Abstract: Transuranic waste generated at Department of Energy operations have been packaged to a large extent in unvented fifty-five gallon steel drums and have been stored with the intention of future retrieval. There are safety concerns regarding these drums because of a potential presence of hydrogen and methane generated by radiolysis of hydrogenous wastes and/or of traces of combustible volatile organic compounds contained in original waste materials. Methods and apparatus are provided for penetrating the packed drums and drum liner lids and for sampling and analyzing headspace gases as well as for purging undesirable gas mixtures and installing high efficiency particulate air filter vents. The steps of the method are performed by automated apparatus which is configured to isolate the drums having contents being tested from the surrounding environment and for inserting vents with filters concurrently with performing the tests.