The distribution of geothermal resources in relation to the location of population centers in the U.S. is considered. Capital aspects of district heating systems are discussed. Estimates are given of distribution network capital investment as a function of population in service area. Swedish and Icelandic cost experience is taken into consideration. The need for more specific assessment of the potential for direct use of geothermal energy is cited. (JGB)

Work performed since the last Workshop meeting is summarized. The studies have been divided into the following sections: (1) response of albedo neutron dosimeters to low energy neutrons; (2) discussion of dose-equivalent conversion factors; (3) modification of the A-B remmeter; (4) the effect of distance from the body on the response of albedo neutron dosimeters; (5) comparison of albedo neutron dosimeter techniques; and (6) modified NAD badge for additional beta shielding and albedo neutron dosimetry.

The interest in the properties of very dense hydrogen is prompted by its abundance in Saturn and Jupiter and its importance in laser fusion studies. Furthermore, it has been proposed that the metallic form of hydrogen may be a superconductor at relatively high temperatures and/or exist in a metastable phase at ambient pressure. For ten years or more, laboratories have been developing the techniques to study hydrogen in the megabar region (1 megabar = 100 GPa). Three major approaches to study dense hydrogen experimentally have been used, static presses, shockwave compression, and magnetic compression. Static tchniques have crossed the megabar threshold in stiff materials but have not yet been convincingly successful in very compressible hydrogen. Single and double shockwave techniques have improved the precision of the pressure, volume, temperature Equation of State (EOS) of molecular hydrogen (deuterium) up to near 1 Mbar. Multiple shockwave and magnetic techniques have compressed hydrogen to several megabars and densities in the range of the metallic phase. The net result is that hydrogen becomes conducting at a pressure between 2 and 4 megabars. Hence, the possibility of making a significant amount of hydrogen into a metal in a static press remains a formidable challenge. The …