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The tricolor nuclear policeman plans to examine whether French nuclear reactors can continue to operate for 60 years or more, and may be influenced by American practices in doing so. On Monday, January 23, during the press conference to present well wishes, Bernard Doroszczuk, chairman of the Nuclear Safety Authority (ASN), said, "We want to enrich ourselves with experience abroad, particularly from the Americans.".

To increase the sector's visibility and provide crucial information for the formulation of French energy policy, the response must be given as soon as possible. "Some energy scenarios [in particular scenario N03 developed by the operator of the electricity transport network RTE within the framework of the Energy Futures 2050 report, editor's note] take reactor operation up to 60 years, or even longer, into consideration.

These scenarios, however, only make sense if they are reachable. Julien Collet, the deputy general director of ASN, warns that if they don't, they'll cause us problems.

In order for the energy policy to be in compliance with the safety limits, he continues, "We must estimate the associated calendar deadlines.". The nuclear policeman requests that EDF conduct a thorough investigation of the situation in order to deliver a thorough report by the end of 2024.

According to the president of the supervisory body, "We want to see this deadline included in the following PPE [multi-annual energy program]. Then, with the assistance of IRSN, its technical arm, ASN plans to review this comprehensive file in order to formulate a position by the end of 2026 at the latest.

A deviation from the rule At the moment, there is no lifetime connection with French nuclear reactors. Nevertheless, 40 years were spent performing safety calculations on the component parts.

As a result, the continuation of their operations past this point is subject to a control review, known as the renown ten-year inspection, which happens every ten years. In specific terms, there are two parts to this review.

Insuring compliance and controlling aging phenomena make up the majority of the first. The second is to raise the level of safety by getting as close as possible to the EPR's safety goals, which are those of a third-generation reactor.

The reactor is therefore qualified to function for an additional ten years after passing the test. However, ASN now wants to develop a more forward-looking strategy in parallel with this doctrine, which is based on the ten-yearly outages, in order to ascertain how long it would be possible to continue operating the reactors.

An excellent start for the nuclear policeman philosophy. The ten-year step, according to Bernard Doroszczuk, "is not appropriate for anticipating with enough time.".

"We are conducting extensive research on the prospects for living past 60 years.". The initial calculations for this work will be done using the French calculation techniques currently in use, but the nuclear policeman also requests that EDF look into the use of other techniques, including some employees in the United States.

Depending on the boundaries we will reach, we might consider altering the justification techniques we employ to determine whether it is possible to go beyond. [Editor's note: This may require changing our calculation techniques.]. As the United States has an advantage over France in this area, we will be inspired by their strategies rather than those used elsewhere, particularly in Europe.

An entirely normal advancement considering that the American nuclear fleet was constructed 10 to 15 years before the French fleet, according to the ASN President. Towards more flexibility in calculation methods The question of method evolution arises in particular for the estimation of the lifetime of the vessel, which is an irreplaceable element and thus determines the lifetime of a reactor. Read moreNuclear: the Senate is accelerating, EDF called to study an extension of its reactors beyond 60 years.

The effects of irradiation cause the tank to become brittle. According to Julien Collet, the mechanical properties of the metal deteriorate over time to the point where they can no longer support continued operation.

France mandates that the largest flaw be taken into account at the location that will penalize the user the most in the mechanical calculations used for this estimate. a technique that is thought to be traditional.

The Americans prefer a probabilistic approach, so they estimate the likelihood that the materials' flaws will be distributed in different ways. Both sides of the Atlantic experience different physical phenomena, which affects how the calculations are done.

In its calculations at the moment, France does not take into account potential beneficial phenomena. By way of illustration, if a crack develops within the tank's material, it may spread to the skin's exterior.

After that, it turns into through. However, as the crack spreads, it will come into contact with hotter and therefore softer material, which could potentially stop the crack.

Julien Collet points out that "it is a recognized hypothesis in some calculation methods in the United States, but not in France.". However, as of right now, the nuclear policeman claims he is willing to lift "a certain number of conservatisms.".

The deputy general manager confirms that the goal is to determine "what are the flexibilities that the we could identify in the mechanical calculations of the tanks without questioning the level of safety.". In light of this, ASN teams recently visited the US to interact with colleagues from the Nuclear Regulatory Commission (NRC) and members of the Electric Power Research Institute (EPRI), an American research institute that focuses on the production of electricity.

According to Bernard Doroszczuk, "What stands out very clearly is that there is a lot of convergence between France and the United States on the most sensitive subjects and the way to approach them.". While it is true that US power plants aren't aging as quickly as their tricolor counterparts, this is still an important factor to consider.

Because atomic energy operates "in base" in the United States. In other words, there are no significant variations in the power output of the reactors, which continuously produce electricity.

