Nuclear power

[José]

Atomic renaissance

Sep 6th 2007

From The Economist print edition

America's nuclear industry is about to embark on its biggest expansion in more than a generation. This will influence energy policy in the rest of the world

OVER the next few months America's Nuclear Regulatory Commission (NRC) expects to receive 12 applications to build new nuclear-power reactors at seven different sites. It is preparing to see plans for another 15 at 11 more locations next year. These will be the first full applications to build new nuclear plants in America for 30 years. If they are all successful, the number of reactors in the country will increase by roughly a third. The output of nuclear electricity would grow even more sharply—the new reactors would be more powerful than older ones. The new enthusiasm for building reactors means America's long-awaited “nuclear renaissance” is about to become reality.

Whether it is a leap forwards or a step backwards remains to be seen. Since the 1970s, far from being “too cheap to meter”—as it proponents once blithely claimed—nuclear power has proved too expensive to matter. The problem is finance: nuclear plants cost a lot to build but are relatively cheap to run, unlike gas-fired ones, for which the reverse is true. So to be profitable they must be built quickly, to minimise the period when no revenue is coming in and interest payments are piling up on construction loans. Yet America's previous generation of nuclear plants was plagued by safety scares, design revisions and time-consuming regulatory procedures, which resulted in ruinously protracted construction.

America's most recent nuclear plant, at Watts Bar in Tennessee, started operations in 1996. But it took 23 years to complete at a cost of $6.9 billion; a second reactor at the site has been under construction, on and off, since 1973. Another plant, at Shoreham in New York, was completed and tested, but never allowed to start commercial operations because of local opposition. By the time it was decommissioned, in 1994—21 years after construction had begun—the costs had exploded from $70m to $6 billion. The local utility was able to pass most of this bill on to its customers. Not all energy firms have been so lucky: in 1988 Public Service Company of New Hampshire became the first American utility to go bust since the Depression, thanks largely to the fallout from a much-delayed nuclear project.

Even when they were switched on, nuclear-power stations did not fulfil their promise. They were supposed to run almost constantly, but proved much less reliable. In the early 1970s, for example, the average nuclear plant produced power for under half the time. Since most utilities had planned to run them flat out to generate enough revenue to repay their debts, this poor performance led to further financial troubles. And, as anti-nuclear activists complain, all this happened despite the government's generous subsidies to help cover the costs of developing new designs and building prototypes.

As for safety…

What is worse, nuclear power has a spotty safety record. There have never been any catastrophic releases of radiation in Western countries. But one did occur in 1986 at Chernobyl, in what was then the Soviet Union and is now Ukraine. America came perilously close to such a disaster in 1979, when a reactor at Three Mile Island in Pennsylvania overheated and began to melt down. There have been lesser safety scares and scandals in many countries, including Britain, Germany and Sweden. In August an earthquake resulted in several small leaks of radioactive material from a nuclear reactor in Japan.

The next generation of nuclear plants is said to be very different. Firms which make them, such as America's General Electric and Westinghouse, and foreign manufacturers like France's AREVA, insist that such episodes will soon be a thing of the past. Their latest designs, they maintain, are simpler and safer than existing nuclear plants. That should make it easier to obtain operating permits, allow them to be built faster and be cheaper to run—and so much less risky financially. Meanwhile, contractors are said to be getting better at building them, the NRC better at regulating them and utilities better at running them. Although nuclear power's boosters welcome a smorgasbord of new subsidies that Congress has approved to nourish the industry, they say that in the long run even this will not be necessary because the industry will be able to move forward under its own nuclear-generated steam.

Consolidating reactors

America's utilities have certainly warmed to their existing nuclear-power plants now that they are running them more efficiently. In the 1970s, says Colette Lewiner, of Capgemini, a consultancy, even small municipally owned firms ordered nuclear reactors, imagining they would be no more complicated to operate than their existing power stations, except in so far as workers would need uranium to shovel into the furnace instead of coal. But they found that they had neither the expertise to maintain their new investments, nor the scale to absorb all the extra regulatory costs, nor the clout to secure fuel and parts at competitive prices. Many ended up putting their nuclear plants up for sale.

