Skip navigation
Nuclear Safeguards Education Portal

Signatures for Spent Fuel Presence Verification

One task for inspectors is to verify that an item declared by the facility operator as a spent fuel assembly is in fact a spent fuel assembly.  Furthermore, an inspector may need to verify that certain objects are not spent fuel assemblies.

All of the signatures (both physical signatures and radiation signatures) can be used to verify the presence of spent nuclear fuel.  A spent fuel assembly can be distinguished from an assembly-like item that was irradiated but does not contain nuclear fuel using fission product gamma ray activity or neutron activity. 

Verified -presence

Page 24 / 43