Australasian Mining Review
Issue link: http://ebook.aprs.com.au/i/37922
169 Bougainville Story Bougainville Copper Ltd owns and once operated a large opencut copper mine there until unrest forced the evacua- tion of their expatriate workers and abandonment of mining operations. Due to the volatile situation all equipment was left standing including the concentrator which had fi fteen ball mills and a large number of radiation density gauges that had been needed in the process control. radiation equipment disposal contract at the Panguna Mine site on Bougainville Island in Papua New Guinea. R After the years of unrest passed the effective owner of BCL initiated a program to locate and remove these sources as part of a larger amelioration plan to correct perceived environmental damage on the mine site in general and to re-establish a positive relationship with local land holders. adiation Safety Services has the expertise to “tackle” any radiation task, providing assistance in some interesting places like Bougainville. Early in 2011 RSS completed a This is an on-going program that also involves recovery of the mills and other equipment. This will be a massive job involving dismantling very large units and transporting them to a ship down a winding mountain road to the port of Loloho on the coast where they are taken away for refurbishing and eventual sale. The islanders receive income from these operations and take an active part in the work. RSS involvement was limited to removal of the physical sources plus a radiation survey of the industrial areas to detect any units that may have been removed or damaged during the unrest. This was quite an exercise because in most cases the small pellet located inside the larger source housing had to be physically transferred to a special lead transport container called a ‘transport-pig’ for eventual shipping to a disposal facility in Europe or the Americas. Pellet ‘unloading’ is normally undertaken in a dedicated workshop environment with multiple lead screens and specialised remote handling equipment, none of which was available on the island, and most of which was too diffi cult to get there. As a result the work had to be done with much more primitive equipment and had to work with fi ttings long corroded and impossible to simply unscrew, all undertaken in an environment that included daily downpours. Lead bricks were shipped to site to construct a semi-portable barrier to provide protection against radiation exposure. It was fortunate that many of the local people had worked with or in the mine in past years and they provided a ‘wantok’ network of assistance which changed an impossible job into a merely difficult one. Once the sources were ready for shipping off the island RSS relied on the “wantok” to assist with political and regulatory requirements to export the material from the island. A density gauge source is essentially a steel enclosed lead container with a physically small capsule of radioactive material. The housing provides the necessary shielding; equipped with a specially collimated aperture called a beam port which is opened and closed via a lead shutter. Source holders are manufactured to strict international standards, which dictates that it must withstand impact, vibration, fire, etc. The housings on this mine was subjected to war and managed to maintain their integrity throughout. [Instrumentation and Radiation Management, Safety and Training] _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ issue 2.2