Eliminates coverage for loss or damage from nuclear reaction or radiation or radioactive contamination, except that ensuing fire is explicitly covered. (2) A provision or endorsement found in or attached to virtually all commercial lines liability policies. The standard broad form nuclear energy exclusion most often attached to liability policies, Nuclear Energy Liability Exclusion Endorsement (Broad Form) (IL 00 21), precludes coverage only for liability insured under a nuclear energy liability policy or for which indemnity is available from the US government. The exclusion does not normally apply to liability arising from radioactive isotopes, the most common commercially used nuclear materials.