The AREVA EPR– the French Reactor

The AREVA EPR is one of the three contenders listed in the Ontario RFP and perhaps, a candidate for the reactors under discussion in Alberta and Saskatchewan and maybe for new reactors at Bruce Power if that occurs.  The second New Brunswick reactor will undoubtedly be an AECL product, most likely the first ACR-1000 but I can only hope they will choose an EC-6.

So what does EPR stand for? Well strangely enough it means one thing in Europe (European Pressurized Reactor) and another in the US (Evolutionary Pressurized Reactor) although apparently they are talking about exactly the same reactor design.  Apparently, the AREVA marketing department has concluded that confusion might still arise and they push the expression “US EPR” to drive the point home that their reactor is not merely a European artefact. It’s not clear what they believe is the best name choice for Canada.  

That may be typical of government owned companies. Well over 80% of AREVA is owned by the government of France with some minority interest by Siemens and others.  From recent episodes concerning takeover bids for other companies and the recent announcement of a second EPR for France, it’s clear that the CEO of AREVA takes direction on important issues directly from the President of France. One would think that fact alone might hamper AREVA’s reactor sales in the United States but probably not in Canada where we are more accustomed to state-owned companies such as AECL for example.

Most of the power reactors in France are actually Westinghouse designs but the last four French reactors completed by 2000 were designed by Framatome (since absorbed into AREVA) and form AREVA’s main experience in reactor design with a lesser contribution from Siemens experience with German reactors in the more  distant past.

The EPR is a light (ordinary) water reactor using it both for moderation and coolant. Its fuel is enriched uranium with up to 5% uranium-235. In those respects, it is generically similar to its Westinghouse rival, the AP1000. However, one area in which it is very different is its power output, 1,600 MW (e) (electrical) compared to a powers of about 1,100 MW (e) for the AP1000 and 1,050 MW (e) for the AECL ACR-1000. The EPR is a more powerful unit than its rivals which is advantageous in terms of brute power production but could be a disadvantage in flexibility for deployment on the Ontario grid where an EPR would roughly be the equivalent of two Darlington reactors.

In my opinion the design appears to have become overly complex by attempting to address a great many issues at the same time. For example, it has a complex containment system consisting of a steel shell attached to a concrete shell presumably to harden the reactor against an aircraft strike. By now even the least sophisticated terrorists have realized that driving an aircraft into a reactor containment structure is unlikely to lead to the havoc they would wish to create. In some sense the old aphorism that   “generals always prepare for the last war” seems to apply to the EPR.

To counter an accident in which a hot reactor core of molten fuel might burrow into the earth, the notorious “China Syndrome”, the EPR has a “core catcher” consisting of a concrete basin specially designed to prevent this happening. Other features are separate compartments for the heat transport (coolant) pumps and a pool of water at the base of the reactor.

It seems that these special features may have caused some of the delays and cost overruns experienced during the construction of the first EPR at Olkiluoto, Finland which is already 25-50% over budget and more than two years behind schedule. Problems in welding the steel containment shell and pouring concrete to the required specifications for the core catcher are reported to have been problems.  The second EPR being built at Flamanville Normandy is also having some construction problems but apparently less severe than in Finland showing that AREVA is well on the learning curve.

Difficulties in constructability are just one class of the teething problems to be expected in bringing any new complex engineering design into operation and probably will be typical of all three of the so-called Generation 3 reactors under consideration in Canada. The AREVA projects are simply the furthest along whereas the first AP1000 has just started construction and the ACR-1000 has at least another four years to go before a construction start can be made. 

Although I have my own personal misgivings, the EPR would likely prove to be an adequate reactor for use in Canada.

2 Responses to “The AREVA EPR– the French Reactor”

  1. Don Jones Says:

    Re The AREVA EPR – the French reactor

    The U.S. EPR looks like a French N4 series with a core-catcher, more engineered safety systems and beefed up containment. Not much passive safety like the AP 1000 and the ACR-1000. Does this make it a Generation 3+ reactor.

    The U.S. EPR is based on the four Framatome (subsequently AREVA) 1,475 MWe (net) N4 series reactors, a completely French design, that was the latest reactor series to be put into service in France between 1996 and 2000, and on the three Siemens 1,400 MWe (net) Konvoi series units in Germany. The earlier French reactors that started up in the late 1970s and after were based on a Westinghouse design supplied under the “atoms for peace” initiative of President Eisenhower. The four French N4 series reactors suffered serious safety related design problems and delays in commissioning that extended over several years.

