Влияние распределения гадолиний содержащих твэлов реактора ВВЭР-1000 на выгорание

Различный состав и пространственное распределение выгорающих поглотителей по-разному влияют на размножающие и теплофизические свойства реактора. В работе создана расчетная 3D модель ТВС реактора с выгорающими поглотителями. В качестве выгорающих поглотителей используются традиционно-применяемые Gd2O3-содержащие твэлы и твэлы с AmO2. Проведенные расчеты позволили исследовать нейтронно-физические свойства реактора и нивелировать, возникающие офсеты энерговыделения в переходных режимах эксплуатации

Ein regelbasiertes Entscheidungsunterstützungssystem für Maßnahmen zur Gewässerstrukturverbesserung

The survey of the river basins in 2004 in the context of the European Water Framework Directive (WFD) identified intense morphological deficits of the German watercourses. The WFD asks for a good ecological status of all surface waters. Fair morphological structures are a precondition for the good ecological status. Research studies show a more or less significant correlation between the morphological quality and the diversity of species of the riparian vegetation, the species population of the macrozoobenthos and the fish fauna. The task of this work is the development of a decision support system (DSS-WRRL) for the determination of programmes of measures. The system shall help the responsible persons to preselect measures improving the morphological deficits in watercourses. Based on the theory of decision making and water resources planning the developed DSSWRRL offers a tool for determing and assessing rehabilitation measures for entire rivers or river sections. It is a DSS that includes a newly developed rule-based model for the selection of feasible combinations of measures. It also provides a prognosis of the effects of the measures on the morphological quality. The knowledge-based model is based on two consecutive rule bases. These bases contain the knowledge of an interdisciplinary expert group about measures improving the morphological quality of rivers. The use of the pareto efficiency concept reduces the amount of solutions that are further evaluated. Afterwards the programmes of measures are assessed and ranked using the PROMETHEE method. The criteria for the assessment are the costs and the morphological quality. The validation of the DSS-WRRL demonstrates the comparability of the prognosis of the measure effects and the developments observed in real river rehabilitions measures. Especially the meagre data base and the fact that special local features are not considered in the DSS-WRRL allow only a validation for some parts. The effects of the different DSS parameters on the identified programmes of measures are determined by a sensitivity analysis at selected river sections. The results of the sensitivity analysis show that the system reacts in a plausible way to changes in the parameters. Overall, the results of the DSS-WRRL are very promising