Transient processes in radiative transfer have recently become of interest in the modeling of astrophysical phenomena, particularly with regard to the brightness of novae, supernovae, and perhaps even galactic clouds adjacent to quasars. Analytic solutions to a particular class of Marshak wave problems are presented with and without the Marshak (Milne) boundary condition. The choice of boundary condition can have a decisive effect on the coupling of radiative energy to the material energy in the vicinity of a material boundary. The analytic solution obtained can be useful as a tool for calibrating numerical calculation techniques.

Some criteria for identifying dense plasmas are given. The theoretical analysis gives the following: general characteristics of dense plasmas, statistical model for compressed atoms, and ionization equilibrium in dense plasmas. (MOW)

Actinide cross section data at thermonuclear neutron energies are needed for the calculation of ICF pellet center burnup of fission reactor waste, viz. 14 MeV neutron fission of the very long-lived actinides that pose storage problems. A major advantage of pellet center burnup is safety: only milligrams of highly toxic and active material need to be present in the fusion chamber, whereas blanket burnup requires the continued presence of tons of actinides in a small volume. The actinide data tables required for Monte Carlo calculations of the burnup of /sup 241/Am and /sup 243/Am are discussed in connection with typical burnup reactor fusion and fission spectra. 2 figures.

Current practice in the nuclear industry and elsewhere is to specify the seismic input to design calculations at the surface of the site, rather than at bedrock. This paper investigates the implications of such a specification by comparing the site response of a surface specification to the site response of a corresponding bedrock specification. The investigation considered six different sites consisting of three soil profiles with average shear wave velocities of 800, 1800, and 5000 ft/sec and two oil depths: 200 ft. and 400 ft. Seismic input to these sites consisted of two synthetic accelerograms: one corresponding to Blume's statistically averaged surface response spectrum taken as surface input, the other accelerogram was, in our judgment, a typical bedrock acceleration time history related to the surface synthetic accelerogram. The site response was calculated using the program SHAKE. The deconvolution results indicate that Blume's statistically averaged surface response spectrum envelops all the spectra from lower levels for hard and intermediate sites. When the corresponding bedrock acceleration is used as input for a convolution, the surface acceleration can be greater than Blume's surface spectral acceleration. It is very difficult to calculate physically meaningful results for the soft sites for both convolution and deconvolution. …

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