Areva: 'safety is in our DNA'

"First, as early as 14 March, Areva provided an emergency aid in the form of a donation of 1 million Euros to the Japanese Red Cross, in response to the humanitarian disaster from the tsunami. Then, more specifically on the nuclear side, we have provided several tons of protective equipment as well as boric acid made available by EDF. At TEPCO's request, 20 Areva experts were sent to Japan to provide assistance to manage the crisis, backed by large teams in France, Germany and the USA. Also, [CEO] Anne Lauvergeon has travelled twice to Tokyo since the events to meet Japanese officials. One of the first concrete results of which was the fact that [in April] TEPCO accepted Areva’s solution to treat contaminated water [see p.17]. These are very practical actions and reactions that we have provided.”

How do you see the consequences of the incident for the industry?

“What I can say is that, excepting Germany, which has a really specific, emotional and relatively irrational reaction, we see the same thing in all countries. They confirm that nuclear power is a key component in the energy mix to provide low-carbon and affordable electricity. Obviously the nuclear industry has to take the lessons from this event, and answer the public’s questions to reinforce public confidence in nuclear safety. ‘Safety first’­ is a fundamental basic value for all the nuclear industry and it is part of Areva’s DNA.

“Areva has been designing reactors with a higher safety level; this event confirms that this is the right strategy for long-term public acceptance.”

Are you referring to criticisms of the EPR after losing out to a Korean design in the UAE?

“Yes, exactly. ‘Less expensive because less safe’ was never an option. I think that we were right not to have this position.”

What level of seismic activity is the EPR designed to withstand?

“Each reactor is designed according to the most extreme scenario the plant could face on a given site. If we look at plants we have built, in Finland [Olkiluoto 3], the plant has to withstand a 0.1g ground acceleration. Our plant in South Africa [Koeberg 1&2] can withstand 0.3g. In Flamanville 3 [in France], Taishan 1&2 [in China], and different sites we are working on, the peak ground acceleration to be considered is 0.25g.

So, if we had to build an EPR in a zone like Fukushima, we would have taken the necessary actions. In the Fukushima case, apparently, the peak ground acceleration was between 0.3-0.5g. And, given the level of margins in the design, the EPR reactor can withstand a peak ground acceleration of 0.6g without damage that would impair the operability of its safety systems.”

How does the EPR cope with total loss of external power?

“I will make this simple. We consider that the EPR would have resisted the Fukushima Daiichi event. What I will describe are the effects of the tsunami rather than the earthquake. Power would not have been lost in the EPR because there are several layers of backup. There are four safeguard divisions with four emergency diesel generators in two separate buildings. All buildings are anti-seismic, and specifically laid out to provide protection against floods and tsunamis. Then these are backed up with two additional and redundant station blackout diesel generators. Then, if everything were lost, there are batteries. The diesel generators, which have their own protected fuel supply, last 72 hours. The station blackout generators, which have also their own protected diesel supply, would last 24 hours. Then battery power would last 12 hours. This would give staff valuable additional time to re-establish a stable situation.

“What I described also applies to the Atmea PWR and Kerena BWR. We fulfil the right balance between active and passive systems.”

How would you characterise that balance?

"Safety is not a simple subject. The debate between passive versus active systems is not the right debate. What is important is to achieve the highest level of safety. From this view, passive systems have advantages. But they are not perfect. Because of the complexity of the processes sometimes involved, passive systems are difficult to model and test, so reactors relying solely on passive safety systems may not adapt and react as expected. Also they are usually ‘one-shot’ safety systems. Once they have been used, or activated, then they cannot operate again. Finally these passive systems can also fail. You therefore need active systems in case of a failure of passive systems to complete your safety arsenal and achieve the highest level of safety. This is why all Areva reactors leverage both active and passive technologies to provide complementary, diverse and redundant solutions.”

What are examples of passive systems in the EPR?

“The core catcher, for instance. This unique device is designed to capture the core [in case of a core meltdown] and keep it cool within the double-wall concrete shell building that protects the reactor. At the bottom of the reactor, there is also a big pool, the IRWST [in-containment refuelling water storage tank], which also works in a passive mode. And there are hydrogen recombiners that make hydrogen explosions impossible.

"Generally speaking, safety relies on the design of the plants, and also the capability of systems to manage the crisis. One of the big lessons of Fukushima is that power plants work in three dimensions: design, operations and crisis management. A reactor design fulfils safety standards. But you also need trained and experienced teams to safely operate the plant and be able to manage an eventual crisis, no matter how unlikely.

Are there any lessons for the EPR design from the event?

“We have received some questions, but because of the characteristics of the design and its history [safety authorities were strongly involved in the EPR design from the early stages], I feel confident that the examination, which is absolutely normal, is not going to force us to make major changes to the EPR design.”