“Surveyor”: An underwater system for threat material detection Vladivoj (Vlado) Valkovic, 1 Davorin Sudac, 2 Karlo Nad, 2 Jasmina Obhodas, 2 Dario Matika, 3 and Robert Kollar 4 1 A.C.T.d.o.o., Prilesje 4, 10000 Zagreb, Croatia 2 Institute Ruder Boskovic, Bijenicka c.54, 10000 Zagreb, Croatia 3 Institute for Researches and Development of Defense Systems, Ilica 256b, 10000 Zagreb, Croatia 4 EOD,d.o.o., Crnciceva 29, 10000 Zagreb, Croatia (Dated: May 23, 2008) The bottoms of the coastal seas, and oceans as well, are contaminated by many man-made objects including a variety of ammunition. This contamination is world wide spread with some areas being highly polluted presenting a serious threat to local population and to visitors as well. All littoral nations are investing lots of effort into the remediation of their coastal areas. Once the presence of the anomaly on the bottom of the shallow coastal sea water is confirmed (by visual identification and by using one or several sensors, namely magnetometer, sonar and optical cameras) it is necessary to establish if it contains explosive/chemical warfare charge. In our work we propose this to be performed by using neutron sensor installed within an underwater vessel – “Surveyor”. When positioned above the object, or to its side, the system inspects the object for the presence of the threat material by using alpha particle tagged neutrons from the sealed tube d+t neutron generator. I. INTRODUCTION Security is no longer only exclusive part of the mili- tary and political spheres, but a complex phenomenon that demands a comprehensive approach, which includes socio-economic and environmental issues. One critical as- pect of this integral approach concerns seas and coasts, on which local population relies for sustenance and liveli- hood options, and which underpins vital economic sectors such as trade, tourism, energy and defence. In light of this one has to consider all material which has been dumped into the coastal seas or oceans. The dumping of material in the sea waters has a long history. Objects are dumped into the sea in a variety of ways. Sea dumping, as currently defined as any deliberate dis- posal into the sea of wastes or other matter from vessels, aircraft, platforms or other man-made structures. The legacy of conflicts which resulted in the world wars and local fightings is especially worysome. Industrialized nations stockpiled record numbers of munitions in prepa- ration for what would become World War I, and later, World War II. With the end of these wars came the ur- gent need to dispose vast quantities of left over munitions from battlefields around globe. Having limited options and few resources available during the reconstruction pe- riod, “dumping at sea” was adopted as the method of choice. Seas and inland waters used for disposal, weapons de- velopment, or “live fire” training, are today littered with the remains of some of the most powerful weapons ever created. These practices continued as we moved into the nuclear age, and radioactive materials have since been added to the mix. Since the end of World War II, there has been a number of treaties dealing with the limitations, reductions, and elimination of so-called weapons of mass destruction and their transport systems. The easiest and “cheapest” way to “eliminate” chemical weapons and munitions following World War II was to dump them into the oceans. As en- vironmental awareness has increased, and the ecological repercussions of such actions have made them unaccept- able, steps have been taken to prohibit the manufacturing and use of chemical weapons. However, questions as to the short and long-term effects, and ultimately the reme- diation of areas and populations damaged by weapons and munitions dumping, have been largely left alone. Useless, obsolete, recovered ammunitions, explosives and war material of any sort have been dumped in oceans and seas for decades. Among the military ordnance dumped at sea, chemical weapons (CWs) and riot control agents represent a not negligible percentage. The yearly rate of dumping is slowly diminishing also because of the entry into force of international conventions stimulating the adoption of other disposal practices. However, the actual amount of dumped war material, subject to the corrosive action of sea water which causes the release of chemical products, has to be considered as a relevant source of persistent pollutants in need of in-depth scien- tific investigations. Taking into consideration the extension of the dump- ing sites, the wide dispersion of the dumped war material due to trawling fishery, their increasingly rusted condi- tions and a number of other factors, there is a need for data and information suitable to provide a sound scien- tific base to carefully evaluate costs and benefits deriving from possible clean up activities at sea. Remediation of marine chemical weapons and muni- tions dumpsites is technically challenging because of the nature of the material dumped and the uncertainty sur- rounding the quantities, type, locations and the present condition or stability of these materials. Dumped munitions, and in particular the disturbance of dumped munitions by seabed activities, e.g., fishing, sand and gravel extraction, dredging and dumping oper- ations and the placement of cables and pipelines, is an important issue and should be addressed. It is essential