Radiation protection issues related to Canadian museum operations.

摘要

Museums in Canada have been found to possess radioactive items. The origin of the radiation can be broadly categorized as either natural (generally, radioactive ores) or anthropogenic (generally, luminous gauges). Radioluminescent gauges, especially bearing radium (226Ra), can also generate significant radiation fields. This is especially true if many gauges are located in close proximity. In addition, the radon may out-gas from these gauges, and generate a loose contamination problem in enclosed spaces (such as display cases). Radioactive ores, bearing naturally occurring uranium and thorium, can generate radiation fields many times greater than the ambient background levels. In addition, they will increase the ambient radon level and potentially generate loose contamination. In this paper, we discuss the specific results of radiological decommissioning at three museums: the National Air Force Museum of Canada (Trenton, Ontario); the Quebec Air and Space Museum (Montreal, PQ); and the Canadian Museum of Nature (Aylmer, PQ). In addition, a radiological survey performed at Canadian Forces Detachment Mountain View (Mountain View, Ontario) of surplus aircraft is included. The primary conclusion is that museums holding radioactive materials may have detectable levels of loose Ra and progeny contamination. They, therefore, have a requirement to be surveyed for loose contamination periodically with the potential for periodic decontamination caused by radon out-gassing. In addition, public access to displays bearing radioactive material should generally be restricted, and comprehensive radiation safety and security programs at museum facilities should be developed and enacted.