Release of Ammunition-Related Compounds from a Dutch Marine Dump Site.

After World War II, large amounts of ammunition were dumped in surface waters worldwide, potentially releasing harmful and toxic compounds to the environment. To study their degradation, ammunition items dumped in the Eastern Scheldt in The Netherlands were surfaced. Severe damage due to corrosion and leak paths through the casings were observed, making the explosives in the ammunition accessible to sea water. Using novel techniques, the concentrations of ammunition-related compounds in the surrounding seabed and in the seawater were analyzed at 15 different locations. In the direct vicinity of ammunition, elevated concentrations of ammunition-related compounds (both metals and organic substances) were found. Concentrations of energetic compounds ranged from below the limit of detection (LoD) up to the low two-digit ng/L range in water samples, and from below the LoD up to the one-digit ng/g dry weight range in sediment samples. Concentrations of metals were found up to the low microgram/L range in water and up the low ng/g dry weight in sediment. However, even though the water and sediment samples were collected as close to the ammunition items as possible, the concentrations of these compounds were low and, as far as available, no quality standards or limits were exceeded. The presence of fouling, the low solubility of the energetic compounds, and dilution by the high local water current were concluded to be the main causes for the absence of high concentrations of ammunition-related compounds. As a conclusion, these new analytical methods should be applied to continuously monitor the Eastern Scheldt munitions dump site.

Microscopic characterization of defect structure in RDX crystals.

Three batches of the commercial energetic material RDX, as received from various production locations and differing in sensitivity towards shock initiation, have been characterized with different microscopic techniques in order to visualize the defect content in these crystals. The RDX crystals are embedded in an epoxy matrix and cross-sectioned. By a treatment of grinding and polishing of the crystals, the internal defect structure of a multitude of energetic crystals can be visualized using optical microscopy, scanning electron microscopy and confocal scanning laser microscopy. Earlier optical micrographs of the same crystals immersed in a refractive index matched liquid could visualize internal defects, only not in the required detail. The combination of different microscopic techniques allows for a better characterization of the internal defects, down to inclusions of approximately 0.5 µm in size. The defect structure can be correlated to the sensitivity towards a high-amplitude shock wave of the RDX crystals embedded in a polymer bonded explosive. The obtained experimental results comprise details on the size, type and quantity of the defects. These details should provide modellers with relevant and realistic information for modelling defects in energetic materials and their effect on the initiation and propagation of shock waves in PBX formulations.