Detection, Recovery, and Destruction System for Sea-Disposed Chemical Munitions: Port Kanda, Japan

AbstractAt Port Kanda, Japan, a systematic project for detection, recovery, and destruction of sea-disposed chemical munitions is ongoing. This project is unique in its size, scope, and the complexity of operations, and, therefore, provides an excellent case study. The systems used include a high efficiency magnetometer system for detection and identification of chemical munitions, a chemical agent resistant diving gear, a double-walled container for chemical munitions recovery and transport, and a DAVINCH® float detonation system. The development of the systems is described together with the testing results and operating record.The surveyed and cleaned-up area is 650 ha, and over 2,700 chemical munitions have been recovered and destroyed. The pre- and post-recovery sampling and analysis results are disclosed to the public to gain their acceptance and assure them that no contamination remains. The potential impacts to seafood from arsenic-bearing compounds were a concern and are briefly discussed.A deep sea operation system involving a remote recovery sealing-up container, and DAVINCH®, a floating detonation system on the recovery site, are proposed. The authors introduce the concept of "Critical Depth" for the munitions clean-up. This is the reasonable depth to which recovery of a potential source of contamination should be considered and beyond which it should not.