Nuclear Structural Engineering最新文献

One of the ultimate methods proposed for high level radioactive waste disposal is to contain the activity in ceramic bodies and bury them underground or in deep sea. The limit of the activity that can be incorporated in such bodies is decided by the temperature rise in the body due to the absorption of nuclear radiation. This paper discusses the temperature distribution in a solid sphere containing long-lived gamma emitters and buried in a medium having the same thermal properties. Analytical expressions are given for heat source distribution and for calculations of temperature distribution in and out of a solid sphere containing gamma activity. Numerical values obtained with energies in the range of 0.5 to 3 MeV and in spheres of radii 10, 20 and 30 cm are presented. The results are compared with those of the beta case.

The general theory of the plastic analysis of axisymmetric shells of revolution is discussed and conditions for the construction of a complete solution and bounds to it are defined. It is shown that the various approaches to the collapse of the cylinder/sphere intersection may be placed in one of two categories. Approximate solutions, in conjunction with yield surfaces for cylindrical shells, are outlined.

Description of an electrical analog network for the thermal analysis of nuclear fuel shipping casks under fire accident conditions. The network allows to simulate the thermal behaviour of a wide range of cask dimensions for any given fire temperature curve. Changes in thermal properties of the materials involved, melting of the lead shield, and any changes in the heat transfer coefficients during the fire may all be presented.

An elastic-plastic solution is given for pure tension, pure bending and pure shear at hyperbolic notches in flat plates. In order to illustrate the practicality of the formulation and method of solution three problems are illustrated, representing the three different types of loading conditions.

The differential equation of a conical shell subjected to axisymmetrical temperature distributions is derived. The temperature distributions may vary in the meridional direction and linearly through the thickness. In order to obtain a particular solution to the differential equation, the expression for the temperature distributions is assumed to be the sum of hyperbolic and cubic functions. The particular solution is superposed on the homogeneous solution and all the formulae for a complete analysis are given.

This paper gives the analytical solution of the set of differential equations describing, in the multigroup removal-diffusion approximation of Boltzmann's transport equation, the neutron flux distributions in the multi-layered plane shield of a nuclear reactor. The solution is obtained in closed form of a linear combination of some well-defined auxiliary expression, which can be easily integrated and differentiated.

The new “ASME boiler and pressure vessel code for nuclear vessels” permits design of nuclear reactor vessels for water reactor plants of up to 1500 MW. The problems of design, material procurement, and inspection are surveyed.

The transient temperature distributions in bonded end caps of solid cylindrical fuel elements subjected to sudden change in temperature are determined analytically. The solution for the temperature distributions is expressed by products of Bessel functions, exponential functions and coupling relations between the end cap and the fuel section of the fuel element. A numerical example is given for enriched uranium oxide dispersed fuel elements with zircaloy cladding and bonded zircaloy end caps. From the calculated results of the example several conclusions are drawn (see section 4).