That allowed bigger firms to acquire reactors on the cheap, and thus to achieve economies of scale and to capitalise on their experience. These nuclear specialists have been able to speed up the refuelling process, keep shutdowns for maintenance to a minimum and so keep the reactors going more of the time. Last year the average nuclear reactor in America was in use 90% of the time. Better still, utilities have found ways to improve the non-nuclear parts of the power station, such as the steam turbines. These so-called “uprates” have increased America's nuclear capacity by almost 5,000MW since 1977, the equivalent of about five new nuclear reactors, according to the Nuclear Energy Institute, an industry group. At the same time, the NRC has agreed to extend the working life of about half of America's nuclear plants for an extra 20 years.

All this has turned nuclear-power plants into virtual mints—as long as the bill for construction has been paid down or written off. In most of America, the wholesale power price is closely linked to the price of natural gas, since gas-fired plants tend to provide the extra power required at times of peak demand. So the price of power has risen along with that of gas over the past few years, whereas the operating costs of nuclear plants have remained relatively stable. According to the Energy Information Administration, a government agency, the average wholesale power price in 2005 was 5 cents per kilowatt-hour (kWh); the Nuclear Energy Institute, an industry group, reckons that the average operating cost of America's nuclear plants was 1.7 cents per kWh that year. So their margins were almost 200%.

No wonder that utilities are rushing to the NRC with their plans for new reactors. But to get any of them off the ground they must not only persuade the NRC of the safety of their designs, but also convince potential creditors that there will be no repeat of the financial meltdowns of the 1970s and 1980s. They point to three reasons for optimism: changing conditions in the energy business, a streamlining of the NRC's process for obtaining permits and an overhaul of construction techniques.

Until recently coal-fired plants seemed to be safer investments. But nowadays most utilities expect—and in some cases are calling for—Congress to limit emissions of greenhouse gases in the near future to temper climate change. Coal-fired plants, which have a working life of 40 years or more, spew out globe-warming pollution, whereas nuclear ones produce almost no greenhouse gases at all. So coal is now subject to a massive “regulatory risk” of its own. Utilities are piling into green-generation technologies, such as wind turbines and solar panels. But for a constant source of clean power, they have few choices other than nuclear.

Meanwhile, to avoid the fiascos of the past the NRC has simplified its procedures. It used to require utilities to obtain two different licences, the first to build a nuclear plant and after that a second licence to start it up. Both applications involved lengthy reviews, which culminated in interminable public hearings. New reactors, like the one at Shoreham, could be finished at great expense and yet never secure an operating licence. So the NRC is combining the two stages: utilities can now apply for a single “combined construction and operating licence”. Construction need not start—and for most bits of the plant is not allowed to—until the licence is issued.

To speed things up even more, the NRC is allowing firms selling nuclear reactors to get designs cleared in advance. That way, when a utility applies to build a reactor of an approved design, the NRC will only need to review the modifications that are unique to its site. Westinghouse has already got its AP-1000 model cleared; the NRC is in the process of certifying GE's latest design, called the ESBWR, and AREVA is about to submit an application for its new offering, the EPR.

By the same token, utilities can now ask the NRC to approve a location as suitable for a nuclear-power station before they go to the trouble and expense of applying for a combined licence. Four firms have asked for these “early site permits” and two have already received them. Another short cut involves submitting the environmental part of a combined licence before the part that deals with the design. UniStar, a joint venture between America's Constellation and Électricité de France (EDF), filed that sort of paperwork in July for a new reactor in Maryland.

The NRC has also made a point of asking utilities about their nuclear plans before any applications arrive. This is so it can be sure it will have enough staff to handle them—which is how it knows how many new plants are in the works. It is hiring about 200 new staff every year, and since most of the utilities contemplating nuclear plants are in the South, has set up a field office in Georgia to co-ordinate with them directly. It is even planning to suggest to Congress possible amendments to the relevant laws to reduce the hassle and uncertainty of licensing even more.

The process will still be time-consuming: the NRC reckons it will need two and a half years to review each application and a further year to conduct hearings on its conclusions. Certification of new reactor designs might take as long as four years: AREVA says its application for the EPR runs to 17,000 pages and fills a small bookcase. Nonetheless, the NRC aims to issue its first new licences at some point in 2011.

