DECOMMISSIONING

To remove nuclear facilities from service and to reduce residral radioactivity to a level allowing unrestricted use.
Removal of spent fuel is considered to be an operational activity, so not included in decommissioning
Non-radioactive structures and materials aren't involved
~%85 of a nuclear power plant is not radioactive
~%99 of radioactivity is shipped away as spent fuel and low level waste right after shut down.

GEOLOGICAL DISPOSAL

Especially for High Level Waste (HLW) or Spent Fuel (SF), adaptable to non-HLW:
Put it into a deep hole underground and fill up the hole, later seal the underground cavities
2 principal objectives;

1. isolation of waste from people to make incidental or intentional access to the waste highly imprbable
2. isolaiton of waste from groundwater which is the most likely (if not the only possible) vehicle to carry to people

In the long run, achieve these objectives without maintenance or survelience.

RADIOACTIVE WASTE

Any waste material whose radioactivity exceeds certain limits, established by goverments or local authorities, guided by recommodations of ICRP (international commision radiation protection) (defines MPC's in H2O and air)

JOB of NUCLEAR WASTE MANAGEMENT

To prevent radioactive contamination of the biosphere by nuclear wastes, down to a level so small compared to background as to be generally accepted as tolerable.