[en] A conceptual layout of a Hanford Nuclear Energy Center comprised of 20 and 40 reactors with associated fuel cycle facilities has been developed based on limited technical studies. During the past year these studies have emphasized meteorological effects and heat sink management aspects of an HNEC, station electric power, and socioeconomic impacts. The studies to date have not revealed any insurmountable technical or socioeconomic problems, but areas of major uncertainty continue to relate to: (1) Changes in meteorological conditions caused by large heat releases, particularly those related to fog/humidity, rain/hail, ice, and wind generation. (2) Devising a heat sink management plan which results in an acceptable balance among environmental effects, economics, and resource (land, air, and water) utilization compared to dispersed siting. Of the four meteorological aspects which must be analyzed--changes in fog/humidity, rain/hail, ice, and wind--only the fog/humidity aspect has been investigated for an HNEC. (Adequate analytical tools and supporting data for the others are not presently available.) This work indicates that extensive use of cooling ponds and mechanical draft towers will be unacceptable because of increased ground-level fog and/or decreased visibility (though criteria are not available to judge this with certainty). Once-through cooling (to the extent it can be used) and tall mechanical draft towers appear to alleviate the ground-level fog situation. The cloud cover aspects of tall towers have not been examined. Dry or wet/dry cooling systems would probably be acceptable from both ground level fog and cloud cover aspects, but such systems would increase power generation costs 1-2 mills/kW-hr