Obstreperous local authorities could still put a spanner in the works. It was opposition from county and state officials, for example, that finally did in the Shoreham plant. Although they have no explicit authority to block a new reactor, local officials can withhold permits to use the water from a river for cooling, for example, or refuse to co-operate on emergency planning. But utilities are hoping to avoid such pitfalls by locating their new reactors only in welcoming jurisdictions—preferably next door to existing ones. Locals in such places know that expanding existing nuclear facilities will bring more jobs and produce more tax revenue. Moreover, they have grown accustomed to having nuclear reactors nearby and do not find the idea particularly frightening. As Dale Klein, chairman of the NRC, puts it, the staff and management of nuclear plants, and local residents, all go to church together.

Fast builders

Utilities are also confident that they can build new reactors more quickly than before. Many have already placed orders for the parts that take a long time to build. They have also brought in partners that have completed nuclear projects on time and on budget in other countries. Westinghouse, for example, points to the exemplary record of its parent company, Toshiba, in Japan. Similarly, GE has teamed up with Hitachi, another respected Japanese nuclear contractor. AREVA, meanwhile, looks to the series of successful plants it has built in conjunction with EDF in France. All three vendors say they plan to save time and money by using as many identical parts as possible for the different nuclear plants they build in America—unlike the bespoke designs of the past. All this should reduce the time required for construction to four years, they say, which would allow the first new reactors to enter service in 2015 or 2016.

But bankers are still sceptical. They are worried that when the new designs and the NRC's new procedures are put to the test, hidden flaws will emerge. After all, the first of AREVA's EPR designs is under construction in Finland and is two years behind schedule and dramatically over budget. To avoid such nasty surprises, NRG Energy, a power-generation company that is applying to build two new reactors in Texas, has opted for one of GE's older and already-proven designs, even though GE insists that its ESBWR will be cheaper to build and to run. Other utilities are planning to build nuclear plants in the regulated markets of the South, in the hope that the regulators will allow them to pass any cost over-runs on to their customers.

Even so, says David Crane, NRG's boss, banks are simply not prepared to lend money to build nuclear plants in America without some extra surety. The Energy Policy Act, which Congress approved in 2005, is supposed to provide that. It offers four different types of subsidies for new reactors. First, it grants up to $2 billion in insurance against regulatory delays and lawsuits to the first six reactors to receive licences and start construction. Second, it extends an older law limiting a utility's liability to $10 billion in the event of a nuclear accident. Third, it provides a tax credit of 1.8 cents per kWh for the first 6,000MW generated by new plants. Fourth, and most importantly, it offers guarantees for an indeterminate amount of loans to fund new nuclear reactors and other types of power plant using “innovative” technology.

The scope of these loan guarantees is the subject of great controversy. Some politicians fear that the costs of the programme might balloon; others complain that the Department of Energy, which will administer it, is too stingy. Meanwhile, some financial experts argue that the rules, as drafted, would not allow issuing banks to repackage and sell on the loans in question, making them less attractive. There is also some debate about what proportion of a nuclear plant's debt should be covered: the act says up to 80% of the costs of construction, but that might be sufficient to cover the full amount borrowed, leaving banks with no risk at all. Until all this is settled, utility bosses insist, new nuclear plants will not get built.

Clearing up afterwards

The fate of America's nuclear waste, which the government has vowed to sequester for a million years, is another unresolved issue. In theory, the Department of Energy is in charge of looking after it all. It requires utilities to set aside a tenth of a cent for each kilowatt-hour of nuclear power they generate to help defray the costs of transporting nuclear waste to a safe repository and storing it there permanently. The only hitch is that no such repository yet exists.

Most countries with nuclear power have determined that the safest way to store their waste is underground, deep in the bedrock in air- and watertight containers. But no one has actually built such a facility. America has got as far as selecting a site for one, at Yucca Mountain, a ridge in the middle of a former nuclear-testing ground in Nevada. The Department of Energy is planning to submit an application to the NRC next year to build a repository there. The NRC, in turn, thinks the application will take about three years to review. Officials say the facility will be open for business in 2017.

But Harry Reid, a senator from Nevada, has vowed to derail the scheme. As it is, Congress has been cutting funding for the Yucca Mountain project, which was first proposed in 1978 and has since been the subject of several lawsuits. Now that Mr Reid has become Senate majority leader the odds of the repository ever getting built have diminished.

Meanwhile, nuclear waste continues to pile up in ponds and containers at nuclear plants around the country. The NRC monitors these and claims that they are safe for the foreseeable future. But Mr Klein, its chairman, tactfully hints that it would be prudent for the government to find a more permanent solution, especially since it is encouraging a dramatic expansion of nuclear power.

