Hello, I am looking for about 500 words and some references to describe these particular methods used by the IAEA to confirm the absence of undeclared nuclear activities and material at the different nuclear facilities within the nuclear fuel cycle, particularly just a focus on methods used for Isotopic (IDMS,...) and Particle (α-spectr,...). If you can add a link to a good descriptive picture, that would be great too. Let me know, thanks.