Computation of the fluence of fast neutrons in the reactor pressure vessel of Unit T of Kozioduy NPP

The procedure of computation of the fluence of fast neutrons in the pressure vessel of the WWER-440 reactor of Unit I of the Kozioduy NPP, Bulgaria, by the method of the discrete ordinates using lhe neutron transport code TORT and the cross-section library SAILOR is outlined. The principal results for cycles 16, 17 and 18 are reported. together with a comparison between measured weight specific activities of(54)Mn (a product of lhe reaction (54)FE(n,p)^54Mn) in shavings taken from different locations on the inner surface of weld no.4 of the pressure vessel of unit I after the end of cycles 17 and 18 and the corresponding predicted values on the basis of lhe computed fluence of fast neutrons at these locations. © 1999 Elsevier Science S.A. All rights reserved.