Nonetheless, Mr Klein believes that the expansion of nuclear energy is now in motion and is unlikely to be slowed down by concerns about what to do with the waste. The only thing that could stop a nuclear renaissance now, he suggests, is a serious accident at an existing plant. Unfortunately, it would not be the first.

http://www.economist.com/science/displayst…tory_id=9762843

[Invité jabial]

Je suis très dubitatif sur les risques supposés des centrales nucléaires. Le cas de Tchernobyl a été étudié en long, en large et en travers et ce n'est pas un hasard si cet accident s'est produit dans un pays décrépit et corrompu ; la liste de manquements graves au bon sens élémentaire y est longue comme le bras, et encore la plupart des conséquences affichées de cet accident (le fameux "nuage radioactif" qui devait semer la mort sur son passage) sont-elles plus que discutables.

Quand on voit qu'il a fallu le niveau de relâchement extrême d'un Tchernobyl pour que se produise un accident, je pense que les chances que ce genre de chose arrive en Occident sont tout simplement nulles. Il est clair que par contre, dans des pays à l'économie faible et à l'administration corrompue, comme par exemple en Iran, un accident est possible, mais même dans ce cas j'en doute.

[0100011]

Quand on voit qu'il a fallu le niveau de relâchement extrême d'un Tchernobyl pour que se produise un accident, je pense que les chances que ce genre de chose arrive en Occident sont tout simplement nulles. Il est clair que par contre, dans des pays à l'économie faible et à l'administration corrompue, comme par exemple en Iran, un accident est possible, mais même dans ce cas j'en doute.

Je suis plutôt pro-nuke mais il y a des arguments anti qui se tiennent. Notamment le fait que la dangerosité d'un accident (ou d'un sabotage) pousse à l'étatisation extrême du filon nucléaire. Clairement il faut pouvoir surveiller (par la police, l'armée) toute une filière nucléaire quasiment du début à la fin. Ok Westinghouse ou Areva peuvent construire des centrales mais elles doivent coopérer ultra étroitement avec les états (genre si Areva se dit qu'elle peut aller faire du buisness en Iran pour se faire des sous j'ai du mal à croire que ça se passe comme une lettre à la poste). D'autre part ce n'est pas exagéré de dire qu'il est un peut léger de léguer des déchets qui resteront mortels pendant des centaines d'années aux générations futures.

On peut comparer avec le gaz, le pétrole ou le charbon qui ne nécessitent pas d'infrastructre de sécurité si élaborées.

[Invité jabial]

Peut-être que c'est précisément parce que c'est l'Etat qui a développé le nucléaire que les procédures sont si inefficaces. On ne pourra juger de tout ça qu'a posteriori. Par contre, l'argument des déchets, au vu des volumes produits, ne tient pas.

[Quartier-maître Quentin]

la plupart des conséquences affichées de cet accident (le fameux "nuage radioactif" qui devait semer la mort sur son passage) sont-elles plus que discutables.

Même si les conséquences annoncées n'ont pas forcément toutes eu lieu, il y a quand même des morts, des malformations et un environnement dégradé encore un bon petit moment.

Les conséquences d'un accident sont pour moi l'argument le plus recevable des anti-nucléaire.

Et notamment parce que l'Etat veut s'en occuper (mais ça c'est pas dans leur argumentaire).

[Invité jabial]

En prenant uniquement les cas prouvés et pas les extrapolations fantaisistes, y a-t-il eu plus de morts que dans l'accident de Seveso?

[h16]

… Si ces arguments sont recevables, on se demande cependant pourquoi ils (les anti-nucléaire) ne mettent pas autant de verve et d'allant pour contrer la voiture (qui provoque par an plus de morts par accidents que tous les accidents radiologiques réunis) ou les tondeuses à gazon…

[Quartier-maître Quentin]

En prenant uniquement les cas prouvés et pas les extrapolations fantaisistes, y a-t-il eu plus de morts que dans l'accident de Seveso?

193 personnes, soit 0,6 % des habitants de la zone concernée, ont été atteintes de chloracné, essentiellement des enfants. Aucune n'est décédée, un petit nombre seulement a gardé des séquelles. Parallèlement, la moyenne des cancers et des malformations fœtales n'a pas augmenté de manière significative.

