Design problems with AREVA EPR and the Westinghouse AP1000 (Updated March11, 2014)


Update: This is one of the most popular posts on this blog and so deserves an update. The EPR continues to limp along. The Finland EPR is now bogged down in lawsuits and startup is further delayed; the EPR at Flamanville France is doing only slightly better. These problems I attribute to an overly elaborate design that is very difficult to construct. In fact, AREVA seems to be veering away from the EPR by pushing a newer design. The AECL reactor ACR-1000 as reported elsewhere in this blog is dead. As for the Hitachi ABWR nobody is going to look at it after Fukushima. The good news is that the Westinghouse AP1000 has overcome its initial problems with new construction going well in China and the US. Plans for new reactor construction in various provinces of Canada have all been squelched. As reported here in other posts, the Canadian nuclear enterprise is now focused on refurbishing the Ontario reactors.

In September, I chatted informally with several AREVA people in France about the construction problems the EPR was having in Finland. Many of them blamed the Finns, especially the Finnish nuclear safety agency, as very difficult customers following what appeared to be the AREVA party line. One engineer was perhaps more frank than his colleagues admitting that “it’s been a long time since anyone built a reactor” which is probably close to the truth.  I also had a glimpse of the second EPR under construction at Flamanville on the Normandy coast. It looked to be going well. I left France with the impression that the schedule slippage and cost overruns on the EPR were just first-of-a-kind teething problems to be expected in building what I consider already an overly engineered and too complex reactor.

Imagine then my dismay when soon afterwards when it was reported that the nuclear regulators of the UK, France and Finland declared that the design of the EPR control system was fundamentally flawed. The operating and safety systems seemingly are not independent! Of course, they must be completely independent to provide the necessary high degree of safety. It’s as if they had built a car with the brake and accelerator systems somehow coupled. If the regulatory judgements turn out to be true then this is a momentous blunder in a reactor specifically engineered to ensure a high degree of safety.  If the designers have failed in such a basic principle then what other mistakes have they made? It is reported that AREVA has now lashed up some work-around analogue system but personally I have lost any residual confidence I may have once had in this design. I guess it also shows the Finns are not so dumb after all.

Over in the other corner the Westinghouse AP1000 has been found to have a faulty structural design for the so-called shield building which surrounds the containment structure as a first line of defence against severe storms and other possible impact events. It seems the shield building cannot take the loads that it has to support, especially the thousands of tons of dousing water at the top of the containment. Apparently this problem has been known to US nuclear regulators for at least a year and various tests and possibly redesigns are underway to correct this major flaw.  This again is a disappointing situation.

Is the GE-Hitachi ABWR faring any better than these two?   It wasn’t a contestant in the Ontario competition and so I haven’t been following it very closely. However, it does seem to be flying somewhat below the radar compared to the EPR and the AP1000.

These problems with its former competitors shouldn’t cause any joy in AECL. Its ACR-1000 is still firmly stuck on the drawing board with no realistic prospects of construction.  While their design “won” the Ontario competition, there is no indication that either the feds or Ontario are willing to incur yet more debt (another $20 to 30 billion or likely much more) in these tough economic times by building two ACRs at Darlington. The two levels of government are supposed to negotiating the cost split but I’m not optimistic.

Meanwhile there is no chance New Brunswick Power (now owned by Hydro Quebec) will build any new reactor after the Pt Lepreau refurbishment fiasco. Saskatchewan is fixated on a research reactor (but only if the feds ante up 75% of the costs).

That leaves Alberta with its own large deficit as the only other prospect for an ACR. Who knows maybe a reactor to get rid of it coal-fired generating plants would help in shielding the oilsands province from the attacks of the warmers? It’s probably better than just being perceived as a province of deniers since the warmers in spite of the recent allegations of scientific fraud have clearly won the day as the great Copenhagen dog and pony show unfolds.  Is that a realistic scenario?  Probably not!   

Let’s hope 2010 proves to be a better year for the nuclear enterprise than 2009.  

 

Refurbishment: maintaining Canadian nuclear expertise

If it ain’t broke, we didn’t build it.

 

Well not really, it just seems that way.

 

The need to replace the pressure tubes in CANDU reactors after 25 years or so of operation has always been considered a significant disadvantage of the design. Retubing is very complex since the tubes are integral parts of the reactor core. The whole operation must be done in high radioactivity fields in cramped spaces within the reactor confinement structure. Special remote handling tools and techniques need to be developed on a custom basis since each reactor will be somewhat different. To make matters even more complicated, often the owners “take the opportunity” to replace many other components, steam generators for example, while the reactor is down. The whole process has come to be called refurbishment.

 

To be fair other types of reactors also need mid-life repairs. In the past ten years or so the tops (lids) of several US light water reactor pressure vessels have had to be replaced due to premature corrosion. This is a big undertaking in itself but is still a much smaller job than retubing a CANDU. Many US reactors are licensed for 40 to 60 year lifetimes and the possibility of an 80 year or longer lifetime is being researched. 

