TECHNOLOGY

Generation III

EPR reactor

Areva's advanced PWR reactor, known as European Pressurized Reactor or Evolutionary Pressurized Reactor (EPR), was derived from design of French N4 reactor and German Konvoi reactor and is advanced PWR reactor. It meets stringent EUR requirements, and was confirmed as the new French standard design. In France EPR was certified in 2004. Reactor is 4 loop design with power capacity of 1630 MWe, burn-up level of 65 GWd/t and efficiency of 36% (net efficiency). It can operate with full load of MOX fuel. Capacity factor is claimed to be 92%, during 60 year lifetime.

One of the problems during its operation is to adjust electricity generation to demand. Although most of French reactors work in load-following mode, gen III designs have better capabilities. For example EPR is able to increase power from 25% to 60% by 2,5% per minute, and from 60% to 100% by 5% per minute. In average this means, that reactor can go from 25% to 100% in 22 minutes. For such large unit it is strongly good result.

A US version of EPR design, to be certified by US NRC need to be modified. Application for licence was submit in 2007, and certificate is supposed to be given in 2012. Power capacity of US-EPR is 1580 MWe, and considerable effort (million man hours of work) is being put to adjust output electricity frequency to 60 Hz.

EPR differ from AP1000 with changed security philosophy. In EPR can be found active nuclear security systems instead of passive safety. However high level of safety is ensured by four redundant and separate systems. They are not all needed in the same time. Multiplication of safety systems gives opportunity to service, and they increase operating reliability during reactor malfunctioning or breakdowns. Preventive measures had been taken into EPR design caused that during accident without core melt, there is no need to taking any activity for people living around nuclear power plant. Even for core melt accident, radioactive emission is limited to not be dangerous just after breakdown. Pressure reduction system, double reinforced concrete containment, molten core catcher system with passive cooling system and multiplied active safety system make EPR design highly safe construction, even in situations of very serious disasters. Additionally , according to researches, reactor safety containment (with summary thickness of 2,6m) is endure for Fantom F4 fighter impact. [19],[21]

All described factor has caused that two EPR reactors are currently being built at Olkiluoto (Finland) and at Flamanville (France). However, manufacturers assurance about short construction time has appeared to be untrue. Constructions are delayed now. It can be explained that they are FOAK (firs of a kind) constructions, and many problem has came out after building started. Nevertheless current retardations, next two reactors build is being started at Taishan (China), one at Penly (France) will be in the near future, and further orders in UK and US (after certification) are expected. [36],[37],[38],[40],[41],[43],[44]

  • Copyrights 2011 © Michal Wierzbowski