En revanche, sur le plan écologique, la catastrophe est tangible : outre les 3 300 animaux domestiques morts intoxiqués, il faut abattre près de 70 000 têtes de bétail. Par ailleurs, les sols agricoles et les maisons nécessiteront de lourds travaux de décontamination.

… Si ces arguments sont recevables, on se demande cependant pourquoi ils (les anti-nucléaire) ne mettent pas autant de verve et d'allant pour contrer la voiture (qui provoque par an plus de morts par accidents que tous les accidents radiologiques réunis) ou les tondeuses à gazon…

Attention, j'ai dit : "le plus recevable". Je ne suis pas anti-nucléaire.

Comme pour l'interdiction des voitures, l'argument le plus recevable pour moi serait le nombre de morts.

Mais il ne l'est pas pour autant.

[h16]

Attention, j'ai dit : "le plus recevable". Je ne suis pas anti-nucléaire.

Je n'ai jamais imaginé telle chose

Comme pour l'interdiction des voitures, l'argument le plus recevable pour moi serait le nombre de morts.

Mais il ne l'est pas pour autant.

Oui.

[Invité Arn0]

… Si ces arguments sont recevables, on se demande cependant pourquoi ils (les anti-nucléaire) ne mettent pas autant de verve et d'allant pour contrer la voiture (qui provoque par an plus de morts par accidents que tous les accidents radiologiques réunis) ou les tondeuses à gazon…

Y a des gens qui meurent à cause des tondeuses à gazon ?

[Quartier-maître Quentin]

Oui, dans Braindead.

[h16]

Y a des gens qui meurent à cause des tondeuses à gazon ?

Oh, ça doit bien exister. Même une framboise peut tuer.

[Frozenlock]

Oh, ça doit bien exister. Même une framboise peut tuer.

Comme le montre cette photo:

Ci-haut: Une framboise s'apprêtant à sauter violemment sur la pauvre petite tortue sans défense, puis à la digérer très lentement dans d'atroces souffrances.

[Ronnie Hayek]

Oh, ça doit bien exister. Même une framboise peut tuer.

Ce n'est pas Lucilio qui te contredira: http://youtube.com/watch?v=s8q4XZ3U5cU

[A.B.]

Oui, dans Braindead.

Ben non ils sont déjà morts.

[José]

Ce n'est pas Lucilio qui te contredira: http://youtube.com/watch?v=s8q4XZ3U5cU

Toi, t'es déjà mort !

[0100011]

Boby Lapointe, tu veux dire le chanteur sous exta qui prend des amphétamines au petit déjeuner ?

Pour le coup on dévie un peu du sujet de base du fil. Pour s'y ramener on pourrait dire qu'il dansait comme un isotope instable en pleine désintégration.

[john_ross]

Pour tout ceux qui s'interrogent sur le stockage des dechets nucleaires, il y a des informations interresantes dans la nature notament a Oklo qui est le seul endroit connu de réacteur nucléaire naturel.

[h16]

Merci pour cette excellente référence.

[Mike]

Même si les conséquences annoncées n'ont pas forcément toutes eu lieu, il y a quand même des morts, des malformations et un environnement dégradé encore un bon petit moment.

Les conséquences d'un accident sont pour moi l'argument le plus recevable des anti-nucléaire.

Et notamment parce que l'Etat veut s'en occuper (mais ça c'est pas dans leur argumentaire).

Je pense qu'une bonne partie de l'explosion des affections thyroidiennes est à mettre sur le dos de Tchernobyl. C'est inquantifiable bien entendu, mais au 19ème siècle il y avait beaucoup moins d'insuffisance thyroidienne qu'aujourd'hui, c'est un fait qu'il faut bien expliquer et la catastrophe de Thernobyl est la plus solide explication. Le problème c'est que les méthodes de dépistage ont évolué pile après la catastrophe, du coup on ne peut que difficilement dissocier l'augmentation des malades dues aux améliorations des méthodes de diagnostique de l'augmentaion réelle. J'avais lu un article au lycée dans Alternatives Economiques (mauvaise ref, je sais, mais pour le coup ça semblait pertinent) qui concluait en disant qu'un tiers de l'augmentation était inexpliquée -- donc l'amélioration des méthodes de diagnostique explique 2 tiers. Dans mon entourage, beaucoup de mes amis qui étaient bébés en 1986 sont victimes de problèmes thyroidiens sans pour autant avoir de l'hérédité en la matière (l'hérédité est prépondérante pour ce type d'affection). D'autre part ces maladies essentiellement féminines se masculinisent, et seul un facteur exogène peut expliquer une telle évolution.