    In France the 58 PWR reactors, including the four of the N4 type on which the U.S. EPR is based, had an annual utilization factor (allows for unit being available but output restricted due, say, to load following) of 80.2 percent in 2007, down from 83.6 percent in 2006. The N4 type has been around 75 percent, and the Konvoi type at over 90 percent. The capacity factor of the French nuclear fleet is low, at around 77 percent, partly due to load following.

    The ACR-1000 does not have to shut down for refuelling although it will be necessary to shut down every three years, for three weeks, to do routine maintenance that cannot be done when the unit is operating. The ACR-1000 and the PWRs like the EPR-1000 are designed for a life of 60 years but the ACR-1000 will require a shutdown of less than a year, after 30 years service, to replace the pressure tubes that pass through the calandria because of dimensional and material property changes due to radiation. This will also provide an opportunity to replace obsolete equipment and do other refurbishment to meet contemporary standards. Such refurbishment is taking place on the CANDU 6 reactor in New Brunswick that started up in 1983 and had a lifetime capacity factor of 82.1 percent up to the end of 2007 and will also be done soon on the reactors in Korea (Wolsong Unit 1) and Argentina that started up in 1983 and 1984 respectively and had lifetime capacity factors of 85.7 and 84.9 percent respectively at end of 2007. The PWRs need to shutdown for refuelling and maintenance for around three weeks every one to two years so, all in all, lifetime capacity factors of the new reactors after 60 years could be expected to be similar at around 93 percent.

    There are economies of scale with larger unit size like the EPR but the larger the unit, the larger must be the operating reserve on the grid in case that unit is lost. Typically, today, the operating reserve on the Ontario grid is around 1,400 MW with the largest single unit being a Darlington size unit of around 878 MWe (net). Reactors of the size of the U.S. EPR would require an additional 1,000 MW of operating reserve. Coal-fired generation is a significant part of the operating reserve but this is to be phased out in Ontario by 2014.

    Even though China is building two EPRs, after a sweet deal with AREVA with generous financial support from the French government, it seems more interested in AP1000 technology than the EPR which it regards as more expensive and complex with engineered rather than passive safety systems.

  2. Dr Singh Says:

    I agree about the all important power reserve issue being greater with the EPR. But, it doesn’t disqualify the design. Besides, the coal power plants are not to be demolished but remain as emergency standby. And Ontario’s 4000MW+ of interconnects mitigates this issue (unlike Sask/Alberta where interconnects are lacking).

    Perhaps a more relevant issue is load following capability (virtually non existent in old CANDUs). To get the most out of investment its preferable to operate nuclear units 100%. But, many months of the year (ie Oct) low or even avg power required doesn’t reach 14000MW prescribed as limit for nuclear by OPA.

    Where-as existing CANDU units are typically shutdown, a new reactor designed for load following could be left on and contribute in place of gas and coal which are normally used for load following.

    Incidentally, is net power of the contending designs being matched evenly? 2 EPR are competing against 2 AP1000/ACR-1000 (3200MW vs 2200MW) or against 3 of the smaller units (3300MW) – to add to today’s 11000MW.

    In 2010-2014 Ontario will have plenty of power thanks to Bruce refurb and coal remaining. But by ~2014-2016 Pick B and BruceB are hitting 30 year marks where they’ll either be decommissioned or refurb, either case removing their power contribution. AECL’s scenario of refurb both and my addition of 1100MW new builds at 2017 and 2018, and assuming “generous” 3 year refurb leads to following running totals:

    year, total MW nuclear
    2008 11406
    2009 10656
    2010 10656
    2011 12156 <- 2 Bruce A’s return to service
    2012 11874 <- all BruceA runing but PickB refurb
    2013 11052 <- 1st BruceB refurb
    2014 9198 <- 2nd BruceB refurb
    2015 9408
    2016 10230 <- Pick B refurbs returning offset by BruceB undergoing refurbs.
    2017 12362
    2018 13403 thereafterwards Darlington refurbs.

    At 2014, Both PickA, 4 BruceA and 4 Darlington running. 2 BruceB and all PickB under refurb, 6 total + new build underway all at the same time. Clearly stressfull.

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