A BBC reporter has finally gives some insight into how to disassemble a nuclear device without having to go through the hassle of arming it.

Most revealing was how inspectors make sure nobody walks off with some plutonium using tape, glue and glitter:

...[A] seal is used to ensure a room or box is not tampered with during times inspectors are not physically watching it.

These are surprisingly low-tech. A purple strip of adhesive goes across a door hinge. If it is moved then the colour changes and a warning appears on it.

Additionally, the seal has a blob of glue with multi-coloured glitter inside. This is photographed close-up by the inspectors once it is in place and then again when inspectors return.