Deterioration study of sea‐dumped munitions in the eastern Scheldt

Vast amounts of surplus ammunition were dumped in surface waters around the world. After degradation and corrosion of shells, both metal compounds and the energetic contents of the ammunition end up in the environment. These compounds or their metabolites are toxic to the environment and human health. Also in the Netherlands, ammunition was dumped over a period of several decades after World War II at several marine sites. One of these dumpsites is the Eastern Scheldt near Zierikzee. During the monitoring campaign of the ammunition dumpsite in the Eastern Scheldt in 2020, ammunition items were surfaced. The corrosion and presence of leak pathways of sea‐dumped munition were studied for a selection of munition items after being more than 50 years on the seabed in the Eastern Scheldt. For some of the items an estimated uniform corrosion rate of 0.01–0.03 mm/year was determined. Furthermore, a non‐destructive inspection technique based on an ultrasonic method was applied to measure the casing thickness profile. The obtained results corresponded well with the manually determined thickness profiles. The ultrasound method opens the possibility to measure the casing thickness of even intact munition items, thus avoiding the dissection of the munition item and removal of the explosive fill.