1- Samples collected in the early stage of the debris retrieval will be extremely valuable and analysis need to be carried out as completely as possible to meet decommissioning requirements.
 For example, recriticality evaluation is inevitably important for designing the debris retrieval process, which requires the accurate concentration of U, Pu, other actinides, Gd, and other
 neutron absorbers and distribution of these elements, isotopic ratio etc.
This requires the expert combination of various analysis techniques, including chemical analysis (e.g. ICP-MS, ICP-AES, etc.), microscopic analysis (SEM/EDX, SEM/WDX, TEM, etc.),
 and radiation analysis (α/γ-spectrometry, neutron measurement, etc.)

2- differences in composition may be caused by the difference in formation mechanism of these particles