Terrestrial perturbation experiments as an environmental assessment tool

The National Environmental Policy Act of 1969 (NEPA) was initially interpreted as requiring full disclosure of the environmental impacts of a federal action. Because of the limitations of time, money, and manpower, this requirement that all impacts be considered has led to superficial analysis of many important impacts. The President's Council on Environmental Quality (CEQ) has provided a solution to this problem by reinterpreting NEPA as requiring analysis of those impacts which have significant bearing on decision making. Because assessment resources can now be concentrated on a few critical issues, it should be possible to perform field perturbation experiments to provide direct evidence of the effects of a specific mixture of pollutants or physical disturbances on the specific receiving ecosystem. Techniques are described for field simulation of gaseous and particulate air pollution, soil pollutants, disturbance of the earth's surface, and disturbance of wildlife. These techniques are discussed in terms of their realism, cost, and the restrictions which they place on the measurement of ecological parameters

Model of the PCB and mercury exposure of mink and great blue heron inhabiting the off-site environment downstream from the US Department of Energy Oak Ridge Reservation. Environmental Restoration Program

The growing interest in safety problems had led physicists to try to increase their knowledge of the neutron leakage phenomenon, both by calculation and by experiment The flux calculation in a heterogeneous assembly is frequently performed by collision probability method On the contrary, neutron leakage is calculated for a flux-weighted homogenized assembly, which is a good approximation for a non-voided assembly (PWR in normal conditions) In a LOCA situation, the assembly may contain void zones, and this model for leakage calculation may become insufficient We propose here a new theoretical model, taking into account the effect of heterogeneity of the assembly on neutron leakage, and which was implemented as TIBERE procedure in the multigroup transport assembly code APPOLO-2 One of the advantages of this new model is to allow a perfectly consistent definition of cell reaction and cell leakage rates used in the equivalence procedure As well as this theoretical work was made, an experimental program concerning this phenomenon was performed as a part of EPICURE experiment Comparisons of experimental and calculational results point out better agreement of the new model with the measurement