Challenging cycles of Dukovany NPP with highly enriched fuel optimized by the Athena code

article in a collection out of WoS and Scopus

English

The Dukovany NPP has operated four WWER-440 reactor units. Starting 2009 power of third unit has been up rated, so reactor is operated at power level of 1444 MWt instead of 1375 MWt used up to now. Innovation of secondary circuit and electrical equipment leads to electrical output of 500 MWe. During four years all four units will be up rated this way. Power up rates together with outage shortages are challenges for fuel cycles optimization. Reactors of Dukovany NPP have already operated in incomplete five-year fuel cycles based on modified Gd-2+ fuel design called Gd-2M with 4.38 % average enrichment now. New fuel types with high enrichment were proposed by fuel manufacture (4.87 % average enrichment) and by SKODA JS Company (4.76 % average enrichment). These fuels should allow complete five year fuel cycle with higher power and has also ability to allow incomplete six-year fuel cycle. Fuels should economize fuel assemblies and operational costs. The SKODA JS Company together with the University of West Bohemia has developed new optimizing code called Athena. The code has been used to optimize fuel cycles from twenty fifth cycle of third unit of Dukovany NPP up to thirty fourth cycle with new fuel types presented above. Comparison between fuel cycles with Gd-2M fuel and with mixed loading patterns (Gd-2M mixed with new types) has been calculated. Positives and negatives are discussed from physical, safety, operational, and economical points of view. New fuels allow 330 to 340 FPD long cycles with up rated power, but are very challenging to radial power distribution parameter (FdH). Results show, that operational parameter limit of FdH used until now should be increased from 1.54 to 1.58. Couple of fuel assemblies is economized. Results are a part of study of applicability and feasibility of new fuels and might be important for additional development of fuel design. Results will also be used as a comparison of presently used optimization code Optimal and new Athena code.

Optimization; Loading Patterns; Fuel Cycle

KATOVSKÝ, K.; FEJT, F.; ČADA, R.

20. 9. 2010

AER - Kiadja az MTA KFKI Atomenergia Kutatointezet

Budapest, Hungary

978-963-372-643-3

Proceedings of Atomic Energy Research Symposium on WWER Physics and Reactor Safety; Hanasaari, Espoo (Finland); 20-24 Sep 2010

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