 

Refurbishment of CANDUs has had a chequered history. The first two Pickering reactors had to be retubed in the 1970’s because a poor alloy was originally selected for the pressure tubes. This set the precedent for refurbishment as an expensive and lengthy undertaking. Refurbishing all four of the Pickering A reactors by OPG cost at least $3 billion total for just two of the reactors. It was subsequently decided that refurbishing the other two was too expensive and they were essentially shut down permanently.  Bruce Power has been soldiering on for the last few years refurbishing two or three of the four Bruce A reactors at a total cost apparently approaching $4 billion. The New Brunswick reactor overhaul, as reported previously in this blog, continues to be over budget and is lagging months behind  schedule with no end in sight.      

 

As for future CANDUs, it’s disappointing to me that the ACR -1000 design envisages refurbishment after 25-30 years. My hope was that they could have avoided this problem by designing more robust pressure tubes. It could be more even difficult to retube an ACR (if one is ever built) because the core has much smaller dimensions – hell in a very small place?

 

In spite of all its problems, there is an upside to refurbishment. With no possibility of building new reactors for five or ten years or more, it’s the only game in town for Canada’s nuclear industry. 

 

The funding for these projects buys goods and services provided by the many companies, great and small, that comprise the nuclear industry. Without it many of them wouldn’t survive.  Cost overruns are mainly labour costs which keep highly skilled engineers employed; preserving the specialized expertise needed to eventually build new reactors. Furthermore, it is apparent that even though refurbishing an existing reactor is costly, it is still much cheaper than building a new one.

 

So roll on refurbishment, it will likely continue to be the sustaining activity of our nuclear industry for years to come.

Refurbishment Problems in New Brunswick?

Are fiddleheads hallucinogenic?

 

The reason I ask is that it could be an explanation for the upbeat optimism of the New Brunswick government on all matters nuclear. They have repeatedly expressed the desire for a second reactor apparently to produce electricity for export to the New England states. What’s more instead of just cloning their first and only reactor, the CANDU 6 at Pt. Lepreau, they want to take on the first-of-a-kind ACR-1000. In my opinion this would be an extremely daunting task for a relatively small utility in a one of the smaller provinces. Massive federal support would be essential but New Brunswick seems sanguine about getting it.

 

New Brunswick is the best prospect for the first ACR-1000. I believe that a few years from now,  after the current recession,  when Alberta and Saskatchewan get around to choosing reactors to build, they will probably choose the AREVA EPR in part because they would prefer a foreign reactor rather than one from eastern Canada on political grounds. The past tells me that both Bruce Power and OPG would prefer not to have any more CANDU reactors and if the Ontario government can get a low-risk fixed-price deal from AREVA, they will go with two EPRs for Darlington, assuming that Westinghouse is indeed out of the contest.

 

With respect to Ontario there was a recent newspaper report that some unions involved in the nuclear business would be content with foreign reactors and willing to work with offshore companies. They must be using the same crystal ball as I am. Of course, the AECL professional union was not in favour but whatever the outcome of the Ontario competition, their members will still have decades of work on CANDU refurbishment.   

 

By the above reasoning New Brunswick is the most likely site for the first ACR-1000. Unfortunately for AECL, the refurbishment of the Pt. Lepreau reactor has run into problems. The expected cost overruns as yet are only up to $90M on a total budget of $1.4B – a mere bagatelle in the refurbishment business- but still enough to cause rumblings in the local press. I note that the refurbishment of the very similar Gentilly II reactor in Quebec has been estimated to cost $2B so I’d advise the NB media to hang on to their hats in terms of the final cost. There was a Keystone Cops episode concerning turbine rotors falling off a barge and the demise of a local NB firm making the new end fittings involved in retubing, particularly distressing because the refurbishment was supposed to grow new industrial activity in the province and enhance exports sales.

 

Whether the above developments are making a dent in the provincial government’s nuclear optimism and what impact that might have on the plan for a second reactor remains to be seen.

No Nuclear Renaissance in a Recession?

What effect will today’s bad economy have on the nuclear renaissance?

As I see it, any Canadian politician that wants to fund a nuclear Megaproject (actually Gigaproject) in a time of severe recession is going to have a very tough time selling it as part of an economic stimulus package. Rhetoric about ‘building for the future’ or ‘just carrying out plans already made” simply isn’t going to cut it with the public.  Of course, the Tennessee Valley Authority and the Hoover Dam are examples of massive US energy projects built during the Great Depression of the 1930’s. However, I think the public perception of nuclear reactors is very different; they don’t have the same image as hard core infrastructure projects that employ large numbers of people. Roads, bridges, water mains, parks, public transit and so forth directly relate much more closely to people’s lives and thus, are a “politically better” use of the large but limited construction capacity in the province.

