2. Activated Waste Assessment Program for Nuclear Power Plants

For decommissioning of nuclear power plants, radiological characterization is required in advance. The radioactive wastes arising during
decommissioning of nuclear power plants are activated wastes and contaminated wastes. The activated wastes are generated by neutron
activation of reactor vessel and its surrounding structures. The life-time distribution of neutron fluxes in the reactor vessel and its surrounding
structures is analysed with MCNP code based on operation history of nuclear power plant. Using this distribution,activation of the reactor
vessel and its surrounding structures is analysed with ORIGEN code based on their constituent materials.
In order to exactly assess the quantity of activated wastes, the activation analysis should be performed at each location in three dimensional
coordinate system, which requires treatment of huge number of data. NESS has developed a computer program of RANA(Reactor Activation
aNd waste Assessment) to automatically assess the quantity of activated wastes arising during decommissioning of nuclear power plants.