Mobile nondestructive assay and examination instruments

A compact system that evaluates radioactive materials can furnish a big savings to taxpayers by ensuring that only properly identified nuclear waste is sent to a Department of Energy (DOE) radioactive waste storage area. The Los Alamos National Laboratory's Advanced Nuclear Technology Group has developed and field tested two esily transportable, self-contained modules: one x-rays the contents of special 208-l shipment containers, the other assays the contents. The assay and evaluation system is a simple, portable solution to a complex problem that ensures that only properly packaged transuranic (TRU) wste is shipped to the Department of Energy's Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. Caustic chemicals, liquids, and other objects or materials tht could cause a container leak during shipment are the objects of an x-ray and video camera used in the system. The camera inspects the contents of 208-l drums that are brought into the system on a conveyor and rotated, one at a time, in front of the x-ray source. Free liquids can be detected by shaking the drum; the sloshing liquid is visible on the video screen. After the drum is x-rayed, it is conveyed to the assay module where precision instruments measure the amounts of TRU isotopes present in the waste. If the drum contains fissile TRU isotopes above the safety limit, it is rejected and sent to an appropriate facility for repackaging; if the drum contains less than the 100 nCi/g lower-level limit for TRU, it is rejected and sent to a low-level nuclear waste burial site. Drums whose contents fall between these limits are accepted and certified for shipment to the WIPP. Made to fit on flatbed trailers, the entire system can be transported to a DOE facility and be ready for operations within 5 hours after arrival

The use of sewage treatment works as foraging sites by insectivorous bats

Sewage treatment works with percolating filter beds are known to provide profitable foraging areas for insectivorous birds due to their association with high macroinvertebrate densities. Fly larvae developing on filter beds at sewage treatment works may similarly provide a valuable resource for foraging bats. Over the last two decades, however, there has been a decline in filter beds towards a system of “activated sludge”. Insects and bat activity were surveyed at 30 sites in Scotland employing these two different types of sewage treatment in order to assess the possible implications of these changes for foraging bats. Bat activity (number of passes) recorded from broad-band bat detectors was quantified at three points within each site. The biomass of aerial insects, sampled over the same period as the detector surveys, was measured using a suction trap. The biomass of insects and activity of Pipistrellus spp. was significantly higher at filter beds than at activated sludge sites. In addition, whilst foraging activity of Pipistrellus spp. at filter beds was comparable to that of adjacent “good” foraging habitat, foraging at activated sludge sites was considerably lower. This study indicates the high potential value of an anthropogenic process to foraging bats, particularly in a landscape where their insect prey has undergone a marked decline, and suggests that the current preference for activated sludge systems is likely to reduce the value of treatment works as foraging sites for bats