Shields is a research topic. Over the lifetime, 1456 publications have been published within this topic receiving 10896 citations.

Some design criteria for hydrogen-metal reactor shields

Abstract: The detailed distributions of thermal flux were investigated for a series of multilayered systems of iron and water, and the experimental data were interpreted on the basis of a three-group model. This model attempts to describe the three basic features of neutron behavior in shields, viz. the flight of virtually uncollided neutrons (described in the model by removal'' theory), the slowing down of neutrons subsequent to scattering out of the uncollided group, and the diffusion of neutrons at thermal energies. For an adequate interpretstion of the data on the basis of this model, however, it was necessary to obtain some of the three-group parameters empirically for iron and water. The three-group model described provides a prediction of the thermal flux (to an accuracy of better than 20%) and the epithermal flux. Ease of application to complex multilayered systems is achieved at the expense of using the empirical parameters. (auth)

Influence of the Cable Accessories Installing Method on the Partial Discharge Activity in Medium Voltage Cables

Abstract: This article proposes a method to modify the construction of a medium voltage (MV) heat shrinkable cable termination in cases of atypical damage to the shields of cross-linked polyethylene (XLPE) insulated cables. The proposed solutions include a modified method of assembling electric field control coating. An attempt was made to check the effect of such damage to the shields of MV cables with XLPE insulation on the level of occurrence of partial discharges within the cable termination. The investigations included testing the XRUHAKXS 1 × 240/25 cable type using the electric method (ME) and high frequency (HF) method with sinusoidal AC test voltage. As a result of the measurements, the values of total charges in the period and phase-resolved partial discharge (PRPD) patterns were obtained. The presented experimental results show the influence of the damage of the semiconducting coating surface on the occurrence of a defect in the cable termination without a modified method of control mantissa pinning. We suggest new methods of assembling MV cable accessories in the case of the presented coating damage in MV cable insulation.

Finite Element Method for the Prediction of Magnetic Fields in Underground SF6 Insulated Cables

Abstract: This paper presents a finite element method for predicting magnetic field above ground, generated by an underground SF6 insulated cable First, with the aid of Ansys software the magnetic field in underground SF6 insulated high voltage cables under and above ground is computed and then, currents and losses in the shields of the cables are computed The influences of the operating parameters on these quantities are also examined