Radiation analysis of various vehicle and payload configurations for the reusable nuclear shuttle

Radiation analyses were performed and shielding weight requirements were estimated for various candidate vehicle and payload configurations for use with the reusable nuclear shuttle. The analyses included both point kernel and Monte Carlo approaches. The effects on reduced shield weight were determined for propellant ranks with pointed conical tank bottoms and for one case of a cluster of small tanks. This later case, however, had an arrangement which had no center tank in the upper tier of tanks. This effect negated most of the gain of going to the smaller tanks. A range of shield weights is presented for various light and heavy manned payload configurations when used in conjunction with a single liquid hydrogen propellant tank, 33 ft in diameter with a 15 deg conical tank bottom

Improved estimation of mineral and fluid volumetric concentrations in thinly bedded carbonate formations

We recently introduced new petrophysical and compositional methods for joint interpretation of multiple conventional well logs. These inversion-based methods are suited for petrophysical interpretation of rock formations that exhibit complex solid composition, include thin beds, and are subject to mud-filtrate invasion. They combine nuclear and resistivity logs to assess porosity and volumetric/weight concentrations of mineral and fluid constituents, and are ideal for the quantitative interpretation of carbonate formations. We document the successful application of the newly introduced inversion-based interpretation methods to three carbonate formations. Interpretation results are compared to those obtained with commercial software and core/X-ray diffraction (XRD) data whenever available. For two of the carbonate field examples where XRD data are available, nonlinear joint inversion of well logs improves the assessment of porosity by more than 30% and up to 100% in the presence of thin beds when compared to conventional interpretation methods. </jats:p