The Korea Atomic Energy Research Institute (KAERI) has launched a decommissioning program of the uranium conversion plant.
The sludge waste, which was generated during the operation of the plant and stored in the lagoon, was characterized for the
development of the treatment process. The physical properties were measured and chemical compositions and radiological properties
analyzed. The main compounds of the sludge were ammonium nitrate, sodium nitrate, calcium nitrate, and calcium carbonate.
All heavy radioactive elements such as uranium, thorium and 226Ra were precipitated and deposited at the bottom, and were not dissolved in the concentrated nitrate solution. A possible
flow-scheme for processing is presented.