NUKLEONIKA 2005, 50(3):113-120
D. Ancius1, D. Ridikas2, V. Remeikis1, A. Plukis1, R. Plukiene1, M. Cometto2
1 Institute of Physics, 231 Savanoriu Ave., LT-02300 Vilnius, Lithuania
2 CEA Saclay, DSM/DAPNIA/SPhN, F-91191 Gif-sur-Yvette, France
Ignalina NPP Unit 1 with the RBMK-1500 type reactor enters the preparatory stage for its decommissioning.
A big volume of graphite has to be dismantled and managed. This paper evaluates the composition of
radionuclides in irradiated graphite on the basis of the calculation scheme with computer codes
MCNPX and CINDER’90. Full scale calculations take into account the whole energy spectrum of neutrons,
the spatial neutron flux in different reactor structures and the impurities of RBMK-1500 graphite
measured by two independent methods. Principal contributors to the total activity as well as other
radionuclides important from the radiological point of view are identified. The uncertainties of such
calculations are discussed.