STUDY OF 40 MW PRESSURIZED WATER, BOILING WATER, AND ORGANIC MODERATED REACTORS FOR PRODUCTION OF PROCESS STEAM

The study efforts were toward the creation of a reactor design for each of the three types and the development of each concept to a point where the range of costs could be established. The studies presented have high burnup cores of low enrichment in an effort to minimize fuel costs. Of the three designs presented to deliver 1.25 x 10/sup 5/ lb/hr of 380 deg F steam at 196 psia the PWR core is the most favorable. (W.D.W.

Mapping more of terrestrial biodiversity for global conservation assessment

Global conservation assessments require information on the distribution of biodiversity across the planet. Yet this information is often mapped at a very coarse spatial resolution relative to the scale of most land-use and management decisions. Furthermore, such mapping tends to focus selectively on better-known elements of biodiversity (e.g. vertebrates). We introduce a new approach to describing and mapping the global distribution of terrestrial biodiversity that may help to alleviate these problems. This approach focuses on estimating spatial pattern in emergent properties of biodiversity (richness and compositional turnover) rather than distributions of individual species, making it well suited to lesser-known, yet highly diverse, biological groups. We have developed a global biodiversity model linking these properties to mapped ecoregions and fine-scale environmental surfaces. The model is being calibrated progressively using extensive biological data sets for a wide variety of taxa. We also describe an analytical approach to applying our model in global conservation assessments, illustrated with a preliminary analysis of the representativeness of the world's protected-area system. Our approach is intended to complement, not compete with, assessments based on individual species of particular conservation concern.SCOPUS: re.jinfo:eu-repo/semantics/publishe