Areva dit qu'un accident de type Tchernobyl a une probabilité de survenance de une fois tous les 50 000 ans par réacteur EPR. Si on construit quelques centaines de réacteurs, ce risque est acceptable -- si on en construit 50 000, il ne l'est plus.

[0100011]

Je pense qu'une bonne partie de l'explosion des affections thyroidiennes est à mettre sur le dos de Tchernobyl. C'est inquantifiable bien entendu, mais au 19ème siècle il y avait beaucoup moins d'insuffisance thyroidienne qu'aujourd'hui, c'est un fait qu'il faut bien expliquer et la catastrophe de Thernobyl est la plus solide explication.

Rapport complet de l'institut de veille sanitaire là : http://www.invs.sante.fr/presse/tchernobyl…byl_020424.html

Et d'après eux :

En conséquence, les évolutions temporelles et spatiales de ce cancer ne vont pas dans le sens d’un éventuel effet " Tchernobyl ". Les résultats permettent plus plausiblement d’évoquer un effet possible de l’évolution des pratiques - notamment diagnostiques - conduisant à détecter un grand nombre de cancers de petite taille (<1cm) qui auraient pu échapper au diagnostic auparavant. Ces résultats sont appuyés par l’analyse des données du registre de la Marne et des Ardennes qui mentionne une évolution du taux des petits cancers de moins d’1 cm passant de 4,3 % en 1970 à 37 % en 1998.

Les données d’incidence concernant les enfants de moins de 15 ans sont d’interprétation délicate en raison de la faible fréquence comprise entre 0,56 et 1,77 par million sur une base de 4,5 millions d’enfants actuellement surveillés. Aucune augmentation n’est manifeste sur la période 1978-1997. Une validation des données anciennes et une actualisation des données étendues à l’ensemble du territoire national est en cours. Elle devrait permettre de procéder prochainement à une nouvelle analyse.

[Mike]

Ils ne prennent en compte que les cancers, et pas l'insuffisance thyroidienne en général. C'est pourtant l'hypothyroidie qui est le problème le plus étendu, pas les cancers qui ne sont ni plus ni moins qu'une phase terminale de l'hypothyroidie et qu'on arrive à éviter quasi systématiquement de nos jours.

[LaFéeC]

Quand nous sommes revenus de Kiev (en 89) un médecin nous a confié qu'il était probable que d'ici qq années, une partie d'entre nous pouvait rencontrer des pb de thyroide..

Je n'ai rien, ma mère a des pb depuis 91.

Comme Jabial, je pense que Tchernobyl c'est avant tout dû à l'état de la centrale et de son personnel.

J'ai aussi un pb avec les déchets, même si leur volume ne représente pas gd chose..

Sinon, pour les risques, je pense plus à l'écoterrorisme en fait.

[Sekonda]

Un chiffre intéressant (dans un autre article de The Economist) pour relativiser (sans minimiser non plus) :

It may be that fears of nuclear power are overblown: after all, the UN figure of around 4,000 eventual deaths as a result of the Chernobyl accident is lower than the official annual death-rate in Chinese coal mines.

[Rincevent]

Ils ne prennent en compte que les cancers, et pas l'insuffisance thyroidienne en général. C'est pourtant l'hypothyroidie qui est le problème le plus étendu, pas les cancers qui ne sont ni plus ni moins qu'une phase terminale de l'hypothyroidie et qu'on arrive à éviter quasi systématiquement de nos jours.

Et l'hyperthyroïdie ? Après tout, si les cellules se reproduisent anarchiquement (cancer), on aurait plutôt tendance à croire qu'elles produiraient davantage, non ?

[Mike]

Et l'hyperthyroïdie ? Après tout, si les cellules se reproduisent anarchiquement (cancer), on aurait plutôt tendance à croire qu'elles produiraient davantage, non ?

Les cellules cancéreuses ou noduleuses ne produisent plus du tout. L'hyperthyroidie c'est assez rare, et ça rentre dans l'ordre tout seul dans beaucoup de cas, sinon il faut enlever la thyroide et le problème se transforme en hypo totale, qu'on soigne de la même manière que n'importe quelle hypo.