Partial boron credit implementation assessment relating to pool at reactor of Dukovany NPP

In 2005 the Czech Republic commemorates the anniversary of the commission of Dukovany NPP where four units of VVER-440 have been operating since 1985, when the first unit came into the operation. In between, the working fuel assembly design has been changed several times: from the uniform fuel assembly (FA) of 3.6 wt.% U-235 through the horizontally profiled FA of av. 3.82 wt.% to the horizontally profiled FA of av. 4.38 wt.% with Gd2O3 burnable absorber (entitled as 'Gd-1' FA), which has already been working, and finally the horizontally profiled FA of av. 4.25 wt% with Gd2O3 burnable absorber (entitled as 'Gd-2' FA), which has been just loaded into Dukovany Unit 3. The step-by-step increasing enrichment of the VVER-440 fuel brings about a general issue of re-licensing pools at the reactors. Although the pools have been partly reracked a new criticality assessment is being performed to open the way of the PBC/BUC storage technology implementation in the near future. First results obtained for the PBC implementation resulted from calculations using KENO VI Monte Carlo code are presented. (author)