VVER 440 fuel cycles optimization by the ATHENA code
21st Symposium of AER on VVER Reactor Physics and Reactor Safety (2011, Dresden, Germany)
Core design, monitoring and fuel management
Abstract
For VVER reactor, especially for Dukovany NPP, the optimizing code ATHENA has been
developed in collaboration of SKODA Nuclear Engineering and the University of West
Bohemia for several years. The ATHENA code serves for reducing number of fresh fuel
assemblies, which are necessary to insert into the core for each cycle, and for optimizing the
positions of fuel assemblies. The operation of the ATHENA code for practical use in
Dukovany NPP is at the beginning, but already now some studies by this code are performed.
Ten cycles with new fuel study is one of them. The new fuel has an average enrichment of
4.38% of 235U and is without central hole. Together with inserting new type of fuel the reactor
thermal power was increased from 1444 MWt to 1471 MWt. The results show good
improvement of the length of the cycle including increasing of thermal power.
Besides the fuel with an average enrichment of 4.38%, other similar fuel with average
enrichment of 4.76% is considered. This highly enriched fuel is still only experimental.
Several cycles of this fuel also show better performance, especially the length of the cycle.
The results of the studies are summarized and will be shown below.