In Ontario, a multi-billion dollar nuclear project at Darlington doesn’t have the same political attraction as many smaller infrastructure projects spread all the province. Additional new reactors at Bruce and Nanticoke would increase the total costs to the province so much as to counteract any benefits they might bring in terms of geographical spread. The timing of that idea wouldn’t work in any case since these projects are not likely to begin until well after the new Darlington reactors. One could try to spin a single project at Darlington by correctly pointing out that many components would be built in other areas and in many ways the project benefits the whole province.  Nevertheless, justifying the construction of even two new reactors at a total of $10-15 billion would be a very hard sell when compared to the $1.3 billion provincial contribution to the recent Big Three automotive bail out. In fact, the optics is so bad that I doubt any smart politician would even attempt it in a failing economy.

In Alberta the precipitous drop in the price of oil has knocked the bottom out of any idea of building reactors there. The huge oil sands projects that would be very profitable with oil at $140 a barrel are marginal at $40 a barrel and the overheated Alberta economy is cooling fast. I very much doubt that Alberta politicians are going to push new reactors as a cure to the province’s economic problems. My guess is the thinking in Saskatchewan would be similar.

New Brunswick is the exception. We can only assume that news of the recession hasn’t reached there. Recently, the government announced they were going to build not one but two new reactors (ACR-1000s?) A mode of bullish optimism prevails (‘I’ll have what he’s having”) It is said that the new reactors will supply the New England electricity market assumed to be expanding in spite of the current US economic problems. However, as far as I know, the studies (one of them from AECL) justifying this strategy have never seen the public light of day and therefore, we don’t know what the provincial government is really thinking. I suppose New Brunswick is also assuming that the federal government via AECL will back stop the large cost overruns inevitable on first-of-a kind projects.  The feds, however, are already unhappy about running a deficit and I frankly can’t see them being any happier in absorbing New Brunswick’s cost overruns. Of course, if the feds agreed to that , they’d also have to do it for Ontario’s reactor overruns.

My fearless but realistic prediction is that the nuclear industry like every other will have to hunker down and ride out the storm until the economy improves. Certainly routine activities will continue at a dull roar probably including some refurbishment but I can’t see any new-build Gigaproject start-ups. In other words, the nuclear renaissance will be on hold during the years of the recession/depression the world is now experiencing.  Let’s hope for everyone’s sake it will be a short downturn.

 

Why not the CANDU- 6?

“The best way to skin a bear is to skin a bear”

I’m told the foregoing is an aboriginal proverb that points out the virtues of the direct approach to problems.  To be direct we need to be absolutely clear about the objective of building new reactors in Canada. Clearly the aim is to supply much needed electricity for the nation. It is not the development and testing of new reactor types such as the ACR-1000.  

If governments decide that the best course is to construct Canadian reactors for domestic use then I strongly believe the CANDU-6 is now a much better bet than the ACR-1000.

The CANDU-6 has been the workhorse of the AECL fleet for the last 25 years. It’s a tried and tested design with good performance that’s been successfully built and operated in New Brunswick, Quebec, Korea (4), Rumania (2), and China (2). The last CANDU-6’s were built in time frames in the order of five years and (miraculously for the nuclear industry) on budget. This reactor is now called the EC-6, Enhanced CANDU-6, and I can only hope that this renaming is mostly for marketing purposes and the fundamentally robust design is there. 

 The CANDU-6 is an unmitigated AECL success story achieved well before the MAPLE disaster and without the uncertainties of the ACR-1000.

Three of the first CANDU-6’s (in NB, Korea and just announced in Quebec) are now undergoing refurbishment. This means that the technical knowledge, personnel with necessary skills and the supply chain for this reactor type are all currently available domestically and ready for new construction. Furthermore, the design has been licensed by the CNSC for many years and recent environmental assessments related to refurbishment projects have been done.

It would not be an exaggeration to say that several CANDU-6 reactors could be quickly put in place using only Canadian resources.

I simply don’t understand why a small province like New Brunswick would want to go through the long and painful process of bringing the first ACR-1000 on line particularly with the risks raised by the MAPLE fiasco. Why not just build a second CANDU-6 beside the current one now being refurbished? There are so many obvious advantages in terms of operations, maintenance, training and so forth.  Needless to say there’s no way that Generation III+ reactor projects would be feasible in Alberta or Saskatchewan.

As for Ontario, the McKinsey report said “[the differences in life time costs] are not enough to rule out a contending design as fundamentally disadvantaged — save the EC6, which would not benefit from the same economies of scale as its Generation III+ competitors.” My feeling is that the report underestimates the longer times and higher costs associated with bringing Generation III+ reactors into service. In my opinion they’ve got it wrong.

As for the argument that Canada needs to successfully build and operate an ACR-1000 at home so it can export them, that falls under the category of nuclear R&DD and not electricity supply. Assuming, of course, that there is any export market left after the domestic demonstration is done. AECL may want to continue developing the ACR-1000 which would be OK for the future. For the present, let’s build CANDU-6’s.

The one problem I can see with is strategy is the heavy water supply issue discussed previously on this blog.