In contrast to France, where nuclear production varies greatly, this is very different. Tristan Kamin, a nuclear safety engineer, explains to La Tribune that EDF reduces the airfoil when demand is very low, particularly at night, or when the wind turbines partially take over because there is wind.

Furthermore, there are effects to this phenomenon known as "modulation.". We explain to the ASN that the reactors exposed to significant temperature variations "are more stressed mechanically" similar to a "car engine" that "prefers to always run at the same speed.".

This invariably causes fatigue and, as a result, causes some parts to wear out more quickly. On Monday, Bernard Doroszczuk himself made reference to this issue: "With the cessation of controllable production of fossil origin, [] fluctuations in electricity demand will have to be absorbed by the nuclear fleet.

Is there a chance that this will have specific effects on the fleet's growth? he asked. Modulation reduces safety margins, especially given that the topic is more broad and includes possible replacement of parts as well as wear of parts.

As a matter of fact, these fluctuations also narrow the safety margins that are in place in France. In more concrete terms, a reactor's primary circuit experiences extremely high neutron fluxes when its power is suddenly increased.

However, an EDF engineer who asked to remain anonymous emphasizes that if an accident happens at this crucial time, "the impact on the tank will be potentially very significant.". As a result, ASN must adjust its safety regulations to account for this "worst-case" circumstance, which raises the necessity for expanding the fleet.

The EDF engineer is adamant: "Whereas the Americans, they shouldn't adapt to it! They have far fewer variables to take into account when deciding on the lifespan of a plant. The British have also adopted the same stance on the subject as their counterparts on the other side of the Atlantic: "When EDF sold its EPR in England, the company also proposed its control mode, i.e. the possibility of routinely varying the reactor's power.

The English, however, claimed that they did not want to use it in that way in order to preserve their safety margins, he continues. The question really arises, said the EDF safety engineer, "should we also limit the modulation of the fleet in France, in order to preserve the tricolor power stations as much as possible, and this, at a lower cost? Drawing inspiration from taking disparities into account.".

For instance, by switching the order in which the means of production are called up on the market so that erratic wind power is now given preference over predictable nuclear power. He thinks that it might even be possible to do this by preventing changes in the output of some of EDF's reactors.

We challenge the ASN's assertion that "it is not possible in France.". Because the fleet's power output is greater than its consumption, Julien Collet explains that the power must be modulated by several hundred megawatts, particularly at night.

It must be acknowledged that on the other side of the Atlantic, the energy mix is also very different from ours. For example, while nuclear power could theoretically meet nearly 75% of France's electricity needs, this percentage is only around 30% in the United States. In short, it will therefore be a matter of drawing inspiration, in part, from American practices, without, however, forgetting these significant disparities.

The maintenance schedule for nuclear power plants could be jeopardized by strikes, according to RTE. "The power of the fleet exceeds consumption, so we have to modulate the power by several hundred megawatts, especially at night," says Julien Collet. It must be acknowledged that on the other side of the Atlantic, the energy mix is also very different from ours. For example, while nuclear power could theoretically meet nearly 75% of France's electricity needs, this percentage is only around 30% in the United States.

In short, it will therefore be a matter of drawing inspiration, in part, from American practices, without, however, forgetting these significant disparities. The maintenance schedule for nuclear power plants could be jeopardized by strikes, according to RTE. "The power of the fleet exceeds consumption, so we have to modulate the power by several hundred megawatts, especially at night," says Julien Collet.

It must be acknowledged that on the other side of the Atlantic, the energy mix is also very different from ours. For example, while nuclear power could theoretically meet nearly 75% of France's electricity needs, this percentage is only around 30% in the United States. In short, it will therefore be a matter of drawing inspiration, in part, from American practices, without, however, forgetting these significant disparities.

The energy mix also turns out to be very different from ours: while nuclear power theoretically meets nearly 75 percent of France's electricity demand, this number does not exceed 30 percent in the United States. Read alsoStrikes could threaten the maintenance program for nuclear power plants, worries RTE the energy mix also turns out to be very different from ours. In short, it will therefore be a matter of drawing inspiration, in part, from American practices, without, however, forgetting these significant disparities.

The energy mix also turns out to be very different from ours: while nuclear power theoretically meets nearly 75 percent of France's electricity demand, this number does not exceed 30 percent in the United States. Read alsoStrikes could threaten the maintenance program for nuclear power plants, worries RTE the energy mix also turns out to be very different from ours. In short, it will therefore be a question of taking inspiration, in part, from American methods, without however forgetting these significant disparities.

RTE is concerned that strikes could endanger the maintenance schedule for nuclear power plants.

The deputy general manager confirms that the goal is to determine "what are the flexibilities that the we could identify in the mechanical calculations of the tanks without questioning the level of safety.