The present invention relates to systems and methods to facilitate replacement between runs of a kit or cassette from an automated radiosynthesis device located in a hot cell. The method and apparatus of the invention enable automated disconnection of the outlet line by sealing the tubing hermetically by means of heat and by cutting the tubing where it is sealed in such a way that there is no risk of environmental contamination with radioactive material. The invention enables disconnection of the outlet line without manual intervention before opening the shielded enclosure.